Ghana OCTP Block Phase 1 ESHIA

Transcription

Eni S.p.A.
Exploration & Production Division
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GHANA OCTP BLOCK Phase 1 - ESHIA
Ghana OCTP Block Phase 1 ESHIA
ABSTRACT
This report outlines the conditions of the environment that will house the project, describing the identification
of any potential significant and adverse environmental, social and health effects and identifying the
environmental resources and social and health aspects that could be impacted.
J. Deffis
20/01/2015
03
Issued for submission
to Authorities
ESL-eni
TEAM
F. Cavanna
G. Nicotra
E. Lago
A.K. Armah
Date
Revision
Revision Description
Prepared
Checked
Approved
This document is a property of eni S.p.A. who will safeguard its rights according to the civil and penal provisions of the Law
Eni S.p.A.
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Summary of Revisions
Code
Date
Rev.
Revision Description
Prepared
Checked
Approved
J. Deffis
02/10/2014
02
Issued for submission to Authorities
ESL-eni TEAM
F. Cavanna
G. Nicotra
E. Lago
A.K. Armah
09/04/2014
20/03/2014
01
00
Issued for submission to Authorities
Issued for comments
ESL-eni TEAM
ESL-eni TEAM
M. Leonardi
J. Deffis
T. Bentil
A.K. Armah
M. Leonardi
J. Deffis
T. Bentil
A.K. Armah
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TABLE OF CONTENTS
1
1.1
1.2
1.3
1.4
1.5
1.5.1
1.5.2
1.5.3
1.5.4
1.5.5
1.6
2
INTRODUCTION
BACKGROUND OF THE PROJECT
PROJECT PROPONENT
PURPOSE OF E(SH)IA
THE ESHIS TEAM
ESHIS PROCEDURAL FRAMEWORK IN GHANA
Registration
Screening
Scoping / Terms of Reference
From E(SH)IA to E(SH)IS
Environmental Permitting Decision
REPORT STRUCTURE
PROJECT DESCRIPTION
9
9
10
10
12
12
14
15
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16
18
18
20
2.1
PROJECT JUSTIFICATION
20
2.1.1 The Need for the Project
20
2.1.2 Project Key Drivers and Benefits
20
2.1.3 Envisaged Project Sustainability
21
2.2
PROJECT OPTIONS
21
2.2.1 Do Nothing Option
22
2.2.2 Project options
22
2.3
PROJECT DESCRIPTION
25
2.4
PROJECT SCENARIO
26
2.5
PROJECT OVERVIEW
27
2.6
PROJECT LOCATION
29
2.7
DRILLING AND COMPLETION OPERATIONS
31
2.7.1 Description of the Drilling Unit
31
2.7.2 Sequence of operations
41
2.7.3 Drilling Activities
42
2.7.4 Production Tests
48
2.7.5 Completion Activities
48
2.7.6 Techniques to Prevent Environmental Risks during Drilling
51
2.7.7 Safety Equipment (Blow-Out Preventers)
52
2.7.8 Drilling Parameters Monitoring
54
2.7.9 Estimated Drilling and Completion Duration
54
2.7.10
Design Choices Aimed at Reducing Environmental Impact
54
2.7.11
Resources Consumption, Waste Generation, Air and Noise Emissions During
Drilling and Completion Activities
56
2.8
SUBSEA PRODUCTION SYSTEM (SPS)
65
2.9
RISERS AND FLOWLINES (R&F)
72
2.9.1 TRANSPORTATION & INSTALLATION (T&I)
76
2.10 FPSO AND MOORING SYSTEM
77
2.10.1
FPSO Operational Components
90
2.10.2
FPSO Control & Safeguarding Systems
92
2.10.3
Natural Resources Consumption, Waste Generation, Air and Noise Emissions
During FPSO Operation
98
2.11 SYSTEM COMMISSIONING PHILOSOPHY
103
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2.12
2.13
2.14
3
DECOMMISSIONING AND ABANDONMENT
PROPOSED PROJECT CONTINGENCY PLAN
PROJECT EXECUTION SCHEDULE
LEGAL REQUIREMENTS AND POLICY FRAMEWORK
3.1
3.1.1
3.1.2
3.1.3
3.1.4
3.1.5
3.1.6
3.1.7
3.1.8
3.1.9
3.1.10
3.1.11
3.1.12
3.2
3.2.1
3.2.2
3.2.3
3.3
4
4.1
4.2
4.2.1
4.2.2
4.2.3
4.2.4
4.2.5
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.5
4.4
4.4.1
4.4.2
4.4.3
4.5
4.5.1
4.5.2
4.6
4.7
4.7.1
4.7.2
4.8
4.8.1
4.8.2
NATIONAL LEGISLATION
The Ghanaian Constitution
Environmental Protection Act
Environmental Assessment Regulations
Environmental Guidelines
Petroleum Legislation
Maritime Legislation
Water Resources Legislation
Pollution Control
Radiation Protection Instrument
Protection of Coastal and Marine Areas
Labour and other Social Responsibility Laws
The Local Content Policy
INTERNATIONAL CONVENTIONS, INDUSTRY BEST PRACTICES AND STANDARDS
International Environmental and Social Performance Standards
International Protocols & Conventions
Industry Best Practices, Standards and Guidelines
ENI HSE POLICIES AND STANDARDS
BIOPHYSICAL BASELINE
GEOPHYSICAL AND ENVIRONMENTAL SURVEY
CLIMATE AND METEOROLOGY
Rainfall
Temperature
Relative Humidity
Barometric pressure at MSL
Wind
MARINE ENVIRONMENT (OCEANOGRAPHY)
Currents
Wind
Squall
Wave
Tides
BATHYMETRY, SEABED TOPOGRAPHY
Bathymetry
Seabed morphology
Shallow Geology
SEDIMENT AND WATER QUALITY
Sediment quality
Water quality
ATMOSPHERIC AIR QUALITY AND NOISE
PLANKTON
Phytoplankton Analysis
Zooplankton
BENTHIC ORGANISMS
Data treatment
Phyletic Composition
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4.8.3 Rank Abundance and Dominance
4.8.4 Primary Variables and Univariate Analysis
4.8.5 Sample Data [0.1m2]
4.8.6 Species Accumulation and Richness Estimation
4.8.7 Multivariate Analysis
4.9
CORAL REEF
4.9.1 Coral reef location
4.9.2 Coral Reef nearshore
4.9.3 Coral reef – Deep Water Corals
4.10 CHEMOSYNTHETIC ORGANISMS
4.11 MARINE MAMMALS
4.11.1
Common bottlenose dolphin (Tursiops truncatus)
4.11.2
Clymene dolphin (Stenella clymene)
4.11.3
Spinner dolphin (Stenella longirostris)
4.11.4
Pantropical spotted dolphin (Stenella attenuata)
4.11.5
Atlantic spotted dolphin (Stenella frontalis)
4.11.6
Long-beaked common dolphin (Delphinus capensis)
4.11.7
Fraser's dolphin (Lagenodelphis hosei)
4.11.8
Rough-toothed dolphin (Steno bredanensis)
4.11.9
Risso's dolphin (Grampus griseus)
4.11.10 Melon-headed whale (Peponocephala electra)
4.11.11 Pygmy killer whale (Feresa attenuata)
4.11.12 Short-finned pilot whale (Globicephala macrorhynchus)
4.11.13 Killer whale (Orcinus orca)
4.11.14 False killer whale (Pseudorca crassidens)
4.11.15 Cuvier's beaked whale (Ziphius cavirostris)
4.11.16 Dwarf sperm whale (Kogia sima)
4.11.17 Sperm whale (Physeter macrocephalus)
4.11.18 Humpback whale (Megaptera novaeangliae)
4.12 SEA BIRDS
4.13 SEA TURTLES
4.13.1
Olive Ridley (Lepidochelys olivacea)
4.13.2
Green Turtle (Chelonia mydas)
4.13.3
Leatherback Turtle (Dermochelys coriacea)
4.13.4
Hawksbill Turtle (Eretmochelys imbricate)
4.13.5
Loggerhead Turtle (Caretta caretta)
4.13.6
Kemp's ridley sea turtle (Lepidochelys kempii)
4.14 FISH ECOLOGY
4.14.1
Small pelagic species
4.14.2
Large Pelagic Species
4.14.3
Demersal Species
4.14.4
Deep Sea Species
4.14.5
Protected or Endangered Species
4.15 MARINE HABITATS AND PROTECTED AREAS
4.16 BIOPHYSICAL BASELINE CONCLUSION
4.16.1
Sediment remarks
4.16.2
Benthic macrofauna remarks
4.16.3
Coral reef remarks
4.16.4
Water remarks
4.16.5
Marine mammals remarks
4.16.6
Sea turtles remarks
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5
271
SOCIO-CULTURAL BASELINE
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5.1
5.2
5.3
5.4
5.4.1
5.4.2
5.4.3
5.5
5.6
5.6.1
5.6.2
5.7
5.7.1
5.7.2
5.7.3
5.7.4
5.7.5
5.8
5.8.1
5.8.2
5.8.3
5.9
5.10
6
ADMINISTRATIVE STRUCTURE
HISTORY AND CULTURE
DEMOGRAPHICS AND GEOPOLITICS
LOCAL ECONOMY AND LIVELIHOOD RESOURCES
Regional Economic Activities
Economic Activities at Coastal Districts
Economic Activities by District
LAND TENURE
WELFARE
Poverty
Education
SOCIAL INFRASTRUCTURE AND SERVICES
Water
Electricity
Telecommunications
Police Services
Fire Services
TRANSPORT INFRASTRUCTURE
Roads
Ports and Harbours
Airports
WASTE AND SANITATION
COOPERATION AND DEVELOPMENT
HEALTH BASELINE
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290
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292
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6.1
REGIONAL HEALTH STATUS
6.2
HEALTH STATUS IN COASTAL DISTRICTS
6.2.1 HIV/AIDS and Tuberculosis
6.3
HEALTH FACILITIES IN COASTAL DISTRICTS
294
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301
303
7
306
7.1
7.1.1
7.1.2
7.1.3
7.2
7.3
7.4
7.4.1
7.4.2
7.4.3
7.4.4
7.4.5
7.5
7.5.1
7.5.2
7.5.3
7.5.4
7.5.5
7.5.6
7.6
7.7
IMPACT IDENTIFICATION AND ASSESSMENT
ASSESSMENT METHODOLOGY
Potential Impacts Identification and Characterisation
Potential Impacts Indicator Parameters
Impacts Evaluation
POTENTIAL IMPACT IDENTIFICATION AND CHARACTERISATION
POTENTIAL IMPACTS INDICATOR PARAMETERS
EVALUATION OF IMPACTS ON THE BIOPHYSICAL ENVIRONMENT
Impact on Air Quality
Impact on Water Quality
Impact on Seabed and Marine Subsoil
Impacts on vegetation, flora, fauna and ecosystems
Underwater noise-generated impacts
IMPACTS ON THE SOCIO-ECONOMIC ENVIRONMENT
Disruption of Economic Livelihood Activities
Increased Government Revenue
Employment Opportunities Generation
Procurement of Goods and Services
Increase in Marine Traffic
Perceptions and Expectations of Local Communities
IMPACTS ON HEALTH
SUMMARY OF IMPACTS
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8
MITIGATION AND MANAGEMENT MEASURES
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8.1
IMPACT ASSESSMENT RECOMMENDED MITIGATION MEASURES
8.1.1 Mitigation of Impacts on the Biophysical Environment
8.1.2 Mitigation of Impacts on the Socio-economic Environment
8.1.3 Mitigation of Impacts on Health
385
385
386
388
9
389
ENVIRONMENTAL MANAGEMENT PLAN
9.1
9.2
9.3
9.4
9.5
9.6
9.6.1
9.6.2
9.6.3
9.6.4
9.6.5
9.6.6
9.6.7
9.6.8
9.6.9
9.6.10
10
EMP APPROACH
EMP OBJECTIVES
STRUCTURE AND RESPONSIBILITY
EMP IMPLEMENTATION FRAMEWORK
CORE ELEMENTS OF EMP
GUIDELINES FOR MITIGATION MEASURES
Roles and Responsibilities
Training and Awareness – Site Induction
Communications
ENI Environmental Policy Objectives
Environmental Control & Monitoring
Environmental Audit
Waste Management
Waste Water Management
Oil Spill Contingency Plan
Safety Philosophy
389
389
390
390
391
392
392
392
393
393
394
396
396
397
398
398
DECOMMISSIONING
403
SUMMARY AND CONCLUSIONS
404
REFERENCES
405
ANNEX 1
421
COPY OF SCOPING APPROVAL LETTER
ANNEX 2
EVIDENCE OF RESPONSE TO GHANA EPA SCOPING REPORT REVIEW
COMMENTS
422
ANNEX 3
LIST OF ATTACHMENTS TO GHANA OCTP BLOCK PHASE 1 E(SH)IA
REPORT
424
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INTRODUCTION
This introductory chapter presents and overview of the project, provides details of the E(SH)IA
team and outlines the approach adopted to elaborate the E(SH)IA report. In addition the structure
of the remainder of the report is outlined.
The EIA process as stipulated in the Ghanaian EPA regulation encompasses all environmental,
social and health issues to be addressed and as such the use of Environmental Social and Health
Impact Assessment (ESHIA) is synonymous with EIA; for the purpose of this report, E(SH)IA may
be used in alternation with EIA throughout the document.
1.1
BACKGROUND OF THE PROJECT
The Offshore Cape Three Points (OCTP) block licence, is located approximately 60 km offshore in
the Western Region of the Republic of Ghana(Figure 1-1). The OCTP joint venture, composed of
eni Ghana Exploration and Production Limited (“eni Ghana”) Operator of the block holding
47.222% participating interest, Vitol Upstream Ghana Limited (“Vitol”) holding 37.778%
participating interest and GNPC 15% participating interest carried by the Contractor, made three
(3) non-associated gas discoveries, Sankofa Main in 2009, Gye Nyame in 2011, and Sankofa East
in 2012 (the “Gas Discoveries”) and two oil discoveries in Sankofa East in 2012 (Cenomanian and
Campanian reservoirs -the “Oil Discoveries”).
Figure 1-1
Location of OCTP Block
The development scheme consists in:
 14 subsea wells (8 oil producers of which 2 re-entry, 3 water injectors and 3 gas injectors)
 one new conversion FPSO unit to be installed above the fields to collect and process
produced oil.
 a subsea network with flexible flowlines and risers
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A new conversion double hull/double balcony FPSO unit will be installed above the main oil and
non-associated gas reservoirs inside the OCTP Development and Production Areas (as defined in
the PA), at about 63 km from shoreline (Sanzule), and it will be controlled and operated by the
OCTP Operator.
The FPSO unit is expected to treat all crude oil and associated gas (to be re-injected for reservoir
pressure support) produced from the OCTP license. Crude oil will be separated from associated
gas and water, stabilized and stored into storage tanks in the FPSO unit before being metered and
offloaded. Oil producers, gas and water injection wells will be connected directly to the FPSO unit
(no manifolds are foreseen) through flexible risers and flowlines. Treated oil will be delivered to
tankers and associated gas will be re-injected in the reservoir
Produced water will be separated and treated at the produced water treatment unit in order to
comply with specifications for water injection then mixed with treated seawater before being
injected in the reservoirs (both Cenomanian and Campanian) for pressure maintenance.
Associated gas produced from the oil separation train will be compressed, dehydrated before being
re-injected into the reservoirs (Cenomanian and Campanian) according to the specified demand.
Part of this gas will be used as fuel for power generation on the FPSO.
1.2
PROJECT PROPONENT
Eni Ghana Exploration and Production Limited was incorporated in Ghana on 26th May 2009,
following the signature on the 25th March 2009 of a Farm-in Agreement between eni Ghana and
Vitol Upstream Ghana Ltd. (VUGL). Eni Ghana is a wholly owned subsidiary of eni S.p.A, an
integrated energy company. Active in 77 countries, with a staff of 78,400 employees, it operates in
oil and gas exploration, production, transportation, transformation and marketing, in
petrochemicals, oilfield services construction and engineering. Eni has become one of the leading
global operators in the deepwater sector, one of the biggest challenges faced by the oil and gas
industry. Eni is executing several worldwide deepwater exploration projects (depths greater than
450 metres) and in very deep waters (depths greater than 1,500 metres). The offshore activities in
very deep waters, such as those being carried out in Ghana, are also ongoing in the Gulf of Mexico
and along the coast of Mozambique and Brazil, where the company is involved, as operator or
partner, in offshore exploration projects, some of which have already given positive results.
eni is a member of the International Association of Oil & Gas Producers (OGP) and the
International Oil Industry Environmental Conservation Association (IPIECA). Eni operates globally
and is in contact with a large variety of natural environments, from deserts to tundra, from rain
forests to the Arctic and Antarctic polar regions, from the Mediterranean marquis to coral reefs. Eni
has started assessment programmes and mitigation projects for the potential impacts of its own
activities, considering the conservation of biodiversity as one of the objectives of environmental
protection. More information is available on the eni Website – www.eni.com.
1.3
PURPOSE OF E(SH)IA
The Ghana Environmental Assessment Regulations (1999) stipulates that oil and gas field
development is an undertaking that requires a mandatory full Environmental Impact Assessment
(EIA) to be done as a means of ensuring environmental soundness and sustainability in the
development of the undertakings. The undertaking also requires registration and authorisation by
the Ghana Environmental Protection Authority (EPA). eni Exploration and Production Limited (eni
E&P) has commissioned ESL Consulting (ESL) referred to as the EIA team to undertake the EIA
for the OCTP Block Development Project.
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Guidance on how to undertake the EIA is provided in the EPA Sector (Oil & Gas) Guidelines for
Environmental Assessment and Management in Ghana.
The EIA process as stipulated in the Ghanaian EPA regulation encompasses all environmental,
social and health issues to be addressed and as such the use of Environmental Social and Health
Impact Assessment (ESHIA) is synonymous with EIA. For the purpose of this report E(SH)IA will
be used.
The Environmental Assessment Regulations 1999 defines:
 environmental assessment as “the process for the orderly and systematic identification,
prediction and evaluation of the likely environmental, socio-economic, cultural and health
effects of an undertaking; and the mitigation and management of those effects”, and
 Environmental impact assessment as “the process for the orderly and systematic evaluation
of a proposal including its alternatives and objectives and its effects on the environment
including the mitigation and management of those effects; the process extends from the
initial concept of the proposal through implementation to completion, and where
appropriate, decommissioning.
Furthermore, the purpose of the E(SH)IA is to provide information to regulators, the public and
other stakeholders to aid the decision-making process.
Consequently, the present E(SH)IA study considers, the possible direct and indirect impacts on the
bio-physical environment, the wellbeing of the people involved in the oil and gas operations
(health) and those individuals/communities the oil and gas operations may affect (Community
issues), at the pre-construction, construction, operation and decommissioning phases. In detail, the
main objectives of the E(SH)IA are as follows:





To define the scope of the project and the potential interactions of project activities with the
natural and anthropic (socio-economics and health) environment that should be defined
and assessed during the E(SH)IA.
To review national and international legislation, standards and guidelines, to ensure that all
stages of the proposed project through its complete lifecycle take into consideration the
requirement of Ghanaian legislation, internationally accepted environmental management
practices and guidelines, and project-related “Environmental Health and Safety” (EHS)
policies and standards.
To provide a description of the proposed project activities and the existing physical,
chemical, biological, socio-economic and human environment that these activities may
interact with.
To assess the potential environmental and social impacts resulting from the project
activities and identify viable mitigation measures and management actions that are
designed to avoid, reduce, remedy or compensate for any significant adverse
environmental and social impacts and, where practicable, to maximise potential positive
impacts and opportunities that may arise due to the project.
To provide the means by which the mitigation measures will be implemented and residual
impacts managed, through the provision of an outline Environmental Management Plan
(EMP). This will also require the development of monitoring plans for various environmental
and social impacts and a mechanism for audit, review and corrective action.
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1.4
THE ESHIS TEAM
The core ESHIS team involved in this ESHIS is listed below in the table.
Name
Role
Juan Deffis (eni Ghana)
Giuseppe Nicotra (eni SpA)
A.K. Armah (ESL)
Anthony Bentil (ESL)
Adu-Nyarko Andorful (ESL)
Marco Leonardi (eni)
Luigi Trovarelli (eni)
HSE & Community investment Manager
HSE Project Manager
Project Director ESL
Assistant Project Manager
Socio-Economic Expert
ESHIA Study Coordinator
Biological & Marine Environment Expert, Impact
Assessment Expert
Air Quality & Noise Expert
Physical Environment Expert
Socio-economic,
Health
&
Stakeholder
Engagement Expert
Giuditta Di Caro (eni)
Luca Della Santa (eni)
Valentina Invernizzi (eni)
Qualifications,
Experience
M. Sc. 8 years
M. Sc. 7 years
M. Phil, 20 years
M. Phil, 5 years
M. Phil, 8 years
M. Sc. 30 years
M. Sc. 25 years
M. Sc. 8 years
M. Sc. 15 years
M. Sc. 4 years
The contact details of the team are provided below:
HSE & Community investment
Mngr eni Ghana
Address
Tel:
Email:
Project Director ESL
Address
Tel:
Email:
1.5
Juan Deffis
1st Floor Una Home Building, No.12
Airport Bypass
Airport City.
PMB KA 185 Accra, Ghana
+233-302 761 790 ext 227
[email protected]
Mr. A. K. Armah
ESL Consulting Limited
Off Liberia Road Extension
Ministries Annex
P. O. Box Lg 239
Legon, Ghana.
+233 (0) 302 514614/683206
[email protected] / [email protected]
ESHIS PROCEDURAL FRAMEWORK IN GHANA
Environmental Assessments are required to be carried out on specific projects in Ghana as a
means of ensuring environmental soundness and sustainability in the development of projects.
The Environmental Assessment systems refer to the relevant procedures for ensuring that:


the planning phase follows and satisfies the provision for environmental soundness and
sustainability in the various decision-making processes, alternatives and options for the
eventual preferred scheme of development.
the operational phase follows the required management provisions to achieve environment
soundness and sustainability in the implementation of the project.
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The planning phase of a project is covered by an Environmental Assessment, while the operational
phase is covered by Environment Management Plan. The Ghana Environmental Assessment
Procedures involves a step-wise system with provisions for:







Registration
Screening
Scoping/Terms of Reference
EIA Study
Review & Public Hearing
Appeals
Timelines for decision-making
Public Participation is expected to occur at all levels of the process (screening, scoping, EIA study
and Review stages).
The overall process under the Ghana EPA’s regulation is shown in Figure 1-2.
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Figure 1-2
1.5.1
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The Ghana Environmental Assessment Procedure
Registration
Ghana legislation requires in this phase that the Proponent accurately provide all relevant
information concerning the proposal by preparing and submitting a registration document that
addresses all the requirements. Full and accurate descriptions of the project location, proposed
activities, the existing environment, potential impacts, and proposed mitigation are required.
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This phase coincides with the Submission of the EA Application (Registration Form). The ENI’s
OCTP Phase 1 development was submitted for registration with the EPA on the 13th of September
2013.
1.5.2
Screening
Screening is a preliminary assessment to determine whether a proposed project may cause
significant environmental, social and health impacts. The EPA, within 25 days after the submission
of the registration form, placed the development at the appropriate level of assessment. The EPA
determined that the development falls into the category of undertakings (Sch. 3) for which a full
E(SH)IA is required.
1.5.3
Scoping / Terms of Reference
The principal objective of scoping is to identify environmental, social and health sensitivities and
those project activities with the potential to contribute to or cause impact to environmental, social
and health receptors. Scoping involves the identification and the consultation with all relevant
stakeholders (interested and affected parties/communities such as the government departments,
ministries, local authorities, etc.) with the aim of identifying all key issues and to determine how the
concerns of all parties will be addressed in the E(SH)IA.
This phase also helps to focus the E(SH)IA to be carried out on the key areas/issues of concern or
impact. The output of scoping is the scoping report with the terms of reference (TOR) for the
E(SH)IA.
The Terms of Reference (ToR) set out the scope or extent of the Environmental, social and Health
Impact Assessment to be carried out, and included methodologies, apparatus and strategies that
were to be utilized to direct the baseline data collection and the impact assessment.
The following steps were undertaken in the E(SH)IA scoping phase, and are described below.



desktop review;
stakeholder engagement visit; and
preparation of the Scoping Report
Desktop Review
This step comprised the following:




initial review of relevant legislative and guidance;
identification and review secondary data;
development of an outline description of the planned Project activities;
and development of a plan for stakeholder engagement (Chapter 6 and Chapter 7.4) and
consultations on the scope of the E(SH)IA.
Initial Legislative Review
Chapter 3 of this E(SH)IA Scoping Report provides a review of legislation and industry guidance
relevant to the ESIA for the proposed Project.
Identification and Review of Secondary Data
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Existing baseline information on the environmental, socio-economic and health context of the
Project area has been collected and reviewed and sources of other existing information identified.
The E(SH)IA team has undertaken an initial review of existing information sources that contributed
to an understanding of the environmental, socio-economic and health context of the Project (see
Chapter 6). Available data sources have been identified for the following subjects.




Physical environment: oceanography, climate, geology, topography, bathymetry;
Biological environment: benthos, fish, birds, marine mammals, turtles.
Health (health status, common illness, healthcare delivery service etc.)
Socio-economic environment: fisheries, demographics, livelihoods and cultural heritage.
This desktop review also focused on identifying where gaps in information exist and informed the
data gathering requirements and the Terms of Reference for the remainder of the E(SH)IA.
Outline Project Description
The Project description in Chapter 2 of this E(SH)IA Scoping Report provides an overview of the
various Project components and activities to a level that allows those activities with the potential to
cause environmental, social and health impacts to be identified (e.g. physical presence, noise,
emissions, wastes and discharges). Project planning, decision making and refinement of the
Project description will continue throughout the assessment process as a result of the development
of the Project and in response to the identified impacts.
Stakeholder Engagement
Project stakeholder engagement started at the E(SH)IA Scoping stage and will continue throughout
the assessment and through operations to ensure that stakeholder concerns are addressed and
regulatory as well as legislative requirements are met. The E(SHI)A team has developed a
proposed process for engaging stakeholders (outlined in Chapter 6 and 7.4) to ensure that
engagement is undertaken in a systematic manner, improves the E(SH)IA process and builds
relationships whilst managing expectations.
Stakeholder Engagement Visit
A series of consultation meetings with national stakeholders in the Gt. Accra and key stakeholders
in the Western Region (Takoradi and in the 6 coastal communities) were undertaken to provide
Project information, collect baseline data and understand key stakeholder concerns.
Preparation of the Scoping Report
The Scoping Report, included Terms of Reference (ToR), was compiled as part of the E(SH)IA
process in accordance with the regulatory requirements stipulated in Regulation 11 of the
Environmental Assessment Regulations (1999). The Scoping Report and ToR were submitted to
the EPA for their consideration for a thirty day period. The Scoping Report was also made
available to stakeholders through the Project website, and hard copies provided on request.
1.5.4
From E(SH)IA to E(SH)IS
In accordance with the regulatory requirements stipulated in Regulation 13 of the Environmental
Assessment Regulations (1999), the Agency informed eni Ghana to submit an environmental
impact statement (EIS) based on the scoping report.
The proponent commissions the Environmental Impact Assessment based on the agreed TOR.
Environmental Impact Assessment normally involves baseline survey and inventory, development
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proposal options, potential impact identification, prediction, mitigation and alternative
considerations and other requirements of the TOR.
During the study, eni Ghana as per legislative requirements intiated a public information
programme for the area likely to be affected by the undertaking. Copies of all reports of the study
shall be made available to EPA and relevant stakeholders. Public concerns shall be recorded and
will be addressed in the EIS.
The findings of the Environmental Impact Assessment shall be compiled into an Environmental
Impact Statement, which shall form the basis for the required decision-making on the undertaking
for an Environment Permit. Twelve (12) copies of the draft EIS will be submitted to the EPA for
review and decision making. In certain cases the EPA may request for additional copies of the draft
EIS in order to distribute to key stakeholders.
Review of E(SH)IS and Public Hearing
The EPA Agency upon receipt of an environmental impact statement, publishes for 21 days a
notice (which shall be in accordance with the form specified in Appendix 3 of the EA Regulations
1999) of the environmental impact statement in the mass media. It also posts at appropriate and
opportune places such parts of the environmental impact statement as it considers necessary. The
applicant shall also submit copies of the environmental impact statement as per Agency directions
to sector Ministries, government departments and organisations of relevance to the undertaking.
Copies of the EIS are also placed at vantage points including the EPA Library, relevant District
Assembly, EPA Regional Offices and the Sector Ministry responsible for a particular undertaking.
The general public, relevant public agencies, organisations, NGOs, Metropolitan, Municipal and
District Assemblies and local communities may review and make any comments, and suggestions
on any matter in the draft EIS within 21 days of issuance of the public notice.
The draft EIS is also reviewed by a cross- sectoral Environmental Impact Assessment Technical
Review Committee (EIA/TRC) made up of representatives of various Ministries, Departments and
Agencies. The review committee is expected to assist the Agency in reviewing the EIS and make
recommendations to the Executive Director as to whether the undertakings as proposed must be
accepted and under what conditions, or not to be accepted and the reasons thereof, as well as
provide guidance on how any outstanding issues/areas may be satisfactorily addressed. In certain
instances the support of international EIA institutions and experts may be solicited to review EISs.
Upon receipt of the draft EIS the Agency may hold a public hearing on the undertaking as part
of the review when:



a notice issued under regulation 16 of the LI 1652 results in great public reaction to the
commencement of the proposed undertaking;
the undertaking will involve the dislocation, relocation or resettlement of communities and
the Agency considers that, the undertaking could have extensive and far –reaching effects
on the environment.
The outcome of the public hearings are expected to be addressed by the proponent and
considered in decision making by the Agency. Where a public hearing is held, the review of the
draft EIS may extend beyond the prescribed timeline of 25 days required for EPA’s actions and
decision-making on the report.
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Environmental Permitting Decision
Where the draft EIS is found acceptable, the proponent is notified to finalize the report and submit
eight (8) hard copies and an electronic copy. Following submission to EPA, an Environmental
Permit shall be issued to the proponent within 15 working days and a gazette notice published.
It is customary that Environment Permits are issued with a set of conditions. Key conditions include
the requirements to:
i.
Submit Annual Environmental Reports every 12 months,
ii.
Submit Environmental Management Plans within 18 months of issuance of permit which are
to be revised every three years,
iii.
Submit periodic monitoring reports (frequency will be specified),
iv.
Give notice of commencement of operation of the undertaking and
v.
Obtain Environment Certificate within 24 months of satisfactory operations and compliance
with environmental permitting conditions.
1.6
REPORT STRUCTURE
The proposed structure of the ESHIS will follow that provided by the EPA. The content may alter
slightly during the evolution of the Project and the EIA process however the content will align
broadly within the suggested framework. An outline of the proposed contents of the final E(SH)IS is
hereby provided.
Table 1.1
E(SH)IS Report Structure
Chapter
Title
1
Introduction
2
Project Description
3
4
Legal Requirements and Policy
Framework
Biophysical Baseline
5
Socio-cultural Baseline
6
7
Health Baseline
Impact Identification and
Assessment
8
Mitigation and Management
Measures
9
Environmental Management
Plan
10
Decommissioning
11
12
Summary and Conclusions
References
Contents
Introduction to the Project and Project proponent;
Project purpose, E(SH)IA team and overview of EA
procedure.
Project justification; Technical description of the
project and alternatives considered; Project
contingency plan and execution schedule.
An overview of relevant national and international
legislation, and industry standards and guidelines
Description of the relevant, existing conditions of the
natural environment
Description of the relevant, existing socio-cultural
and economic conditions of the anthropic
environment
Description of the relevant, existing health conditions
Outline of impact assessment methodology;
identification and evaluation of potential
environmental, social and health impacts.
Description of mitigation and control measures
approach; outline of proposed impact
mitigation/enhancement and management measures
Summary of the monitoring and management that
will be executed to verify environmental, social and
health performance
Description of the decommissioning approach of
facilities at end of Project/field’s life
Summary of conclusions drawn from E(SH)IA study
A list of references and websites cited and analysed
Eni S.p.A.
Annex 1
Copy of Scoping Approval Letter
Annex 2
Evidence of Response to Ghana
EPA Scoping Report Review
Comments
Annex 3
List of Attachments to Ghana
OCTP Phase 1 E(SH)IA Report
ATTACHMENTS
Attachment
Attachment A
Title
Stakeholder Engagement
Report
Attachment B
Baseline Results
Attachment C*
Fisheries Impact Assessment
Attachment D
HSE-PLAN-003 “Drilling Oil Spill
Contingency Plan – OCTP
Block”
Attachment E
Waste Management Plan
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in report elaboration
Copy of Scoping approval letter issued by Ghana
th
EPA 10 February 2014.
A summary table highlighting how eni Ghana has
taken into due consideration and provided response
to review comments issued by Ghana EPA on the
th
10 February 2014 to the Scoping Report for
proposed Ghana OCTP Phase 1 Field Development
Project
Attachments to the present report are listed.
Contents
Report on outcome of stakeholder analysis,
consultations undertaken during the E(SH)IA
process, comprehensive of list of stakeholders,
meeting minutes, attendance registers and photos.
Detailed description of baseline methodology
adopted for the E(SH)IA
Fisheries baseline; identification and evaluation of
impacts on fisheries; proposed mitigation and
management measures
The Plan contains organisational responsibilities,
actions, reporting requirements and resources
available to ensure the effective and timely
management of an accidental oil spill; and supplies
the Emergency Response Team (ERT) with a high
level strategic document that covers the main
procedures and information required during an oil
spill response.
This plan details the overall strategy adopted by eni
Ghana for the management of waste to be generated
during the course of conducting project operations
(rigs, seismic, charter vessels, etc.). It covers
collection, storage, treatment, transport, disposal,
discharge, reporting and data management.
* a stand alone document to be delivered directly to the Ghana Fisheries Commisssion.
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PROJECT DESCRIPTION
2.1
PROJECT JUSTIFICATION
This chapter presents the needs, benefits and value for the eni’s proposed Offshore Cape Three
Points (OCTP) phase 1 Wells drilling programme; Laying and operation of Transport Systems
(flowlines); Installation and operation of FPSO(Floating Production, Storage and Offloading)/
mooring system and Installation, operation/ removal of well heads as well as the envisaged
environmental, social, health, economic and technical sustainability.
2.1.1
The Need for the Project
The proposed project which involves the drilling, Laying and operation of Transport Systems
(flowlines); Installation and operation of FPSO/ mooring system etc., of a number of wells in the
Ghana Offshore Cape Three Points (OCTP) block is specifically needed to:

Increase oil production,

Maintain proper reservoir pressure for gas lifting for enhanced hydrocarbon recovery,

Ensure that ENI complies with Ghana national policy on environmental protection,

Support ENI Ghana’s long term oil growth targets,

Stimulate interest of stakeholder’s,

Increase economic reserves,

Maintaining ENI Ghana’s business profile.
2.1.2
Project Key Drivers and Benefits
The production start-up is foreseen in 2017. Peak oil production is expected to be in the range of
45-50K BOPD. According to these features, the project will allow to improve Ghana oil production,
without compromising environment and sharing revenues with local industry and population.
Key drivers of the project are:
 Economics and time to production;

Maximize local industry involvement;

Compliance with local laws and Company policy;

Concept of “zero flaring”;

Flexibility for future expansions.

No sensitive impact on ecosystem
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Envisaged Project Sustainability
Economic and Commercial Sustainability
Throughout its design life span, the proposed project is envisaged to be economically and
commercially sustainable because of the confirmed large oil resource base within the OCTP Block
and the current global high demand of petroleum products.
Technical Sustainability
The proposed project is technically sustainable because of the proven expertise and track record
of ENI in offshore oil and gas exploration, development and production activities, as well as the
adoption and application of best available technologies (BAT) by the company in this project
execution. ENI E&P have considerable worldwide experiences in oil and gas-related design,
construction, installation, and commissioning to oversee the project development and
implementation. ENI will ensure that contractors adhere strictly to internationally and nationally
acceptable engineering design and construction standards and codes of practice at all stages of
development.
Also, incorporation into the design of several energy-efficiency measures that reduce fuel gas
consumption – such as use of high efficiency turbines and, where practicable use of waste heat
recovery mechanisms and heat exchangers in place of energy intensive heating and cooling
systems will greatly enhance the technical sustainability of the project.
ENI will develop standard operating procedures manuals and appropriate documentation regarding
the proposed activities. These materials will be used as the basis for providing facility-specific
training to relevant personnel prior to start-up to further ensure technical sustainability of the
project.
Environmental Sustainability
The OCTP Block project shall involve drilling, Laying and operation of Transport Systems
(flowlines); Installation and operation of FPSO/ mooring system etc; the project will be
environmentally sustainable because of the impact minimization and mitigation measures designed
into the project as documented in this ESHIA. The on-going monitoring and management programs
to be implemented as recommended in the EMP will help ensure environmental sustainability of
the project.
Social and Health Sustainability
Social and health sustainability will be guaranteed through impact minimization and monitoring
according to the measures already planned for within the project document. Mitigation measures
address impact areas such as sanitation (responsible use of fresh water supply), health (adequate
health care so as to prevent spread of local and new diseases subsequent to the arrival of
workers), livelihood resources (controlled use of, and interference with, locals’ access to
subsistence raw materials).
2.2
PROJECT OPTIONS
The project alternatives considered were based mainly on Health, Safety and Environment (HSE)
requirements as well as economic and technical feasibilities.
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2.2.1
Do Nothing Option
This implies that no hydrocarbon well drilling, Laying/operation of flowlines; Installation and
operation of FPSO/ mooring system etc. This means the non-implementation of the planned
activities in the project area.
The implications of this are that the benefits outlined in par. 2.1 would not be achieved. For
example:
 Impacts associated with oil and gas exploration and production will remain as it is in the
area,

The huge reserve of crude oil would remain unexploited.

Pressures in the target reservoirs would continue to decline
This option was therefore rejected.
2.2.2
Project options
This project entails wells drilling; Laying and operation of Transport Systems (flowlines); Installation
and operation of FPSO (Floating Production, Storage and Offloading) with mooring system and
Installation, operation/ removal of well heads in the project area. This shall be carried out using the
most up-to-date and proven technology. Also, International ENI HSE Guidelines and Standards
and acceptable best practices shall be adopted at all phases of the project execution. This option,
which assures the realization of the aspirations of the Ghana Government and the stakeholders
with its various benefits as well as the sustainability, has been selected for implementation. The
potential direct benefits to the region and the country from the exploitation of natural resources are
financial income and local business opportunities. Secondary indirect benefits are a potentially
increased standard of living and better education, social services and amenities, all of which can
potentially help raise awareness of the importance of environmental protection in the area.
OCTP field is located in the 63 Km offshore Ghana, in an area with existing and future nearby
developments. This area is represented in Figure 2-1.
OCTP
Sankofa
Main
N
Oil & Non Associated Gas Dev. Areas
SK9
Sankofa
East
106
Bcf
Oil Dev. Area
(88 Sqkm)
SK-2AST SK-2A SK9 E
SK-1A
Campanian
Gye
Nyame
GN-2A
Gas well with completion
SKE-3A
Oil & gas well
Gye Nyame-1
WCTP-2X
SKE-1X
SKE-2A
SK7b
WCTP-3X
SK7b E
SK7b
Figure 2-1
LEGENDA
Gas well
Sankofa
Gas Dev.
Area (92 Sqkm)
OCTP Development Project Area map
Gye Nyame
Gas Dev. Area
(46 Sq km)
Dry well
Campanian NAG
Sankofa East-2A
Cenomanian Oil
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Due to the reservoir target position (approx. 500-1000m water depth) and considering the West
Africa area offloading parcel, the natural solution to develop the field is through a Floating
Production Storage and Offloading facility (FPSO).
The following options have been analysed during the Concept Selection Phase:
1. FPSO position
-
Approx. 600m water depth,
o
Over the canyon
o
On the east side of the canyon between Sankofa field and Gye Nyame field;
-
Approx. 800m water depth, over the canyon
-
Approx. 1000m water depth, in Sankofa field area.
Figure 2-2
OCTP Development Project FPSO evaluated position
2. Mooring configuration
Both Turret and Spread mooring configuration have been taken into account.
3. Oflloading configuration
For Spread mooring FPSO, oflloading configuration have been evaluated with a dedicates
buoy and with tandem configuration.
4. Flowlines
Equally rigid and flexible flowlines solutions have been considered. Consequently subsea
layout solutions able to accomodate the previous options have been evaluated.
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To shorter the distance between the FPSO and the wells, in order to minimize the problems due to
the fluid characteristics and cost impact, the best case for the FPSO position has been considered
just over the canyon.
Spread mooring configuration have been selected to allow the possibility to anchor the FPSO
outside the canyon and at the same time guarantee a major flexibility and less impacts in case of
subsea layout modifications due to updates of reservoir study.
Offloading system availability has been investigated. An offloading study has been conducted and
tandem configuration has been selected as preferred solution from technical/economic point of
view.
In the end, due to the unkown seabed nature flexible flowlines have been selected as preferred
solution.
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PROJECT DESCRIPTION
This chapter presents the technical details on the planned activities in the OCTP Block
concessional area of eni Ghana. The planned activities include; Wells drilling programme; Laying
and operation of Transport Systems (flowlines); Installation and operation of FPSO/ mooring
system and offloading activities, Installation, operation of well heads, decommissioning and
abandonment operations. The planned activities shall take place in an area in the Ghana Deep
Offshore, located in the Gulf of Guinea, in the Republic of Ghana, approximately 60 km south of
the village of Sanzule (Figure 2-3).
Figure 2-3
Location of OCTP Block
Specifically, the following sections are the matter of interest:
 The project scenario, describing previous activities in the proposed project area.

The description of the location of the proposed wells.

The proposed well summary, which includes the well targets, reservoir prognosis
including predicted volume of recoverable resources and the potential geological risks
in the area.

Laying and operation of Transport Systems (flowlines).

Installation and operation of FPSO, mooring system and offloading.

Installation and Operation of Well heads and Umbilicals.
Eni S.p.A.
2.4

Waste management plan for the proposed project activities.

Proposed project contingency plan.

Decommissioning and abandonment plan

Overall project execution schedule.
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PROJECT SCENARIO
The Government of the Republic of Ghana, Ghana National Petroleum Corporation (“GNPC”) and
the Contractor entered into a Petroleum Agreement on March 2nd 2006 relating to the OCTP
contract area which was ratified by the Parliament of the Republic of Ghana on March 15th 2006.
Currently eni Ghana’s and Vitol’s participating interests (as Contractor) and GNPC’s participating
interests under the PA are as follows
 eni Ghana (Operator) 47.222%

Vitol 37.778%

GNPC
15% (carried by the Contractor in accordance with the PA)
Three non-associated gas fields have been discovered in the Offshore Cape Three Points (OCTP)
licence: Sankofa Main, Sankofa East and Gye Nyame. An additional oil field made of two separate
pools at Campanian and Cenomanian has been discovered in 2012 by Sankofa East-1X and
Sankofa East-2A. The discovered fields are located in the Republic of Ghana, Offshore at a
distance of approximately 55 Km South of the town Atuabo and 60 km South of the village of
Sanzule. Regionally they fall in the in the Tano sub-Basin, part of the wider Cote d’Ivoire Basin,
limited southward by the Romanche Fracture Zone. They are located immediately off of the
present-day continental shelf break at a water depth ranging between 500 and 1000 m
To date, the OCTP JV (composed of eni Ghana, Vitol and GNPC) has made, in the OCTP Contract
Area: (i) two (2) oil discoveries (Sankofa East Cenomanian and Sankofa East-2A Campanian
reservoirs); and (ii) three (3) NAG discoveries (Sankofa Main, Sankofa East and Gye Nyame) with
the potential of becoming the first Non-Associated Gas development in Ghana.
During the exploration and appraisal campaign (2009-2013), a total of eight (8) wells (Sankofa-1,
Sankofa-2A and 2STA, Gye Nyame-1, Gye Nyame-2A, Sankofa East-1X, Sankofa East-2A and
Sankofa East-3A) were drilled in the OCTP block. The campaign allowed to discover three nonassociated gas fields (Sankofa Main, Sankofa East and Gye Nyame) and two oil fields (Sankofa
East Cenomanian and Sankofa East-2A Campanian reservoirs).
During the exploration period, the Contractor fully complied with all the PA and requirements. In
particular, the Contractor duly fulfilled its obligation with respect to training fee payments, surface
rental, technology support payment, training on the job for GNPC’s resources. The minimum work
programs and expenditures set out in the PA for the exploration period have been fully achieved.
The total amount financed by the Contractor during the exploration period exceeds 600 M$
(100%). In addition to the PA requirements, Contractor encouraged and supported specific local
content training through international masters (petroleum engineering, HSE, energy and
environmental-economics management). Moreover, and in the frame of its engagement with local
communities, social projects were implemented in Jomoro and Ellembelle districts.
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PROJECT OVERVIEW
The Base Case field development is the exploitation with subsea wells connected to a stand-alone
FPSO, oil will be exported with shuttle tankers; gas and production water will be re-injected in the
reservoir after appropriate treatment and analysis, to maintain pressure and increase reserve
recovery.
For the exploitation of the oil and gas discoveries of the OCTP license, a development plan is
foreseen based on 14 subsea wells (8 Oil Producers, 3 water injection, 3 gas injection), subsea
facilities, one FPSO located inside the development area, flowlines system, risers and umbilicals.
First oil is planned for 2017.
The development of the Sankofa and Gye Nyame fields is carried out by means of a spread
moored FPSO, which collects both the oil and gas production from different regions of the fields to
collect and process the Oil (dehydration and stabilization) (Figure 2-4 and Error! Reference
source not found.).
Figure 2-4
OCTP Block
The produced Oil will be separated from both water and associated gas, stabilized and stored into
storage tanks in the FPSO prior to be properly metered and offloaded. Condensates produced later
on, during the following non associated gas project, will be separated offshore and blended with
the oil on the topside facility of the FPSO.
The produced water will be separated and treated in the produced water treatment unit in order to
comply with specification for water injection before being mixed with treated seawater and to be reinjected into the Cenomanian reservoir for pressure maintenance.
The Associated Gas (AG), produced from the oil separation train, will be dehydrated and
compressed before being re-injected into the Cenomanian reservoir according to the specified
demand. Part of this gas will be used for fuel for power generation.
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Sankofa field can be divided in 4 regions: North East, North West, South East and South West,
while Gye Nyame is around 15 km East.
Because of the well distance, the majority of the wells are satellite. Gas wells can be developed
stand alone or in daisy chain with a single production line, Oil wells need to be looped in order to
guarantee circulation and preservation strategy.
Oil production wells are arranged in a daisy-chained configuration around the FPSO, with 3 flow
loops in the NE, SE and SW regions. The loops in the NE and SW regions are piggable. Each of
these loops serves up to 3 OP wells, each of which is branched off from the main flowline by
means of an actuated FLET (Flowline End Termination). There is a single well (OP-CAMP 2) in the
SW which is on a dedicated heated flowline back to the FPSO.
Gas and Water Injection wells are also arranged in a satellite configuration around the FPSO. Each
of these wells is branched off from the main flowline by means of a passive FLET with spare
connector on the header, allowing the flowline to be extended for future expansion.
No routine flaring of gas was assumed and no regional gas gathering system has been considered
available, therefore gas disposal through gas injection wells has been planned.
Depending on drilling and completion requirements, use of satellite wells may be envisaged for
injection wells. Drilling centers will be tied-back to the FPSO by means of a flow-line and risers
system. An umbilical system will provide control and chemicals to all sub-sea manifolds and trees
from the FPSO. Crude oil will flow continuously from subsea trees through subsea flowlines via
risers to the process facilities on the FPSO.
Figure 2-5
OCTP Phase 1 Schematic Layout
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Processed crude oil will be stored in the cargo tanks. Shuttle tankers will periodically be moored to
the FPSO and the stored crude oil will be pumped to the shuttle tanker via an offloading hose.
Exported crude will be fiscally metered on board of the FPSO. The normal production will not be
affected by the crude export operations.
2.6
PROJECT LOCATION
The Offshore Cape Three Points (OCTP) block is located in the Gulf of Guinea, in the Republic of
Ghana, and is situated approximately 55 km South of the town of Atuabo and 60 km South of
Sanzule. The water depth in the development area ranges from approximately 800 m to 1,000 m.
The reservoirs discovered are: Cenomanian and Campanian oil bearing of Sankofa East and
Campanian non associated gas (Sankofa Main, Sankofa East & Gye Nyame fields).
A total number of 14 wells will be drilled
 8 Production wells

3 Gas injection wells

3 Water injection wells
Eni S.p.A.
Table 2.1
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Wells to be drilled
The development of the Sankofa and Gye Nyame fields is carried out by means of a spread
moored FPSO, which collects both the oil and gas production from different regions of the fields.
Canyon crossing has been assumed not feasible due to its depth and slope instability. Therefore
the FPSO has been located above the canyon, in order to avoid flowline crossing, gathering the
production from all the Sankofa field regions and Gye Nyame as well.
Table 2.2
FPSO Location
Eni S.p.A.
2.7
2.7.1
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DRILLING AND COMPLETION OPERATIONS
Description of the Drilling Unit
The well drilling operations shall be performed using a Drilling Unit Saipem 10000 or equivalent rig,
capable of operating in water depths up to 3000 m. Relevant information from the technical
specifications for the drilling unit are presented in Table 2.3 and pictorially presented in Figure 2-6.
The seaworthiness certification as well as Eni’s Safety, Health and Environment standards require
that safety precautions will be taken to minimise the possibility of an accident during drilling
operations. Collision prevention equipments include radar, multi-frequency radio, fog horns, etc.
Additional precautions include a supply vessel normally stationed at the well location, 24-hour
watches, establishment of a 500 m radius exclusion zone around the drilling unit, and access to
current weather data.
The rig Saipem 10000 is an advanced semi-submersible, highly versatile drilling unit. In keeping
with the highest environmental regulations, the Saipem 10000 is ‘zero pollution’ and ‘zero
discharge’. The unit is classified as ABS + A1 (E), “Drilling Unit”, + FPSO + AMS, + ACCU, + DPS3, OMBO, DLA, CDS.
Eni S.p.A.
Table 2.3
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Saipem 10000 Sepcifications
.1.0 Unit Owner Data
1 Rig Owner
:
Saipem Portugal Comercio Maritimo
.2.0
1
2
3
:
:
:
Saipem 10000
Dynamic Positioned Drillship.
ABS + A1 (E), “Drilling Unit”, + FPSO + AMS,
+ ACCU, + DPS-3, OMBO, DLA, CDS
Samsung
1999 – 2000
Samsung Heavy Industries
Dynamic positioning DP-3
12
4
5
6
7
8
Unit General Data
Unit Name
Unit Type
Unit Classification
Unit Design
Year of Unit construction
Unit construction shipyard
Unit Positioning system
Maximum speed
:
:
:
type
Knots
.3.0
1
2
3
4
5
6
7
8
9
Main Dimensions of the Unit
Length overall
Length between perpendicular
Breadth
Depth
Lightweight
Dead-weight
Displacement
Moon Pool Dimensions
Accommodation for max. Nor of men
m
m
m
m
mton
mton
mton
m-m
No.
.4.0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
Unit Storage capacities
Fuel
Drilling water
Potable water
Liquid mud (active & reserve)
Mud processing Tank
Waste liquid (mud & washing water)
Brine
Oil base Mud
Crude Oil
Bulk bentonite/Barite
Bulk Cement
Sack storage
Ballast water
Total Riser joints deck racking capacity with buoyancy
Total Riser joints deck racking capacity w/out buoyancy
Total Joints of production Riser
Casing Joints deck racking capacity
M
3
M
3
M
3
M
3
M
3
M
3
M
3
M
3
M
3
M
3
M
No.
Bbls
No./ft
No./ft
No./ft
No./ft
18 Drill pipes/Collars deck racking capacity
1.0
1
2
3
Unit operational depths
Max. designed water depth capability
Max. outfitted water depth capability
Min. outfitted water depth capability
3
No./ft
Ft
Ft
Ft
227.8
219.4
42
19
35337.5
61117.9
96455.4
25.6 x 10.26
172
6342 Diesel Oil or Heavy Fuel Oil
2886
1300
1955
50 included in above
477
700
477
22256
450
520
10.000
440000
126 total (90 ft long) with or without buoyancy
see above
N.A.
18
jts 32” or 30 joints 36”
100
jts 20” or 20 joints 26”
203
jts 16”
416
jts 13 3/8”
660
jts 9 5/8”
420
jts 7”
118 D.C. / 3500 ft 2063 D.P. / 78900 ft
10.000
10.000
1500 To be evaluated on a case by case basis
(depending on location and environmental
conditions).
Eni S.p.A.
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4 Max. Drilling depth capacity (5” DP)
.2. Unit Variable Load
1 Variable Load In transit mode
Ft
Mton
2 Variable Load In Drilling mode
Mton
3 Variable Load In Survival mode
Mton
.3. Unit Environmental Limits
1 Max. wave height
2
3
4
6
7
8
Related wave period
Max. wind velocity
Max. current velocity
Max. unit heave (dual amplitude)
Max. unit pitch (dual amplitude)
Max. unit roll (dual amplitude)
M
Sec
Knots
Knots
M
Deg
Deg
.4. Operational Limits Vs Unit Motions
1
2
3
4
During drilling and tripping (dual ampl.)
During running riser & BOP (dual ampl.)
During running casing (dual amplitude)
Max. unit offset % of water depth
1 Built according to any Rule
2 Classified as per
.1
1
2
3
4
5
6
Propulsion/Thrusters
Total Thrusters
Thrusters (azimuth)
Driven by electric motors
Electric motor
Electric motor
Electric motor
.2.
1
2
3
4
5
6
7
8
9
Dynamic positioning Control system
Manufacturer name
.3.
1
2
3
4
Acoustic positioning system
D.P. Acoustic Position reference
Transponder Spare
DP Computer Control system
Back-up DP Computer Control system
Location
Joystick manual DP Control system
.4. Vertical Reference Units
30000
17000 (Without crude oil, at 8.5 m draught)
20000 (With crude oil, at 12 m draught)
20000 (Without crude oil)
18000 (With crude oil)
20000 (Without crude oil)
15.000 (With crude oil)
The ship has the capability to drill worldwide
included the summer window for UK sector
and excluded Norwegian sector.
Refer to separate document provided by
Saipem.”
“Downtime Analysis” dated 13-12-1999” and
“Dynamic Positioning Capability Plots” dated
12-12-1999.
See above statement
See above statement
See above statement
See above statement
See above statement
See above statement
HEAVE
m
:
:
:
:
ROLL
deg
See above statement
See above statement
See above statement
See above statement
:
:
IMO MODU – IMO MSC/Circ. 645
ABS/IMO MODU DPS-3
No.
Type
No
Make
Type
HP
PITCH
deg
6
Ulstein Type TCNP 156/M-380
6
ABB
AMB 710 L8L VAF MTB
5440
Make Kongsberg Simrad
Type
SDP 22 (Wheelhouse) + SDP12 (ECR)
No. 1
Type SDP-12 engine control room
No. 1
Type SDP-22
: whellhouse
No. On main & back-up panels + one portable
Type SDP-OT
No
Type
Type
No.
Including well spud-in reference point.
2 ARRAYS (2 set of 5 transponders each)
HPR port HiPAP SSBL/LBL
HPR stbd HiPAP SSBL/LBL
5
Eni S.p.A.
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No
Type
3
SEATEX MRU roll and pitch sensor MRU-5
.5. Differential Global Positioning Satellite (D.G.P.S).
System
1 D.P.G.S. Position Reference System
2 D.P.G.S. Position Reference System
No
Type
4
DGPS System with antennas
2 INMARSAT Correctional Signal
1Spot Beam Correctional Signal
.6.
1
2
3
No:
Type
No:
3
DEIF Wind Measuring
The surface current is calculated by DP
system
1 Vertical Reference Unit
2 Vertical Reference Unit
Wind & Current Speed & Direction Sensors.
D.P. Wind speed and direction sensors
D.P. Wind speed and direction sensors
D.P. Current speed and direction sensors
4 D.P. Current speed and direction sensors
Type
.7. Heading Sensors.
1 Heading Sensor
2 Heading Sensor
No:
Type
3
-
.8. Riser angle Indicators.
1 Riser angle Indicators
2 Riser angle Indicators
No:
Type
4 (1 upper + 3 lower)
1 inclinometer upper
2 inclinometer lower via Mux cable
1 differential acoustic inclinometer
.9.
1
2
3
4
5
Uninterrutable Power system.(UPS)
UPS number of units
UPS
UPS
UPS running time of each Unit at full load
UPS running time of each Unit at ½ load
No:
Make
Type
Min
Min
.1
1
2
3
4
5
6
Windlass
Winches
Winches
Winches
Driving system (Electric, Hydraulic,)
Rated Pull
Low Gear Speed
No
Make
Type
:
Mt
m/m
1 set
Pusnes
0-15 CUL 10.15+250HW 15M.10
Hydraulic
54.4
9
.2
1
2
3
Mooring winches
Winches
Winches
Winches
No
Make
Type
Hullside
15
MGE
Topside
2
ASTRID
30
50
60
4 Driving system (Electric, Hydraulic,)
5 Rated Pull
6 Low Gear Speed
:
Mt
m/m
4 Sets
Pusnes
200HW47M.53 (1 set)
200HW54M.10 (3 sets)
Hydraulic
20
15
.3
1
2
3
4
Anchors
Anchors Quantity
Anchors
Anchors
Anchors Weight
No
Make
Type
Mton
1
Inchon Iron & Steel Co. Ltd.
JIS Stockless
18.8
.4
1
2
3
4
Mooring Lines
Mooring Lines
Mooring Lines Nominal diameter
Mooring Lines
Mooring Lines Weight per unit length
No
Mm
Type
kg/m
9 sets
32
Wire rope
5.5
Eni S.p.A.
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M
5 Mooring Lines Useful Length
.5 Ship Fending System
No
Make
Type
1
2
3
4
.5 Landing System
Quantity
Type
1 Loading Hose Location (port/stbd)
No
:
200
Appliances allow mooring along sides of
shuttle-export-tanker and Supply vessels.
S/Vs in four positions bow and astern.
4
6
KUMNAM
KUMNAM
2.5 x 5.5 m
1.5 x 3 m
1
As per Company Request Dwg GS STR 901
Yes on both side
.1.
1
2
3
Potable Water Loading hoses
Quantity
Size
Connection
No.
In
Type
2
5”
Weco Union Fig. 100
.2.
1
2
3
Drilling water Loading hoses
Quantity
Size
Connection
No.
In
Type
2
5”
Weco Union Fig. 100
.3.
1
2
3
Fuel Loading hoses
Quantity
Size
Connection
No.
In
Type
2 with check valve
4”
Avery Hardoll Connection
.4
1
2
3
Bulk Barite/Bentonite Loading hoses
Quantity
Size
Connection
No.
In
Type
2
5”
Weco Union Fig. 100
.5
1
2
3
Bulk Cement Loading hoses
Quantity
Size
Connection
No.
In
Type
2
5”
Weco Union
.6
1
2
3
Oil Base Mud Loading hoses
Quantity
Size
Connection
No.
In
Type
2 with check valve
4”
Avery Hardoll Connection
1
1
2
3
4
5
6
7
8
Rotary Table
No
make
type
in
Mton
make
type
Hp
2
Wirth
RTSS 60 ½” hydraulic
60 ½”
907
Maximum Opening
Rated capacity
R.T. driven by motor
Output Power
Two speed Gear box Type
.1 Top Drive
Yes/No
35 of 425
Hydraulic
240 kW cont. - 600 kW int.
One gear
Eni S.p.A.
1
2
3
4
5
6
7
8
9
9
10
11
12
Top Drive System quantity
Top Drive
Top Drive
Static Rated Load Capacity
Top Drive integral swivel
Wash pipe working pressure
Access Fitting for Wireline on Gooseneck
Washpipe Minimum Inside diameter
Top Drive Driven by motor
Driven by motor
Electric Motor Cooling system
Top drive max. output torque
At max. rotation speed
.2
1
2
3
4
5
Top Drive Pipe Handler system
Top Drive Pipe Handler system
Max. break-Out Torque
Link elevators for drill string
Link elevators for running casing
No
make
type
Mt
Yes/No
psi
Yes/No
in
make
type
type
ft.lbs
RPM
make
type
ft.lbs
size
size
Remote operated Inside BOP
Inside Diameter
Outside Diameter
Max. working pressure
3.2
1
2
3
4
5
6
Manual operated Inside BOP
100.000
350 – 500 sTon
750 sTon
1 each top drive
Hydralift
Hydril
3 1/16”
8 5/8”
15.000
Inside Diameter
Outside Diameter
Max. working pressure
No
make
type
in
in
psi
1
Hydralift
Hydril
3 1/16”
8 5/8”
15.000
.1
1
2
3
Engine Room
Quantity
Engine room walls fire proof type
Engine Room positive Pressurised
yes/no
yes/no
2
Yes
Yes
.2
1
2
3
4
5
Diesel Engines
Quantity
No.
make
type
hp
:
6
Wartsila Nsd Co.
18V32LNE
9910
IP54
.3
1
2
3
4
5
6
AC Generators
Quantity
No.
make
type
KVA
Hz
V
6
ABB
HSG900XU10
8750
60
11000
Max. Continuous Power of Each
Frequency
Output Volts
.4 SCR / Inverter System
1 Quantity
32000
300
Hydralift
No
make
type
in
in
psi
Max. Continuous Power of Each
Diesel engine water proof type
36 of 425
Suitable for all Dp’s size changing only the
saver sub
3 Top. Drive Inside BOP
.3.1
1
2
3
4
5
6
2
Hydralift
HPS 750 2E
680
Yes
7500
Yes
3 1/16”
General Electric
GE AC
Air cooled
122.500
Zero
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No.
18
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
2
3
4 SCR Output Voltage
5 SCR Output Amperage
6 No. of motors that SCRInverter can run simultaneously
make
type
V
A
No./
kW
37 of 425
ABB
Various
600
1030.76 for mud pumps and top drive
1254.21 for drawwork
18
.5
1
2
3
4
5
Transformer System
Quantity
Max. Output Power
Max. Output Voltage
Max. Output Amperage
Frequency
No.
KVA
V
A
Hz
2
7200
600
6936
60
6
5200
1750
1716
60
6
7
8
9
10
Quantity
Max. Output Power
Max. Output Voltage
Frequency
No.
KVA
V
A
Hz
2
2500
450
3208
60
2
200
450
3566
60
11
12
13
14
15
Quantity
Max. Output Power
Max. Output Voltage
Frequency
No.
KVA
V
A
Hz
2
1500
450
1925
60
2
300
230
502
60
16
17
18
19
20
Quantity
Max. Output Power
Max. Output Voltage
Frequency
No.
KVA
V
A
Hz
2
125
230
314
60
:
On upper deck, port side
.1 Diesel engine
1
2
3 Max. Continuous Power
make
type
hp
HAEIN / CATERPILLAR
CAT 3516 DITA
1350 kW
.2
1
2
3
4
5
make
type
KVA
V
A
HAEIN / CATERPILLAR
SR 4
1687.5
450
2165
1 Emergency Power Generator Location
AC Generator
Max. Continuous Power
Max. Output Voltage
.3 Emergency Generator starting system
1 Starting automatically in case of Main Power supply
failure
.4
.4.1
1
2
3
4
5
6
Main Users connected with :
Emergency Lighting
At every Life Boat Station
In Living Quarters
In Machinery Spaces
In Control Rooms
In all other Essential Spaces
On Helicopter Deck
.4.2 Navigation Signals
1 Navigation Lights
Yes/No
Yes
:
:
:
:
:
:
Yes
Yes
Yes
Yes
Yes
Yes
:
Yes
Eni S.p.A.
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:
Yes
.4.3 Communication System
1 Radio-telecommunication
2 All internal Tele-Communication Equipment
:
:
Yes
Yes
.4.4
1
2
3
4
5
Equipment related to Drill Operations
BOP Control system
Wellhead disconnecting system
BOP accumulator Recharging pump
R.O.V
Others
:
:
:
:
:
Yes UPS
Yes UPS
Yes
No
.4.5
.
1
2
3
4
Safety Monitoring and alarm system
Fire Monitoring and alarm system
Gas Monitoring and alarm system
H2-S Monitoring and alarm system
Ballast Control system
:
:
:
:
Yes
Yes
Yes
Yes
.4.6
1
2
3
4
5
6
Other Safety System
One Fire water Pump
Personal Lifts
Bilge Pump
Electrical air compressor
One Mud Transfer Pump
Electrical Battery Charger
:
:
:
:
:
:
Yes
Yes
Yes
Yes
Yes
Yes
3
Enough for 24 hrs running time at full load.
24
2 Sound Signals
.5 Diesel Engine Fuel tank
1 Fuel tank capacity
2 Time of feeding of all the above Users
.1.
1
2
3
4
5
6
BOP Stack
BOP Stack size
Guideline or Guidelineless
API specification
Last BOP Periodical Inspection
Last BOP Complete Overhaul/ Inspection
Spare BOP stack
.1.1
.1.1
.1
1
2
3
4
5
6
7
8
BOP Stack Composition (from Top to Bottom)
Riser Adaptor
.1.1
.2
1
2
3
4
5
6
Flex Joint
Quantity
Top connection
C/W choke & kill kick-out subs
C/W Booster kick-out sub
C/W Booster line valve
C/W Rigid Conduit kick-out sub
Flex Joint Quantity
Flex Joint
Flex Joint
Flex Joint Max. Deflection
Max. applicable tension load
Spring load rate
M
Hr
in-psi
:
:
:
:
Yes/No
No.
make
type
type
no/psi
no/psi
type
type
No.
make
type
deg.
lbs
ft.lb/de
g
18 ¾ - 15.000 PSI
Guidelineless
API 16 A
N/A new system
N/A new system
No
1
ABB Vetco Gray
N.A.
HMF-H
2 x 15.000 PSI
1 x 5000 PSI (kick in)
1 x ball valve 5000 psi
2 x 5000 PSI + 1 glycol line 15.000 psi
1
Oilstates
N/A
10 deg
2000000 lbs
40,000 ft-lbs
Eni S.p.A.
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1
2
3
4
5
39 of 425
Upper Annular Preventer
No.
make
type
in-psi
in-psi
1
Shaffer
Yes
18 ¾” – 10.000
Two side oulets. One blanked. One fitted with
dual fail closed bleed-off valve 10.000 psi
1.1. Upper Hydraulic Connector
4
1 Quantity
2
3
4 Size
No.
make
type
in-psi
1
ABB Vetco Gray
HD – HAR
18 ¾ “ – 10.000
1.1. Lower Annular Preventer
5
1 Quantity
2
3
4 Size
No.
make
type
in-psi
1
Shaffer
Suitable for 3000 m w.d.
18.3/4” - 10.000
No.
make
type
:
in-psi
1
Shaffer
NXT
Double
18 ¾ “ – 15.000
Yes
Yes (Any sensor fitted)
Yes (Any sensor fitted)
2
3 1/16 x 15.000 PSI
Quantity
Size
C/W two side outlets for bleed-off valves
1.1.
6
1
2
3
4
5
6
7
8
9
10
Ram type Preventer
1..1
.7
1
2
3
4
5
6
7
Ram type Preventer
Quantity
Single /double/triple
Size
C/W Large shear seal bonnet
C/W Provision for Temperature sensor.
C/W Provision for Pressure sensor.
Side outlet each Ram
Side outlet size
Quantity
Single /double/Triple
Size
C/W Large shear seal bonnet
C/W Provision for Temperature sensor.
8 C/W Provision for Pressure sensor.
9 Side outlet each Ram
10 Side outlet size
1.1.
8
1
2
3
4
BOP Ram Available
1.1.
9
1
2
3
4
BOP Ram Available
BOP Ram Quantity
BOP Ram
BOP Ram Size
Seal packer
BOP Ram Quantity
BOP Ram
BOP Ram Size
Seal packer
Yes/No
Yes/No
Yes/No
No.
in-psi
No.
make
type
:
in-psi
Yes/No
Yes/No
Yes/No
No.
in-psi
1
Shaffer
NXT
Triple
Yes
N.A.
Yes, with combined pressure / temperature
sensor)
See above
2
3 1/16 – 15.000 PSI
No.
type
in
type
2
Variable
3 ½” - 5”
®
Multiram
H2S trim
2
Variable
5” – 7”
®
Multiram
H2S trim
No.
type
in
type
1
Fixed pipe
5
SL-D H2S trim
1
Fixed
5.1/2”
SL-D-H2S trim
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1.1.
10
1
2
3
4
BOP Ram Available
1.1.
11
1
2
3
4
5
Lower Hydraulic Connector(W.H. Connector)
1.1.
11
A
1
2
3
4
5
6
Lower Hydraulic Connector(W.H. Connector)
BOP Ram Quantity
BOP Ram
BOP Ram Size
Seal packer
Quantity
Size
Rated bending moment
Quantità
Size
Rated bending moment
Shearing Capacity
1.1. Funnel Down
12
Quantity
1.1. BOP STACK Valves
13
1 Valves Quantity
2 used as
No.
type
in
type
1
Shear
13.3/8” Csg
Casing Shear H2S
trim
1
Shear/blind
6.5/8 x 34.01 lb/ft DP
Type “V” H2S trim
No.
make
type
in-psi
ft.lb
1
ABB Vetco Gray
HD - H4
18.3/4” - 15.000
4 M ft-lbs
No.
Make
Type
In-psi
Ft-lb
1
ABB VETCO GRAY
SHDH4
18.3/4” – 15.000
7 M ft-lbs
14” CSG - 106 ft/lb - N80 Shearable
No.
Make
1
ABB VETCO GRAY
No.
:
4
2
1
1+1
Kill and
Choke. Dual
Block. Bop
Mounted Fail
Safe Close
Test Valves
LMRP.
mounted.
Fail Safe
Open
Gas Bleed
Off valve.
One dual
block
1 dual block
BOP
mounted fail
safe close
1 LMRP
mounted Fail
Safe Open
3
4
make
type
5 Size
in-psi
SHAFFER
HB -Double-block-Hydraulic-Fail close actuator
suitable for 3000 m w.d.
3.1/16-15.000 psi
No.
in-psi
type
2
3 1/16” – 15.000 PSI
Flex Loop
1.1.
14
1
2
3
BOP STACK Kill & Choke Lines
Kill & Choke Lines Quantity
Kill & Choke Lines size
Kill & Choke Lines
Eni S.p.A.
Figure 2-6
2.7.2
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The Drilling Rig Saipem 10000
Sequence of operations
Pre drilling
The sequence foresees the positioning of the rig in the well location and the jetting of 36”
conductor pipe. The drilling of 24” phase is made with sea water and viscous pillows, the cutting
will be scattered on the sea bed because there isn’t connection with the surface facilities through
the marine riser. Then the 20” casing with wellhead housing is run and cemented in place.
The next sequence is to run the BOP stack with the marine riser and latch it on wellhead housing.
After that all the drilling fluids and debris will be managed from the surface facilities of the rig.
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The operations will carry on in the same way until the 9 5\8” liner is set.
At that time the well is temporary suspended, the riser and BOP are recovered and the rig will
move in the location of another well.
Re-entry and completion campaign
At the end of the drilling campaign will start the completion phase, so the rig will be back on the
well, the corrosion cap will be removed and the Horizontal X-tree will be landed and installed with
the BOP (Blow Out Preventer) on top.
The last 8 1/2 ”drilling section is performed through X-Tree, then the cased hole logs are recorded.
Now the well is completed with lower, gravel or frac pack, and upper completion, tubing string
packer and safety valves.
The last operation before to install the corrosion cap on X-Tree will be the well clean up.
Well start up
At the end of all the drilling and completion activities is highly recommended a well production test.
The main purpose of the operation is to eliminate all the debris from the well in order to avoid some
damages of the downhole and surface equipments.
The test is usually done from the rig as soon as finished the completion job.
The period of the clean-up is quite short, around 3-4 hours, but it can hold up about 24 to better
understand the productivity of the well.
2.7.3
Drilling Activities
Drilling process involves the use of a 'drilling string' made up of standard lengths of steel pipes.
The drilling string is tipped with a drill bit, which grinds through the rocks as the drilling string is
rotated. The drilling string is supported by a derrick (a steel framework tower) that is mounted on
the drill floor with the rig. The derrick houses the winching equipment needed to lower and raise
the drilling string, the rotating table used to turn the drilling string, and the power unit.
Drilling is achieved using a bit (Figure 2-7) set at the end of a string of hollow circular pipes, each
approximately 10 meters long. These pipes are screwed together so that they can be lowered into,
and removed from, the well. They transmit the rotary motion (generated at the surface by the Top
Drive System), circulate the drilling mud and exert weight on the drilling tool.
Figure 2-7
Drilling Bit
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As the drilling process proceeds, drilling has to stop periodically to replace the drill bit and to allow
new lengths of pipes to be added to the string. Steel casing is run into completed sections of a
borehole and cemented into place. This casing provides structural support to maintain integrity of
the borehole and protect the water column from contamination by oil or drilling fluid
The Drilling system: includes rotating parts, mud circuit and safety equipment. The rotary system
transfers the rotary movement from the surface to the drill bit. It is made of an injection head, top
drive and drill string. The top drive produces the rotary motion. The top drive is essentially made up
of a high power engine the rotor of which is connected to the drill string. The top drive also includes
the injection head (which can pump mud into the drill string while it is turning), a makeup-breakout
system for connecting-releasing the drill string and a valve to control the mud pumped into the well.
The pipes that make up the drill string are divided into drill pipes and extra-heavy pipes (of greater
diameter and thickness). An appropriate number of the latter are installed upstream of the bit to
ensure that adequate weight is brought to bear on the bit itself. All pipes in the string are screwed
together so as to ensure that the torsion is transmitted to the bit and hydraulic seal.
Mud Circuit
In a drilling system, the mud circuit is particularly complex since it must also include a system able
to separate drilling debris and treat the mud itself.
The mud is fed into the drill pipes using high pressure pumps; it exits the special holes in the bit at
the bottom of the well, incorporates the drilling debris and then rises back up to the surface. When
exiting the well it passes through the Solids Treatment System composed of equipment such as
vibrating screen, desilter, desander, etc. which separate the mud from the drill cuttings: before the
mud is reconditioned in special tanks and then pumped back into the well; the latter are collected in
specific containers, stocked and transported onshore via the supply vessels.
Various storage tanks are also part of the circuit; they keep an adequate reserve of mud on hand
to handle any sudden needs that may arise due to leaks in circulation or absorption of the well.
Circulation of the mud ensures that the debris created by the bit is removed from the well. The
composition of the drilling mud is controlled to ensure that it meets specific density and viscosity
characteristics. It also serves to counterbalance the pressure exerted by fluids in the rock being
drilled through as well as provide support for the wall of the well during the drilling phase. The
hydrostatic pressure exerted by the column of mud is, in fact, greater than the normal hydrostatic
gradient and even abnormal pressures can be contained by adding substances that increase the
density of the mud. Rotary drilling makes drilling of boreholes relatively simple, rapid, even when
thousands of meters deep.
Once the borehole has been drilled, in order to insulate the rock formations passed through and
provide support for the rock walls, the well is coated with steel pipes (i.e. the lining column called
the casing) which are jointed together and cemented into the borehole itself. Then a bit having a
smaller diameter is lowered into the casing to drill the next section which is then protected by
another casing. The prospecting goal is achieved by drilling boreholes of decreasing diameter,
each protected by a casing (Figure 2-8).
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OCTP
OP
Figure 2-8
Oil well sketch
The drilling operations are continuous, performed over the entire 24 hour period.
The initial borehole diameter is several decimetres (16-30 inches), but it decreases according to
the number of casing columns used. At the bottom it is reduced to 10-20 centimetres (4-8 inches).
The borehole is normally vertical; only on rare occasions is it perfectly vertical but in most cases
the deviation in verticality is kept within a few degrees and thus the shift in coordinates between
the bottom of the well and the surface is on the order of a few dozen meters.
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In some cases, in order to reach underground targets as much as a few hundred meters away, the
borehole is intentionally deviated off vertical, reaching a slope of as much as 50 – 60°. Thus, from
a single surface structure, it is possible to drill several wells that reach the reservoir from different,
distant points.
In recent years, with the aid of special equipment and techniques, it has become possible also to
drill horizontal bore sections (Figure 2-9). This technique makes it possible to cover considerable
lengths, mining them through the system of fractures that allows hydrocarbons to drain through the
reservoir rocks, thus improving recovery of the fluids throughout the production life of the well.
BALAKANI
Figure 2-9
Directional and Horizontal Wells
The type and pressure of the fluids contained in the rock being drilled through varies as the depth
increases and such variation can be quite unpredictable.
One must be fully aware of the lithology, geological age of the succession of rock being passed
through, meter by meter as well as the nature and pressure of the fluids contained therein. Such
research must be performed both prior to drilling of the borehole — through a seismological survey
— and during the course of drilling — through rock sequence analysis performed on drilling
samples and through the use of special instruments (logs) that can take electronic measurements
and process them to determine the characteristics of the rock and fluids contained therein.
Once the drilling operation will be completed, purposely made “production tests”, will give accurate
information on the nature and pressure of the produce water
The well must be drilled in such manner as to prevent uncontrolled emissions of these formation
fluids from the well. This is achieved using a mud whose density is able to offset the formation
fluids and using a system of valves located upstream of well opening (well head and BOP) able to
close the well.
When the borehole is being drilled (i.e. before lowering the casing column that insulates the
borehole from the rock formations), the drill string and mud are in direct contact with the rock
formations that have been laid bare.
During this transitory phase, instability of the newly drilled borehole is always possible and can
lead to anomalies vs. smooth progression of the operations. Such anomalies can include:
absorption of the mud into the fractures and pores in the rock, collapse of the walls of the borehole,
catching of the bit or of the drill string against the ground, breakdown of the drill string due to
difficult working conditions.
For production wells, the drilling phase is completed once the entire borehole is lined with steel
casing pipes (production string) or, for barren wells, with complete abandonment well using cement
plugs.
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Drilling and Completion Fluids
The drilling fluids are normally made up of a liquid (water or oil) set in a colloidal state and
weighted down with specific products. The colloidal properties achieved with special clays
(bentonite) and enhanced by particular compounds (i.e. Carboxyl Methyl Cellulose - C.M.C.) that
give the mud particular rheological properties, turning it into a gel able to keep the weighting
additives and debris in suspension, even when circulation is cut off.
In sum, the purpose of the drilling fluids is to:
 Remove debris from the bottom of the well and carry it up to the surface thanks to its
rheological properties.

Cool and lubricate the drilling bit.

Contain the fluids present in the rock formations thanks to its hydrostatic pressure.

Consolidate the walls of the borehole and reduce infiltration into the formation by
creating a panel to coat the borehole.

To satisfactorily perform all its functions at once, the drilling fluids must be continually
enhanced with chemicals and their rheological properties checked.
The type of mud (and its chemical components) is determined according to the rock being drilled
and the temperature. In fact, the drilling fluids interact with the rock formations and thus using the
correct type of mud will prevent borehole collapse and damage to the production formations.
Moreover, excessive temperatures can alter the rheological properties of the mud (temperatures
can exceed 200°C).
Selection and definition of the drilling fluids are based on experience accrued in the field. Past
experience has shown that the main problems encountered could be:
 mud losses at the surface phases,

reactive shale and uncertain mud density causing the pipe at the middle or phases
deeper than 2000 m,

tight hole.
Therefore a mud system with a high inhibitive capacity shall be selected for the deep phases. In
terms of environmental protection — less impact on the marine environment, lower waste
discharges — and operating difficulties Synthetic Oil Based Mud system SBM has been selected
as the drilling fluid.
Given the above mentioned problems, some preventive and control plans shall be programmed.
The various types of materials for circulation shall be stocked at the rig site in sufficient quantity to
make up for losses along with suitable pills (to free stuck pipe).
The surface riserless intervals 24” and 42” will be drilled with Sea Water (Water Based Mud WBM)
and Hi-Vis Sweeps. The sweeps will be circulated up to sea bed to keep hole cleaning.
Non Aqueous Drilling Fluid (NADF) will be used to drill 17 ½”, 14 ¾”, pilot hole 8 ½” and sidetrack
12 ¼” and 8 ½” sections.
Eni S.p.A.
Casing Size
(in)
36”
20”
16” LNR
13⅝”
--------9⅝”
7” LNR
Hole Size
(in)
42”
24”
17½”
14¾”
Pilot hole - 8½”
Side track - 12¼”
8½”
Table 2.4
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Estimated Mud Type
(Type)
Sea water + HV pill
Sea water + HV pill
NADF
NADF
NADF
NADF
DIF – Low Solid
Drilling Mud Type
NADF can be made with synthetic or low toxic mineral base fluid. These systems possess
properties that are highly desirable and are not completely obtainable wi\th water-based systems.
One of these is the very low level of reaction with the formation, combined with minimal penetration
of the fluid phase into the formation. This leads to maximum borehole stability over a long-lasting
time span and lets the cuttings come to the surface solids removal equipment in such a size range
that a significant portion can be removed. Moreover, fluid loss control is another important
characteristic of non-aqueous fluid system.
The main advantages that lead to the choice of a non-aqueous drilling fluid can be summarized as
follows:
 Maximum level of shale hydration inhibition. Gauge holes can be drilled in reactive
formations.

Consistent fluid properties.

High tolerance to drilled solids contamination.
The drilling rig shall be equipped to properly process and handle the NADF and the cuttings in
accordance with government regulations.
The margin between anticipated circulating pressures and fracture gradients is quite wide. In any
case all precautions should be taken to avoid the risk of mud losses.
For the open hole section a Drill-in fluid will be used. Drill-in fluids (DIF) are drilling fluids used to
penetrate the pay zone, reducing the potential formation damage. A drill-in fluid must provide hole
cleaning, lubricity and inhibition with respect to interstitial clays and shale inter-beds, while being
minimally damaging to the permeability of the formation. In order to realize the full potential
productivity of a reservoir, formation damage from drilling fluid leaking off into formation as well as
cake impairment must be eliminated. A DIF should be prepared avoiding the use of damaging
solids (barite) that can block pore throats. Its filtrate has to be compatible with the formation, too.
Calcium carbonate is normally used as bridging agent.
DIF can be water-based or oil-based. A water-based DIF is usually prepared starting from solid
free brine, whose density depends on the type of salt. Sized calcium carbonate has to be used as
bridging agent and not as weighting agent in order not to increase the solid volume fraction within
the system to a too high level.
An oil-based DIF, in comparison with a water-based one, offers some advantages in terms of
tolerance to contaminations, rock wettability alteration and permeability chemical impairment. Non
damaging surfactants and weak wetting agent that can alter rock wettability and permeability are of
primary importance.
Final choice of DIF type will be made taking into account formation damage minimization.
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Correct and suitable pills must be used to clean the wellbore e surface tanks before a different type
of fluid (from Water Based Mud to SBM) is set into the hole.
2.7.4
Production Tests
The performance of specific “production tests” on conclusion of the drilling operations will provide
accurate information concerning the presence of hydrocarbons on the strata investigated, their
nature and their pressure characteristics; pointers to their quantity will also be obtained.
At present, the intention is to perform production tests on each field. These tests will vent the
levels and provide estimates of their potential; the gas and the oil obtained will be sent to the flare.
2.7.5
Completion Activities
The term completion is used to indicate the operations performed on a well at the end of the drilling
phase, before it is set into production. Completion serves to make permanent arrangements for
production and to secure the drilled well.
The major construction principles used in completion of the drilled wells are as follows:

The hydrocarbons are brought up to the surface from the deposit by a series of production
pipes called the “completion string”. This string is composed of a series of tubings and other
equipment that ensure well production function and safety.
 If there are several production levels in the wellbore, only one completion string is used,
composed of several tubings able to independently produce from different levels.
 An SCSSV (“Surface Controlled Subsurface Safety Valve”) is installed along the completion
string. This valve automatically closes the production string if operating emergencies arise
(i.e. well head failure).
An indication of the main completion equipment is provided below:
 Completion String
o Tubings
o Packer
o Safety Valves
 Completion Wellhead
o Tubing Spool
o Christmas Tree
Completion String
Tubings: these pipes generally have small dimensions (4 1/2” - 2 1/16”) but high pressure
resistance; they are screwed together in series according to the depth of the well.
Packer: a metal unit with rubber gaskets to ensure a tight seal. They hydraulically insulate the
section in communication with the production zones from the rest of the string. For safety
purposes, it is kept full of completion fluid. The number of packers in a string depends on how
many production levels the well has.
Safety Valves: these are installed in the pipe string. They are used in gusher wells and serve to
automatically close the entire tubing if the well head fails, thus blocking hydrocarbon flow to the
surface.
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Tubing Hanger
Casing 13-3/8”
GHANA
OCTP
OIL
OP
5-½” TR-SCSSV
Casing 10-¾” x 9-5/8"
5-½” Tubing
13-3/8" x 9-5/8"
Liner Hanger
13-3/8" Csg Shoe
5-½” Tubing
5-½” Injection Nipple
5-½” Permanent Downhole Gauge
L. Nipple
6-5/8" Completion Packer
L. Nipple
9-5/8" x 6-5/8" GP Packer
9-5/8" Csg Shoe
Open Hole Gravel Pack
Cenomanian Layer
Figure 2-10
6-5/8" Screens
OIL WELL COMPLETION SKETCH
Completion Well-head
Above the first elements in the well head, additional well head completion elements are hooked
and flanged onto the casings installed during the drilling phase. These elements provide the well
head with enough valves to control production. The main parts of the completion well head are:
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Tubing spool: the lower part of this spool holds the production column tightness elements while the
upper part holds the housing for the steel block with gasket, called the “tubing hanger” which
supports the completion string.
Christmas tree: a well completion unit connected to the well head by special mechanical or
hydraulic connectors. It consists of a series of gated cut-off valves having a hydraulic or pneumatic
actuator, or manual valves located on a T or V cross.
 Xmas Tree estimated dimensions [m]: 4(L) x 4(W) x4(H)

Xmas Tree Estimated Weight: 50,000 kg

FLET draft dimension [m]: 4(L) x 2(W) x2(H)

FLET/XT arrangement (well jumper estimated length < 150m)
Figure 2-11
Potential X-mas tree
Design Criteria for Trees and Manifolds
Based on nearby developments subsea production trees are preliminarily assumed to be 5" x 2"
nominal bore, horizontal type, 345 bar (5000 psi) design pressure.
Design temperature rating for subsea production trees is preliminary assumed from 5,5°C (10°F)
below either the normal ambient seafloor temperature or the lowest normal temperature (that can
be seen during manufacturing and operation onshore or offshore, whichever is colder) to 120°C
(250°F). Choke, wing valve connector and seal assembly downstream of choke is assumed to
have a preliminary low design temperature of -29°C.
Gas injection trees rating is assumed to be from -29°C (-20°F) to 120°C.
Water injection trees rating is assumed to be from 5.5°C below either the normal ambient seafloor
temperature or the lowest normal temperature to 120°C.
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Each tree shall include a choke valve, sand sensor, and pressure and temperature gauges.
The valves shall be operable by electro-hydraulic control system or by remotely operated vehicle
(ROV). All the valves to be remotely operated (including chokes and downhole valves) will be
equipped with hydraulic actuator. Chokes will feature electronic position sensor.
The Subsea manifolds shall be 4-slot standard production or injection manifolds that shall be easily
expandable with a 2-slot production or injection expansion module to increase capacity up to 6
wells. The 2-slot expansion module shall be easily applied to the manifold before installation or
after installation by removing the pigging loop or the pressure caps at the end of the manifold. As
an alternative to expandable 4+2 slots manifold, a conventional 6 slot manifold can be foreseen.
The subsea manifolds are preliminary assumed to have 345 bar of design pressure and a
temperature rating from -29°C to 120°C (from 5,5°C below either the normal ambient seafloor
temperature or the lowest normal temperature to 120°C for water injection manifolds only). The
subsea manifolds shall have suction piles foundations and shall serve as a central gathering point
for production from subsea wells for each drilling centre. Production manifolds will be run and
retrieved independently of their foundations. The manifold will be installed from a MODU or by a
construction vessel.
Connection between manifolds and between trees and manifolds will be via rigid pipe jumpers with
vertical connectors or flexible jumpers connectors as an alternative. Connection between the
manifolds and flowlines could be by rigid jumpers (in case of rigid pipeline) or direct connection
with the use of a gooseneck connector (in case of flexible lines). As an alternative also other
connection systems may be proposed.
If Injection wells (water or gas injection) are arranged as satellites, in case of flexible flowlines,
these will be directly connected to the tree flowbases.
All production wells shall be equipped with a subsea multiphase meter.
2.7.6
Techniques to Prevent Environmental Risks during Drilling
Pollution Prevention Measures
The systems are "impermeabilised" or sealed; in other words they are able to prevent any type of
dumping of rainwater, drilling mud or bilge oil into the sea.
All work decks (derrick floor, main deck, cantilever deck, B.O.P deck, helideck) are tight and fit with
coaming. In addition, drainage pits are present around the edge of the platform and these are
connected by a manifold so that, by force of gravity, they collect rainwater, system wash water and
any mud spills on the decks.
The liquids collected are periodically pumped into tanks on the supply-vessel located in the
immediate vicinity of the plant and are then carried to land for treatment and disposal in suitable
receptacles. There are no dispersions of these liquids in the environment.
Civil wastes (sewage, water from washbasins, showers, the caboose) are treated with approved
systems, as to achieve legal concentration limits, before being discharged into the sea.
The machine room, pump zone and engine area located below the main deck are also fitted with
coaming and bilge to collect oily liquids. These fluids can also be derived in all areas where
lubrication oil spills may occur. The fluids are gathered and sent to an oil-water separation system.
The water separated out is sent to the liquid waste collection tank while the oil is stored in special
drums to be transferred to land for disposal.
The drilling system is manned from a supply vessel that not only serves as temporary storage for
drilling materials (diesel fuel, water, bentonite, barite) but also holds drums of dispersant and
equipment with special arms for deployment in the sea in the case of accidental oil spills.
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Drilling Mud
Given its hydrostatic pressure, the mud serves to prevent formation fluids from entering the
borehole (see Figure 2-12). To do so, the hydrostatic pressure exerted by the mud must always be
greater than or equal to that of the fluids (water, oil, gas) contained in the permeable rock
formations being drilled through. For this reason, the drilling mud must be weighted to achieve
adequate density. The surface sections will be drilled with a sea water-bentonite mud system and
high viscosity pills. During the deepest phases, a synthetic oil-based mud system will be used. To
the purpose of reaching the residual oil content fitting regulation’s limits, it will be necessary to
install a vertical centrifuge besides of the standard solids removal equipment, to allow the
discharge of drilled cuttings.
Under particular geological conditions, the pressure of the formation fluids may be higher than
incurred by the normal hydrostatic gradient alone. In such cases, there may be a sudden inflow of
formation fluids into the borehole and, since such fluids are less dense than the mud, they will rise
to the surface.
Figure 2-12
Drilling Mud Functions
The condition just described, the so-called kick, is unmistakable as it induces an increase in the
volume of the mud in the tank. During this phase of well control, to prevent eruptions, some safety
equipment must be installed upstream of the underwater well head. These units go by the name of
blow-out preventers (B.O.P.) and they always close the well — both when it is free and when it
contains equipment (pipes, casings, etc.). The two fundamental types of B.O.P. are annular and
ram.
Special shut-off cocks (inside BOP and kelly cock) are arranged to ensure that, once the B.O.P.
has closed the ring, no formation fluid can flow into the drilling pipes on the drill string and into the
top drive.
2.7.7
Safety Equipment (Blow-Out Preventers)
Annular B.O.P., also called BOP Bags given their bag-like shape (see Figure 2-13). They are
installed upstream of everything else. They have a suitably shaped rubber element and, when a
hydraulic piston exerts an axial pressure against this element, it adheres to the internal shape, thus
closing it tight. Such closing is ensured for every diameter and for every drill string or casing, no
matter what the shape. Even when the borehole is free of the drill string, the annular B.O.P. always
ensures tightness.
Eni S.p.A.
Figure 2-13
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Safety Equipment – Annular BOP
Ram-type B.O.P. These units have two prismatic gates appropriately shaped to fit the diameter of
the equipment in the borehole and may be secured together with a hydraulic mechanism. The
number and size of the rams depend on the diameter of the elements in the drill string (see Figure
2-14).
Figure 2-14
Safety Equipment – Ram-type BOP
There is also a set of shear rams that ensure total closing of the borehole when it is free of any
equipment. In an emergency, these rams can even sear the drilling pipes if they are present when
it is tripped.
These elements are normally assembled to form the “BOP stack” generally composed of 1 or 2
BOP Bags and 3 or 4 rams. The BOPs are operated hydraulically from 2 remote panels.
The formation fluids are circulated and expelled using high pressure lines — called choke and kill
lines — and special variable section valves — called choke valves — able to control the pressure
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and ejection flow rate. Floating deep-sea off-shore rigs use a BOP stack installed on the well head
at the sea floor. Like the valves and kill and choke lines, the BOPs are operated from the surface
using electrodynamic controls. All functions and controls are redundant and “fail safe”.
Number and type of BOP actually employed for the activities planned in the project area depends
on the typology of the drilling equipment (Jack-up drilling unit) employed end on the features of
drilled formation and waters encountered
2.7.8
Drilling Parameters Monitoring
Drilling parameters are monitored by two independent systems of sensors that operate in
continuous mode and throughout all drilling operations (such monitoring is essential as it permits
prompt recognition of any operating anomalies). The first monitoring system is inserted into the
drilling rig, the second is composed of a computerized unit manned by skilled personnel and
installed on the drilling rig. The latter provides geological assistance and controls drilling activities.
2.7.9
Estimated Drilling and Completion Duration
An estimated drilling and completion total duration has been planned for 40 months baring offsets
situations and drilling difficulties.
2.7.10
Design Choices Aimed at Reducing Environmental Impact
The Drilling Operations Environmental Philosophy shall adopt the following principles:
 Use of resources: efficient use of chemicals, material, natural resources and energy
sources, aimed at resource conservation and minimization of discharges;

Emission to air: minimization through abatement at source of gaseous emissions (no
flare emissions) that have the potential for negative impact on the environment;

Discharge to water: minimization through abatement at source of aqueous effluents
which have the potential for negative impact on the environment;

Solid waste: Correct handling, treating and disposing of solid wastes to avoid/eliminate
liabilities in the future and to meet the requirements for due diligence;

Use of Best Available Technology Not Entailing Excessive Costs (BATNEEC) and good
international oil field environmental practices.

The volume or relative toxicity of liquid or solid wastes will be reduced, to the minimum
possible; the four principles of waste minimization process (recycling, reduction, reuse
and recovery) shall be adopted as applicable.

For effective implementation of proper handling and appropriate waste disposal
methods, waste materials generated in the course of this work will be defined,
segregated, preferably at source into clearly designated bins at strategic locations, the
same shall be done during operation phase.
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Emission to Air
The engineering design approach shall be to minimize emissions to the atmosphere where
practical and economically possible and to apply good engineering practice in the choice of
materials and equipment to minimize fugitive emissions. Where emissions are unavoidable, the
approach shall be for point sources, to provide stacks of adequate height to ensure good
dispersion.
The main sources of emissions (continuous or non-continuous) resulting from Project activities
include the following, as a minimum:
Exhaust gas emissions produced by the combustion of fuels in diesel engines and power generator
turbines can be the major source of air emissions from the facilities.
Gas venting/Flaring during production test or emergency situations is arranged by venting/flare to
the atmosphere.
Fugitive emissions may be associated with leaking piping, valves, connections, flanges, pumps,
open-ended lines, packing, pressure relief valves, tanks or open pits/containments.
Principal pollutants from these sources include: nitrogen oxides (NOx), sulphur oxides (SOx),
carbon monoxide (CO) and particulates.
Wastewater
Waste liquid effluents may mainly arise from:
 oily and accidentally oily waters (e.g. drainage waters, wash waters, plant bilge waters,
etc);
 civil sewage.
The project envisages the reinjection of the production water after mixing with seawater, process
cooling water and test water; nevertheless, in the present document potential impacts deriving from
discharge of the production water into the sea are described. In that case, production water will be
discharged after treatment to reduce the oil content in line with applicable regulation and best
practices.
Oily and accidentally oily waters are stored in special drums to be transferred to land to be properly
disposed/treated.
Civil wastes (sewage, water from washbasins, showers, the caboose) are treated, as to achieve
legal concentration limit, with approved systems before being discharged into the sea.
Solid Waste
All waste produced during drilling operations which cannot be reused, will be managed and
disposed of in accordance with National Regulations. All wastes associated with hydrocarbons,
oils, hydraulic fluids, oily sump water, etc. shall be recycled, treated or placed in an appropriate
facility.
All debris, spoil materials, rubbish and other waste shall be cleared regularly from the site and
disposed of.
Contaminated wastes or hazardous waste), shall be stored in suitable tanks or skips and
transported to shore by supply-vessel.
Drilling fluids
The drilling fluids programmed are WBM in the riser-less phases and NADF in the riser phases.
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The base fluid used in the NADF will be an environmental friendly ultra Low Toxic synthetic or
mineral Oil Based Mud (LTOBM).
The type of waste that can be discharged into the sea are the following:
 Exhausted WBM

Cuttings contaminated by WBM

Cuttings contaminated by NADF
2.7.11
Resources Consumption, Waste Generation, Air and Noise Emissions During
Drilling and Completion Activities
Natural Resources Consumption
The main consumption of natural resources related to project activities are:
 Fossil fuel consumption for drilling and transportation activities

Water consumption for civil use by the rig’s crew
Amount and quality of fuel are defined in the following sub-sections, in order to assess polluting air
emissions.
Water may be transported to the site via barge as may be necessary. Potable water will be
supplied by bottled water; during drilling activities will be used also desalinated sea water for
project needs.
Water consumption is estimated using data collected by eni for Saipem 10000 in years 2008-2013
(Table 2.5).
Table 2.5
Estimated Water Consumption
Water Withdrawal
Fresh Water (from
3rd party)
Water Withdrawn (not including
non-desalinated water used for
engine cooling, ballasing,
steam generation)
Sea Water
(desalinated)
3
3
3
(m )
-
(m )
13.515,00
28.336,00
(m )
13.515,00
28.336,00
2011
-
24.440,00
24.440,00
2010
4.955,00
17.901,00
22.856,00
2009
15.838,00
17.300,00
33.138,00
2008
16.661,00
17.445,00
34.106,00
2013 3rd Q
2012
2011
2012
Working day
2013
Working day
341
Water/ working day (mc)
312
Working day
248
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90,84
Discharged water /working day (mc)
63,25
87
Waste Generation
The wastes produced on the platform are stored temporarily in suitable yard structures. As regards
the well drilling phase, diesel engines and mechanical moving parts are used with the inevitable
production of noise and polluting atmospheric emissions.
The wastes produced are:
 drilling wastes (excess mud, debris mixed with mud),

solid urban wastes (cans, cartons, wood, rags, etc.),

sewage (from w.c. washbasins, showers).

oily and accidentally oily waters (e.g. drainage waters, wash waters, plant drainage
waters, etc);
Drilling wastes
The management of drilling wastes is based on Eni’s experience in similar environments and
complies with local Regulations.
Local regulation permits the discharge into the sea of drilled cuttings contaminated by
synthetic/pseudo oil based mud system with a residual oil on cuttings content less than 3% of dry
matter if discharged beyond 500 m water depth (“Ghana EPA Guidelines for Environmental
Assessment and Management in the Offshore Oil and Gas Development” article 12 and section 7).
However, EPA in the Permit n° CE00217880115, issued in relation to the OCTP Block
Development Project, stated the requirement of ensuring that NADF cuttings discharged to sea
must have an oil concentration lower than 2% by weight on dry cuttings.
To the purpose of reaching the right residual O.O.C., it will be necessary to install Thermo
mechanical Cuttings Cleaner besides of the standard solids removal equipment, to allow the
LTOBM drilled cuttings discharge.
Thermo mechanical Cuttings Cleaner
In order to meet the residual oil on cuttings content < 1% it is necessary to install a TCC. It use a
technology designed to separate the various components on cuttings and contaminated soils,
where NADF is used during drilling operations, or where soil has been contaminated with oil.
Direct thermo-mechanical desorption is different from thermal separation technologies, based on
external heating sources and indirect heating of waste, in that it achieves thermal separation by
transforming kinetic energy into thermal energy through friction created by the hammer mill in the
waste itself. It is the only thermal treatment equipment can be installed on offshore rigs.
Exhausted LTOBM will be stored in a dedicated tank on the rig and will be transported to shore to
be properly treated with a thermal desorption method by the waste service company in our waste
treatment and disposal area.
The estimated produced cuttings volume is:
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Table 2.6
Estimated quantity of cutting produced
3
Cuttings m (single well)
3
Cuttings m (12 wells)
Riserless phase
580
6960
Riser phase
480
5760
The above estimation is based on the following considerations:
30% excess for 42” and 24”
20% excess for 17 ½”, 14 ¾” and 12 ¼”
10% for 8 ½”
NADF remaining on cuttings after Vertical centrifuge treatment 15% v/v
Civil wastes
During positioning and installation/sealing activities and throughout the entire sequence of drilling
activities it is estimated that an average of about 120 operatives will be present on the jack-up
drilling unit; on the basis of the data available in the literature for drilling sites similar to the one
under consideration, we can provide an initial estimate as follows:
 Civil waste water: 100 l x 30 days x 120 pers = 36000 lt/month (12000 l/day)
Food waste is shredded and dumped at sea through a sieve with an aperture of 25 mm., as
determined by "MARPOL (Marine Pollution) international standards."
Civil sewage discharged from w.c., washbasins, showers and camboose — are treated in a
purification system before being dumped into the sea. Discharge is compliant with "MARPOL"
international standards. A biological-type purification system is used. The sewage to be treated is
conveyed to an aeration chamber where it remains for approximately 24 hours, mixing with water
containing a high concentration of aerobic bacteria which breakdown the organic substances
contained in the sewage being treated.
A compressor injects pressurized air into the sewage in order to keep the bacteria active, create a
certain degree of agitation and keep the particles containing the organic substances and bacteria
in suspension. This suspension is then passed into the clarification chamber where, in
approximately 6 hours, the flakes settle and the supernatant is stratified into zones containing the
clarified supernatant liquid, particles still in suspension and the settled flakes.
The supernatant liquid overflows into a chamber where it remains in contact with hypochlorite for
30 minutes (to eliminate the residual bacteria), the dissolved oxygen content and pH are checked,
and then it is dumped into the sea.
The material still suspended and the settled materials are sent on by insufflation into an aeration
chamber where the treatment cycle continues.
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Domestic waste water treatment system
Oily and accidentally oily waters (bilge water)
Bilge liquids are composed of oil and water mixed together. From the bilge oil/water, where
collected, are sent via a pump to a separator. The oil is filtered and collected in a tank to be
subsequently put into barrels and transferred to shore, while the cleaned water is sent to the liquid
waste collection tank and then dumped into the sea.
Figure 2-16
Table 2.7
Bilge liquids separator
Total amount of water produced
Water peroduced
3
(m )
2013 3rd Q
10.564,00
2012
8.069,80
2011
21.566,00
2010
17.838,00
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2009
2.198,00
2008
897,00
Hazardous/non-hazardous wastes
The whole amount of waste generated is estimated using data collected by ENI for Saipem 10000
in years 2008-2013 (Table 2.8).
Table 2.8
Estimated quantity of waste produced
Hazardous Waste
Non-Hazardous Waste
Waste
tons
tons
tons
2013 3rd Q
599,93
495,27
1.095,20
2012
765,11
543,35
1.308,46
2011
792,67
410,59
1.203,26
2010
996,71
379,15
1.375,86
2009
4.152,29
230,82
4.383,11
2008
2.769,51
226,20
2.995,71
High amount of hazardous waste in 2008 and 2009 was caused by the fact that drill cuttings were included in the reported data.
2011
2012
Working day
2013
Working day
341
Working day
312
Water/ working day (mc)
71,68
90,84
Discharged water /working day (mc)
63,25
87
248
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2008
2009
2010
2011
2012
2013
3rd Q
0,00
Hazardous waste
Batteries & accumulators
0,50
0,05
0,48
1,43
7,60
Contaminated soil
0,00
0,00
38,50
0,00
0,00
0,00
Electronic apparatus
Exhausted oils (from engines, hydraulic
circuits and other greases)
0,00
0,20
0,71
6,33
3,00
11,46
82,52
22,40
60,97
9,50
16,77
24,73
Light Tubes
0,20
0,31
1,15
0,09
1,02
0,00
Medical Waste
0,34
0,23
0,31
0,07
0,14
0,05
Mixed Industrial Hazardous Waste
0,00
0,00
2,50
135,20
0,00
320,50
Oil Filters
0,75
0,50
1,17
5,47
0,61
0,71
Oily Water
0,00
0,00
594,25
548,14
259,07
134,90
2.624,70
4.029,20
206,38
69,30
418,70
53,00
0,00
0,00
0,08
0,00
2,00
0,00
60,00
99,00
90,12
17,16
56,20
54,58
0,50
0,40
0,09
0,00
0,00
0,00
Other Hazardous Waste (*notes)
Paints, varnishes and solvents
Sludge and mud from Waste Water
treatment plants
Worn out printing toner (cartridges
included)
Non-hazardous waste
Absorbents, filtering materials, rags,
protective clothing
0,00
9,90
0,00
0,00
0,00
0,00
14,70
18,22
16,49
0,09
0,26
23,21
81,10
32,50
138,38
100,40
120,90
118,50
Mixed industrial Non-Hazardous Waste
0,00
0,00
21,13
0,00
0,00
0,00
Mixed urban waste
0,00
0,00
34,00
0,00
0,00
0,00
Other non-hazardous waste
0,00
21,60
8,00
65,10
0,00
0,00
Paper and cardboard
47,00
71,00
55,48
69,66
95,60
65,00
Plastic
74,40
73,50
75,08
96,84
153,09
184,76
Cooking organic waste
Ferrous metal refuses / Steel / Non-ferrous
metal refuses
Wood
TOTAL
9,00
4,10
30,60
78,50
173,50
103,80
2.995,71
4.383,11
1.375,86
1.203,27
1.308,45
1.095,20
Atmospheric emissions
The following sources of atmospheric emissions are considered:
 discharge of exhaust gases from the engines of the drilling unit

discharge of exhaust gases from the engines of the supply vessels

emissions of gas burning during production tests.
The fuel considered for the project activities is diesel, with a sulphur content below 0.2% by weight.
Drilling unit emissions
Data on fuel consumption of Saipem 10000 are available from eni’s environmental database
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Table 2.9
Fuel consumption and electricity generation of Saipem 10000
Diesel
Self-generated electricity.
from non-renewable sources
Efficiency
performance
indicator
M3
(kWh)
(lts diesel/kWh)
15165
13763
12283
26209
35232
32168
0.380
0.580
0.390
Year
2010
2011
2012
Considering the annual activity days of Saipem 10000 in years 2010-2011-2012, a mean daily
consumption of 37.64 m3 of diesel is calculated.
Table 2.10 shows the mean atmospheric pollutant emissions. This estimates is based on data
reported in ENI environmental database.
Table 2.10
Pollutant emission factors for Saipem 10000
EMISSION FACTORS
POLLUTANT
Methane (CH4)
Carbon dioxide (CO2)
Nitrogen oxide (NOx)
Sulphur dioxide (SO2)
g/kg(diesel) Year :
2010
0.002123
47.351954
0.003336
Not Available
EMISSION
FACTORS
g/kg(diesel) Year :
2011
0.001927
42.974279
0.003028
Not Available
EMISSION
FACTORS
g/kg(diesel) Year :
2012
0.001720
38.353053
0.002702
Not Available
Supply Vessels Emissions
Three 5000/6000 hp supply vessels, 70/80 min. in length, capable of storing muds and chemicals,
are present during drilling and completion phase. One remains stationary at the concession field
while the others travel back and forth (meaning that 2 vessel are always on the field). An on-board
crew of 15 is forecast.
For the supply vessels, used to carry materials and waste, the emissions have been determined
using literature emission factors Saipem Corporate Criteria “Emission Estimation Methodology –
CR-COR-HSE-075-E” for diesel internal combustion engine (see Table 2.11).
Table 2.11
Pollutant emission factors of supply vessel
POLLUTANT
Methane (CH4)
Carbon monoxide (CO)
Nitrogen oxide (NOx)
Sulphur dioxide (SO2)
EMISSION FACTORS
g/kg(diesel)
0,20
3.137,00
20,08
55,93
20,00
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Fuel consumption is estimated, according to a precautionary approach, considering two (2) supply
vessel docked using 0,1 kg/s of diesel with a sulphur content of 0.2%, as reported in Williams et.
al., 2003.
Production Tests
In Table 2.12, data on foreseen production test of OCTP field-1 are presented. The maximum gas
flow rate is used in order to estimate the gas flow rate in production test of the field, according to a
cautionary approach.
Table 2.12
East
Relevant parameters of production tests of Sankofa
Tests will be performed in flow-rate steps for more accurate monitoring of the wells’ performance;
the planned tests will have the following characteristics:
- duration of production test: 4,5 days
- flow-rate of gas burnt in flare: 11,25 MScf
Naturally, the estimates of times and flow-rates are purely guideline. During production tests,
emissions are mainly due to flare combustion, operation unavoidable as the connection to flowline
occurs only in one second time.
A low amount of H2S in the OCTP gas flared during production tests is foreseen so the gas can
be classified as “sweet”.
The Ecoinvent database, from the Swiss Centre for Life Cycle Inventories, is the world's leading
supplier of consistent and transparent life cycle environmental inventory (LCI) data, with more than
4’000 LCI datasets in the areas of agriculture, energy supply, transport, biofuels and biomaterials,
bulk and speciality chemicals, construction materials, basic and precious metals, metals
processing, as well as waste treatment, etc.
Table 2.13 shows the air emission related to 1 Nm3 of sweet natural gas burned in flare, according
to Ecoinvent. SOx emissions are estimated using maximum value of H2S in Table 2.14.
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Table 2.13
Estimated atmospheric emission from gas flaring
POLLUTANT
Methane (CH4)
Nitrogen oxides (NOx)
EMISSION FACTORS
g/Nm3 gas flared
0,25
2.451,60
0,54
12,13
Ecoinvent data for “air emissions from combustion of crude oil drilling test” is presented in Table
2.14, in order to describe the emissions of oil burned in production test.
Table 2.14
Estimated atmospheric emission from oil flaring
POLLUTANT
Methane (CH4)
Nitrogen oxides (NOx)
Sulphur dioxide (NO2)
EMISSION FACTORS
g/kg oil burned
0,121
3500
54
9,03
0,606
Noise emissions
On the drilling rig, the sources of noise are the diesel engines, rotary table, winch, pumps and
cementing unit.
The noise produced is low frequency noise and the noisiest side of the platform is the side where
the engines are located. In previous wells, the noise detected in the vicinity of the noise generation
sources was as follows (see Table 2.15):
Table 2.15
Noise levels from previous well drilling activities
engine zone
Leq (A)
105.5
derrick floor (rotary table
and winch) Leq (A)
93.6
pump zone
Leq (A)
85.6
cementing unit
Leq (A)
104.2
Source: EIA
The values in Table 2.15, expressed in dB(A), indicate the A-weighted equivalent continuous sound
level.
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SUBSEA PRODUCTION SYSTEM (SPS)
The Subsea Production System (SPS) is tied back through Subsea Umbilicals, Risers and
Flowlines (SURF) to a spread moored Floating Production Storage and Offloading (FPSO) unit,
installed in approximately 1000m water depth.
Subsea Architecture
The subsea field Oil development is divided into 5 main regions (Sankofa NE, SE, SW, and NW
plus Gye Nyame), with a spread moored and double balcony FPSO located above the Sankofa
Canyon at approximately 1000m water depth and some 60km from the shore (Sanzule).
It is envisaged to develop a total of 14 (fourteen) wells consisting of 8 (eight) Oil Producers (OP), 3
(three) Water Injectors (WI) and 3 (three) Gas Injectors (GI) all tied-back to topsides on the FPSO
by means of flexible flowlines and risers.
Oil Production wells are arranged in 3 (three) daisy-chained loops by means of single branch
FlowLine End Terminations (FLET), while the WI, GI and GP wells, plus OP-CAMP2 are arranged
in a satellite configuration.
The relative distances between the 3 main OP loops are in the order of 6 and 10 km. A canyon is
also present in the central part of the field, limiting the layout flexibility.
In such conditions of dispersed wells field, the use of Daisy Chain configuration allows:
 large spread between wells
 minimize dead legs to improve flow assurance
 minimize Lead Time and time to market
 minimize Flowline crossings
Hereinafter the main components of the system are described:
 Subsea Completion System
 Subsea Structures System
 Flowline Tie-in System
 Subsea Control System
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SUBSEA COMPLETION SYSTEM
To optimize and standardize, all XTs are Horizontal Drill Through, with the same spool body and
wing block. Each Tree is equipped with the same Subsea Control Module (SCM) and a retrievable
Flow Control Module (FCM), which is configured to suit the specific service (OP, WI and GI).
Acoustic Sand Detection (ASD) is installed on the OP XTs.
All XT valves shall be remotely operated by an electro-hydraulic control system and, as a back-up,
overridden by ROV.
Chemical injection porting shall be the same for all X-tree blocks. For XTs which don’t need all
chemical injection points, chemical injection Throttle Valves are supplied for metered chemical
delivery at each XT from a common umbilical header for each service. MeOH is unmetered for bulk
transient and remedial purposes only.
The preservation strategy to increase No Touch Time (NTT) on the OP XTs and FLETs etc shall
be insulation for the OP system. All other XTs are not thermally insulated. GI XTs shall have the
ability to inject MEG on a continuous basis at such a level as to preserve the lines indefinitely in
case of shutdown. Due to the uncertainties regarding fluid composition, sour service is required.
OP XTs provide controls and signals to its local a-FLET. Downhole penetrations at the TH / XT
interface shall be standard for all XTs, whilst unused DH service valves etc. may be left off the final
XT assembly. Each TH shall have the same standard number of penetrations for all types of well,
with unused functions capped at the DH end. The SCSSV shall have two (2) hydraulic HP
penetrations in the TH for its remote control.
SUBSEA STRUCTURES SYSTEM
FLET Systems
The Flowline End Termination (FLET) is be terminated to the flowline by a subsea connector and
includes a foundation and interface supports. A standardized single branch design is considered as
the Base Case solution for all FLET types.
Tie-in and Connection Systems
For Ghana OCTP Development Project the Tie-in System base case considers that all Risers and
Flowlines are flexible. Jumpers and Spools are Rigid for all the lines but Water and Gas Injectors,
directly connected to the X-Trees.
For the thermally insulated Production Flowlines, the Tie-in Connection System includes a thermal
insulation system designed to avoid any cold spots.
SSIV Systems
The SSIVs consist of one 6” ID Gas Injection, two 8” ID for Gas Producers and one 22” SSIV for
the Gas Export system. Each has a single piggable Header with connectors for the flowline and
riser. This excludes the Gas Export (GE) SSIV, whose header is not piggable.
The header has an hydraulically actuated Ball Valve (SSIV) providing FSC protection from Gas
flowline inventory. A header access valve arrangement is included for ROV intervention.
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The SSIVs are controlled via direct hydraulic supplies from a dedicated control panel on the FPSO.
With a healthy ESD signal to the local control panel, the hydraulic output to the SSIVs valve
actuator can be manually reset thereby applying hydraulic pressure on dedicated dual redundant
umbilical cores via the SSIV UTA and HFL to the valve actuator to open the SSIVs. The SSIVs
maintain an open position whilst hydraulic pressure is maintained.
Subsea Control System
The Subsea Production Control System is used to provide supervisory control and data acquisition
for the Subsea Production System during normal operating conditions. It is an electro-hydraulic
multiplexed control system, with communications network overlaid on the power distribution
network (Communications Overlaid on Power, COP).
The hydraulic system architecture is an open loop system with bio-degradable, water glycol based
hydraulic fluid venting to the subsea seawater environment.
An appropriate level of interlocks shall be provided to ensure safe and reliable operation.
The Subsea Control System is composed of the following major items:
-
Topsides:
 Master Control Station (MCS) and associated Workstations
 MPFM processing station system
 Electrical Power Unit (EPU)
 Hydraulic Power Unit (HPU)
 Electrical Junction Boxes
 Topside Umbilical Termination Unit (TUTU)
 SSIV Local Control Panel(s)
-
Subsea system:
 Umbilical System, including Umbilical Termination Assembly
 Subsea Control Modules (SCMs)
 Subsea Instrumentation
 Flying Leads (Hydraulic and Electrical)
-
Installation, Workover, Running and test equipment
Table 2.16
Foreseen umbilicals
Line Tagging
From
To
Umbilical Type
Static Length
(m)
Dynamic Length
(m)
UNE1
FPSO
SkE-1x
Oil Production
-
2354
UNE2
SkE-1x
OP-5/OP-7
Oil Production
3883
-
UNE3
OP-5/OP-7
GI-1
Oil Production
2458
-
UNE4
OP-5/OP-7
WI-3
Oil Production
1116
-
UNE5
SkE-1x
SkE-C
Mini umbilical
621
USSIV 1
FPSO
SSIV UTA
SSIV
-
3615
USE 1
FPSO
GI-2/OP-4
Oil Production
-
3578
USE 2
GI-2/OP-4
OP-3/SkE-D
Oil Production
3084
-
USW 1
FPSO
UTA
Oil Production
-
3540
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USW 2
UTA
SkE-2A
Oil Production
2399
-
USW 3
SkE-2A
OP-CAMP1
Oil Production
2164
-
USW 4
UTA
Sk-D
Oil Production
1333
-
USW 5
Sk-D
WI-1
-
SkE-2A
OP-CAMP2
Oil Production
Oil Production
777
USW 6
UNW 1
FPSO
UTA
Oil Production
-
3776
UNW 2
UTA
WI-CAMP1
Oil Production
2084
-
UNW3
UTA
GI-CAMP1
Oil Production
1655
-
UNW3
UTA
GI-CAMP1
Oil Production
2261
-
427
Subsea control umbilicals and respective umbilical termination assemblies (UTA) provide required
control, communication, and chemical injection services from FPSO to XT by means of electrical
and hydraulic flying leads.
Subsea Control System - Topsides
The topside equipment provides all necessary hydraulic and electric power to feed the subsea
equipment and provides the necessary interface for operators to monitor the subsea process
parameters and issue commands and shutdowns.
Subsea Control System - Subsea part
All SCMs are subsea retrievable with ROV assistance.
To guarantee maximum inter-changeability among the Flying Leads, their configuration is
standardized as far as possible.
SUBSEA PRODUCTION SYSTEM EXPANSION PHILOSOPHY
General
The facilities design ensures that the subsea infrastructure can accommodate future tie-ins to the
offshore architecture of up to 20% extra capacity within the control system.
Oil Production Expansion Capability
Operating strategy for the OCTP field Development is that the production risers, flowlines and
FLETs shall be pigged during the field life. Therefore, flowline loops are installed within each oil
production flowline system to allow round-trip pigging and circulation of each Flowline loop from the
FPSO with the exception of the ROP6 production riser which is electrically heated.
Should there be a requirement to tie-in new well, it is possible to disconnect the flexible flowline
and tie-in an additional flowline and FLET by firstly purging the system, isolating the section to be
modified and then breaking the production loop.
Flow Assurance considerations may limit subsea expansion capability considerably.
Gas Production, Injection and WI System Expansion Capability
There are three WI, three GI risers and five Gas Production risers, all configured as satellite wells.
The Gas Production flowlines are terminated with a FLET which will allow each flowline to service
more than one well. WI and GI flowlines are terminated direct to the XT, and will have to be
disconnected from the XT and connected to a new FLET should future expansion be required.
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FLOW ASSURANCE / PRODUCTION CHEMISTRY
Production Fluid Characterization
The main activities were as follows:
- Steady state analysis and deliverability of the target production profile;
- Turndown scenarios and flow stability analysis;
- Calculation of the cool-down time;
- Shutdown and preservation philosophy;
- Restart philosophy;
- De-pressurization;
The main result of the flow assurance study was the review of the field layout according to the
updated production profiles. The turndown and transient analysis contributed to define the
availability of the field; the operating philosophy determined in the previous phase was generally
confirmed.
The flow assurance analysis confirmed or updated the requirements of the SPS, RFI and FPSO
packages in terms of:
- Line diameters;
- Insulation requirements;
- Pressure and temperature operating conditions;
- Chemical injection requirements;
- Gas lift flow rates;
- Slug catcher volume.
On the basis of the available oil characterization, the following considerations about expected
issues on deposition, hydrate and emulsion formation can be highlighted:
Wax appearance: based on performed tests the critical temperature is fixed at 39-46°C for the
Cenomanian oil and at 40°C for the Campanian oil.
Asphaltene deposition: no asphaltene instabilities were shown by the tests on the Cenomanian oil.
However, in case of commingled production between oil and condensates, asphaltene deposition
is expected when the condensate is more than 70% in volume. No samples were available for the
Campanian oil.
Oil Gelling: as far as gel formation concerns, the critical temperature of the Cenomanian oil is
18°C. No samples were available for the Campanian oil.
Stable Emulsion formation: The emulsifying capacity of the Cenomanian oil is very low and no
stable emulsion formation is expected.
Naphthenate (Soap) Formation: no microscopic calcium-naphtenate solid formation was observed
for the Cenomanian oil.
The identified risks reported above are considered manageable through appropriate chemical
injection and operating procedures (i.e. hydrate management) which will be implemented during
normal operation and shut-down/restart phases.
An indication of chemicals requirement and injection point are reported in the table below:
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Foreseen umbilicals
Chemical
Injection Requirements
Injection Point
Hydrate inhibitor
(Production)
At start-up and during planned/
unplanned shutdown
On the X-T, into the production
bore, between PMV and PWV.
Hydrate inhibitor
(Injection)
For remediation, in case of hydrate
plugs.
On the X-T, into the injection bore,
between PMV and PWV.
Wax inhibitor
(compatible with PPD)
Injection required mainly for transient On the X-T, into the production bore
conditions. Continuously injected only
between PMV and PWV
during some periods of the field life.
Pour Point depressant (PPD)
(compatible with Wax inhibitor)
Injection required only in transient
conditions.
On the X-T, into the production bore
between PMV and PWV
Asphaltene inhibitor
Continuous injection
Down hole into the production
tubing as low as possible
Scale inhibitor
Continuous injection
Down hole into the production
tubing as low as possible
Flow Assurance and Hydrates Management
The following main flow assurance activities have been performed for full field subsea
development:
-
Hydrocarbon transportation system sizing
Flow assurance analysis of the selected development concept, to deeply analyze system
deliverability and identify possible operability issues;
Flow assurance analysis of transient operations, in order to evaluate feasibility and
criticalities during system start-up/restart and turn-down;
Evaluation of system cool-down time, for the definition of preservation strategy and
requirements.
The carried out simulations validate the configuration and confirm the possibility to deliver
production at the required conditions on the topside starting from the available bottom-hole
pressures.
For oil production network, gas lift injection is required only in the SW loop. In the other regions,
the increase in GOR predicted from the reservoir is enough to deliver the fluid to the FPSO.
No thermal issues have been identified for oil network for most of the field. Operating
temperatures are maintained at outside hydrate formation region, nevertheless wax deposition is
expected during the first years of production for the fluid of the well OP-CAMP1 and during the last
years of production for the fluid of the well OP-3. For thermal reasons, the well OP-CAMP2 is
required to be connected alone to the FPSO, choked topside, and the line is required to be
electrically heated.
The OHTC required for the flexible flowlines and risers of the oil production network is 4 W/m2K.
No insulation is foreseen for gas production network (13 W/m2K has been considered).
In case of a field shut down, the loop SW and SE are displaced simultaneously. The loop NE can
be displaced soon after finishing preservation of the SW loop.
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Transient analyses (shut-down, restart, start-up and turndown) for the full field system were
performed. The main results and findings are summarized here below:
-
Hydrate formation risk was assessed: a hydrate management philosophy and hydrate
inhibitor requirements are defined;
Temperatures were continuously monitored during transient simulations in order to verify
that the temperature limits for WAT and hydrate formation were not exceeded.
In case of start up or restart, methanol injection is required for a certain amount of time with the
aim to not have hydrates issues until the flowline is in safe operating conditions.
Slug management: based on the sensitivities performed, during steady state the current design of
subsea production system no slug flow is expected. The production HP separator is able to handle
moderate slug volumes, which is sufficient to manage the restart operations.
Subsea Layout
The preliminary Subsea layout for the Sankofa Field considers an FPSO positioned in the centre of
production and injection wells.
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RISERS AND FLOWLINES (R&F)
Following Project Procurement Strategy, this package consists of an Engineering, Procurement,
Construction (EPC) Contract for the supply of all flexible lines’ systems.
Oil development consists in the development of a total of 14 wells consisting of 8 (eight) oil
producers, 3 (three) water injectors, 3 (three) gas injectors, all tied-back to topsides by means of
flexible flowlines and risers.
Oil production wells are arranged in 3 (three) daisy chained loops by means of single branch
flowline end terminations (FLET), while the WI, GI and GP wells, plus OP-CAMP2 are arranged in
a satellite configuration. Artificial gas lift is required at SkE-2A riser base (SW production loop).
All risers and flowlines are made of unbounded flexible pipes. Well jumpers are made of rigid
pipes.
All flexible lines are designed to withstand the external environmental to which they will be exposed
and to be suitable to the Project operating conditions requirements, throughout their design life (20
years).
Risers Configuration
The Lazy Wave riser configuration has been selected on the basis of the studies carried out to
evaluate the most promising solution between two different riser configurations (Free Hanging and
Lazy Wave arrangements).
The main advantage of the Lazy Wave configuration is the capability to decouple the vessel
motions from the TDP. Lazy waves are, however, prone to configuration alterations if the internal
pipe fluid density changes during the riser lifetime.
The Lazy Wave configuration foresees a set of buoyancy module made of synthetic foam which
has the property of low water absorption; the buoyancy module need to be clamped tightly to the
riser to avoid any slippage which could alter the riser configuration and induce high stress in the
armor wires. Buoyancy modules tend to lose buoyancy over time and wave configurations shall be
designed in detail phase in order to accommodate a certain buoyancy loss.
Figure 2-17
Typical Lazy Wave configuration
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The quasi-static analysis provides the static equilibrium configuration due to static loading: weight,
buoyancy, top tension, current, equivalent wave; static analyses have been performed using a
nonlinear FE approach.
Following the setting and the quasi-static results obtained in the configuration assessment study a
global dynamic analysis has been performed and discussed in terms of strength response and
mutual interference between all the involved lines (flexible risers, umbilicals and mooring lines).
The above riser configuration shall be checked against interference issues, which is an analysis
part of the detailed engineering of EPC Contractor.
Table 2.18
Risers & Flowlines Design Data
PHASE 1
Oil Production
WI
GI
GL
ID [inch]
4"
6"
8"
10"
6"
6"
4"
Design Life [years]
20
20
20
20
20
20
20
Design WD [m]
1300
1300
1300
1300
1300
1300
1300
Max Op. WD [m]
1000
1000
1000
1000
1010
1000
1000
Service Type
Sour
Sour
Sour
Sour
Sour
Sour
Sour
H2S content [ppmv]
40
40
40
40
50
40
40
OHTC [W/m2K]
4
4
4
4
NA
NA
NA
TBD
TBD
TBD
TBD
TBD
415
1
Max Op. Pressure (Note 4)
(normal conditions) [bara]
254
254
58
68
376
460
100
Max Op. Pressure (Note 4)
(shut-in) [bara]
267
267
267
267
410
495
112
Pressure built-up due to
chemical injection (Note 4)
[bara]
345
345
345
345
583
583
NA
Design Pressure [bara]
345
345
345
345
583
583
345
-43
-29
-29
-29
4
4
-30
Max Op. Temperature@shutin [°C]
60
103
103
97
60
70
100
Max Op. Temperature
(normal conditions) [°C]
60
103
103
97
60
70
100
Design Temperature [°C]
80
120
120
120
80
80
120
Fluid Density
(shut-in) [kg/m3]
850
850
850
850
1035
410
160
268
162
162
170
990
310
35
Min Op. Pressure
[bara]
(Note 4)
Min Op. Temperature
[°C]
Min. Fluid Density
(operation
(Note 5)
flowline
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conditions)
[kg/m3]
Max Fluid Density
(operation
conditions)
[kg/m3]
riser
245
143
49
163
flowline
644
644
360
489
riser
515
305
317
301
1000
1000
1000
1000
Ref. height for above max
and min pressures
[m WD]
1025
395
52
1010
1010
878
Flexible Lines’ Preliminary Lengths
The following tables summarize required risers and flowlines lengths for Oil and Gas Development
Project.
Lengths will be confirmed by T&I EPCI Contractor which, as part of his SoW, shall review and
optimize the Subsea Field Layout.
Table 2.19
Project
Phase
1
1
1
1
1
Risers and Flowlines Preliminary Lengths
Wells
OP-CAMP1, SKE-2A Production Loop
OP-CAMP2
OP-3, OP-4 Production Loop
OP-5, OP-7, SKE-1x Production Loop
WI-1
1
WI-3
1
WI-CAMP1
1
GI-1
1
GI-2
1
GI-CAMP1
1
ROP2 Riser Base
Table 2.20
COMPANY
Reference
Application
OHTC
[W/m2K]
ID
[inch]
Length
[m]
ROP1
Production Riser
4
10
2554
FOP1
Production Flowline
4
10
4639
FOP8
Production Flowline
4
10
2029
FOP2
Production Flowline
4
10
2616
ROP2
Production Riser
4
10
3593
ROP6
Production Riser (DEH)
4
4
2514
FOP6
Production Flowline (DEH)
4
4
3245
ROP3
Production Riser
4
6
2349
FOP3
Production Flowline
4
6
3294
FOP4
Production Flowline
4
6
2837
ROP4
Production Riser
4
8
3500
ROP5
Production Riser
4
8
3597
FOP5
Production Flowline
4
8
2406
FOP9
Production Flowline
4
8
100
FOP10
Production Flowline
4
8
125
FOP7
Production Flowline
4
8
3694
ROP7
Production Riser
4
8
2399
RWI1
Water Injection Riser
NA
6
2665
FWI1
Water Injection Flowline
NA
6
2027
RWI3
NA
6
3425
FWI3
NA
6
1845
RWI-CAMP1
NA
6
2462
FWI-CAMP1
NA
6
3634
RGI1
Gas Injection Riser
NA
6
2618
FGI1
Gas Injection Flowline
NA
6
6481
RGI2
Gas Injection Riser
NA
6
2861
FGI2
NA
6
1038
RGI-CAMP1
Gas Injection Riser
NA
6
2443
FGI-CAMP1
NA
6
2944
RGL1
Gas Lift Riser
NA
4
3564
Flexible Lines Preliminary Lengths – Overall Quantities
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Oil Production
Flexible
Risers
Flexible
Flowlines
Water
Injection
Gas
Injection
Gas Lift
ID [inch]
4"
6"
8"
10"
6"
6"
4"
Qty
1 off
1 off
3 off
2 off
3 off
3 off
1 off
Total
Length
[m]
2514
2349
9496
6147
8552
7922
3564
Qty
1 off
2 off
4 off
3 off
3 off
3 off
-
Total
Length
[m]
3245
6131
6325
9284
7506
10463
-
5759m
8480m
15821m
15431m
16058m
18385m
3564m
84km
Figure 2-18
OCTP proposed overall subsea layout
Figure 2-19
OCTP proposed overall subsea layout plotted on the slope
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TRANSPORTATION & INSTALLATION (T&I)
The offshore installation philosophy focus on achieving first Oil as early as possible. In order to
reach this goal, the scope of work has been divided in 3 (three) campaigns for Oil development,
one for each regions.
The other main constrains considered are as follow:
 SPS equipment delivery - 4 (four) separate batches
 Drilling rig completion campaign sequence – main principle applied is zero SIMOPS
 FPSO arrival in the field and mooring – (zero SIMOPS)
The South East region development accounts for the 1st Oil milestone. It consists of 2 off
production wells, 1 off gas injection and 1 off water injection well from the South West loop.
Note that the water injection well (WI-1) is not required for the 1st oil, nevertheless the installation
of this system is included within the installation campaign.
The South West region development accounts for the 2nd Oil milestone. It consists of 3 off
production wells, 1 off gas injection and 1 off water injection well.
The North East region development accounts for the 3rd Oil milestone. It consists of 3 off
production wells, 1 off gas injection and 1 off water injection well from the north west loop.
Description of installation activities
For installation of the flexible flowlines, flexible risers, infield umbilicals and dynamic umbilicals the
installation methodology will be the same. It is foreseen a flexible pipelay vessel complete with a
Vertical Lay Tower (VLS) for depth water installation. The products (flexibles etc) will be
transported on the installation vessel using carousels or installation reels. The vessel will have
onboard Work Class ROV (Remotely Operated vehicle) – all operation are diverless. This
installation vessel is the main one, and there may be another vessel in the field to support all the
above described activities, for example for connection of flying leads, support etc. This support
vessel is normally called Light Construction Vessel, which is a small vessel compare to the main
installation vessel.
Flowlines and umbilicals
Installation of the flowlines (production, water injection and gas injection) will be performed by a DP
lay vessel which will lower the flowlines between the FPSO location and subsea structures.
Pruduction Wells and subsea structures will both be connected via rigid jumpers.
Installation of the control umbilicals will proceed in a manner similar to installation of flowlines and
by the same lay vessels that installs the flowlines.
Risers
Installation of umbilical risers, production risers, and the gas and water injection risers are required
to complete the FPSO installation. The installation vessel will perform the installation of the risers:
the bottom end of the riser will first be connected to the flowlines, then the top termination will pass
to the FPSO, or viceversa.
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Pipeline laying (for Rigid Pipeline only)
Figure 2-20
Pipeline-laying vessel
The rigid pipelines will be built of sections of about 12 m. The, use of a laying vessel that will be
navigated along the planned pipeline route is forecast, typically using 8 mooring points which will
be relocated when necessary with the help of one or more tugs.
The bars are welded in succession on the launch line and progressively deposited on the sea bed.
The welds are protected against corrosion by coating the possibly affected area of pipe with resine
of adequate thickness and density.
2.10 FPSO AND MOORING SYSTEM
FPSO
The OCTP FPSO unit will be designed for the following main purposes:
 Separate, Process, Store and Offload both oil and condensates at export specification
 Separate, Dehydrate, Compress and Re-inject the Associated Gas
 Separate, Treat and inject or Dispose of the Produced Water
 Lift, Treat and Inject Sea Water
 Seperate, treat through a Dew Point Control Process the future Not Associated Gas (NAG)
 Seperate Condensates from the NAG and mix them with the Oil production
The FPSO unit will have all necessary utilities for the safe operation during the most harsh weather
conditions that have been reported in the project design basis.
Crude oil will flow continuously from subsea trees through subsea pipelines via risers to the
process facilities on the FPSO (Floating, Production, Storage and Off-loading). Processed crude oil
will be stored in the cargo tanks. Shuttle tankers will periodically be moored to the FPSO and the
stored crude oil will be pumped to the shuttle tanker via an offloading hose. Exported crude will be
fiscally metered on board of the FPSO. The normal production will not be affected by the crude
export operations.
The FPSO systems shall allow efficient and safe operations of Unit at site, providing the following
main functions:
 to mitigate oil pollution risks by means of appropriate measures;

to store crude oil, ballast water and operational fluids in dedicated segregated tanks;
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
to allow the transfer of stored liquids from tanks to the final utilisation equipment;

to offload oil into shuttle tankers;

to provide accommodation for operations personnel;

to provide the full range of hotel services which are required to support operations;

to provide the full range of utility services to guarantee the process and vessel
functionality;

to guarantee the safety of personnel and environment both during normal and
emergency conditions;

to allow the control and management of all the on board activities.

to provide electrical power supply to both topside and vessel users.
The FPSO and mooring systems will be designed using International Standards.
In particular, the following International Conventions are applicable;
 IMO – “International Convention for Safety of Life at Sea”, (SOLAS) 1974, as actually
amended.

IMO – “International Convention for Prevention of Pollution from Ships”, (MARPOL) and
amendments.

DNV

API RP 2SK
"Recommended Practice for Design and Analysis of Station keeping
Systems for Floating Structures"

OCIMF
"Mobile Offshore Units - Position mooring (POSMOOR)"
Prediction of Wind and Current Loads on VLCCs
FPSO Topside Facilities
The FPSO unit nameplate capacities are reported in the following table:
Table 2.21
FPSO unit nameplate capacities
FPSO (New conversion)
Design
Min Oil storage
Mooring &
Risers System
1.4 MMbbls
Spread Moored
Double balcony
58,000 bblsd
Including Cond’s and 10% over design
150 MMScfd
55,000 bblsd
210 MMSCfd
210 MMScfd
Oil Treatment
Gas Injection
Water Injection
NAG Treatment
NAG Booster Comp.
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Oil Process Description
Inlet System
The production fluids from the Cenomanian reservoir will be produced separately in dedicated
flowline loops and risers before being routed to a separate oil manifold. This manifold will transport
the fluids to the inlet separator, operated at 20 bar.
The production fluids from the OPCamp2 well will have a dedicated manifold routing the production
to a dedicated HHP separator which will be operating at higher pressure as the arrival pressure at
the FPSO is expected to be significantly higher than the other oil wells.
Oil Stabilization and Storage
Initially, the oil will be stabilized in multiple separation stages (HHP, HP, MP and LP). Process
heating has been designed to prevent wax deposition within the process train. Additional
Dehydration and Desalting facilities are provided to reach the export specifications.
A single oil processing train will be designed to deliver a stabilized product to the storage tanks in
the FPSO for subsequent export. Oil will be fiscally metered before export.
In order to prevent wax formation within the subsea system, the well OPCAMP2 requires a
dedicated direct electrical heating system within its flowline.
Gas Compression and Dehydration System for Gas injection
Gas liberated from LP separator is compressed in reciprocating LP compressor and combined with
MP gas collected from MP production separators before being sent to a reciprocating MP gas
compressor.
After MP compression, the gas is mixed with HP gas from HP separator and sent to the first stage
of the centrifugal HP gas compressor train.
Associated Gas separated from the Oil stabilization train is compressed to approximately 70 bar
before Gas Dehydration using a TEG unit. The total amount of expected associated gas is 150
MMScfd.
A further two stages of compression are needed to reach the pressure required at the topside for
gas injection, 430 bar.
Gas Process Description
Inlet System
The production fluids from the Campanian reservoirs will be produced separately in dedicated
flowlines and risers before being routed to a separate condensate manifold. This manifold will
transport the fluids to the inlet slug catcher, initially operated at 70 bara. The slug catcher will
additionally be designed to separate gas, condensate and a mixture of MEG (Mono Ethylene
Glycol) and water.
Future Booster compression (expected 2026) is required to handle the decline in arrival pressure
from 70 bara to 20 bara.
Condensate Stabilization and Storage
Condensate, separated from the slug catcher and the dew-point control, unit is mixed before
heating to 30 deg C. The heated condensate is further stabilized in the condensate separator
operating at 3 barg. The liberated flash gas from the condensate separator is relatively rich in LPG
and is therefore further compressed before being sent to the dew-point control unit.
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Gas Dew-point Control Unit
Gas from the slug catcher and condensate separator is pre-cooled in a Gas/Gas Exchanger before
further chilling across a Joule-Thompson valve. The resulting condensate shall be separated in a
low temperature separator whilst the conditioned gas will pass through the Gas/Gas Exchanger
before being routed to the onshore receiving plant.
MEG is also injected within the process to prevent the formation of hydrates.
The dew point control unit is targeted at ensuring an acceptable HC/water dew-point to prevent
significant liquid drop out in the pipeline to the onshore receiving plant. However, the design also
ensures that stabilized liquid that can be mixed or spiked into the crude oil without exceeding
export specifications.
Main Utilities
Utility units are design to satisfy both Oil and Non Associated Gas (NAG) process requirements.
Chemical Injection System
The chemical injection system consists of all equipment and distribution piping (tubing) associated
with chemical injection, including storage tanks, injection pumps, transfer pumps, and all required
instrumentation up to the individual points of injection (or as the chemical leaves the FPSO for
subsea injection points).
Chemical injection facilities provide a means of assisting the production facilities system to meet
product specifications and disposed fluid specifications as well as protect the production facilities
from corrosion and hydrate plugging.
The chemical injection facilities supply specific chemicals through injection rate controlling devices
at their identified injection points throughout the process facilities at the dosage rate necessary for
achieving the above. An injection rate-controlling device is also installed on the pipe manifold area
to allow proper distribution to the end users.
Stand-by pumps (N+1 configuration) have been provided at all chemical units to guarantee
continuous performance, even for high volume pumps. Each injection point is in the centre of the
pipe.
Dosage rates for the metering pumps can be manually set up at each pump or controlled using the
injection rate controlling devices. Each injection point has online flow meter (transmitter). For
single-headed pumps, the pump is stopped if no chemical injection is required for that injection
point. For multi-headed pumps where chemical is pumped to both high and low pressure points,
individual pump head can be offloaded back to the storage tank via a back pressure control valve if
no injection is required.
Flare, Vent and Blowdown System
The System is designed to satisfy the zero flaring philosophy that has been adopted by the project.
The Flare / Vent System provides safe egress of hydrocarbon fluids that are relieved from process
equipment and/or from PSVs, BDVs, and PCVs/ PVs during start-up and/or process upset
conditions. Major equipment associated with the flare is listed below:
The facility is equipped as a minimum with 2 (two) independent flare systems, one operating at
high pressure (HP) and the other at low pressure (LP). The system is designed for emergency
burning and also has a backup of the ignition system. The systems are designed to operate
simultaneously.
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The HP Flare system is provided with a sonic flare tip whereas the LP Flare system is provided
with a pilot type flare tip.
The flare system is designed and constructed in accordance with API 520 Design and Installation
of Pressure Relieving Systems and with API STD 521 Pressure-relieving and De-pressuring
Systems.
The system is designed to do not exceed allowable noise or radiation limits as shown on API STD
521, when continuously relieving and burning the full gas production rate or blowing down the
process system.
Glycol Regeneration for Hydrate Inhibition
This unit is considered as option as it is only related to the NAG production.
Flowline MEG Regeneration & Reclamation System is required for salt removal and regeneration
of water-rich MEG that is recovered from produced fluids from the gas/condensate reservoirs. Lean
MEG is injected subsea to inhibit hydrate formation.
In the early years of production, when formation water has not yet broken-through the reservoir,
the MEG/water produced with the gas reservoir fluids will be salt free. Hence, no reclamation
process is required for recovery of the MEG. During this period, the rich MEG from the Flowline
MEG Separation System is sent to the Process MEG Regeneration System for treating. In this
design, the capacity of the Process MEG Regeneration System is sized to accommodate the
capacity of the rich MEG from the Flowline MEG/ Condensate system as well as MEG from the
Process MEG/Condensate System. During the early production years, when the rich MEG from the
flowline system is directed to the process MEG Regeneration System.
According to the latest production profile there is an opportunity to avoid the future installation of
this unit if there is no presence of free water throughout the full life of the field. Presently the Unit is
considered as a “FUTURE” item, and provisions for space, utilities and tie-ins are already foreseen
in current topside design of the FPSO.
Fuel Gas System
The Fuel Gas Conditioning System provides clean, superheated natural gas, suitable for gas
turbine combustion (fuel gas requirements to be specified by chosen turbine supplier), and delivers
superheated fuel gas to each of the other end users at their required flow rates and pressure
levels.
The Low Pressure Fuel Gas Conditioning System (for blanketing the process equipment, purging
of flare headers) is designed for low pressure fuel gas users.
Fuel gas system is designed for a flowrate about of 30 MMscfd. Treated gas enters the fuel gas
conditioning system from the downstream of the TEG Outlet Coalescer within the Gas Dehydration
System. The pressure is let down and sent to the HP Fuel Gas Scrubber. Any condensed liquid is
separated in the scrubber and returned to the Safety Gas Knockout Drum. The gas from scrubber
passes through a Coalescing Filter where finer filtration of liquid droplets is done before being
heated in the Fuel Gas Heater to provide a minimum superheat. This process ensures Generator
Gas and Booster Gas Turbine (optional NAG future turbo-compressor) fuel gas quality
requirements are met. The fuel gas then flows through the Fuel Gas Filter to remove any fine
particulates. The superheated gas is then distributed to each of the turbines, compressor seal gas
panels and other users.
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Fuel gas for low pressure consumers is let down from the turbine fuel gas pressure level. This gas
is used as a low pressure fuel gas supply to the flare header purges, flare tip pilots, for blanketing
of vessels as well as for marine boilers. As part of fuel gas system to boilers, the following are
installed; deck gas valve skids, gas valve enclosures, extraction air fans. Fuel gas system is
designed to have sufficient hold-up volume to permit smooth switchover (without shading any
running electrical loads) of all the running power generation turbines from fuel gas to diesel fuel.
Power Generation System
Main power generation
The main power generation for the entire FPSO Unit shall be provided by gas turbines/engines
driven synchronous generators. The electrical power generation unit must ensure adequate
capacity to feed both Topside and Vessel loads, and in general all the electrical loads of the FPSO,
in all the operating conditions, with a minimum sparing philosophy of N+1 (with N=2 as a
minimum). This means that, in the event that one main power generator is not available for
shutdown or maintenance, the others shall be able to run the production at 100%.
The firm capacity of the main power generation system (with “N” of the “N+1” generators in
operation) shall be capable of supplying continuously the 120% of the load balance, at the
maximum design ambient temperature. This contingency may be eroded during detailed design
development, but on completion of the project a margin of at least 10% spare capacity shall exist.
Essential power generation
Essential diesel generators shall be provided in order to cover the loads necessary for life, support,
accommodation, communication, the loads necessary during navigation and when the FPSO is not
producing, plus the loads classified as emergency and safety and the loads required to start up the
first main power generator.
Facilities to synchronize and operate in parallel the Essential Diesel Generators shall be provided.
The sparing philosophy for essential power generators shall be N+1.
Emergency power generation.
A diesel power generation shall be provided to ensure the emergency power supply to all
emergency users of the FPSO (both topside and vessel) and shall be located in a dedicated
shelter/container.
On loss of main power, the emergency electrical system shall ensure the shutdown of the
production facilities in a safe manner, while the emergency control, the management and life
support systems shall continue to function, normally and safely. A minimum autonomy of 24 hours
shall be guaranteed.
Produced Water Treatment
The purpose of the Produced Water System is to remove oil from the produced water stream and
sand management in order to comply with injection requirements and applicable overboard
discharge regulations in case of unavailability of the water injection system.
The Produced Water System is sized to process 45,000 bblsd of produced water with an output oil
in water content of 20ppm.
Fire fighting system
The FPSO shall be protected by various fire-fighting systems depending on the location and the
risks associated with the area to be protected.
Topsides shall be protected by a pressurized water and foam deluge system, which shall be
activated manually from the CCR or automatically via fire detectors, depending on areas to be
protected.
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The cargo tank, deck, helideck, and offloading station shall be protected by a low-expansion foam
system. The cargo tank deck underneath the topsides modules shall be covered by a fixed foam
spray system.
Machinery and equipment spaces shall be equipped with the fixed Hi-expansion foam fire
extinguishing systems or clean agent extinguishing system depending upon requirements for the
space.
Oil & AG
Facilities
Figure 2-21
NAG & Condensate (Base Scope)
FPSO Main System Layout
NAG & Condensate (Future)
Common
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Hull and Offloading
The FPSO unit shall have a minimum design life of 20 years starting from the date of completion of
the vessel conversion (VLCC – fig. above). The FPSO unit shall be CLASSED for uninterrupted
service, without the needs for dry-docking during the expected service life, with on-site class
surveys for classification status maintenance.
The required storage capacity for the OCTP development project is 1.4 MMbbls which will be
guaranteed in the case of converting a VLCC as the standard storage capacity of such vessel is
around 2 MMbbls. The expected tanker hull to be used for the FPSO conversion will be of “Double
Hull” type meeting the minimum requirements specified by eni and applicable international
standards.
Figure 2-22
Typical General Arrangement
The offloading configuration is foreseen as Tandem type offloading using an offloading hose.
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Figure 2-23
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Pictorial of tandem offloading configuration
Mooring System
The FPSO selected mooring system is the Spread Mooring System with a double balcony riser
approach, allowing higher flexibility in number of riser slots and in adding future risers (if required).
The FPSO unit design will foresee a minimum of 30 risers needed for production, gas injection,
water injection, umbilical and gas export. A reasonable number of spare slots (3) is considered to
accommodate future developments and expansions.
Figure 2-24
Pictorial of double balcony FPSO
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Figure 2-25
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Mooring Layout
The mooring system shall be designed according to the following criteria:
 The anchoring will provide sufficient restoring in order to retain the vessel riser tie-in location
within excursion limitations ensuring the feasibility of the under-water riser system.

The maximum anchor leg tensions will be kept as low as possible in order to minimise, within
the full respect of the Factors of Safety, the size and cost of the mooring system
components.

The anchoring system suspended weight applied to the FPSO will be minimised, to avoid
heavy supporting structures. The anchor legs will nevertheless be terminated on their FPSO
extremity by a small length of chain, for several reasons:
-
allow the use of chain-stoppers, which permit a relatively easy adjustment of each
anchor leg pretension during installation;
-
a chain segment in the splash zone is more robust than a wire rope in case of collisions
against any (unidentified) floating object.
The design of the mooring system will be based on a spread mooring configuration with 4x4 lines
(16 total) chain, steel wire, anchoring with suction piles L=20m e D=5m; the offset is 5% of water
depth with intact lines and 8% of water depth with one line damaged
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Figure 2-26
Mooring pattern
Table 2.22
Lines characteristics
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Figure 2-27
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FPSO with a Spread Mooring System
The initial activity will be to install three mooring spread and a temporary support buoy to support
the lines prior to the FPSO hook-up.
The work will be undertaken using a pair of large anchor handling vessels (AHVs) or anchor
handling tug supply (AHTS) vessels and will last approximately two to four weeks.
The FPSO will retain the original marine engine and propulsion systems for the transit from the
conversion and pre-commissioning site to the installation site in Ghana. Hook-up of the FPSO to
the mooring spread will be performed by a Dynamically Positioned (DP) construction vessel with
the assistance of three AHVs mentioned above. The vessel will pick up the upper end of the
preinstalled mooring lines, move toward the FPSO and connect the mooring wires to the FPSO.
In case of DRAG anchor the required hypothesized marine spread could be:
1 vessel anchor handling as following ARMADA THUA 104-105,
2/3 tug vessel 30/40 ton as following Armada Tuah 26.
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In case of Vertical Load Anchor (VLA) or Suction pile the required hypothesized marine spread
could be:
1 vessel anchor handling as following Normand Installer.
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FPSO Operational Components
Cargo Systems
The main purpose of the cargo system is:
 To receive, distribute and store on-spec crude oil from the process facilities into the
cargo tanks,

To receive and store off-spec crude oil from the process facilities into the dedicated offspec cargo tank,

To offload the crude oil stored in the cargo tanks into a shuttle tanker at regular
intervals
The main operating targets of the cargo oil system are:
 Continuous loading of stabilised crude oil (from the process facilities).

Offloading at regular intervals into a shuttle tanker.

Simultaneous loading and offloading

Fiscal metering of the crude oil parcel to be conducted on board the unit during
offloading

Inspection and maintenance of cargo tanks and piping systems to be conducted on
board the unit in between offloads.

Crude oil washing of cargo tanks (in between offloads and during offloading).

Water washing of cargo and shop tanks.

Stripping of the cargo tanks and discharging to the slop tanks.
Besides the above primary operations the following operations will be also performed by the
system:
 Metering the crude oil partially offloaded during offloading,

Transfer of crude oil between cargo tanks,

Transfer of off-spec crude to process facilities,

Transfer of crude to the pigging pump on Topsides,

Stripping water from the bottom of cargo tanks and discharging to produced water / slop
tanks,

Crude oil washing of a cargo tank during offloading,

Crude oil washing of cargo tanks in between offloading,

Hot water washing of a cargo tank or produced water / slop tank in between offloading,
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
Flushing of the export hose,

Emergency ballasting of cargo tanks with seawater,

Inspection and maintenance of cargo tanks and piping systems in between offloading.

Transfer of polluted ballast water to the slop tanks.
The vessel and cargo operating requirements and philosophies developed are relevant to the
following systems:
 Cargo Oil and Ballast Systems.

Inert Gas and Tank Venting System.

Crude Export System.
Cargo Oil and Ballast Systems
The purpose of the ballast water system is to maintain hull trim/list, balance the hull stress and
provide extra stability without complete dependence on the cargo oil tanks to do the same.
The main operating targets of the cargo oil and ballast system are:
 Continuous loading of stabilised crude oil (from the process facilities).

Offloading at regular intervals into a shuttle tanker.

Simultaneous loading and offloading.

Fiscal metering of the crude oil parcel to be conducted on board the unit during
offloading.

Inspection and maintenance of cargo tanks and piping systems to be conducted on
board the unit in between offloads.

Crude oil washing of cargo tanks (in between offloads and during offloading).

Water washing of cargo and slop tanks.

Stripping of the cargo tanks and discharging to the slop tanks.
Inert Gas and Tank Venting System
The main operating targets of the inert gas and tank venting system are:
 Initial inerting of empty cargo tanks and slop tanks,

Topping-up,

Re-inerting of a cargo tank or slop tank after tank inspection / maintenance,

Purging of a cargo tank or slop tank,

Temporary inerting of ballast tanks when required.
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Crude Export System
The main operating targets of the crude export system are:
 The amount of cargo, which is transferred from the FPSO to the shuttle tanker shall be
determined by a metering unit.

The offloading hose string will be according to the latest OCIMF recommendations and
will consist of one main line. The length will be such that the largest expected shuttle
tankers can be accommodated.

In the event of an emergency on board the shuttle tanker, e.g. fire, explosion or extreme
environmental conditions, a quick release mechanism will be provided to enable the
operators to release the mooring hawser from the FPSO. The system will continuously
monitor and record the load measurements and will have local and remote alarms fitted,
at the mooring station and the Central Control Room.
System Isolation and Blow- down Philosophy
The following Guidelines regarding the Topside process system isolation are proposed:
The Oil Production Train and the Compression Trains will be equipped with actuated isolation
valves to allow the possibility of remote isolating sections of the production facilities in case of
emergency (i.e. fire). Definition of these isolation sections will be performed as part of the
basic/FEED engineering. Each section will be equipped with actuated depressurisation valves to
allow the possibility of remote depressurising sections of the production facilities in case of
emergency. The Emergency Flare & Blow-down System will be sized for the contemporary
discharge of all the sections. Implementation of any sequence for a phased blow-down procedure
shall be evaluated during the basic/FEED engineering.
The blow- downstream gathering philosophy is aiming to avoid the mixing of cold high pressure
gas streams (i.e. from the Compression Trains, leading to cold stream after the blow-down valves)
with wet gas/liquid streams coming from the Oil Production Train.
This philosophy should prevent possible ice formation in case of simultaneous discharge.
Therefore:
- Outlets from depressurisation valves and PSVs installed on the Gas Compression Trains shall
be routed to the high-pressure KO drum and HP flare.
- Outlets from depressurisation valves and PSVs installed on the Oil Production Train (except for
high pressure separator) are routed to the low-pressure KO drum and LP flare.
The Flare KO Drums final design will be performed during basic/FEED engineering according to
API requirement and Project Safety Philosophy.
2.10.2
FPSO Control & Safeguarding Systems
General Description
The Control and Safeguarding System includes Process Control System (PCS), Emergency
Shutdown System (ESD) and Fire & Gas System (FGS).
The Process Control System (PCS)
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The process control allows the operator to monitor the process condition and apply corrective
actions when necessary. The control functions during the start-up period will be executed from the
central control room or locally, dependent upon the complexity of the start-up sequence of each
process area or module. Where local operation is required, a dedicated local human machine
interface will be provided. The concept of a distributed control system is also applied to the process
package units, which have their own standard control system. The start-up and normal stop control
functions shall be executed from the location where the control equipment is located. The
necessary signals, which are relevant to remote control and monitoring in conjunction with other
process area, are interfaced with the PCS through an agreed standardized protocol (i.e. MODBUS
or Ethernet).
Process Control System (PCS) is fully independent from the Emergency Shutdown System (ESD).
The system architecture follows a decentralized concept with local control panels on the Topside
modules and in the Local Equipment Room (LER). The Fire & Gas System (FGS) is a centralized
system consisting of marshalling field termination and system cabinets. The FGS is installed in the
LER with hardwired connection to the FGS interfaces, i.e. F&G matrix, PA/GA, ESD and telecom.
A computer cabinet, consoles, printers and Human Machine Interface (HMI) stations comprising
keyboard and monitor are installed in the CCR. Additional HMI stations are installed in the LER.
The system components described above are linked by means of a dual redundant network.
Hardwired connections are used for critical safety related signals. Local remote I/O panels are
installed on the on the largest topsides modules in order to minimize hook-up cabling work. The
processor units are located in the LER.
Safeguarding System
The goal of the safeguarding system is to protect against un-safe operation of the process and to
perform corrective or suppressive actions in case of hazardous conditions on the FPSO
This safeguarding system however consists of the following sub-systems:
 Emergency Shutdown System, which is indicated as ESD, to perform the safeguarding
of equipment against abnormal values of process variables.

Fire & Gas system (FGS), which performs the safeguarding against hazardous fire and
gas situations.

Public Address/General Alarm system (PA/GA) to alert personnel on the existence of a
potential hazard and to transmit instructions.
The ESD is based on hierarchical levels of shutdown. The design of the ESD System is fail-safe
and the design of FGS is fault-tolerant (i.e. by the use of voting system, line monitoring function
and enhanced component diagnosis). The design of the safeguarding system also takes into
consideration the possibility of regular system testing, which allows the desired reliability level to be
maintained.
Telecommunication Systems in The FPSO
The existing Telecommunication system, after refurbishment of system and Telecommunication
Room, will provide FPSO of the following requirements.
Internal Communications
A Public Address/General alarm (PA/GA) system is installed to facilitate public announcements
and provide audible and visual alarm signals. Means will also be provided for "talk-back" at key
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locations. System loudspeakers are installed to enable audible alarms to be heard throughout the
FPSO. In addition, status lamp assemblies shall be provided for visual alarm indication in areas
with high background noise. The system is certified for use in hazardous areas where applicable.
The system interfaces with the FGS. Talk-back stations are installed at key locations.
An automatic telephone system is installed with an electronic public exchange switchboard and
telephone sets throughout the FPSO. Telephones are certified for use in hazardous areas where
applicable and where installed in areas of high background noise, are provided with audio/flash
unit and a noise protection booth.
External Communications
GMDSS (Global Maritime Distress & Safety System): A radio console (compliant with the GMDSS
A3 regulations) shall be located in the Communication Room.
Satellite Communication: A VSAT (Very Small Aperture Terminal) shall be installed for voice, fax
and data communication with other ships and shore and the existing IMMARSAT B Satellite
Communication Systems will be used for backup.
Aeronautical Communication: The VHF (AM) radios enable communication between the vessel
and aircraft. A non-directional beacon provides a means for aircraft to locate the FPSO in
conditions of poor visibility.
Operational MF/HF: This unit is fitted in the Telecommunications Room for communication
between the shore and other vessels.
SART/EPIRB: The FPSO is equipped with SARTs (search and rescue transponders) and EPIRBs
(satellite emergency position indicating radio beacons).
VHF (FM) SYSTEM: This equipment is fitted in the Central Control Room for communication
between the FPSO and other vessels in the field.
UHF (FM) SYSTEM: The UHF system provides internal radio communications for the production
and maintenance department’s personnel.
Personnel Safety
Personnel safety shall be the highest priority of the OCTP development project. The goal shall be
an accident-free workplace. Personnel safety will be the first priority in decisions that will involve
design options, construction procedures, and cost/schedule trade-offs. The OCTP project HSE
Plan shall describe the overall approach to safety management together with specific safety
requirements and deliverables. Safety of design shall be another important aspect. It will require
assessment of hazards and risks as described below. The goal of safety of design shall be to
ensure the facility is safe for personnel and has reduced risks to facilities and the environment to
the lowest practicable level.
Human Factors: Good Human Factors practices will be used in evaluating access to and viewing of
operating data, manipulation of controls, installation of isolation devices, removal and replacement
of equipment (e.g. equipment and personnel access and egress, lifting points, etc.). Human
factors engineering will focus on facility modifications and equipment additions, while retaining
consistency with existing systems where changes would otherwise increase the chance of human
error. Human factors will be addressed with project specifications provided within ITT for EPC.
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Risk Management: The general approach shall be to identify and eliminate hazards during the
design through appropriate design selection and risk management. Where hazards cannot be
eliminated, their significance will be evaluated and those that are considered significant shall be
reviewed to ensure that appropriate risk reduction measures are employed.
A Risk Screening will be adopted for assessing tolerability criteria. However, as far as possible, the
approach of applying the most restrictive standards will be followed, in order to guarantee a safe
design from the early steps. Within this approach, the Risk Screening methodology will not be used
to justify any derogation from the applicable standards; it will be used just to improve safety of the
plant beyond the application of the standards.
All identified hazards will undergo preliminary screening to establish their classification. In first
instances this will form part of the HAZID studies that will be conducted using the Risk Matrix and
Severity Scales shown below
Dropped Objects: As general approach, the risk from dropped object shall be reduced by proper
design of the piping arrangement and of the handling procedures:
 lifting of items above hydrocarbon equipment shall be avoided as far as possible;

as general rule, items shall be lowered from their usual position to deck level, and then
moved at deck level to a lay down area (e.g. by a trolley).
However, despite a good design of the piping arrangement and of the handling procedures, in
some points a protection against dropped object could be necessary. The design criteria for
equipment protection from dropped object loads are dependent on the impact energy, their location
and the frequency with which lifting operations will be performed Where significant dropped object
potential exists, impact protection criteria for equipment shall be based on the risks associated with
potential dropped objects.
Vessel Impact: The supply boat landing is located alongside the ballast tank. The hull side at the
supply boat landing shall be protected from collision with a supply boat. The impact of other vessel
collisions will be evaluated and practical, cost effective measures developed to mitigate risks.
Partial double hull shall be justified and assessed in order based on the result of collision study.
Therefore, a collision study is mandatory for partial double hull.
Fire and Blast: In general blast walls or reinforced structure have to be incorporated into the design
based on the result of overpressure analysis, rather than subjecting the cost of the installation to
Cost Benefit Analysis. As alternative design criteria, qualitative judgement may be used with some
limitation, i.e. only when it is based on assumptions that can easily demonstrated, and when the
approximations are towards higher safety.
The design intention for the FPSO shall be to minimize explosions on the main (cargo) deck by
minimizing the routing of any topsides process hydrocarbon lines on this deck.
The cargo deck will be closed and vented far from topside equipment.
In addition, means of minimizing gas clouds from riser/fluid transfer line releases reaching this
deck shall be developed by appropriate layout/location of equipment such that possibility of leaks
onto main deck will be minimized.
Evacuation, Escape and Rescue: As the whole section, the following considerations have to be
considered in conjunction with the HSE Philosophy. However, general requirements for the FPSO
shall be as follows:
 Each of the topsides designated areas and/or modules that may be manned shall have
at least two means of escape. Equipment, pipework and their supporting structures
shall be positioned to encourage development of this escape philosophy. This
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requirement also shall apply to enclosed areas and rooms that are not continuously
manned

Stairs shall be installed to ensure proper and easy access between all levels of the
facilities

All escape ways and related doors/openings shall be clearly marked with luminescent
signs or painting. The markings shall function during loss of main illumination in an
emergency and in poor visibility or smoke. All exits used as escape ways (including
stairs) shall be sized to accommodate personnel with full fireman suits and gear and for
easy transportation of injured person on a stretcher.

Facilities shall be provided to rescue persons from the water and to safely recover them
to a place of safety.

Appropriate helicopter crash equipment shall be provided adjacent to the helideck of
each facility.

Boat landings and a helideck will also provide an evacuation location for the facilities.

Life rafts, buoys, lifejackets, and other safety equipment will be provided as defined in
HSE Philosophy.
Active Fire Protection: Active fire protection needs to be applied to all vulnerable vessels,
pipework, support structures and other plant and equipment.
Other Protection: Total saturation suppression systems in accordance with API, ABS and SOLAS
rules are to be provided in the relevant rooms. The company Philosophy is to avoid the use of
Carbon Dioxide in enclosed manned space.
Miscellaneous Fire Fighting Equipment: Portable fire extinguishers shall be located in all areas of
the installation. Type, size and locations shall be selected based on the encountered risk and in
accordance with company specifications. Firefighting equipment, including firefighting suits and
gear, shall be provided in accordance with the applicable standards and with the emergency
response plan. The equipment provided shall be stored in a cabinet/locker located near the
primary muster area for each facility.
The company Philosophy is to avoid the use of Carbon Dioxide in enclosed manned space.
Passive Fire Protection: Passive fire protection (PFP) will be used where necessary throughout the
facilities. For further detail see HSE Philosophy Requirements for PFP shall be reviewed during
basic design to take into account the applicable fire loads.
Fire and Gas Detection: A suitable number and type of Fire and gas detectors will be used
throughout the facility.
Occupational Health: Occupational Health Hazards will be identified during reviews of the facility
modifications and focus on changes to the existing FPSO systems. The reviews will focus on
specific occupational issues including, but not limited to:
 Noise,

Chemical exposures,
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Exposure to carcinogens, and Lighting.

Lighting
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ITT for EPC shall contain the Design Specifications for Health. MOH will perform design
verification before construction. In addition, industrial hygiene surveys will be conducted after
facility start-up to assess chemical exposures, noise levels and lighting adequacy to confirm design
specifications were achieved. The schedule of the surveys will be reported in the relevant
document of the installation.
Noise Control: Noise limits for offshore facilities will be provided to the contractors in the
specifications for detailed design. A maximum sound pressure level of 85-dB(A) will be used for
external working areas. The objective of this engineering control shall be to minimize noise levels
and eliminate the need for hearing protection. Special areas such as offices, control rooms, living
quarters, etc. will have specific tighter sound level limits as it will be specified in the HSE
Philosophy and other specific design documents. The contractor shall provide data and
calculations to the company to substantiate that the plant noise complies with the workplace noise
criteria as described in the design documents.
ESD System: An automatic and hierarchical Emergency Shut-Down System (ESD) shall be
foreseen on the FPSO including a vessel shutdown system, a topsides shutdown system.
Flaring: The installation design incorporate a blow-down system to minimize the consequences of
equipment rupturing by reducing the quantity of inventory that may feed a fire or gas cloud. The
installation flare system will provide a safe and efficient way of collecting and disposing of
hydrocarbons associated with the following scenarios:
 discharge from the safety valves during pressure relief conditions

partial or total installation depressurization
Thermal Radiation: A flare radiation study and flare location assessment is required. The API 521
rules shall be applied in a early stage of the project before place order for flare system.
Power Generation: An emergency Power Generator shall be foreseen on the FPSO. It shall be
located in a dedicated safe area, far from Main Power Generation system and a specific protection
shall be considered during design for the system integrity against fire or explosion events.
An Uninterruptible Power Supply system shall be provided, located in a dedicated safe area
Telecommunication: Dedicated telecommunication systems shall be provided on the FPSO to
support safety and efficient operations; these systems include internal communication, telemetry
systems, telecommunication network and external communication
Helideck: A helicopter deck shall be installed on the FPSO, in compliance with Company
specification (Doc. N° 17002.VOF.OFF.PRG, “Aeronautical Design Criteria for Helidecks on
offshore installation”) and with relevant International Regulation Authorities.
Asbestos removal: A complete asbestos removal shall be foreseen.
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Natural Resources Consumption, Waste Generation, Air and Noise Emissions
During FPSO Operation
Natural Resources Consumption
Foreseen quantities of consumed cooling water and fire-fighting water from eni environmental
database):

Cooling water extinguishing water = 110.000 mc per month.
Waste Generation
The wastes produced on the FPSO are stored temporarily in suitable yard structures.
The wastes produced are:
 Cooling water,
 Production water
 Bilge water
 solid urban wastes (cans, cartons, wood, rags, etc.),
 sewage (from w.c. washbasins, showers).
Cooling water
Seawater is supplied from the marine system using seawater lift pumps, it is then treated by antibiofouling/biocides in order to limit biological activity and is then subject to filtering process to
remove particulate matter, finally going to the cooling water header.
The intake hose is at about 100m and will take water at about 16°C, seawater discharge
temperature will be about 31°C.
After cooling, the effluent shall result in a temperature increase of no more than 3° C at edge of the
zone where initial mixing and dilution take place.
Estimation of cooling water discharge is approximately 1700 m3/h
Typical concentration of biocides / antifouling (chlorine) is around 2 to 5ppm, it may be required to
perform high batch dose of around 400ppm if operational problems are experienced.
Production water
Associated with oil and gas deposits, these waters are brought to the surface along with the
hydrocarbons produced. The quantity and quality of the production water generated during
cultivation activities depends on the type of well, the nature of the geological formation and the
extent to which the well is exploited.
The project envisages the reinjection of the production water after mixing with seawater, process
cooling water and test water; nevertheless, in the present document potential impacts deriving from
discharge of the production water into the sea are described. In that case, production water will be
discharged after treatment to reduce the oil content in line with applicable regulation and best
practices.
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Oily and accidentally oily waters (bilge water)
Bilge liquids are composed of oil and water mixed together. From the bilge oil/water, where
collected, are sent via a pump to a separator. The oil is filtered and collected in a tank to be
subsequently put into barrels and transferred to shore where it shall be disposed, while the cleaned
water is sent to the liquid waste collection tank and then dumped into the sea.
Figure 2-28
Bilge liquids separator
The project envisages the production of about 10/15 mc /month of Bilge water.
Solid urban wastes (cans, cartons, wood, rags, etc.),
Solid urban waste will be collected and disposed every 15 days on land according with Ghana
reculations.
Foreseen quantities of solid urban wastes (data from Eni environmental database):
 Garbage bag not segregated waste = 2160 Kg.

Garbage bag with plastic = 60 Kg.

Garbage bag with cans = 100 Kg.

Garbage bag with carton, wood and paper = 80 Kg.

Garbage bag with glass = 100 Kg.

Garbage bag with plastic bottles = 180 Kg.

Garbage bag with used sulphur filters = 120 Kg.
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Garbage bag with oily rags = 100 Kg.

Garbage bag with empty buckets of paint = 100 Kg.

Garbage bag with used media filters = 50 Kg.
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Civil wastes
During FPSOs operation activities and throughout the entire life cilen of the projected activities it is
estimated that about 60 operatives will be present on the FPSO; on the basis of the data available
in the literature for sites similar to the one under consideration, we can provide an initial estimate
as follows:

Civil waste water: 100 l x 30 days x 60 pers = 180000 lt/month (6000 l/day)
Food waste is shredded and dumped at sea through a sieve with an aperture of 25 mm., as
determined by "MARPOL (Marine Pollution) international standards."
Civil sewage discharged from w.c., washbasins, showers and camboose — are treated in a
purification system before being dumped into the sea. Discharge is compliant with "MARPOL"
international standards. A biological-type purification system is used. The sewage to be treated is
conveyed to an aeration chamber where it remains for approximately 24 hours, mixing with water
containing a high concentration of aerobic bacteria which breakdown the organic substances
contained in the sewage being treated.
A compressor injects pressurized air into the sewage in order to keep the bacteria active, create a
certain degree of agitation and keep the particles containing the organic substances and bacteria
in suspension. This suspension is then passed into the clarification chamber where, in
approximately 6 hours, the flakes settle and the supernatant is stratified into zones containing the
clarified supernatant liquid, particles still in suspension and the settled flakes.
The supernatant liquid overflows into a chamber where it remains in contact with hypochlorite for
30 minutes (to eliminate the residual bacteria), the dissolved oxygen content and pH are checked,
and then it is dumped into the sea.
The material still suspended and the settled materials are sent on by insufflation into an aeration
chamber where the treatment cycle continues.
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Domestic waste water treatment system
Atmospheric emissions
Installation Phase
The impact on air quality due to the implementation phases of the pipeline and the
installation/removal of subsea wells, FPSO anchoring system and the FPSO itself will derive from
different sources such as helicopter movement, supply vessels, engine combustion and
generators.
With the intention of formulating a cautionary assessment of atmospheric emissions produced
during the construction phase of the Project, the activities of wellheads installation and pipeline
launching and laying on seabed have been assimilated to the certainly more costly and challenging
installation of a classic surface platform of considerable size. Furthermore, the set of power
generation plants installed on the pontoon (crane-barge) and engines of the naval support vessels
engines, towing windlass, tug supply vessel, laying barge, personnel transport vessels, etc., were
considered, for a total power of 16,700 HP, to which a total flow rate of exhaust gas of 130,000 m3
at a temperature of 450 ° C is credited.
For assessment purposes it is therefore possible to make reference to the following data relative to
the installation of a surface platform.
Table 2.23
Atmospheric Emissions during sealine laying, well heads, mooring system and FPSO
installation (assimilated to the installation of a surface platform)
Emission type
Unit of measure
Exhaust gas total flow rate
Discharge temeperature
Unburnt hydrocarbons
flow
concentration
Carbon monoxide
flow
concentration
Nitrogen oxides
flow
concentration
Suplhur dioxide
flow
concentration
Polveri – PST
flow
concentration
m /h
°C
g/h
3
mg/Nm
g/h
3
mg/Nm
g/h
3
mg/Nm
g/h
3
mg/Nm
g/h
3
mg/Nm
3
Emissions source
Ensemble of all power generation
plants for a total power of 16,700 HP
130.000
450
800
portata
16
44.000
880
80.000
1.600
13.000
260
3.000
60
The emissions framework associated with the activities of these vessels is not precisely definable,
due to the variability of its technical and operational characteristics, as well as the fact that the
activity of each of these media is distributed throughout the area and along the flowline route, with
a very low level of temporal overlap (all operations will be carried out in sequence, and with rapid
transits of the vessels).
During production phase 2 supply vessels (one in stand by and one commuting) will provide food
and materials to FPSO (i.e. following Armada Aman).
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Production Phase
In the absence of data on emissions from the FPSO, the number and type of vessels present
during the operation phase, and the type of ships engaged in offloading, we adopt the cautionary
assumption that emissions during operation are similar to those caused by spread of vessels
present during the installation of a large platform surface.
Noise emissions
The design of the FPSO and local oceanic conditions affect both the path of the sound into the
water column and how much sound is transmitted.
To carry out offloading operations a marine spread with two supply vessels is required.
Table 2.24 shows data for the emission of noise of two supply vessels of dimensions and installed
power comparable to those of the FPSO and tankers.
Table 2.24
Noise sources (Ocean of Noise WDCS 2006)
LeqA dB re 1 µPa-m
Supply ship
broad
band
0.045-7.07
181
rd
1/3 octave band centre frequencies (KHz)
0.05
162
0.1
174
0.2
170
0.5
166
1
164
2
159
Considering the length of the FPSO, the on-board crew, the type of motors and the DLE gas
turbines which should limit the NOx to less than 50ppm, noise level is normally kept under 90 dB as
per our standards.
2.11 SYSTEM COMMISSIONING PHILOSOPHY
Field installation plan will be elaborated with the aim of reducing the requirements relevant to the
installation spread and its duty and with the objectives of shortening the time lag between the
arrival on site of the FPSO and the first oil. Therefore, all those installation activities, which do not
require the presence of the FPSO, shall be performed before the FPSO arrival on site.
The basic philosophies for the performance of the Commissioning and Start-up Operations are:
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
Commissioning sequence starting with safety and life support systems and completed
with hydrocarbon system;

Optimisation of commissioning of vessel systems related to class inspection and class
test in order to avoid duplications.
The subsea system will be controlled by a multiplexed Electro-Hydraulic (EH) control system
routed from the FPSO facility via a control umbilical to each subsea system. The umbilical shall
consist of hydraulic lines and electrical power/communication lines from topside control system to
each subsea manifold and then to the trees (Well heads). An umbilical system will provide control
and chemicals to all subsea manifolds and trees from the FPSO.
Hydraulic lines will be routed from the Hydraulic Power Unit (HPU) to the Topside Umbilical
Termination Unit (TUTU), and through the subsea umbilicals up to the UTAs. In the same way,
through the subsea umbilicals electrical lines will be routed from the Electrical Power Unit (EPU)
and Master Control Station (MCS) to the TUTU, and then up to the UTAs. The hydraulic power
distribution system shall have fluid supplies at two pressure levels (345 bar (LP) and 690 bar (HP))
with each pressure level having an active redundant line in the umbilical. These lines are assumed
to have a minimum of 3/8 inch I.D.
One hydraulic flying lead and two electrical flying leads will connect the UTA to a SDU mounted on
the manifold. The SDU will distribute hydraulic fluid, chemicals, electrical power and signal to all
wells and manifold SCMs. Each SCM will be retrievable from its mounting base permanently
installed in the hosting tree or manifold.
Electric and hydraulic umbilical services will reach the well from the manifold mounted SDU by
means of Hydraulic Flying Lead (HFL) and Electrical Flying Leads (EFL). One HFL and two EFL
are assumed per well. Two additional EFLs will connect the SCM of each well to the related MPFM
incorporated in the well jumper. All the SCM hydraulic connections, as well as the cabling
connecting the SCM to the tree instrumentation, will be routed through the related SCM mounting
base, which will be populated with the necessary quick connectors.
The umbilicals connected to the FPSO shall be installed in a lazy wave configuration with
distributed buoyancy; alternative configuration may be analysed in the study. The (dynamic)
umbilical riser section and its associated (static) seafloor umbilical will be manufactured as a
continuous length section. Chemicals injection is preliminary assumed to be through dedicated
hoses/tubes in the umbilicals. This depends however on the injection rates that will eventually be
required. Chemicals to be injected are preliminarily assumed as follows:

Methanol. Methanol is assumed to be injected only during start-up and planned shutdown of
each well. The wells are assumed not to be started and stopped simultaneously meaning
methanol hoses/tubes in the umbilical can be sized only for the most demanding well. This
chemical is assumed to be delivered through the umbilical to the SDUs, containing subsea
manifolds that will distribute it to the individual wells via the respective HFLs.

Scale Inhibitor. Scale inhibitor is assumed to be injected downhole into each well
simultaneously, on a continuous basis at an appropriate pressure. If the total quantity of
injection points does not allow for individual injection hoses/tubes in the umbilical, subsea
distribution of this chemical inside the SDU will be necessary as per the methanol. In this
case, due to the need for simultaneous injection, each well will need to be equipped with
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remote operated flow regulation valves and flow metering devices to ensure correct injection
rate of this chemical in each individual well.

Low Dose Hydrate Inhibitor (LDHI). The system shall be capable of injecting LDHI
downhole through the scale DHCI system during slow well start-ups until the well tubing
warms up. If the Scale Inhibitor can be distributed to each well by individual injection lines in
the umbilical, injection of the LDHI will be performed via these same lines (with chemical
mixing on the FPSO). The Scale Inhibitor system shall also be capable of handling up to 10
bpd of LDHI. In case this is not possible, the LDHI will need to be injected via an independent
system similar to that of the Scale Inhibitor, down to upstream the flow regulation valves,
where the two chemicals will be mixed.

Wax Inhibitor and Corrosion Inhibitor. Wax and corrosion inhibitors if required will need to
be provided on a continuous basis into the production manifold at each production header.
Each injection point is assumed to have an individual line in the umbilical. Injection pressures
are the flowing tubing pressures at the manifold. Minimum injection hose/tube I.D. for this
combination of chemicals is assumed to be 1/2 inch.
All chemical injection tubes/hoses are assumed to have a minimum of 3/8 inch I.D., and to have
MAWP of 345 bar (5000psi). A common 3/4” Annulus Service Line (ASL) preliminarily rated to 345
bars shall be provided to all production wells serviced through each umbilical. As an alternative the
Annulus Service Line can be foreseen piggy-backed to the production lines.
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2.12 DECOMMISSIONING AND ABANDONMENT
At the completion of the projects life span the wells head, flowlines, FPSO and associated facilities
shall be decommissioned and abandoned in accordance with International Guidelines for
abandonment of oil and gas facilities. A detailed programme of abandonment and
decommissioning shall be issued based on results from drilling and well testing.
As a minimum however, the reservoirs shall be sealed off with cement plugs and mechanical
barriers while the wellhead shall be securely capped. Also, all equipment and debris shall be
removed from the site while warning signs shall be posted to discourage adventurers from
tampering with the capped wellhead structures left at the site.
Wells, production facilities, flowlines and risers, and infrastructures when they have reached the
end of their design life shall be decommissioned and either dismantled and removed, or
abandoned in accordance to statutory requirements. Sites shall be left in a safe and
environmentally acceptable condition.
In the following the preliminary assumptions are described.
FPSO
The process equipment on the FPSO will be cleaned out, purged and certified gas free.
The mooring lines will be removed and the seabed anchoring system will be left in position.
The FPSO will be towed from site for re-use, refurbishment, decommissioning or dismantling.
Flowlines & Risers
The subsea flowlines, risers and umbilicals will be flushed through and possibly removed.
Subsea System
Subsea trees and well-heads shall be abandoned on the sea floor.
Subsea Wells
All permeable zones shall be plugged individually to avoid any cross flow.
Cements plugs shall be set with top and bottom at least 50 meters above and below each zone.
The top of the cement plugs shall be located and verified by mechanical loading.
A cement plug , at least 150 m long, shall be placed with its top 50 m below the seabed.
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2.13 PROPOSED PROJECT CONTINGENCY PLAN
ENI Ghana acknowledges the risks involved in its operations and the benefits to be gained from
developing sound environmental protection practices; to this end, the company has developed a
comprehensive contingency plan covering every aspect of the proposed project. The contingency
plan has been developed from a six-point strategy for environmental protection based on the
following parameters:

Safe working practices.

Preventive measures to contain operational and accidental spills, fire/explosions and
Personnel injuries.

Understanding of the risk.

An effective emergency response organization with sufficient trained personnel and
equipment to deal with the defined threat / hazard.

A training and maintenance program to ensure an efficient response

Co-operation with those who may share the risk and can participate in the response.
The emergency plan clearly identifies the actions necessary in the event of an emergency. These
include communication network, the individual responsibilities of key personnel and the procedures
for reporting to the authorities, and arranging the logistics of extra labour as may be needed.
Details on the plan are presented in Chapter 7 (Environmental Management Plan).
2.14 PROJECT EXECUTION SCHEDULE
The activities listed below as reported in the project schedule, partially overlap in order to limit the
environmental impacts and their total duration. The activities taken into consideration will start in
April 2014 and will end on May 2018 for a total duration of about 4 years.
The expected duration of the production phase is of 20 years.
Table 2.25
Project Schedule
Activity
Duration (months)
Mobilization/Demobilization drilling rig
1
Wells Drilling and completion
40
Flowlines, Risers, Umbilicals installation
22
Mooring/anchoring system installation
2.5
Production activities
Decommissioning/abandonment
20 years
6
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LEGAL REQUIREMENTS AND POLICY FRAMEWORK
This chapter outlines Ghana’s legal and policy framework as well as, international treaties and
industry standards that are applicable to the oil and gas sector, particularly offshore developments.
3.1
NATIONAL LEGISLATION
The environmental law of the Republic of Ghana is embodied in the Environmental Protection
Agency Act 490 passed in 1994. Act 490 prescribes the establishment of the Environmental
Protection Agency (EPA), describes its functions and responsibilities, provides powers for
enforcement and control, establishes a National Environment Fund, and gives provisions for
administration and operations.
The petroleum exploration, development, and production activities fall under the purview of the
Ministry of Energy. Petroleum operations are governed by the Petroleum Law of 1984. A
Production Sharing Agreement (PSA) is the basic contract between the State, the Ghana National
Petroleum Corporation (GNPC), and private companies.
Guidance regarding mitigation of impacts to environmental resources and guidelines for minimizing
environmental impacts of extractive industry activities are provided in the Ghana environmental
laws and regulations.
3.1.1
The Ghanaian Constitution
The 1992 Constitution of the 4th Republic, which came into force on 7th January 1993, is the
fundamental law of Ghana and provides the foundation on which all other laws stand. Within the
directive principles of State policy, the Constitution has a provision on Environmental protection
and management which states in Article 36(9) that:
“The State shall take appropriate measures needed to protect and safeguard the national
environment for posterity; and shall seek co-operation with other states and bodies for purposes of
protecting the wider international environment for mankind”.
This constitutes the basis on which Government initiates policy actions and legislation to promote
sound environmental protection and management. Also Article 41(k) in Chapter 6 of the
constitution of Ghana requires that all citizens (employees and employers) protect and safeguard
the natural environment of the Republic of Ghana and its territorial waters.
3.1.2
Environmental Protection Act
The Environmental Protection Act (Act 490 of 1994) establishes the authority, responsibility,
structure and funding of the EPA. Part I of the Act mandates the EPA with the formulation of
environmental policy, issuing of environmental permits and pollution abatement notices and
prescribing standards and guidelines. The Act defines the requirement for and responsibilities of
the Environmental Protection Inspectors and empowers the EPA to request that an ESIA process
be undertaken. Also the Act establishes and mandates the EPA to seek and request information on
any undertaking that in their opinion can have adverse environmental effects and to instruct the
proponent to take the necessary measures to prevent the adverse effect.
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Environmental Assessment Regulations
The Environmental Assessment Regulations (LI 1652, 1999) is the principal enactment within the
Environmental Protection Act (Act 490 of 1994) and this legislates the EIA process. The LI require
that all activities likely to have an adverse effect on the environment must be subject to
environmental assessment and issuance of a permit before commencement of the activity. The LI
sets out the requirements for the following:






Preliminary Environmental Assessments (PEAs);
Environmental Impact Assessments (EIAs);
Environmental Impact Statement (EIS) (also termed the ESIA Report);
Environmental Management Plans (EMPs);
Environmental Certificates; and
Environmental Permitting.
Schedules 1 and 2 of the Regulations provide lists of activities for which an environmental permit is
required and EIA is mandatory. Section 3 of the Regulation states that no environmental permit
shall be issued for undertakings listed in Schedule 2 unless an E(SH)IA, in terms of these
regulations, has been submitted to the agency.
3.1.4
Environmental Guidelines
The EPA has issued formal guidance on regulatory requirements and the ESIA process. Among
these we find the following documents:





3.1.5
Environmental Assessment in Ghana, a Guide to Environmental Impact Assessment
Procedures (EPA, 1996);
Environmental Quality Guidelines for Ambient Air (EPA);
EPA Guidelines for Environmental Assessment and Management in the Offshore Oil and
Gas Development (EPA, 2010);
Sector Specific Effluent Quality Guidelines for Discharges into Natural Water Bodies (EPA);
General Environmental Quality Standards for Industrial or Facility Effluents, Air Quality and
Noise Levels (EPA).
Petroleum Legislation
Ghana National Petroleum Corporation Act1983, (ACT 64)
The Ghana National Petroleum Corporation Act (Act 64 of 1983) established the Ghana National
Petroleum Corporation (GNPC) as mandated to:





promote exploration and planned development of the petroleum resources of the Republic
of Ghana;
ensure the greatest possible benefits from the development of its petroleum resources;
obtain effective technology transfer relating to petroleum operations;
ensure the training of citizens and the development of national capabilities;
prevent adverse effects on the environment, resources and people of Ghana as a result of
petroleum operations.
Apart from allowing the GNPC to engage in petroleum operations and associated research, the law
empowers the GNPC to advise the Minister of Energy on matters related to petroleum operations.
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The Petroleum (Exploration and Production) Law (Act 84 of 1984)
The Petroleum (Exploration and Production) Law (Act 84, 1984) establishes the legal and fiscal
framework for petroleum exploration and production activities in Ghana. The Act sets out the rights,
duties and responsibilities of contractors; details for petroleum contracts; and compensation
payable to those affected by activities in the petroleum sector. Act 84 gives regulatory authority to
the Ministry of Energy on behalf of the State. All petroleum operations are required to be
conducted in such a manner as to prevent adverse effects on the environment, resources and
people of Ghana. Act 84 requires that a Plan of Development (PoD) for proposed developments be
submitted and approved by the GNPC, The Ministry of Energy and the EPA before development of
the field. In addition, an Environmental, Health, and Safety (EHS) Manual, containing details on
health, safety, and environmental issues, policies and procedures must be submitted to the GNPC
for review before commencement of development activities. The Act further requires that EHS
audits of operations be conducted by the EPA and the GNPC. The Act requires that emergency
plans for handling accidents and incidents are discussed and agreed upon with the GNPC and the
EPA before the commencement of operations.
The Petroleum Commission Act (Act 821 of 2011)
The Petroleum Commission Act establishes the Petroleum Commission for the regulation and the
management of the utilization of petroleum resources and to provide for related purposes. The
Petroleum Commission is also mandated to coordinate the policies in relation to them. The Act
requires that all persons or contractors involved in the petroleum activities shall comply with
decisions, orders or instructions of the Commission made in writing pursuant to its objectives and
functions under this Act and any applicable laws and regulations.
3.1.6
Maritime Legislation
Ghana Maritime Authority (Amendment) Act 2011, (Act 825)
The objective of this amendment was to make specific provision under the Ghana Maritime
Authority Act, 2002 (Act 630) for the Minister to promulgate regulations for the purposes of fixing
specific levies, fees and charges, to cover the administrative costs associated with the discharge of
the functions and duties specified in the Ghana Maritime Authority Act, 2002.
Following the discovery of oil, the GMA was confronted with many new challenges in particular,
developing the necessary policy, administrative, legislative and human capacity to support offshore
oil and gas development.
Ghana Shipping (Amendment) Act, 2011, (Act 826)
The amendment was intended to inject local content into the oil and gas development by
encouraging Ghanaians to participate in the shipping activities relating to offshore business. The
Ghana Shipping Act, 2003 (Act 645) imposed restrictions on the trading of foreign registered ships
in Ghanaian waters by preserving local trade in Ghanaian waters to Ghanaian ships. However, the
current definition of Ghanaian waters is limited to the 12 nautical mile territorial sea.
The main object of this amendment is to extend the definition of Ghanaian waters to include the
waters within the 500 metre safety zone generated automatically under the United Nations
Convention on the Law of the Sea (UNCLOS) around installations in the exclusive economic zone
beyond the territorial sea. This amendment would in effect extend the scope of local trade to
include the trade from shore to the any oil and gas installations that will be established beyond the
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12 nautical miles territorial sea such as the Jubilee field which is approximately 63 nautical miles
offshore.
The amendment also makes provision for the grant of permit to foreign vessels to trade in
Ghanaian waters in instances where there are no Ghanaian vessels available or capable of
providing those services so as not to create operational bottlenecks.
Ghana Maritime Security (Amendment) Act, 2011 (Act 824)
These amendments were intended to extend the application of the Ghana Maritime Security Act to
offshore installations. The amendments will ensure that the requirements of ISPS Code under the
International Convention on the Safety of Life at Sea (SOLAS) Chapter XI-2 dealing with special
measures to enhance maritime security are fully met in Ghanaian law.
Legislative Instruments
The Ghana Maritime Authority (GMA) has put forward for enactment by Parliament of the following
legislative instruments;
•
Ghana Shipping (Protection of Offshore Operations and Assets) Regulations 2011
•
Ghana Maritime Authority (Maritime Safety Fees and Charges) Regulations 2012(L.I. 2009)
•
Marine Pollution Bill
•
Marine Pollution Prevention and Control Regulations
The Maritime Zones (Delimitation) Law (PNDCL 159 of 1986)
The Maritime Zones (Delimitation) Law (PNDCL 159 of 1986) defines the extent of the territorial
sea and Exclusive Economic Zone (EEZ) of Ghana. The territorial sea is defined as those waters
within 12 nautical miles (approximately 24 km) of the low waterline of the sea. The Act defines the
EEZ as the area beyond and adjacent to the territorial sea less than two hundred nautical miles
(approximately 396 km) from the low waterline of the sea. The Act also grants the rights, to the
extent as permitted by international law, to the government of Ghana for the purposes of:
“exploring and exploiting, conserving and managing the natural resources, whether living or nonliving, of the waters superjacent to the sea-bed and of the sea-bed and its subsoil, and with regard
to any other activities for the economic exploration and exploitation of the zone, such as the
production of energy from the water, currents and winds…”
The Fisheries Act (Act 625 of 2002)
The Fisheries Act (Act 625 of 2002) repeals the Fisheries Commission Act (Act 457 of 1993) to
consolidate and amend the law on fisheries. The Act provides for the regulation, management and
development of fisheries and promotes the sustainable exploitation of fishery resources.
Section 93 requires that the Fisheries Commission be informed of any activities likely to have
substantial effect on fishery resources before commencement of the activity and allows the
Fisheries Commission to require reports and recommendations by the proponent on the likely
effect of the activity and possible means of preventing or minimising adverse effects which shall be
taken into account in the planning of the activities. Part 3 states that the requirement under this
section is in addition to any other requirement of the EPA.
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Water Resources Legislation
The Water Resources Commission Act 1996 (Act 522)
The Water Resources Commission Act (Act 522 of 1996) establishes a commission to regulate and
manage the water resources of the Republic of Ghana. The commission is tasked with establishing
comprehensive plans for the use, conservation, protection, development and improvement of
Ghana’s water resources and is able to grant rights for the exploitation of water resources. No
water may be used without the granting of water rights, which may be granted, on application, by
the Commission. The Act lays out the requirements and process for the application and
subsequent transfer of such rights.
3.1.8
Pollution Control
There is currently no single integrated pollution legislation in Ghana. Pollution control exists as part
of the environmental and water resource legislation and marine pollution is dealt with by the Oil in
Navigable Waters Act 1964(Act 235) (see below).
A Marine Pollution Bill is currently in draft stages of the legislative process which, when enacted,
will empower the Ghana Maritime Authority (GMA) to regulate marine pollution. : The Bill aims to
provide a legal framework to prevent and control marine source pollution in general by
consolidating the major International Marine Pollution Conventions developed by the International
maritime Organization (IMO).
Also in legislative process is the Marine Pollution Prevention and Control Regulations. The
objective of the regulations is to provide rules for offshore installations to prevent pollution of the
marine environment by substances used or produced in offshore petroleum exploration and
exploitation
Section 2(f) of the Environmental Protection Act 1994 (Act 490) enables the EPA to issue
pollution abatement notices for: “controlling the volume, types, constituents and effects of waste
discharges, emissions, deposits or other source of pollutants and of substances which are
hazardous or potentially dangerous to the quality of the environment or any segment of the
environment…”. Section 2(h) of the Act allows the EPA to prescribe standards and guidelines
relating to air, water, land and other forms of environmental pollution. Section 2(j) requires the EPA
to co-operate with District Assemblies and other bodies to control pollution.
Oil in Navigable Waters Act 1964 (Act 235) is the law which is mostly concerned with the control
of water pollution. It was enacted in 1964 to give effect to the International Convention for the
Prevention of Pollution of the Sea by Oil (1954) and also addresses oil pollution in inland waters.
Section 1 of the Act seeks to regulate the discharge of oil into prohibited areas of the sea. The Act
extends the prohibition of pollution to the high seas by ships registered in Ghana and requires that
Ghanaian ships be fitted so as to prevent oil fuel leakages or draining of oil into the bilges (unless
the oil in the bilges is not discharged).
3.1.9
Radiation Protection Instrument
The Radiation protection Instrument 1993 (Li 1559) establishes the Radiation Protection Board
which licenses importers and users of radioactive materials and instrumentation. The Board is
responsible for ensuring operations relating to devices that use radioactive materials are carried
out without risk to public health and safety and the installations and facilities are designed,
installed, calibrated and operated in accordance with prescribed standards.
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Protection of Coastal and Marine Areas
Ghana subscribes to a number of international conservation programmes, however, Ghana has at
present no nationally legislated marine protected areas and there are no international protection
programmes specifically covering the oil and gas sector area. On the coastal areas, there exist the
Wetland Management (Ramsar Sites) Regulations 1999 which provides for the establishment and
protection of Ramsar Sites within Ghana. There are five designated Ramsar wetland sites along
the coast of Ghana including:





Anlo-Keta lagoon complex;
Densu delta;
Muni Lagoon;
Sakumo Lagoon;
Songor Lagoon;
and a sixth Ramsar site (Owabi) situated inland. There is none in the western region where the
project is located offshore, although there exist on land an important bird area called the Greater
Amansuri Wetlands.
3.1.11
Labour and other Social Responsibility Laws
The Labour Act (Act no 651 of 2003) consolidates and updates the various pieces of former
legislation, and introduces provisions to reflect International Labour Organisation (ILO)
Conventions ratified by Ghana (see Section 2.4.6). The Labour Act covers all employers and
employees except those in strategic positions such as the armed forces, police service, prisons
service and the security intelligence agencies.
Major provisions of the Labour Act include the following:
















establishment of public and private employment centres;
protection of the employment relationship;
general conditions of employment;
employment of persons with disabilities;
employment of young persons;
employment of women;
fair and unfair termination of employment;
protection of remuneration;
temporary and casual employees;
unions, employers’ organizations and collective agreements;
strikes;
establishment of a National Tripartite Committee;
forced labour;
occupational health and safety;
labour inspection;
establishment of the National Labour Commission.
Part XV of the Labour Act contains provisions relating specifically to occupational health, safety
and environment. These include general health and safety conditions, exposure to imminent
hazards, employer occupational accidents and diseases reporting.
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Children’s Act
The Children’s Act (Act No. 560 of 1998) defines a child as a person below the age of eighteen
years. Sections 12 and 87 prohibit engaging a child in exploitative labour, defined to mean labour
depriving the child of its health, education or development.
Commission on Human Rights and Administrative Justice Act
The Commission on Human Rights and Administrative Justice Act (Act No. 456 of 1993),
establishes a Commission on Human Rights and Administrative Justice to investigate complaints
of violations of fundamental human rights and freedoms, injustice and corruption, abuse of power
and unfair treatment of persons by public officers in the exercise of their duties, with power to seek
remedy in respect of such acts or omissions.
National Vocational Training Act
The National Vocational Training Act (Act No. 351 of 1970) and the National Vocational Training
Regulations (Executive Instrument 15) oblige employers to provide training for their employees for
the attainment of the level of competence required for the performance of their jobs and to
enhance their career.
Labour Provisions of the Shipping Act
The Shipping Act (Act No. 645 of 2003) regulates the engagement and welfare of seafarers, in
particular with respect to crew agreements, wages, occupational safety and health, required
provisions and water on board, protection of seafarers from imposition and relief and repatriation.
Part VII regulates safety of life at sea. The Act applies to Ghanaian ships wherever they may be
and other ships while in a port or place in or within the territorial and other waters of Ghana
(section 480).
3.1.12
The Local Content Policy
The Ghana Local Content and Local Participation Bill 2013 (LI 2204) stipulates that Ghanaian
citizens should be prioritised in terms of employment in the petroleum industry, and should benefit
from the country’s resources. The bill was passed in November 2013. The implementation of this
new law is expected to ensure that Ghana’s natural resources benefit Ghanaians, while the foreign
oil companies also get fair returns on their investment.
The active involvement of Ghanaians in the oil and gas development, through local content and
participation, has become a major policy issue. The production of the oil and gas will contribute to
the socio-economic development of Ghana and indeed bring prosperity to Ghanaians. It is the
desire of the Government and people that the control as well as the benefits from the oil and gas
discovery and production will remain with Ghanaians.
In fact, the bill – Legislative Instrument (LI) 2204 – seeks to “promote the maximisation of valueaddition and job creation through the use of local expertise, goods and services, business and
financing in the petroleum industry value chain and their retention in the country; develop local
capacities in the petroleum industry value chain through education, skills transfer and expertise
development, transfer of technology and know-how and active research and development
programmes; achieve the minimum local employment level and in-country spend for the provision
of the goods and services in the petroleum industry value chain; increase the capability and
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international competitiveness of domestic businesses; and achieve and attain a degree of control
for Ghanaians over development initiatives for local stakeholders”.
The law also requires that a “contractor, sub-contractor, licensee, the corporation or other allied
entity carrying out a petroleum activity shall ensure that local content is a component of the
petroleum activities engaged in by that contractor, sub-contractor and licensee, the corporation or
allied entity”; and that “an indigenous Ghanaian company shall be given first preference in the
grant of a petroleum agreement or a licence with respect to petroleum activities subject to the
fulfilment of the conditions specified in the regulations”.
Another important part of the bill’s requirements is the clause that “there shall be at least a five
percent equity participation of an indigenous Ghanaian company other than the corporation to be
qualified to enter into petroleum agreement or a petroleum licence”.
Ultimately, the Government of Ghana is committed to deploying an effective local content and local
participation policy as the platform for achieving the goals for the oil and gas sector with full local
participation in all aspects of the oil and gas value chain of at least 90% by 2020. The policy
directions are geared to achieve the following;









3.2
Mandatory local content in Oil and Gas
Interest of a citizen of Ghana in petroleum Exploration, Development and Production
Provision of goods and services by national entrepreneurs
Employment and training of citizens of Ghana
Technology transfer
Local capability development
Gender in oil and Gas
Legislation of Local Content, Local Participation and Implementation
Establish Oil and Gas Business development and Local Content Fund.
INTERNATIONAL CONVENTIONS, INDUSTRY BEST PRACTICES AND STANDARDS
3.2.1
International Environmental and Social Performance Standards
This section outlines the most important environmental and performance standards generally
required by financial institutions and which the project will be taken into consideration.
The Equator Principles (EPs) are an approach by financial institutions to determine, assess and
manage environmental and social risk in project financing. The EPs emphasize that lenders will
seek to ensure that the Project is developed in a manner that is socially responsible and reflects
sound environmental management practices. These Principles have been adopted by a wide range
of banks and lenders all over the world in order to manage the social and environmental risks
associated with their potential investments and are listed below.








Principle 1 Categorization of projects
Principle 2 The borrower has to conduct an Environmental and Social Impact Assessment
(EIA)
Principle 3 Applicable Social and Environmental Standards
Principle 4 Action Plan and Management System
Principle 5 Consultation and Disclosure
Principle 6 Grievance Mechanism
Principle 7 Independent Review
Principle 8 Covenants
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Principle 9 Independent Monitoring and Reporting
Principle 10 Equator Principles Financial Institutions (EPFI) Reporting
The Principles, inter alia, require that the borrower conduct and environmental and social impact
assessment of the proposed project, develop an environmental management system including
plans and performance standards, and carry out adequate consultation and public disclosure
during project implementation.
The IFC Performance Sustainability Framework and Performance Standards comprises three
elements:



Policy on Environmental and Social Sustainability;
Performance Standards’ on Environmental and Social Sustainability; and
Access to Information Policy.
The Performance Standards considered relevant to this Project and are outlined below:





Assessment and Management of Social and Environmental Risks and Impacts;
Labor and Working Conditions;
Resource Efficiency and Pollution Prevention;
Community Health, Safety and Security;
Biodiversity Conservation and Sustainable Management of Living Natural Resources.
The IFC’s EHS Guidelines serves as a technical reference document to support the
implementation of the IFC PS particularly those relating to PS3 (Resource Efficiency and Pollution
Prevention), IFC PS 6 (Biodiversity Conservation and Sustainable Management of Living
Resources), as well as certain aspects of Occupation and Community Health and Safety (IFC PS
4). For the ENI Phase 1 development, the relevant EHS guidelines that would apply include;




EHS General Guidelines
EHS Guidelines for Offshore Oil and Gas Development
EHS Guidelines for Shipping
EHS Guidelines for Crude Oil and Petroleum Products Terminals.
The African Development Bank Policies and Guidelines has a number of policies and
guidelines which will apply to this Project, and must be taken into account through the development
of the Project and EIA process. These are:



3.2.2
The Bank Group Policy on the Environment (2004);
Integrated Environmental and Social Impact Assessment (IESIA) Guidelines (2003); and
Bank Group's Handbook on Stakeholder Consultation and Participation (2001).
International Protocols & Conventions
In addition to national policies and laws, there are also statutory provisions with broad
requirements for conservation and protection of certain species and habitats and prevention of
pollution emanating from international conventions and agreements. The Republic of Ghana is a
signatory to a number of international conventions on environmental protection and conservation
(Amlalo 2005), the following are applicable to Eni Ghana’s planned operations:




Ramsar Convention on Wetlands of International Importance, especially Waterfowl Habitats
(Ramsar, Iran), 1971;
Convention on Biological Diversity (CBD), 1992;
United Nations Framework Convention on Climate Change (UNFCCC), 1992;
Vienna Convention for the Protection of the Ozone Layer, 1985.
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The coastal and offshore waters of Ghana are protected from pollution through a range of
international laws:
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International Convention for the Prevention of Pollution from Ships, 1973, as modified by
the Protocol of 1978 relating thereto (MARPOL 73/78);
International Convention Relating to Intervention on the High Seas in Cases of Oil Pollution
Casualties (INTERVENTION), 1969;
International Convention on Civil Liability for Oil Pollution Damage (CLC), 1969;
International Convention on the Establishment of an International Fund for Compensation
for Oil Pollution Damage (FUND) of 1971.
Ghana is now party to the International Convention on Oil Pollution Preparedness, Response, and
Cooperation
(OPRC),
1990
(International
Maritime
Organization
website,
http://www.imo.org/About/Conventions/StatusOfConventions/Pages/Default.aspx).
Ghana is party to the 1982 United Nations Convention on the Law of the Sea (UNCLOS). UNCLOS
sets up a comprehensive legal regime for the sea and oceans and includes rules concerning
environmental standards as well as enforcement provisions dealing with pollution of the marine
environment.
The International Convention for the Prevention of Pollution from Ships, 1973, as modified by the
Protocol of 1978 (MARPOL 73/78) provides regulations aimed at preventing and minimizing
pollution from ships. Table 3.1 summarizes the MARPOL 73/78 regulations applicable to offshore
exploration activities.
Table 3.1
Activities
Environmental Provisions of MARPOL 73/78 Applicable to Offshore Exploration
Environmental Aspect
Machine
ships
space
drainage
from
Garbage
Drainage water
Transfer
wastes
of
oil
contaminated
Bulked chemicals
Dangerous goods
Accidental oil discharge
Sewage discharge
Provisions of MARPOL 73/78
Ship must be proceeding en route, not within a “special area,” and oil
must not exceed 15 ppm (without dilution). Vessel must be equipped
with an oil filtering system, automatic cut off, and an oil retention
system.
Disposal of wastes other than ground food wastes (to the required 25
mm screen mesh) is prohibited
Oil must not exceed 15 ppm without dilution
Oil loading terminals and repair or other ports must have shore
facilities for the reception of oily wastes. Facilities are required to
meet the needs of the ship without causing undue delay.
Prohibits the discharge of noxious liquid substances, pollution hazard
substances, and associated tank washings. Vessels are required to
undergo periodic inspections to ensure compliance. All vessels must
carry a Procedures and Arrangements Manual and Cargo Record
Book
Packaging, storage, marking, and labelling in accordance with
internationally recognized codes
Oil Spill Contingency Plan is required.
Discharge of sewage is permitted only if the ship has approved
sewage treatment facilities, the test result of the facilities are
documented, and the effluent shall not produce visible floating solids
nor cause discoloration of the surrounding water.
Eni Ghana’s proposed activities have the potential to impact adversely, albeit not to a large extent,
on local marine resource users and several sections of the Convention on Biodiversity (CBD) are
relevant, specifically the following articles:
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Art. 8: requires in-situ ecosystem conservation and protection of threatened species or populations,
as well as of customary use and traditional practices of local communities;
Art. 10: obliges states to adopt measures to minimise effects on biological diversity, to protect
customary community practices, and to support local efforts to remedy degradation of biodiversity;
Art. 11: requires creation of economic and social incentives,
Traditional sea tenure and access to marine living resources should receive support under Articles
8(j) and 10(c), which require protection of sustainable customary use of biological resources, and
preservation of traditional knowledge and practices of local communities relating to conservation
and sustainable use. Article 10(d) requires a Party to support local populations to develop and
implement remedial action in degraded areas where biological diversity has been reduced”.
3.2.3
Industry Best Practices, Standards and Guidelines
There are several industry good practices for offshore development. Those relevant to the ENI
Phase 1 development include but not limited to;






3.3
OGP (2007) Environmental, Social Health Risk and Impact Management Process
OGP (1997) Environmental Management in Oil and Gas Exploration and Production
OGP (2010) HSE Management Guidelines for Working Together in a Contact Environment
OGP (1993) Waste Management Guidelines
IPIECA (2010) Alien invasive species and the oil and gas industry
IPIECA (2011) Guidance on Improving Social and Environmental performance: Good
practice Guidelines for the Oil and Gas Industry.
ENI HSE POLICIES AND STANDARDS
Eni has an in-house Environmental, Social and Health Impact Assessment Standard, elaborated in
alignment with the highest international standards on Impact Assessment and Sustainability
Performance.
According to the eni ESHIA Standard Doc N° 1.3.1.47 the ESHIA is an iterative process that is an
integral part of all stages of project design and implementation, from opportunity evaluation through
operations and decommissioning. It helps to ensure that environmental, social and health
considerations become an integral part of planned activities, and it allows these issues to be
addressed in a timely and cost-effective way throughout the individual project’s lifecycle.
The ESHIA process, its phases and relative activities might vary, depending on the requirements of
the host country and the project. Nevertheless, the eni Standard foresees a common structure
including several key steps that can be defined as shown in Figure 3-1.
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Figure 3-1
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eni Standard basic ESHIA phases, activities and related deliverables
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As shown in the previous figure, a key aspect of the process is the “Stakeholder Engagement”.
Stakeholders should be identified, engaged and consulted throughout all the phases of the ESHIA
process. This is an iterative process, involving a wide range of players (statutory and non-statutory)
and will vary depending on the phase and the significance of the potential environmental, social
and health impacts for individual stakeholder groups. Stakeholder engagement will continue till the
decommissioning stage of an operating project.
Many host countries require formal public consultation as part of the ESHIA approval process.
Even if not formally required by law, a stakeholder engagement process, including information
disclosure and consultation with local communities, helps to improve project design and
management and it is therefore highly recommended. For projects potentially affecting sensitive
issues, such as areas of high biodiversity or ecosystem services value, or those requiring
involuntary resettlement or affecting indigenous people or cultural heritage, international standards
recommend the guarantee of effective and appropriate public participation during the ESHIA and
project development processes.
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BIOPHYSICAL BASELINE
The present chapter provides a description of the current environmental and social baseline. It
underlines the main environmental and social-economic aspects related and influenced by the
project activities.
4.1
GEOPHYSICAL AND ENVIRONMENTAL SURVEY
The environmental baseline survey was conducted along the intrafield flowlines of the proposed
OCTP offshore site of Sanzule, Ghana. The survey was conducted to determine the physicochemical and biological status of the seabed and water column prior to development.
Geophysical Survey
The survey (Phase 1) comprised acquisition of a suite of geophysical data via an AUV
(Autonomous Underwater Vehicle) to provide regional acoustic characterization of seabed and
sub-seabed conditions to inform the selection of infield pipe routes. Analysis of AUV data was
supported by a range of reference information, largely supplied by ENI, and a limited amount of
geological and geotechnical data. The survey area comprised an irregular 29 km by 23 km study
area, covering 630 km2, ranging in depth from 82 m (to the north) to 1390 m (to the south-west).
In the paragraph 4.4 the results will be explained as Bathymetry, Seabed features in continental
shelf and slope, seabed feature as manmade features, seabed sediments and shallow geology of
continental shelf and slope.
Environmental Survey
The environmental survey comprised acquisition of seabed grab samples, water column profiles
and water column samples. Sampling stations largely coincided with geotechnical survey locations.
The total number of stations was pre-determined as 13 (12 for sediment sampling, three for water
sampling). Stations were located along the flowline corridors with equal spacing for site coverage.
The locations of all sampling stations are presented in Table 4.1 and shown spatially in Figure 4-1.
Environmental Sampling Locations
Benthic samples were obtained using a 0.1 m2 dual van Veen grab at 12 stations. Three samples
were collected at each station, two for macrofaunal analysis (FA and FB) and one sub-sampled for
physico-chemical analysis (PC). Water sampling (WS) and profiling (WP) was undertaken at three
stations, including two of the 12 stations sampled for macrofauna / PC, as well as at an additional
station. Water samples were collected at three depths; the first at 1 m, the second at 100 m and
the third at 200 m. Sampling locations are provided in Table 4.1. Locations are shown spatially in
Figure 4-1.
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Table 4.1
Environmental sampling Locations (FA/FB = Fauna sample A or B. PC = Physicochemical sample. W/S= Water sample. W/P = Water profile. Zoo = vertical zooplankton tow)
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Figure 4-1
Seabed bathymetry showing environmental sampling locations
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The following paragraphs will explain the results of environmental survey carried out between 24
and 27 April 2013 by Fugro.
The results data for each environmental component will be compare, where possible, to the nearby
EBS survey carried out by TDI-Brooks International in 2008 (TDI Brooks, 2008). This data is
summarized in the Environmental Impact Assessment (EIA) for the Jubilee Field, prepared by
Environmental Resources Management (ERM) and Tullow Ghana Limited (ERM, 2009).
Results from this survey will be referenced throughout the report as TDI Brooks (2008).
Furthermore secondary baseline analysis data will also be compared, where possible, to
Environmental Baseline results summarized in the Environmental Impact Assessment (EIA) for the
Jubilee Field, prepared by Environmental Resources Management (ERM) and Tullow Ghana
Limited (ERM, 2009).
In particular considering sediment and water results of the current survey, they will be compare,
where possible, to the results from the Phase 2 and 4 study although differences in water depths
are considered when drawing comparisons (Table 4.3 and Figure 4-3). In addition, comparisons
will also made with data from a previous environmental survey carried out in 2009 as part of the
EAF Nansen project (a joint effort between the Ghana Environmental Protection Agency (EPA),
University of Ghana, University of Cape Coast, Survey Department, Marine Fisheries Research
Division and Tullow Oil) (EAF Nansen, 2010).
Results from this survey will be referenced throughout the report as EAF Nansen (2010).
Sampling stations in the EAF Nansen (2010) survey ranged from 28 m to 1300 m, however only
data from stations at similar depths to those surveyed in the current survey, i.e. 250 m to 1300 m,
were used for comparative purposes. This included data from the following EAF Nansen survey
stations: GE4, GE5, GE6, GW4, GW5, GW6, GP4, GP5, J7-1, J7-2, J7-3 and J7-4 (Figure 4-4Table 4.4). Analytical methodologies between this previous survey and the current survey were
assessed and generally were thought to be comparable.
Considering benthic data results reported in TDI Brooks (2008), only benthic stations in water
depths ranging from 942.5 m to 1264.3 m at the Jubilee Field have been selected for benthic
comparative purposes (Stations EBS001, EBS002, EBS004, EBS006 and EBS007) (Figure 4-2Table 4.2).
In general the discussion will be organized considering each environmental component and for
each one the comparison among secondary and primary data.
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Figure 4-2
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TDI Brooks (2008) - Map of Sampling Locations
Table 4.2
TDI Brooks (2008) - Location and depth of EIA stations (SS=sediment sample,
SWS=surface water sample, BWS=bottom water sample, SSR=sediment sample re-take. Blue cells
were sites not successfully sampled)
Locations
Date
Time
Lat.
Long.
Depth (m)
EBS:T3
09/09/2008
08:54:34
N04 55.9778
W001 38.3939
16.6
EBS:T3_CTD
09/09/2008
09:22:28
N04 55.9825
W001 38.3912
17.3
EBS:T3 ALT_SS
09/09/2008
10:04:41
N04 52.6817
W001 36.8161
28.1
EBS:T2_SS
09/09/2008
11:19:42
N04 47.6608
W001 42.5213
33.3
EBS:T2_CTD
09/09/2008
11:33:02
N04 47.6612
W001 42.5264
34.4
EBS:T1_CTD
09/09/2008
18:51:36
N04 40.5986
W002 31.3688
73.6
EBS:T1_SS
09/09/2008
18:57:59
N04 40.5979
W002 31.3806
73.3
Jub_EBS006_SS
09/09/2008
23:05:02
N04 35.0791
W002 49.7665
942.5
Jub_EBS006_CTD
09/10/2008
00:20:51
N04 35.0795
W002 49.77
947.5
Jub_EBS007_SS
09/10/2008
01:36:19
N04 32.1627
W002 51.329
1180
Jub_EBS007_CTD
09/10/2008
01:36:55
N04 32.1621
W002 51.3283
1180
Jub_EBS007_SSR
09/10/2008
07:28:48
N04 32.1616
W002 51.3295
1180
Jub_EBS009_CTD
09/10/2008
09:25:36
N04 27.4913
W002 55.6064
1741.7
Jub_EBS009_SS
09/10/2008
09:33:42
N04 27.4861
W002 55.6122
1745.8
Jub_EBS009_SSR
09/10/2008
10:41:07
N04 27.4902
W002 55.6085
1766.7
Jub_EBS008_CTD
09/10/2008
12:18:45
N04 30.794
W002 55.1232
1441.7
Jub_EBS008_SS
09/10/2008
12:19:07
N04 30.7939
W002 55.1238
1441.7
Jub_EBS005_SS
09/10/2008
13:40:55
N04 33.2307
W002 54.1438
1341.7
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Locations
Date
Time
Lat.
Long.
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Depth (m)
Jub_EBS005_CTD
09/10/2008
13:41:11
N04 33.2303
W002 54.1463
1341.7
Jub_EBS005_SSR
09/10/2008
14:17:50
N04 33.2375
W002 54.1485
1345.8
Jub_EBS004_CTD
09/10/2008
15:32:48
N04 35.5703
W002 53.276
985.7
Jub_EBS004_SS
09/10/2008
15:33:08
N04 35.5699
W002 53.2754
985.7
Jub_EBS002_CTD
09/10/2008
16:44:46
N04 35.9511
W002 56.094
992.9
Jub_EBS002_SS
09/10/2008
16:45:10
N04 35.9526
W002 56.096
996.4
Jub_EBS003_CTD
09/10/2008
17:59:21
N04 32.6502
W002 57.2635
1382.1
Jub_EBS003_SS
09/10/2008
17:59:50
N04 32.6484
W002 57.2649
1378.6
Jub_EBS003_SSR
09/10/2008
18:45:29
N04 32.6479
W002 57.2523
1385.7
Jub_EBS001_SS
09/10/2008
20:11:04
N04 35.7645
W003 0.1693
1264.3
Jub_EBS001_CTD
09/10/2008
20:11:17
N04 35.7623
W003 0.1697
1267.8
EBS:E1_SS
09/11/2008
06:48:48
N04 48.6119
W002 54.1051
74.5
EBS:E1_CTD
09/11/2008
07:14:55
N04 48.6048
W002 54.0901
75
EBS:E2_CTD
09/11/2008
08:00:50
N04 52.7208
W002 56.1984
64
EBS:E2_SS
09/11/2008
08:08:57
N04 52.7146
W002 56.2021
64.5
EBS:E3 ALT_SS
09/09/2008
09:15:20
N04 59.1209
W002 59.477
40
EBS:E3ALT_CTD
09/09/2008
09:44:24
N04 59.121
W002 59.4679
40
EBS:E3ALT_BWS
09/09/2008
12:49:04
N04 59.127
W002 59.4796
41.5
EBS:E3ALT_SWS
09/09/2008
12:49:31
N04 59.1264
W002 59.4778
41
EBS:E2_SWS
09/11/2008
13:51:49
N04 52.7187
W002 56.2057
65
EBS:E2_BWS
09/11/2008
13:52:30
N04 52.7186
W002 56.2068
64.7
EBS:E1_BWS
09/11/2008
15:03:43
N04 48.6058
W002 54.1054
74.7
Jub_EBS001_BWS
09/11/2008
17:25:30
N04 35.7604
W003 0.177
1264.3
Jub_EBS003_BWS
09/12/2008
08:42:27
N04 32.6422
W002 57.2571
1385.7
Jub_EBS003_SWS
09/12/2008
08:43:09
N04 32.6418
W002 57.2586
1385.7
Jub_EBS002_BWS
09/12/2008
09:40:13
N04 35.9558
W002 56.0827
992.9
Jub_EBS002_SWS
09/12/2008
09:40:33
N04 35.9534
W002 56.0837
996.4
Jub_EBS004_BWS
09/12/2008
10:33:41
N04 35.5656
W002 53.2608
985.7
Jub_EBS004_SWS
09/12/2008
10:33:52
N04 35.5652
W002 53.2631
985.7
Jub_EBS005_SWS
09/12/2008
11:11:56
N04 33.2326
W002 54.1396
1346.4
Jub_EBS005_BWS
09/12/2008
11:27:21
N04 33.2357
W002 54.1425
1346.4
Jub_EBS008_SWS
09/12/2008
12:14:41
N04 30.7959
W002 55.1206
1435.7
Jub_EBS008_BWS
09/12/2008
12:24:44
N04 30.7965
W002 55.1183
1435.7
Jub_EBS009_SWS
09/12/2008
13:07:22
N04 27.5013
W002 55.6101
517.8
Jub_EBS009_BWS
09/12/2008
13:15:17
N04 27.4933
W002 55.6082
92.9
Jub_EBS007_SWS
09/12/2008
14:10:38
N04 32.1587
W002 51.3165
521.4
Jub_EBS007_BWS
09/12/2008
14:19:54
N04 32.156
W002 51.3265
1178.6
Jub_EBS006_SWS
09/12/2008
14:57:03
N04 35.0784
W002 49.7678
942.9
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Locations
Date
Time
Lat.
Long.
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Depth (m)
Jub_EBS006_BWS
09/12/2008
15:09:02
N04 35.0769
W002 49.7658
942.9
EBS:E3 R_BWS
09/12/2008
20:37:10
N04 55.0104
W002 57.3632
50
EBS:E3 R_SS
09/12/2008
22:08:07
N04 55.0121
W002 57.3743
50
EBS:E3 R_SWS
09/12/2008
22:25:17
N04 55.0046
W002 57.381
50
EBS:E3 R_CTD
09/12/2008
22:51:45
N04 55.022
W002 57.3748
50
EBS:T1_BWS
9/13/2008
06:35:59
N04 40.5954
W002 31.3866
73.3
EBS:T1_SWS
9/13/2008
06:42:46
N04 40.5964
W002 31.3789
73.3
EBS:T6_SWS
9/13/2008
10:48:16
N04 38.6372
W002 5.0963
52.5
EBS:T6_BWS
9/13/2008
10:53:11
N04 38.6428
W002 5.0989
53.1
EBS:T6_CTD
9/13/2008
11:12:55
N04 38.6369
W002 5.103
53.1
EBS:T6_SS
9/13/2008
11:23:01
N04 38.6367
W002 5.1029
51.9
EBS:T6_SSR
9/13/2008
11:53:23
N04 38.6394
W002 5.1046
52.5
EBS:T5_SWS
9/13/2008
13:23:36
N04 40.4249
W001 58.8556
45
EBS:T5_BWS
9/13/2008
13:32:23
N04 40.4351
W001 58.8604
45
EBS:T5_CTD
9/13/2008
13:46:10
N04 40.4357
W001 58.8554
44.7
EBS:T5_SS
9/13/2008
13:52:42
N04 40.4334
W001 58.8589
45.3
EBS:T4_SWS
9/13/2008
16:08:51
N04 43.0769
W001 52.8862
38.9
EBS:T4_BWS
9/13/2008
16:11:08
N04 43.0778
W001 52.889
38.9
EBS:T4_CTD
9/13/2008
16:23:38
N04 43.0776
W001 52.887
38.7
EBS:T4_SS
9/13/2008
16:32:05
N04 43.0827
W001 52.8965
39.4
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Table 4.3
Environmental Sampling Locations (PHASE 2 & 4 SURVEY) (FA/FB = Fauna sample A
or B. PC = Physico-chemical sample. W/S= Water sample. W/P = Water profile. Zoo = vertical
zooplankton tow)
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Figure 4-3
SURVEY)
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Seabed bathymetry showing environmental sampling locations (PHASE 2 & 4
Eni S.p.A.
Figure 4-4
EAF Nansen (2010) - Map showing the investigated sites
Table 4.4
EAF Nansen (2010) - Information about sampling sites
4.2
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CLIMATE AND METEOROLOGY
Tullow considered the Noble-Denton (2008) meteocean report and Ghana meteorological
recording stations placed in Takoradi and Axim in the western coast to characterize climate and
weather of the Jubilee field. The eia team considers as primary data the Metocean design basis
350300FORB00010 (2012) developed by Saipem S.p.A.
Considering the meteorological and climatic characterization, our primary data confirm the results
and the remarks highlighted in the Environmental Baseline Survey explained in GHANA JUBILEE
FIELD PHASE 1 DEVELOPMENT.
The regional climate in the Gulf of Guinea is influenced by two air masses, one over the Sahara
desert (tropical continental) and the other over the Atlantic Ocean (maritime). These two air
masses meet at the Inter-Tropical Convergence Zone (ITCZ) and the characteristics of weather
and climate in the region are influenced by the seasonal north-south migration of the ITCZ.
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The maritime (humid) air mass originating from the Atlantic Ocean is associated with the southwestern winds. This air mass is commonly referred to as the southwest monsoon; the continental
(dry) air mass originating from the African continent is associated with the north-eastern Harmattan
winds (trade winds). The ITCZ reaches its northernmost extent during the northern hemisphere
summer and its southernmost extent during the northern hemisphere winter.
Considering temperature and rainfall data, Tullow considered data recorded by Ghana
meteorological recording stations located in Takoradi and Axim covering the period 1999-2008,
while our primary source (Metocean design basis) collect and elaborate data taken from African
Pilot (Africa Pilot. Volume I Admiralty Charts and Publications, 1982) that cover the period 19311960 and taken from Russia’s Weather Server of Abidjan station covering the period 2001-2011.
4.2.1
Rainfall
Considering rainfall throughout the year, both group of data show a bimodal pattern that means
two peaks of precipitation respectively in May-June and September-October. The trend of average
monthly rainfall in Takoradi considering data collected from 1999 to 2008 (Tullow - Ghana
meteorological recording station Figure 4-5) and the other that cover the period 1931-1960
(Saipem- Metocean design basis Figure 4-6) are similar with difference for the peaks value.
Figure 4-5
Takoradi average rainfall (Tullow - Ghana meteorological recording station)
Eni S.p.A.
Figure 4-6
4.2.2
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Monthly cycle of precipitation at Takoradi (Saipem- Metocean design basis)
Temperature
Considering temperature the data recorded by Ghana meteorological recording stations located in
Takoradi (Tullow), show high value (comprised between 27-28 °C) from February to May and from
November to December with an annual average range between 24°C-30°C. The coolest period is
usually in August (Figure 4-7). According to African Pilot (1931-1960) (Saipem- Metocean design
basis) the monthly average air temperature range from 22°C-30 °C, the coolest periods are in
August and December/January while the highest ones are from February to April Figure 4-8 and
Table 4.5)
Figure 4-7
Takoradi average temperature (Tullow - Ghana meteorological recording station)
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Figure 4-8
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Monthly cycle of temperatures at Takoradi (Saipem- Metocean design basis)
Table 4.5
Monthly cycle of mean daily maximum temperature, mean highest temperature, mean
daily minimum temperature and mean lowest temperature (°C) at Takoradi (Saipem- Metocean design
basis)
4.2.3
Relative Humidity
Regarding the relative humidity, the data recorded by Ghana meteorological recording stations
located in Takoradi and Axim (Tullow) show that morning values range from 89.7 percent to 93.7
percent and 94.0 percent to 96.6 percent for Axim and Takoradi respectively. Humidity shows an
inverse relationship with temperature (Figure 4-9).
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Figure 4-9
Takoradi and Axim Humidity versus Temperature (Tullow - Ghana meteorological
recording station)
Data taken from Russia’s Weather Server of Abidjan station covering the period 2001-2011, show
a similar trend even if the values are generally higher (Figure 4-10 and Table 4.6).
Figure 4-10
Monthly cycles of mean, maximum and minimum relative humidity at Abidjan
(Saipem- Metocean design basis)
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Table 4.6
Monthly cycle of mean, maximum and minimum of monthly mean relative humidity (%)
at Abidjan (Saipem- Metocean design basis)
4.2.4
Barometric pressure at MSL
The barometric pressure at mean sea level ranges from 1008 to 1016 (Russia’s Weather Server of
Abidjan station covering the period 2001-2011) as shown in Figure 4-11 and Table 4.7.
Figure 4-11
Monthly cycle of the air pressure at Mean Sea Level at Abidjan (Saipem- Metocean
design basis)
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Table 4.7
Monthly cycle of mean, maximum and minimum of monthly air pressure at MSL (hPa)
at Abidjan (Saipem- Metocean design basis)
4.2.5
Wind
Data on wind speed and direction are presented in par. Error! Reference source not found..
4.3
4.3.1
MARINE ENVIRONMENT (OCEANOGRAPHY)
Currents
Water masses offshore the Ghanaian coast consist of five principal layers (Longhurst, 1962). The
topmost layer is the Tropical Surface Water (TSW), warm and of variable salinity which extends
down to a maximum of about 45 m depending on the seasonal position of the thermocline. Below
the thermocline (which varies from 5 to 35 m) occurs the South Atlantic Central Water (SACW, cool
and high salinity) down to a depth of about 700 m. Below this are consecutively, three cold layers,
namely the Antarctic Deep Water (ADP, 700-1,500 m), the North Atlantic Deep Water (NADP,
1,500-3,500 m) and the Antarctic Bottom Water (ABW, 3,500-3,800). Sea surface temperature
typically vary between 27 and 29°C, although strong seasonal cooling occurs during the season
related to coastal upwelling processes.
The principal current along the Ghana coastline is the Guinea Current which is driven by westward
wind stress. When this subsides during February to April and October to November, the direction
of the current is reversed. A small westward flowing counter current lies beneath the Guinea
Current. Below 40 m depth the westward flowing counter current turns to the south-west with
velocities ranging between 0.5 m/s to 1.0 m/s and 0.05 m/s to 1.02 m/s near the bottom. The cold
subsurface water could be a branch of the Benguela Current that penetrates and dominates the
Equatorial Counter Current.
The Guinea Current reaches a maximum strength between May and July during the strongest
South-West Monsoon Winds. For the rest and greater part of the year, the current is weaker. Near
the coast, the strength of the current is attenuated by locally generated currents and winds. The
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current is less persistent near-shore than farther offshore. Geotropic effects induce the tendency of
the Guinea Current to drift away from the coast especially during its maximum strength.
The coastal surface currents are predominantly wind-driven and are confined to a layer of 10 to 40
m thickness. The direction of tidal current around the coast of Ghana is mostly north or north-east.
The velocity of the tidal current is generally less than 0.1 m/s and the maximum velocity of tidal
current observed in a day of strong winds is about 0.5 m/s. The wave induced longshore currents
are generally in the west to east direction which is an indication of the direction the waves impinge
the shoreline. The longshore currents average approximately 1 m/s and vary between 0.5 and 1.5
m/s. The magnitude increases during rough sea conditions.
As described in Metocean design basis 350300FORB00010 (2012), the data used to estimate the
total current speed climate and extremes for the Ghana area are the 5-year, 3-hour hindcasted
data provided by SAT-OCEAN.
For each point the omnidirectional and directional distribution of current at bottom (points
1,2,5,6,7,8) and for each water depth (points 3,4) are shown to define the directional distribution of
current speed (Figure 4-12 and Table 4.8). The currents affecting the area are the large scale
currents, such as surface and subsurface currents, the tidal current and the local currents. The
large scale currents have almost constant patterns while local currents can be highly variable. The
discussion below will take into consideration only the first six points as part of the offshore area.
Figure 4-12
Locations of current points from SAT-OCEAN
Table 4.8
Locations of current points from SAT-OCEAN
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Point 1 (about 1000 m depth) and Point 2 (about 750 m depth), representative of offshore fields,
revealed that at the bottom prevalent directions are going to SE and NW, related to the presence of
the westward Guinea Undercurrent (the NW component) and reflecting the complex dynamics
characterizing the area (e.g. upwelling phenomena, the eastward North Intermediate Current).
Point 3, representative of floater location, was analyzed at different depth (surface, 20m b.s.l., 50m
b.s.l., 100m b.s.l., 200m b.s.l. and 400m b.s.l.). At surface prevalent directions are going to E-SE
reflecting the large scale Guinea current present about until 50m b.s.l. which dominate also on tidal
components. Surface current displays also other directions confirming the presence of local
phenomena. From 50m b.s.l. to the bottom prevalent directions are from SE and NW, related to the
presence of the west-ward Guinea Undercurrent (the NW component) and the complex dynamics
characterizing the area (e.g. upwelling phenomena, the North Intermedite Countercurrent).
Point 4 was analyzed to study directional distribution of current speed at the bottom (about 200 m
depth). The analysis shows that prevalent directions are going to SE and NW, related to the
presence of the westward Guinea Undercurrent (the NW component) and reflecting the complex
dynamics characterizing the area (e.g. upwelling phenomena, the eastward North Intermediate
Current).
Point 5, representative of the platform location, was analyzed at different depth (20m b.s.l., 50m
b.s.l. and 100m b.s.l.). The results of the analysis show the same characteristics reported in Point
3 that are: surface prevalent directions going to E-SE present about until 50m b.s.l. and from 50m
b.s.l. to the bottom prevalent directions are from SE and NW.
Point 6 was analyzed to study directional distribution of current speed at the bottom (about 75 m
depth). The analysis shows that at the bottom prevalent directions are going to SE, related to the
presence of the eastward Guinea Current.
4.3.2
Wind
The surface atmospheric circulation in the region is influenced by north and south trade winds and
the position of ITCZ.
According to the wind characterization of jubilee field area (GHANA JUBILEE FIELD PHASE 1
DEVELOPMENT – Environmental Impact Statement realized by Tullow Oil), achieved using
hindcast models and data from 3 locations in the vicinity of field, the predominant wind direction is
south-western with average speed of 3.7-4.0 m/s and maximum of 8.8-10.8 m/s.
Metocean design basis 350300FORB00010 (2012) considers WANE database that provides time
series of wind parameters, covering the period 1985-1999 with a spatial resolution of 0.3125 deg
lat by 0.625 deg long and used West Africa Gust (WAG) joint industry project – Phase 1. Fugro
GEOS Reference No: C56110/3219/R1. December 2004 to study parameters relative to the squall.
The results about the annual directional distribution and the omnidirectional monthly distribution of
the wind speed and the wind direction are in accordance with the studies achieved by Tullow Oil.
(Figure 4-13).
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Figure 4-13
4.3.3
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Polar diagram of the directional distribution (%) of the wind speed
Squall
According to the Metocean design basis 350300FORB00010 (2012) there are two squall seasons
which correspond with the migration of the ITCZ; one season when the ITCZ migrates to the North
(June – November) and the second when the ITCZ migrates to the South (December – May).
Squall events produce the strongest winds in the area, but generate only weak currents and low
wave heights due to the limited fetch and duration. These remarks are done considering results
from JIP WAG (West Africa Gust (WAG) joint industry project – Phase 1. Fugro GEOS Reference
No: C56110/3219/R1. December 2004) for the Nigerian off-shore. This dataset is the most reliable
in the area and the results of the analysis are considered applicable also for Ghana off-shore due
to the latitude and climatological similarity.
4.3.4
Wave
According to the wave climate characterization of jubilee field area (GHANA JUBILEE FIELD
PHASE 1 DEVELOPMENT – Environmental Impact Statement realized by Tullow Oil), waves
reaching the shores of Ghana consist of swells originating from the oceanic area around the
Antarctica Continent and seas generated by locally occurring winds. The significant height of the
waves generally lies between 0.9 m and 1.4 m. The most common amplitude of waves in the
region is 1.0 m but annual significant swells could reach 3.3 m in some instances. Swells attaining
heights of approximately five to six meters occur infrequently with a 10 to 20 year periodicity. The
swell wave direction is almost always from the south or south-west. Other observations on the
wave climate include a long swell of distant origin with wavelengths varying between 160 and 220
m. This swell has averaged height between 1 to 2 m and generally travel from southwest to northeast.
Metocean design basis 350300FORB00010 (2012) used the 15-years, 3-hourly hindcasted data of
the WANE project performed by Oceanweather, to estimate the sea state climate and extremes for
the Ghana off-shore area.
Point with coordinates Lat. 4.375° N and 2.5° W (point 1 – 1000 m depth) has been selected as
representative of wave conditions at Sankofa and Gye Nyame fields (Figure 4-14).
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Figure 4-14
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The Locations of wave points
The analysis of data put in evidence that waves in Ghana off-shores are prevalently swell waves
being the wind sea component generally much smaller than swell component and that the most
relevant waves are generally from S and SE and the sea wave from S and SW (Figure 4-15, Figure
4-16, Figure 4-17)
Figure 4-15
Polar diagram of the directional distribution (%) of the significant total sea wave
height: the highest waves come from S
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Figure 4-16
Polar diagram of the directional distribution (%) of the significant swell wave height:
the highest waves come from S.
Figure 4-17
Polar diagram of the directional distribution (%) of the significant wind sea wave
height: the highest waves come from SW
4.3.5
Tides
Tides considerations reported on Metocean design basis 350300FORB00010 (2012) for the
Sankofa and Gye Nyame field area, are based on the output of the Global Inverse Tide model
TPXO6.2 (Egbert, G.D., et al 2002). The model outputs come from the elaboration and extraction
of 18.6 years of tidal elevation data. The table below (Table 4.9) shows the results:
Table 4.9
Tidal level elevations (m)
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4.4
4.4.1
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BATHYMETRY, SEABED TOPOGRAPHY
Bathymetry
The bathymetry of the survey area is characterized by water depths that range from a minimum of
82 m in the north to a maximum of 1390 m in the south-west part.
The northern parts of the survey area, to a depth of about 125 m, consists of a very gently dipping
(0.5°) shelf. The width of the shelf surveyed varies from 6 km in the west to 3 km in the east.
Gradients increase at the shelf break reaching a maximum of about 10° (west) to 7° (east) in water
depths of between 175 m and 300 m. In the deeper waters beyond the 300 m contour, the seabed
gradients are moderate to an average of around 2°.
Superimposed on this surface are a profusion of topographic features, including complex canyon
systems, sedimentary mounds, scour features and high standing knolls. Seabed dips reach values
in excess of 40° on the flanks of some of these features and exceed 14° over large areas (Figure
4-18)
Figure 4-18
4.4.2
Bathymetry from AUV Missions
Seabed morphology
The seabed features interpretation is based on an assessment of bathymetry, seabed backscatter
and seabed gradient.
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Continental Shelf
The Ghanaian continental shelf extends over the northern extremes of the survey area in water
depths of between 82 m and approximately 125 m. The shelf is generally very gently dipping at a
gradient of about 0.5°. Although flat, the shelf is far from smooth. In water depths of less than 115
m strike trending outcrops create a rough texture (Figure 4-19). These outcrops appear to be
emergent ridges at the top of a truncated Tertiary progradational wedge and generally have about
5 m of relief and flanks dipping at up to 17° (Figure 4-20). The most significant breech in these
outcrops is aligned with the largest canyon on the slope, in the western parts of the study area.
Figure 4-19
Shaded relief image of seabed, outcrops on shelf (5.0 km x 7.2 km area)
Figure 4-20
Line 083_2 profiler data, shelf showing outcrops
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This may indicate that this canyon was fed by a cross slope channel during geologically recent low
stand conditions. This interpretation is speculative as the limited profiler penetration on the shelf
means that the sub-seabed expression of the breech cannot be directly imaged.
In many areas the outcrops define steps in the shelf profile, perhaps partly by the damming effect
the outcrops have on the most recent sand deposits of the shelf and partly a greater resistance to
erosion in the older packages further north (Figure 4-20).
Preliminary vibrocore logs indicate that these outcrops probably consist of CALCARENITE.
In greater detail the seabed of the shelf is very largely covered by circular seabed depressions of
two distinct size classes. Figure 4-21 shows an absolutely typical portion of the shelf.
Figure 4-21
Images of seabed on shelf, two classes of seabed depressions (800 m x 1150 m area,
shaded relief image above side scan sonar mosaic below)
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The entire seafloor is covered by very small closely spaced pits up to 5 m in diameter to a water
depth of about 275 m. These pits are so closely spaced that they are impossible to avoid; the
affected areas are saturated with small depressions. These small pits are probably best considered
as a seabed texture. The bases of these small pits are approximately 0.1 m to 0.2 m below the
surrounding seafloor.
A class of larger depressions is generally located on and around the areas of outcrop, these
features measure about 15 m to 30 m in diameter and up to 1 m deep. These larger depressions
are less widespread and occur in belts and patches of lower density. The larger depressions are
avoidable.
There is no direct evidence for any of these seabed depressions being caused by gas or fluid
release. Depressions associated with gas release often show great irregularity and patterns of
clustering. It is also difficult to envisage fluid release depressions forming two distinct size classes.
The depressions could be a result of bottom current action combined with very low levels of
sediment input. The shallow waters of the shelf are within the photic zone; biological activity could
be playing a part in the development or maintenance of these depressions.
Continental Slope-Seabed Scour
Immediately south of the shelf seabed dips increase to between 7° (east) and 10° (west)
moderating in water depths beyond 325 m to an average of about 2° to the south-west.
In general the seabed of the slope is smooth, though there are several areas affected by scour.
Six patches of scour are located over the apex of inter-canyon banks. These areas extend to a
water depth of about 500 m and have well defined edges. Currents appear to have eroded the
surficial sediment off the crests of these high standing areas to a depth of about 1 m (Figure 4-22
and Figure 4-23).
Figure 4-22
Shaded relief image of seabed, seabed scour (1.5 km x 2.5 km area)
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The three easternmost patches coalesce into a single belt of scoured seabed which extends up dip
to a water depth of about 325 m. These areas of scour do have a texture that contrasts with the
unaffected seabed. Figure 4-22 shows that the seabed within the scoured area is rougher; Figure
4-23 shows that this surface roughness does reduce the sub-seabed penetration of profiler data.
Figure 4-23
Line 009_1 profiler data, seabed scour
The most extreme area of scour is located in the west of the area affecting an 11 km wide swathe
of the upper slope in water depths between 130 m and 250 m (Figure 4-24). Preliminary
interpretation concluded that this seabed texture was a result of sediment creep. This interpretation
has changed due to the fact that the features are entirely negative in their expression and large in
scale; the base of these features is up to 10 m below the surrounding seabed. The area also lacks
the regularity which can be associated with creep.
Figure 4-24
Shaded relief image of seabed, seabed scour (2.0 km x 3.7 km area)
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Continental Slope-Sediment Failures
Figure 4-25 shows an area of very shallow seated (approximately 1 m thickness) sediment failure
which has been interpreted over western parts of the upper slope. This failure occurred in water
depths of between 115 m and 140 m.
Figure 4-25
Shaded relief image of seabed, seabed failure (1.6 km x 2.8 km area)
The thickness of this zone of failure appears broadly consistent with the depth of the scour over the
inter-canyon banks (as seen in Figure 4-22, Figure 4-23 and Figure 4-25).
There is evidence for a much larger ancient slope failure at the limit of profiler data interpretation
on the slope.
It can be stated that wherever a significant thickness of relatively recent sediment is present at a
dipping seabed then slope failure is at least possible.
Continental Slope-Canyons
Two large scale canyons trend to the south-west in the western parts of the study area.
The canyon to the far west forms a crude Y shape; three proximal branches, which have their
origin in water depths of 350 m, converge at a water depth of about 825 m. This canyon has up to
approximately 100 m of relief with flanks that commonly dip in excess of 16° and up to 25° on parts
of the western flank. In water depths beyond 975 m the canyon floor becomes very broad, fanning
out into a 4 km wide low lying area of mounded deposits (Figure 4-26).
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Figure 4-26
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Shaded relief image of seabed, western canyons (13.9 km x 20.0 km area)
The area’s largest canyon is positioned 5 km east of the canyon described above. The up dip limit
of this canyon occurs at a water depth of 475 m. Up dip of this point a symmetrical arcuate chute
feeds into the head of the canyon. This chute resides in water depths between 475 m and 250 m
and is about 4 km wide. The chute contains numerous dip-orientated gullies.
The gullies are 100 m to 200 m apart and 1 m to 2 m deep. Detail examination shows that the
gullies are cut into a surface which is now covered by 1.5 m of drape (Figure 4-27 and Figure
4-28).
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Figure 4-27
Shaded relief image of seabed, canyon head chute (4.3 km x 6.3 km area)
Figure 4-28
Line 006_2 profiler data, draped chute gullies
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The canyon extends to the south-west limit of data coverage and is approximately 2 km wide with a
floor around 150 m below the surrounding seabed. To a water depth of approximately 950 m the
canyon has a V shaped profile; in greater water depths the canyon has a flat floor up to 600 m
wide. The flanks of this largest canyon dip more gently than those of the canyon to the west. Dips
are commonly in the order of 12°, locally reaching about 20° on the lower east flank.
A far more subtle canyon trends due south in the eastern parts of the area. The eastern canyon’s
northern limit is at the 450 m contour; this canyon’s up dip limit is below the shelf break. The
canyon is gently ‘V’ shaped with a floor some 40 m below the surrounding seabed to a water depth
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of approximately 675 m. At this point the canyon becomes far less pronounced but appears to reestablish itself close to the southern limit of the data coverage. Dips on the flanks of this canyon
reach a maximum of 14°.
The area’s three canyons, while having superficial similarities, have many contrasting
characteristics, indeed in detail they differ in almost every respect. Perhaps the most significant
contrast is the differing orientations. The best developed western canyons trend south-west toward
the ocean basin past the Cote d’Ivoire-Ghana Ridge whereas the canyon to the east trends south
toward a lower slope bounded by the ridge; this may be why this eastern canyon is a relatively
weak feature.
While many canyons have flanks which are faceted by a history of top down sediment failures that
is not the case here. The reasons for this are unclear.
Continental Slope-Knolls
Three large knolls occur in association with the two canyon systems in the west of the study area.
The knolls are positioned on the upper slope in water depths of between 375 m and 500 m (Figure
4-29).
Figure 4-29
Shaded relief image of seabed, two westernmost knolls (3.3 km x 4.8 km area), sea
depth between 375 – 500 m
From west to east the large knolls measure 1540 m x 230 m x 43 m, 1850 m x 1210 m x 95 m and
565 m x 362 m x 98 m.
The knolls are rough and likely to be hard; the steep dips that they maintain and high acoustic
reflectivity support this interpretation. Dips reach at least 40° and probably exceed this figure over
short slope sections.
The knolls occur in relatively low lying parts of the canyon heads; areas where older sediment is
closer to seabed. This may contribute to their formation. The exact composition of these structures
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is unknown but they presumably comprise of some form of carbonate cement. The processes
behind the structures may be geological or biological and could involve supply of hydrocarbons
from depth.
A similar, but far smaller, pinnacle is located in 125 m of water close to the eastern margin of the
data coverage. This feature measures 177 m x 87 m x 5 m (Figure 4-30 and Figure 4-31)
Figure 4-30
Bathymetry image of Pinnacle on Shelf Break (roughly 125 m water depth)
Figure 4-31
Bathymetric Profile images of Pinnacle on Shelf Break
These features are avoidable but it should be noted that the extreme nature of these knolls will
cause disruption and turbulence of bottom currents which could extend over a wider area. Unusual
patterns of sediment distribution around the knolls are testament to the local disruption of bottom
currents. The affected areas are labelled as sedimentary shadows on Figure 4-29.
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Numerous sonar contacts are identified over both the shelf and slope. These are generally
interpreted to represent natural seabed variations such as accumulations of shell gravel or
Methane Derived Authogenic Carbonate (MDAC). It is highly likely than some of these contacts
relate to debris items
Figure 4-32
Image of Outcrop with Pockmarks and High Reflectivity Contacts
Man-made Seabed Features- Wells and associated features
The seabed shows some legacy of human activity, generally related to drilling operations and
fishing.
Eight wells have been drilled in the study area (Table 4.10)
Table 4.10
Exploration Well Locations
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All of these wells have associated areas of drill spoil which tend to be elongated along the strike of
the slope, representing also a strong evidence for active contour currents (Figure 4-33)
Figure 4-33
Side scan sonar mosaic, Sankofa 2A/2AST well (0.6 km x 1.4 km area)
Man-made Seabed Features- Fishing gear and associated features
There is evidence for two types of fishing within the study area. There are numerous seabed scars
which are interpreted as potential trawl marks. These generally occur on the shelf in water depths
of less than 130 m. It is possible that a high proportion of these seabed marks are due to current
scour.
There are also three strings of contacts which are firmly interpreted to be related to some type of
long line fishing. The most significant string of contacts is almost 11 km long and is positioned in
the east of the area orientated along the strike of the slope in water depths of about 600 m (Figure
4-34). It is unknown whether these strings of gear are in active use or are lost in these positions.
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Figure 4-34
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Photograph, longline fishing gear
Seabed Sediments
Seabed sediments consist of slightly silty SAND on the shelf to a water depth of approximately 125
m.
The shelf also features numerous large outcrops of CALCARENITE. In deeper water the seabed
sediments comprise very soft slightly silty sandy CLAY. Exceptions to this general picture are the
large carbonate knolls of the upper slope. Small areas of carbonate or exceptional seabed
sediments may be mapped as sonar contacts.
4.4.3
Shallow Geology
The shallow sub-surface geology is important to describe and detail top few geological layers, to a
maximum of 40 m depth below the seabed, that can influence surface sediments.
On the shelf, in water depths below 115 m, the shallow geology consists of truncated sequences of
calcarenite which are typically covered by surficial sediments of silty sand 1 m to 3 m thick (Figure
4-35). However the calcarenite outcrops at the seabed in trending bands.
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Figure 4-35
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Line 048_1 profiler data, shelf stratigraphy
The southern margin of this silty sand is difficult to map. This is probably due to the absence of the
truncation surface which is mapped as the base of the sand on the shelf.
The shelf has not seen significant amounts of deposition over recent geological time.
On the slope the clay-prone deposits can be identified as well bedded with increased
concentrations of sand and silt layers around the canyons where unusual depositional conditions
have prevailed. In some areas, such as over the apex of the inter canyon banks, fractured units
appear toward the limit of penetration (Figure 4-36 and Figure 4-37)
Figure 4-36
Line 60_1 profiler data, slope stratigraphy, canyon
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Figure 4-37
4.5
4.5.1
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Line 054_2 profiler data, failure deposit
SEDIMENT AND WATER QUALITY
Sediment quality
Particle Size Distribution
Particle size analysis are performed using wet and dry sieving and laser diffraction techniques.
Summarized results and sediment descriptions based on the Wentworth Classification (Buchanan,
1984) are given in Table 4.11. The proportion of fines (<63 μm) are displayed spatially in Figure
4-38.
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Table 4.11
Summary of Particle Size Distribution
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Figure 4-38
Spatial distribution of percentage fines (<63 μm)
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Sediments within the survey area are all very poorly sorted and ranged from fine sand/coarse silt at
most of the shallowest stations (Station 49, 44, 47 and 41), to medium silt at the intermediate depth
stations (Stations 46, 45 and 43), to fine silts at the deepest stations (Station 40, 42, 39 and 38). At
all stations less than 600 m deep, excluding Station 48, the proportion of sand is relatively high
(42% to 85%) and the proportion of silt relatively low (14% to 39%). This trend is reversed at
stations in water depths greater than 600 m, where sediments all consist of more than 79% silt and
less than 21% sand. The amount of coarse sediment material is less than 1% at all stations. These
results are consistent with the seabed features interpretation, which suggests sediments on the
outer shelf comprise silty sand, while slope sediments largely consist of slightly silty sandy clay.
Proportions of fine sediment show a positive correlation with depth (P<0.001), whereas the
proportion of sand show a negative correlation with depth (P<0.001).
The results of the granulometric analysis for the current survey appear to be consistent with
previous literature describing this region that suggest the presence of a range of sediment types,
varying between soft sediments (mud and sandy mud), sandy sediments and hard substrate
(Martos et al., 1991).
Comparable data for fines, sand and coarse sediment percentages from the EAF Nansen (EAF
Nansen, 2010) and the TDI-Brooks surveys (TDI Brooks, 2008) are presented in Table 4.11.
Data are averaged from stations located within the depth range 200 m to 1300 m. Results from the
current survey compare well with the previous EAF Nansen and TDI Brooks surveys, although
variability is slightly greater in the data from these previous surveys. This is most likely due to the
larger spatial area from which data are selected for comparison. Sediments are also in line with the
data collected from the Phase 2&4 surveys from the current program which demonstrate that
sediments towards the end of the proposed pipeline route, in water depths approaching 100 m are
dominated by sand and fine sediments with limited or no coarse components, concurrent with the
predominantly sandy sediments described from the shelf sediments in the current survey area.
Multivariate Analysis
Patterns in the distribution of seabed sediments are also examined by multivariate statistical
analysis, in order to identify clusters of stations with similar granulometry. The influence of
sediment granulometry on other environmental variables means that clusters of stations with
similar granulometry may also exhibit similar chemical and biological characteristics.
Multivariate analyses are undertaken using the Plymouth Routines in Multivariate Ecological
Research (PRIMER) v6.0 statistical package (Clarke and Gorley, 2006). Data for the percentage
composition within one phi unit sieve size classes are analysed using the Bray-Curtis similarity
measure. A cluster analysis, which outputs a dendrogram displaying the relationships between
data based on this similarity measure, is displayed in Figure 4-39. Ordination of samples by nonmetric multi-dimensional scaling (nMDS), which outputs a map or configuration of the samples
based on the similarity matrix, is displayed in Figure 4-40.
The similarity profiling (SIMPROF) algorithm is used to identify statistically significant groupings in
the data (P=0.05), with statistically significant splits shown as black lines and non-significant splits
as red lines. The SIMPROF analysis formed nine clusters. This clustering is considered to be an
over-differentiation of the dataset due to the low variability between samples. Consequently the
dendrogram is divided into two predominant groups which split from one another at a similarity
level of approximately 53% and had over 70% within group similarity (Figure 4-40). The resulting
cluster groups, Clusters A and B, correspond to logical divisions in the dendrogram, thus
demonstrating broader scale changes in sediment type. The partitioning of the stations into these
two groups is consistent with their relative proportions of sand and silt, as described in Section
Particle Size Distribution.
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The mean proportion of sediment in each size class is calculated for each cluster (Table 4.12) and
displayed with example seabed and grab sample photographs (Figure 4-41).
Cluster A shows a bimodal distribution, the main peak at 2 to 3 phi and a second smaller peak at 7
to 8 phi. This cluster contains stations with relatively high proportions of fine sand (2 phi, ~19%)
and very fine sand (3 phi, ~18%), the second peak corresponding to very fine silt (7 phi, ~9%) and
clay material (8 phi, ~8%). Cluster B exhibits a unimodal distribution, peaking at 7 phi. This cluster
contains finer sediments than the stations in Cluster B, with higher proportions of fine silt (6 phi,
~18%), very fine silt (7 phi, ~20%) and clay material (8 phi, ~18%).
The spatial distribution of the sediment clusters within the survey area is displayed in Figure 4-42.
Cluster A contains stations located on the continental shelf and upper slope at relatively shallow
depths (219 m to 561 m). With the exception of Station 48 (427 m), Cluster B contains stations on
the lower slope at depths greater than 600 m.
Figure 4-39
Dendrogram of Bray Curtis similarity of sediment PSD data
Figure 4-40
nMDS ordination of Bray Curtis similarity of sediment PSD data
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Table 4.12
Summary of Sediment PSD Multivariate Clusters
Figure 4-41
Example photographs and PSD for each sediment cluster
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Figure 4-42
Spatial distribution of multivariate sediment clusters
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Microbiological Analysis
In the field, physico-chemical subsamples are analysed for sulphate-reducing bacteria (SRB)
content, using a SRB rapid check kit. High levels of sulphate-reducing bacteria present in a sample
can be indicative of nutrient enrichment and anoxia; however, a key role can be played by SRB
consortia in the anaerobic biodegradation of hydrocarbons in sediments (Perez-Jimenez et al.,
2001).
The SRB rapid check kit results showed SRB levels to range from 103 to 106 cells per ml (see
Table 4.13). From these results, there don’t appear to be any spatial trends in the data. The data
range is similar to that in volume 1, which showed levels of SRB at between 10 3 and 106 cells per
ml at the deeper stations.
Table 4.13
Summary of Microbiological Analysis (SRB)
Organic Carbon Analysis
Organic matter, primarily comprising detrital matter and naphthenic materials, i.e. carboxylic acids
and humic substances, performs an important role in marine ecosystems providing a source of
food for suspension and deposit feeders, which may then be preyed upon by carnivores. This has
led to the suggestion that variation in benthic communities can be influenced to some extent by the
availability of organic carbon (Snelgrove and Butman, 1994).
Organic carbon is also an important absorber (scavenger) of heavy metals and may be of use in
interpreting the distribution of metals (McDougall, 2000). Total organic carbon (TOC)
measurements are made by pre-treating samples with strong acid prior to quantitation, which
liberates inorganic carbonates. Dried samples are analysed for total organic carbon content using
an induction furnace.
The results of the total organic carbon analysis are presented in Table 4.14 and the spatial
distribution of the concentrations of TOC is displayed in Figure 4-43. TOC concentrations across
the survey area ranged from 0.86% to 3.02% (Stations 49 and 40, respectively). These values
compare well with results from the TDI Brooks (2008) survey, which ranged from 1.41% to 2.99%,
although the proportions of fines at the comparison stations are increased (Table 4.14). Organic
carbon content is higher than that reported form the phase 2&4 surveys in shallower water, which
ranged from 0.07% to 1.43%. Higher organics in the deeper water of the current survey area is
likely due to a more depositional environment with higher fine content. Sediment samples are not
analysed for TOC in the EAF Nansen (2010) study and therefore only results from the TDI Brooks
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survey are reported. Note that for comparative purposes only those TOC samples (or samples for
sediment PSD analysis) from the TDI Brooks (2008) survey which were obtained within the depth
range surveyed in the current study are compared to. This included TDI Brooks stations EBS001,
EBS002, EBS004, EBS006 and EBS007.
Table 4.14
Summary of Organic Carbon Analysis
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Figure 4-43
Spatial distribution of Total Organic Carbon (TOC) [%]
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Nutrient Analysis
Sediment samples were analysed for nitrogen, ammonium, nitrate, total phosphorus and available
phosphate. The results of these analyses are provided in Table 4.15, with the spatial distribution of
total phosphorus displayed in Figure 4-44.Nitrogen and phosphorous are essential nutrients for
primary production and the supply of these elements is the most frequent rate-limiting process for
marine production. Marine sediments act as a sink for these elements and benthic fauna play an
important role in releasing nutrients from their organic binding during metabolism, so that they are
once again made available to bacteria, algae (macro and micro), phytoplankton etc. (Barnes and
Hughes, 1999).
Nitrogen concentrations are ranged from 0.09% (Station 49) to 0.39% (Station 46). Nitrate is below
the detection limit (<1.5 μg.g-1) at all stations. Available phosphate concentrations range from 19.3
μg.ml-1 (Station 38) to 37.6 μg.ml-1 (Station 49). Concentrations of available phosphate tend to be
lower at the deeper stations, especially those located at depths greater than 800 m. Total
phosphorous concentrations range from 805 μg.g-1 (Station 42) to 1370 μg.g-1 (Station 49) and
are generally similar at all stations (average 889 ug.g-1), apart from at the shallowest station
(Station 49, 219 m), where values are much higher (1370 ug.g-1). Available phosphate and total
phosphorous are both negatively correlated with depth and percentage fines (P<0.05), although
these trends are not clear cut. For example, considering Stations 41, 44, 46 and 48 only, available
phosphate increase with increasing depth which contrast with the trend when all data are
considered. In addition, removal of Station 38 from the correlation between total phosphorous and
depth resulted in the correlation being not significant.
Total phosphorus concentrations in the present study are higher than recorded in the previous
Jubilee Field survey, which ranged from 400 μg.g-1 to 690 μg.g-1 (TDI Brooks, 2008). Other
comparable nutrients are not measured in previous comparable surveys from the region.
Table 4.15
Summary of Nutrient Analysis
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Figure 4-44
Spatial distribution of total phosphorus [μg.g-1]
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Hydrocarbon Analysis
The extraction of hydrocarbons is undertaken on wet sediment samples. This technique is
considered to extract a greater proportion of the target analytes than dry extraction methods; Wong
and Williams (1980) estimated that around 16% of hydrocarbons determined by wet extraction
procedures were lost as a consequence of the drying process. Comparison with baseline values
from previous surveys or published literature should be undertaken with caution as it is often not
clear whether wet or dry extraction has been employed.
Total Hydrocarbons Concentrations
Total hydrocarbon concentrations (THC), total n-alkanes and carbon preference index (CPI) are
summarized for each station in Table 4.16. The spatial distribution of THC is displayed in Figure
4-45.
Total hydrocarbon concentrations are low at most stations, ranging from 1.5 μg.g-1 to 15.2 μg.g-1
(Stations 49 and 47, respectively), but are considerably elevated at Station 41 (787 μg.g-1).
Excluding Station 41, levels of THC in the current survey are comparable to those recorded in the
previous EAF Nansen survey, where concentrations ranged from less than 1 μg.g-1 to 14.7 μg.g-1
at stations from comparable depths (EAF Nansen, 2010). Background levels of THC (all stations
excluding station 41) are comparable to levels recorded during the phase 2&4 pipeline survey
demonstrating typical THC levels below 10 μg.g-1.
Elevated THC at station 41 is strongly indicative of contamination. Station 41 is located 340 m from
the Gye Nyame-1 exploration well, which is considered to be the source of the contamination.
Further details on the hydrocarbons found at this location are discussed in the sections below.
Table 4.16
Summary of Hydrocarbon Concentration [μg.g-1 dry weight]
n-Alkanes - Total n-alkanes
Excluding Station 41, total n-alkane (nC12-36) concentrations measured during the current survey
are low, ranging from 0.16 μg.g-1 (Station 49) to 2.99 μg.g-1 (Station 47). At Station 41, total nalkane (nC12-36) concentrations are markedly increased (16.8 μg.g-1). The concentration of total
n-alkane (nC12-36) is positively correlated with THC (P<0.001).
Levels of unresolved complex mixture (UCM), which are made up of hydrocarbons of various
origins that cannot be resolved by GC analysis, is also positively significantly with THC and total n-
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alkanes (nC12-36) (P<0.001). UMC is typically low at most station (0.8 μg.g-1 to 12.0 μg.g-1),
although is considerably elevated at station 41 (643.0 μg.g-1).
n-Alkanes - Carbon Preference Index
The carbon preference index (CPI) is used to assess the relative contribution from petrogenic and
biogenic sources in hydrocarbon samples and is determined by calculating the ratio of the sum of
odd to the sum of even-carbon alkanes. The range of alkanes from nC21-36 is of particular interest
as odd carbon n-alkanes from terrestrial plants elute in this region. Pristine sediments exhibiting a
predominance of odd number biogenic alkanes would be expected to have a CPI value of greater
than 1.0, while crude oil or refined products show no preference for odd or even n-alkanes and
achieve a CPI close to unity (1.0) (McDougall, 2000).
The CPI ratios for nC12-36 range between 0.87 and 2.42 (Tab. 7.16). At most stations values are
greater than 1, suggesting a dominance of biogenic/terrestrial n-alkanes. These stations also has a
dominance of odd number, longer chained alkanes (nC21-36), indicating that the major source of
n-alkanes is from terrestrial plants. Notably the CPI ratio for nC21-36 at station 41 is 5.80, which
may, on the face of it, be interpreted as a biogenic signature; this however is not the case as the
actual n-alkane values for the nC21-36 range are very low at station 41 (Table 4.17), dwarfed by
the highly elevated n-alkanes in the nC12-20 range. The CPI for the nC21-20 range at station 41 is
0.82 further indicating that this station is contaminated with petrogenic hydrocarbons.
Several stations has nC12-36 CPI ratios of approximately 1 (Stations 39, 40, 44, 45). These
stations show a dominance of longer chained alkanes (nC21-36). The relatively low CPI ratios at
these stations are not interpreted as petrogenic contamination and are a function of low overall nalkanes values.
Pristane and Phytane
Pristane and phytane are isoprenoidal alkanes which are common constituents of crude oils.
However, phytane is generally absent or only present at low levels in uncontaminated natural
systems (Blumer and Snyder, 1965).
Concentrations of these isoprenoids mirrored THC and n-alkanes, with low levels recorded at all
stations apart from Station 41. Excluding Station 41, pristane concentrations range from 0.001
μg.g-1 to 0.003 μg.g-1 and phytane concentrations range from less than the detection limit (0.001
μg.g-1) to 0.001 μg.g-1. This indicates that sediments at these stations are not contaminated. In
contrast, pristane and phytane concentrations of 0.622 μg.g-1 and 0.229 μg.g-1 are recorded at
Station 41, respectively, indicating petrochemical contamination of sediments at this station.
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Table 4.17
Individual Aliphatic Concentrations [ng.g-1 dry weight]
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Figure 4-45
Spatial distribution of total hydrocarbon concentration [μg.g-1]
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Gas Chromatography Traces
The gas chromatography traces are generally similar at the majority of stations (i.e. Stations 38,
39, 40, 42, 43, 44, 45, 46, 48 and 49) with only minimal variation observed between them. At
Station 41, however, differences in the GC trace are readily apparent
Example GC traces from Station 42 and 41 are displayed in Figure 4-46 and Figure 4-47,
respectively, while all traces are provided in the annex B2.2
Sediment-Hydrocarbon AnalysisGas Chromatography Traces. Examination of the traces shows a slight ‘hump’ of UCM at the
majority of stations with an associated homologous series of odd-carbon dominated n-alkanes in
the higher boiling point range nC23-36 (Figure 4-46). In particular, most traces show peaks eluting
at nC29, nC31 and nC33 (e.g. Station 40 and 47), as evident from review of the individual aliphatic
concentrations (Table 4.17). This signature is thought to be indicative of an input of terrestrial
organic matter into the sediments.
A weak signature is observed around nC21 at all stations that is thought to be of biogenic origin.
As this slight peak is seen on all traces (including those from the phase 2&4 study) it is considered
to be representative of background conditions. Variation in the UCM ‘hump’ is apparent,
independent of depth range, with some stations showing a smaller hump (e.g. Stations 43 and 44)
compared to others. A high peak eluting at the even numbered nC26 alkane is also observed at
many stations (e.g. Station 42, Figure 4-46), again this is not considered to be indicative of
contamination, however the source is not identified.
The GC trace at Station 41 is very different to the rest of the traces (Figure 4-47), higher peaks
being observed in the shorter chain alkanes. Individual aliphatic concentrations for n-alkanes
measured in the range C12 to C21 (and to a certain extent C22 and C23) are highly elevated
compared to all other stations (Table 4.17), however the GC trace shows that relative to the UCM
these peaks are not well resolved, this suggests that the inputs are well weathered and not current.
The GC trace profile suggests that the hydrocarbon contamination at station 41 is likely to be from
drilling muds (probable well weathered low-toxicity mud). It is highly likely this this drilling related
contamination is from past drilling activities at the Gye Nyame-1 exploration well located 340 m to
the south-east of station 41.
Figure 4-46
Example gas chromatography trace (Station 42)
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Figure 4-47
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Example gas chromatography trace (Station 41)
Polycyclic Aromatic Hydrocarbons (PAHs)
Polycyclic aromatic hydrocarbons (PAHs) are evident throughout the marine environment
(Laflamme and Hites, 1978), with natural sources including plant synthesis and natural petroleum
seepage.
However, these natural inputs are dwarfed in comparison to the volume of PAHs arising from the
combustion of organic material such as forest fires and the burning of fossil fuels (Youngblood and
Blumer, 1975). These pyrolytic sources tend to result in the production of heavier weight 4 to 6 ring
aromatics (but not their alkyl derivatives) (Nelson-Smith, 1972).
Another PAH source is petroleum hydrocarbons, often associated with localised drilling activities.
These are rich in the lighter, more volatile 2 to 3 ring aromatics (NPD; naphthalene, phenanthrene,
anthracene and dibenzothiophene (DBT) with their alkyl derivatives). As the lightest and most
volatile fraction, the NPD is the dominant PAH in petrogenic hydrocarbons but is quickest to
degrade and weather over time.
Many different PAHs exist, however certain ones are particularly toxic, prevalent or indicative of
anthropogenic contamination. To assess the level of the most significant PAHs from the collected
sediment samples two sets of PAHs are analyzed, the UK Department of Trade and Industry (DTI)
specified PAHs (now part of the Department of Energy and Climate Change (DECC)), and the US
environmental protection agency (EPA) priority 16 PAHs. A summary of the DTI/DECC specified
PAHs is provided in Table 4.18 and discussed in paragraph Polycyclic Aromatic Hydrocarbons
(PAHs) - Total PAH and the US EPA PAHs are given in Table 4.20 and discussed in paragraph
Polycyclic Aromatic Hydrocarbons (PAHs) - USEPA 16 PAH. Total 2-6 ring PAHs at each station
are displayed on Figure 4-50.
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Table 4.18
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Summary of DECC Specified PAH Concentrations [ng.g-1 dry weight]
Polycyclic Aromatic Hydrocarbons (PAHs) - Total PAH
Apart from Station 41, the sum of all 2-6 ring PAHs are low at all stations, ranging from 3 ng.g-1 at
Station 49 to 58 ng.g-1 at Station 47. At Station 41, however, the sum of all 2-6 ring PAHs is
elevated to 161 ng.g-1.
Total PAH concentrations correlate with both THC and UCM (P<0.001) and show a similar spatial
distribution, with maximum concentrations of all analytes find to be highest at Station 41. PAH
concentrations are considerably lower at all other stations, although slightly elevated
concentrations of the alkylated C2 178 phenanthrene / anthracene group, and to a lesser extent
naphthalene parent and alkylated species, are noted at Station 47.
Excluding Station 41, total PAH concentrations at the Jubilee Field are slightly higher than in the
current survey, ranging from 116 ng.g-1 to 176 ng.g-1, at stations at depths comparable to those in
the current study (i.e. between 942 m to 1264 m). However, no data from stations at shallower
depths similar to those recorded in the current study (i.e. between 200 m and 900 m) are available
for comparison (TDI Brooks, 2008). Levels of total PAHs from the phase 2&4 survey are
comparable to the current survey with values ranging from 1 ng.g-1 to 56 ng.g-1, and not
considered indicative of contaminated sediments.
Polycyclic Aromatic Hydrocarbons (PAHs) - NPD and 4-6 Ring PAH
The ratio of NPD PAH to 4-6 ring PAH is low at the majority of stations, ranging from 0.3 (Station
48) to 0.6 at a number of stations, the exception to this is a ratio of 2.0 and 8.5 at Stations 49 and
41, respectively. Overall levels of 4-6 ring PAHs are generally higher than NPD PAHs indicating a
predominance of pyrolytic sources at station 49 higher NPD : 4-6 ring ratios at the station 49 is a
function of the very low concentrations and should not be interpreted as a sign of petrochemical
contamination. The higher ratio at station 41 however shows a strong dominance of NPD PAHs
which is indicative of petrochemical contamination at this station.
Polycyclic Aromatic Hydrocarbons (PAHs) - Parent / Alkyl Distribution
PAH distribution plots (Figure 4-48 and annex B2.3
Sediment-Hydrocarbon Analysis- Parent
Alkyl Pah Graphs) typically show a slight dominance of 4 to 6 ring (pyrolytically derived) PAHs at
the majority of stations. The higher molecular weight (and therefore more persistent) 4 to 6 ring
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PAHs generally show a preference for parent compounds over alkyl groups, whereas the lighter,
more easily degraded NPD PAHs tend to show a dominance of alkylated compounds. Parent NPD
PAHs are observed, however these tend to be at low values and therefore are not thought to be
indicative of any significant contamination. In contrast, the NPD 2-3 ring PAHs dominate Station 41
(Figure 4-49). Specifically, alkylated C2, C3 and C4 naphthalene groups are found at highly
elevated concentrations at Station 41, indicating significant petrogenic contamination.
Figure 4-48
Total PAH parent alkyl distribution (Station 46)
Figure 4-49
Total PAH parent alkyl distribution (Station 41; note difference in scale to Figure 4-48).
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Table 4.19
Individual DTI Specified PAH Concentrations [ng.g-1 dry weight]
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Figure 4-50
Spatial distribution of total (2-6 ring) PAH concentrations [ng.g-1]
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Polycyclic Aromatic Hydrocarbons (PAHs) - USEPA 16 PAH
Concentrations of United States Environmental Protection Agency (USEPA) specified PAHs
(USEPA 16 PAH) are provided in Table 4.20, where they are compared to National Oceanographic
and Atmospheric Administration (NOAA) Effects Range Low (ERL) concentrations. ERLs are
defined as minimal concentrations over a range at which adverse biological effects have been
observed from ecotoxicological studies. ERLs are not available for benzo(b)fluoranthene and
benzo(k)fluoranthene, and therefore values for these PAHs have been compared against OSPAR
sediment quality guideline action levels (CEFAS, 2003).
Levels of USEPA 16 PAH concentrations were low throughout the survey area. All PAH
concentrations are considerably lower than NOAA specified ERL concentrations or, where
applicable, OSPAR action levels.
Table 4.20
USEPA 16 PAH Concentrations [ng.g-1 dry weight]
Polychlorinated Biphenyls
Polychlorinated biphenyls (PCBs) are synthetic organic compounds with a biphenyl group base
unit. They may be introduced into the marine environment as a component of industrial effluent
and by the dumping of electrical components (Libes, 1992). PCBs are likely to be sequestered in
sediments close to the point where they are introduced due to adsorption and incorporation into
biogenic matter (Libes, 1992).
In the current survey, sediment data are analyzed for PCB28, PCB52, PCB101, PCB118, PCB153,
PCB138 and PCB 180. PCB concentrations are below the detection limit (<5 ng.g-1) at all stations.
Organochlorine Pesticides
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Organochlorine pesticides are chlorinated hydrocarbons which were mainly used in agriculture and
mosquito control in the mid 20th century. Pesticides can be transported into the marine
environment by ground-water runoff from adjacent landmasses; these compounds may then enter
the marine food chain via adsorption onto organisms or active uptake by phytoplankton. Removal
of pesticides from seawater is enhanced by biological activity as these compounds are degraded
by metabolic processes. Biomagnification and bioaccumulation may occur causing organochlorine
pesticides such as DDT to reach very high levels in organisms at the top of the food chain (Libes,
1992).
Sediment data was analyzed for a number of different organochlorine pesticides (see Annex B1.7
for details). Concentrations of all organochlorine pesticides were below their respective limits of
detection at all stations in the survey area.
Heavy and Trace Metal Analysis
Heavy and trace metals (aluminium, arsenic, barium, cadmium, cobalt, chromium, copper, lead,
iron, nickel, vanadium, selenium, and zinc) are analyzed following near total metal digestion using
hydrofluoric acid. Samples are heated at approximately 105°C in hydrofluoric acid, allowed to cool
and then neutralised by addition of boric acid prior to dilution for testing. Concentrations of metals
in the digest are determined by ICPOES (aluminium, barium and iron) or by ICP-MS. Mercury is
determined following nitric acid and hydrogen peroxide digestion, followed by ICP-MS detection.
Full details of the analytical techniques used are provided in Annex B1.7.
Samples acquired from the previous EAF Nansen and Jubilee surveys underwent a strong partial
digestion using nitric acid, followed by detection by ICP MS/ICP-AES (TDI Brooks, 2008; EAF
Nansen, 2010). NOAA ERL concentrations were also derived using the less stringent strong partial
digest. As this methodology will tend to liberate lower concentrations of metals than the
hydrofluoric acid digest used in the current survey, only broad comparisons between the surveys
and ERL values could be made.
Results for the heavy and trace metal analyses is provided in Table 4.21, alongside NOAA ERLs
which indicate the lower threshold at which adverse biological effects have been identified from
ecotoxicological studies (Buchman, 2008). The spatial distribution of chromium, nickel and barium
concentrations are presented in Figure 4-51, Figure 4-52 and Figure 4-53.
Concentrations of the majority of metals (excluding arsenic, chromium and iron) are significantly
positively correlated with the proportion of fine sediment at each station (P<0.05: barium, cadmium,
cobalt, vanadium, zinc; P<0.001: aluminium, mercury, copper, nickel and lead). In addition, several
metals are positively correlated with depth (P<0.05: barium, cadmium, cobalt, vanadium and zinc;
P<0.001: aluminium, mercury, copper, nickel and lead) or negatively correlated with depth (P<0.05:
arsenic).
Metal concentrations are generally low, although arsenic, chromium (Figure 4-51) and nickel
(Figure 4-52) are found to exceed their respective NOAA ERL concentrations at four, ten and
eleven stations, respectively (Table 4.21). Arsenic concentrations range from below the detection
limit (1.0 μg.g-1; Stations 43 and 47) to 32.3 μg.g-1 (Station 49), with four stations exceeding the
ERL value as previously mentioned. This may be the result of the more stringent analytical method
used in the current survey or it may be indicative of the local geochemistry. Notably the highest
arsenic concentrations are found at the station with the highest proportion of sand and coarse
grained sediments (station 49), suggesting a possible influence of local geology rather than
anthropogenic contamination. Arsenic levels are also found to be elevated above the NOAA ELR
at many of the locations in the Phase 2&4 surveys further indicating that these levels are
representative of background conditions of not necessarily indicative of anthropogenic or drilling
related contamination.
A relatively high iron concentration is observed at Station 48 (79500 μg.g-1), however it is difficult
to define this signal elevated analyte to a source, and it is possible it may be from sample
contamination during collection. Barium, in the form of barite, is used as a weighting material to
increase the density of drilling muds and can be present in concentrations ranging from 720 μg.g-1
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to 449,000 μg.g-1 (Neff, 2005). Barium concentrations are highly elevated at station 41 (1890 μg.g1), but generally lower throughout the rest of the survey area, ranging from 64.6 μg.g-1 (Station 49)
to 562.0 μg.g-1 (Station 42). However, background barium levels in the current survey area (i.e. all
stations excluding station 41) are generally higher than those recorded in the EAF Nansen (2010)
survey (average of 94.23 μg.g-1) and the previous Jubilee survey, where concentrations ranged
from 23 μg.g-1 nearshore to 291 μg.g-1 further offshore (ERM, 2009). The phase 2&4 survey also
found levels of barium below that of the current survey (69.7 μg.g-1 to 189 μg.g-1). As barium is
persistent in marine sediments it is possible that the barium levels in sediments in the current
survey may indicate a highly dispersed very low level barium contamination from the numerous
well in the local area.
Barium levels at station 41 are highly indicative of past drilling related contamination, however it is
notable that other metals are not equally elevated at this location suggesting drilling muds are not
heavy contaminated with impurities Station 41 is located 340 m from the Gye Nyame-1 exploration
well (Figure 4-53) drilled in 2011 (SUBSEAIQ, 2013) which is the presumed source of the
contamination.
Mean and maximum concentrations of cadmium, chromium, lead and zinc are higher than those
recorded in the previous EAF Nansen (2010) survey (Table 4.21). Values in the current study
would be expected to be slightly higher due to the stronger analytical method used. Of these
cadmium, lead and zinc are all below their respective NOAA ERL levels. Concentrations of copper
and mercury recorded in the current survey compare well with those from the EAF Nansen (2010)
survey.
Table 4.21
Heavy and Trace Metal Concentrations [μg.g-1 dry weight]
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Figure 4-51
Spatial distribution of chromium concentrations [μg.g-1]
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Figure 4-52
Spatial distribution of nickel concentrations [μg.g-1]
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Figure 4-53
Spatial distribution of barium concentrations [μg.g-1]
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Water quality
Water Profiles
Water profiles are acquired at three sampling stations within the survey area. An example water
profile from Station 46 is presented in Figure 4-54. The complete set of water profiles are
presented in B2.4
Water- Water Profiles.
Water Profiles - Temperature
Sea surface temperatures on the Ghanaian coast typically range between 27°C and 29°C with the
Tropical Surface Water (TSW) surface layer extending down to approximately 45 m, depending on
the season and position of the thermocline (ERM, 2009). Below the thermocline South Atlantic
Central Water (SACW), which is cool and highly saline, extends down to approximately 700 m
(ERM, 2009).
Sea surface temperatures in the current survey are approximately 29.6°C at all stations. A
thermocline is recorded at all stations at approximately 25 m, with temperatures declining by ~10°C
in the discontinuity layer which extended to 75 m deep. Temperatures continue to decrease with
depth to approximately 4.5°C, 5.5°C and 7.6°C at the maximum depths surveyed at Stations 38, 46
and 50, respectively. The temperature profiles are observed to be similar to those recorded in the
previous Jubilee Field survey (TDI Brooks, 2008; ERM, 2009), although a more gradual change in
superficial temperatures are noted in the current survey.
Water Profiles - Salinity
Surface salinity from the current survey is approximately 35 practical salinity units (psu) at all three
stations. Salinity increases to approximately 35.8 psu between 40 m and 70 m at all stations and
remains constant to about 100 m before gradually declining to about 34.75 psu at Stations 46 and
50 at maximum recording depths of ~710 m and 520 m, respectively. At Station 38, salinity values
decline to approximately 34.6 psu at 700 m before increasing slightly to about 34.8 psu at 1121 m,
the maximum depth surveyed.
The salinity profiles in the current survey are broadly similar to those observed in the previous
Jubilee Field survey (TDI Brooks, 2008; ERM, 2009), which shows surface salinity of around 35
psu, a slight increase in salinity sub-surface, and a subsequent uniform water column.
Water Profiles - pH
The pH of the water column ranges from approximately pH 7.85 to pH 8.3 at all three stations.
Surface values range between ph 8.17 and pH 8.29. Values decrease with depth down to
approximately ph 7.84 at 400 m to 450 m at all stations. As with the temperature and salinity
profiles, the main variation in pH is in the depth range 50 m to 75 m (Figure 4-54). Slight
fluctuations in the trend are also seen in all three profiles at around 100 m and 200 m.
These results are broadly comparable to those recorded in the previous Jubilee survey, where
values range from pH 7.33 to pH 8.27 and also decrease with depth (TDI Brooks, 2008; ERM,
2009).
Water Profiles - Dissolved Oxygen
Dissolved oxygen (DO) concentrations in surficial waters are at approximately 100% saturation
(Sat) at all stations, although some readings of supersaturated concentrations of DO are recorded
at the shallowest water depths surveyed indicating either oxygen production by phytoplankton or
surface mixing.
Concentrations decrease relatively rapidly within the top 100 m of the water column to
approximately 80% Sat, generally remaining at this concentration to the maximum depth surveyed
at each station, although a very slight increase in deep water DO concentration is observed at
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Stations 38 and 46. The depth range of the DO discontinuity layer at all stations is relatively
consistent with the discontinuity layer noted for all other variables (except turbidity), indicating
water column stratification between approximately 25 m and 80 m depth.
Profiles at the Jubilee Field survey show a decreasing trend with depth. Profiles taken at deeper
stations (greater than 1000 m) show that oxygen levels tend to increase again at depths greater
than 200 m (ERM, 2009). This is broadly consistent with the results of the current study.
Water Profiles - Turbidity
The water profiles at all stations across the survey area show a non-turbid, clear water column that
do not vary with depth. The turbidity averaged 1.5 NTU at all stations. There are no distinguishable
differences in turbidity observed between the deeper and shallower stations in the survey area.
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Figure 4-54
Water profile - Station 46
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Water Samples
Discrete water samples are collected using a 30 litre Niskin bottle water sampler at three sampling
stations. At each sampling station, water samples are taken from three depths: 1 m (superficial
sample); 100 m; and 200 m.
Table 4.22 displays summary results for some parameters analyzed.
Table 4.22
Summary of Organic Matter, Nutrients, Total Dissolved Solids, Oxygen Demand,
Phenol Index, Cyanide and Faecal Coliforms [mg.l-1], and Chlorophyll a [μg.l-1]
Organic Matter and Nutrients
Total organic carbon, total nitrogen and phosphorus concentrations are all below their respective
detection limits at all stations. The concentration of nitrate is also below detection limits but only in
the surficial 1 m depth samples. At depths of 100 m and 200 m, nitrate concentrations range
between 0.2 mg.l-1 to 0.4 mg.l-1, higher values being recorded at the deeper sampling depth at
each station.
Ammoniacal nitrogen (nitrogen in ammonia) range from 0.4 mg.l-1 to 0.6 mg.l-1. Values are
marginally higher at the deeper sampling locations. Nutrient ranges are similar to those recorded
during the phase 2&4 survey.
Phosphate concentrations range two-fold from 0.06 mg.l-1 to 0.14 mg.l-1. A consistent pattern in
the concentration at 100 m and 200 m at all stations is recorded, of 0.08 mg.l-1 and 0.09 mg.l-1,
respectively. A surficial concentration of 0.06 mg.l-1 is also noted for Stations 38 and 46 at the 1 m
sampling depth, increasing to 0.14 mg.l-1 at Station 50. Phosphate levels are similar albeit slightly
lower to those recorded during the phase 2&4 survey (range of 0.02 to 0.58 mg.l-1).
Total Dissolved Solids
Total dissolved solids range from 38,900 mg.l-1 to 40,000 mg.l-1. No trend in depth distribution is
evident. These results are comparable to those reported by TDI Brooks (2008) and are comparable
to the results of the Phase 2&4 survey
Biochemical Oxygen Demand
Biochemical Oxygen Demand (BOD) refers to the amount of oxygen that would be consumed if all
the organics in one litre of water are oxidised by bacteria and protozoa (ReVelle and ReVelle,
1988).
Organic material contained in manure, slurries, silage effluents, waste milk, vegetable washings
and other produce which enters a water course is broken down by micro-organisms. This process
removes oxygen from the water. In severe cases of contamination, aquatic life can be killed
through oxygen starvation. BOD levels in the present study are below the limit of detection (<2
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mg.l-1) at all stations, indicating that the biochemical demand for oxygen by bacteria and protozoa
was minimal.
Chemical Oxygen Demand
Chemical oxygen demand (COD) refers to the quantity of oxygen used in biological and nonbiological oxidation of materials in water and is commonly used to indirectly measure the amount of
organic compounds in water. Most applications of COD determine the amount of organic pollutants
found in surface water, making COD a useful measure of water quality.
COD (settled) concentrations in the current survey ranged from <2 mg.l-1 (detection limits) at 200
m at Station 46, to 840 mg.l-1 at 1 m depth at Station 38. Concentrations at all stations are
greatest in the surficial 1 m sample and lowest in the 200 m sample. COD levels are comparable to
those of the Phase 2&4 survey (215 mg.l-1 to 460 mg.l-1)
Chlorophyll a
Chlorophyll a concentrations are below the detection limits (0.40 μg.l-1) at all stations and depths,
apart from at 100 m at Station 38 where the concentration is 0.44 μg.l-1. These low values (lower
than levels from the phase 2&4 survey) indicate production by photosynthetic plankton may be
limited at the time of sampling.
Phenol Index, Cyanide and Faecal Coliforms
Faecal coliforms and Cyanide (free) are both below the detection limits at all stations. Phenol index
(C6H5OH) and Cyanide (total) are both below the detection limits (0.05 mg.l-1 and 0.02 mg.l-1,
respectively) at all stations apart from at 100 m at Station 46, where concentrations of 0.13 mg.l-1
and 0.23 mg.l-1 are recorded, respectively.
Hydrocarbons - Total Hydrocarbons and n-Alkanes
Hydrocarbon concentrations (total hydrocarbon concentrations, total n-alkanes and carbon
preference index (CPI)) are summarised for each sample in Table 4.23, values for individual nalkanes are given in Table 4.24. An example gas chromatography (GC) trace is given in Figure
4-55 and GC traces for all samples are provided in B2.5 Water-Gas Chromatography Trace.
Total hydrocarbon concentrations range over from 9.8 μg l-1 to 23.3 μg l-1 (Station 38 at 100 m
and Station 50 at 200 m, respectively). Maximum values are approximately four times greater than
recorded along the proposed pipeline corridor (2.9 μg l-1 to 5.9 μg) in the Phase 2&4 survey. No
depth related trends are apparent. Total n-Alkanes (nC12-36) are less variable than THC
concentrations, ranging from 0.69 μg l-1 to 0.86 μg l-1 (Station 50 at 200 m and Station 46 at 1 m,
respectively). As with THC concentrations, no depth related trends are apparent.
GC traces at all sample depths and stations show low n-alkanes across the range, although peaks
are higher in the shorter chain alkanes compared to the longer chained species (B2.5 Water-Gas
Chromatography Trace).
Higher concentrations of the individual aliphatic compounds are recorded for the shorter chained
nC12-20 alkanes at all sample depths and stations (Table 4.24). The nC12-36 CPI ratio is below 1
at each sampling location, indicating that the n-alkanes present are potentially from anthropogenic
sources. The moderate levels of hydrocarbons recorded in the water samples may be attributed to
shipping activities (i.e. minor spills from vessels) or other highly dispersed sources.
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Table 4.23
Summary of Hydrocarbon Concentrations [μg.l-1 water]
Table 4.24
Individual Aliphatic Concentrations [ng.l-1 water]
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Figure 4-55
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Example gas chromatography trace (Station 46 surface sample)
Hydrocarbons - Polycyclic Aromatic Hydrocarbons
A summary of PAH concentrations is displayed in Table 4.25, UK Department of Energy and
Climate Change (DECC) specified concentrations are displayed in Table 4.25 and USEPA
specified concentrations are shown in Table 4.26.
Total PAH (2-6 ring) concentrations range two-fold from 32 ng.l-1 (Station 46 at 1 m) to 61 ng.l-1
(both Station 38 and 50 at 200 m). NPD/4-6 ring ratios range approximately seven-fold from 1.18
(Station 38 at 200 m) to 8.20 (Station 46 at 200 m), with a strong preference for petrogenic NPD
PAH over pyrolytic 4-6 ring PAH at all stations and depths. In sediments dominance of NPD can be
indicative of petroleum contamination (see paragraph 4.5.1(Polycyclic Aromatic Hydrocarbons
(PAHs)), however PAHs are generally insoluble in water and readily sorb to suspended particles,
eventually being accumulated in bottom sediments.
Levels of PAHs would therefor typically be expected to be greater in sediments than in overlying
waters in the absence of any water born contamination (e.g. oil spills or produced waters from
vessels or oil and gas platforms). The solubility of PAHs decreases with increasing molecular
weight (Moore and Ramamoorthy, 1984) and also decreases with alkyl substitution. Therefore, the
overall dominance of lighter NPD PAHs observed in the current samples may be due to the greater
solubility of these compounds compared to heavier 4-6 ring PAHs. Parent Alkyl graphs (Figure
4-56 and B2.6 Water- Parent Alkyl PAH Graphs) show a similar trend between samples with an
overall dominance of parent rather than alkyl groups, again suggesting the more soluble PAHs are
present in the water samples.
USEPA specified PAH concentrations are generally low (less than 2.4 ng.l-1) at all stations and
depths, with the exception of naphthalene concentrations which range from 6.8 ng.l-1 (Station 46
at1 m) to 18.3 ng.l-1 (Station 50 at 200 m). Values are all within the approximate ranges of levels
recorded from the Phase 2&4 survey.
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Table 4.25
Summary of Polycyclic Aromatic Hydrocarbon Concentrations [ng.l-1 water]
Figure 4-56
Petrogenic Dominated Parent/ Alkyl PAH Distribution – Station 50 at 200 m
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Table 4.26
DECC Specified PAH Concentrations [ng.l-1 water]
Table 4.27
USEPA Specified PAH Concentrations [ng.l-1 water]
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Heavy and Trace Metal Analysis
All heavy and trace metals in all water samples are below detection limits or at very low levels
(Table 4.28). There are no notable differences identified between the stations or within the water
column.
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Aluminium, barium, cadmium, cobalt, mercury and lead are all at or below their respective
detection limits at all stations and depths. Chromium, nickel and vanadium concentrations range
from the detection limit (<0.002 mg.l-1) to 0.003 mg.l-1. Zinc concentrations range from 0.011 mg.l1 to 0.015 mg.l-1 and arsenic ranged from 0.025 mg.l-1 to 0.030 mg.l-1. Most samples detect iron
at the detection limit (<0.01 mg.l-1) or 0.02 mg.l-1, with one sample (1 m at Station 38) recording
0.18 mg.l-1.
Selenium concentrations range from 0.037 mg.l-1 to 0.104 mg.l-1.
All heavy and trace metal concentrations are markedly below the chronic Ambient Water Quality
Criteria (AWQC) (Table 4.28).
Table 4.28
4.6
Total Heavy and Trace Metal Concentrations [mg.l-1]
ATMOSPHERIC AIR QUALITY AND NOISE
The OCTP Block Field is located approximately 60 km offshore and therefore away from any
industries, urban areas or other onshore sources of air pollution.
The only offshore source of air pollution would be vessels travelling along shipping lanes
approximately eight nautical miles south of the field as well as vessels involved in exploration and
appraisal well drilling in the vicinity.
In addition the air quality would be affected by regional air quality. The principal source of
atmospheric pollution across central Africa is biomass burning due to burning of firewood for
cooking and heating, and controlled burning in savannah areas for agriculture (including slash and
burn agricultural practices). It has been estimated that Africa accounts for almost one half of the
total biomass burnt worldwide (Andrae, 1993). The result of this biomass combustion is the
emission of carbon monoxide (CO), oxides of nitrogen (NOx), nitrous oxide (N2O), methane (CH4),
non-methane hydrocarbons and particulate matter.
In term of exposure to fishermen and other users of the area the concentration of pollutants in the
air in the location of the field from these and other sources are expected to be very low due to the
high level of atmospheric dispersion in the offshore environment.
4.7
4.7.1
PLANKTON
Phytoplankton Analysis
Water samples are collected at three stations (Stations 38, 46 and 50) using a Niskin style water
sampler (more commonly called “Niskin Bottle”). At each station separate samples are collected at
depths of 1 m, 100 m and 200 m to identify any vertical zonation of plankton communities. For
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each sample, 100 ml of preserved water is analysed for phytoplankton, with planktonic taxa
identified to the lowest possible taxonomic level, enumerated and expressed as density per litre.
Unidentified centric diatoms include a significant proportion of all individuals. Individuals in this
group are not considered to include any of the families which are identified to a lower taxonomic
level (APEM, Pers comm.). The quantification of centric diatom individuals in the different size
ranges (i.e. <20 μm, 20-50 μm, and >50 μm) are, however, merged into a single 'centric diatom'
taxon category; all further analyses and reporting relates to this single combined group. Raphiated
pennate diatoms have also been treated in this way, i.e. the different size classes (<20 μm and 2050 μm) have been merged into a single taxon. The full planktonic data set, indicating those taxa
which are merged for analysis, is presented in the annex B2.7
Plankton-Phytoplankton
Analysis.
Phytoplankton are photosynthetic planktonic life forms which typically comprise suspended or
motile microscopic algae including diatoms and desmids, dinoflagellates (single celled protozoans),
and cyanobacteria. As well as requiring light for photosynthesis, phytoplankton are also dependent
on nutrients such as nitrogen, phosphate and silicic acid. While this analysis is primarily focused on
photosynthetic plankton, some species of dinoflagellates are known to be mixatrophic or
heterotrophic, for example Protoperidinium spp. (Jeong and Latz, 1994); such taxa have been
included in the current analysis.
It should be noted that the constitution of the plankton is seasonably variable and the following
analysis only represents the state of the community at the time of sampling. As phytoplankton have
fast generation times and as growth and production is strongly determined by resource limitations,
predominantly the availability of sunlight and vital nutrients (Miller, 2003), changes in the levels of
these variables can rapidly affect community structure.
General Description and Diversity
A total of 27 phytoplankton taxa are identified (Table 4.29); this value includes single entries for
centric diatoms and raphiated pennate diatoms as discussed above. The majority of taxa (14 taxa,
51.9%) are diatoms (Bacillariophyceae), followed by dinoflagellates (Dinophyceae) (10 taxa,
37.0%). The remaining taxa are made up of microflagellates, cyanophytes (blue-green algae) and
a single species of silicoflagellate, Dictyocha fibula (Table 4.29 and Figure 4-57).
Microflagellates are the most abundant taxon, containing ~77% of all individuals. Microflagellates
consist of heterotrophic protists, not strictly phytoplankton, although many microflagellates can also
photosynthesise. This taxon contains smaller individuals (<20 μm) which, like dinoflagellates, have
flagella enabling them to move through the water column. Diatoms are the second most abundant
group, comprising ~20% of all individuals. Dinoflagellates make up 2.3% of phytoplankton
recorded, while the cyanophytes and silcoflagellates make up 0.7% and 0.1%, respectively.
Table 4.29
Number of Taxa and Density of Phytoplankton Groups
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Number of Taxa and Density of Phytoplankton Taxonomic Groups
Six of the top ten most abundant taxa/groups are diatoms (Table 4.30), although microflagellates
are ranked number 1 in density and in dominance. It is, however, likely that the microflagellates
group comprise several different species.
Centric diatoms, consisting of several size ranges, are ranked second in density and dominance.
Ranked third in density and dominance are the raphiated pennate diatoms. Highest densities of
diatoms, including both centric and pennate species, are recorded at Station 56 at 1 m depth. No
single taxa/group is found in more than four of the nine samples (44.4% frequency) obtained from
the three stations by three depths sampling array. No phytoplankters are recorded at 200 m depth
at Station 38 or 46.
Table 4.30
Dominant Phytoplankton Taxa by Density and Dominance Rank
Primary and Univariate Analysis
Primary variables (numbers of taxa and density) are calculated for the sample data using the
PRIMER v6.0 DIVERSE procedure (Clarke and Gorley, 2006). Results are presented in Table
4.31.
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The number of taxa, although limited, is most variable between stations in the surficial 1 m
samples, ranging from 2 to 7 to 13 at Stations 38, 50 and 46, respectively. Eight taxa are recorded
at Stations 38 and 46 at 100 m depth; at the same depth only three taxa are recorded at Station
50. At Station 50, only one single taxon is recorded at 200 m, with no taxa recorded at this depth at
Stations 38 and 46. The total number of taxa at each station is greatest at Station 46 (21 taxa) and
roughly equal at Stations 38 (10 taxa) and 50 (11 taxa).
Variation in phytoplankton density is largely related to densities in the two numerically dominant
groups, microflagellates and centric diatoms. Over all depths, total abundance is greatest at
Station 50 (total cells.l-1 = 7776), with numbers declining at Station 46 (total cells.l-1 = 6008).
Numbers are reduced at Station 38 (total cells.l-1 = 2739). Relatively high densities are recorded at
100 m at all three stations, highest densities being recorded at this depth at Station 50. Lowest
densities are recorded at 200 m depth; at this depth only 10 cells.l-1 are recorded at Station 50 and
no cells were observed at the other stations. Density values were generally low at 1 m depth, apart
from at Station 46 where a total of 2399 cells.l-1 are recorded, due to relatively high densities of
microflagellates and centric diatoms.
Shannon-Wiener (H’) diversity vary between 0 and 1.7, and Pielou’s evenness from 0 to 1.
Diversity is highest at 1 m depth at Stations 46 and 50, and evenness highest at all three stations
at the same depth.
Table 4.31
Phytoplankton Primary and Univariate Parameters [l-1]
Multivariate analysis is used to further examine the planktonic community structure and to
determine whether subtle spatial patterns, not apparent in the univariate measures, can be
detected. Analyses are conducted with PRIMER v6.1.15 (Clarke and Gorley, 2006) on fourth root
transformed data (to indicate any variations in community structure potentially masked by the large
variations in densities).
At 200 m depth, both Stations 38 and 46 are denuded of phytoplankton, and Station 50 is largely
depauperate except for a single taxon (raphiated pennate diatoms) at low density. The lack of cells
at this depth is likely to be for the same reason; to the lack of light and/or grazing effects, and
therefore it makes biological sense to consider the samples similar to one another. For this reason,
a dummy variable with a value of 1 is inserted into the data matrix before construction of BrayCurtis similarity (see Clarke and Gorley, 2006; Clarke et al., 2006).
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Clustering with SIMPROF testing (P<0.05) on fourth root transformed data result in two significant
clusters. These clusters essentially separate differences in community structure between depths,
Cluster A containing samples obtained at 1 m and 100 m depth, and Cluster B containing
depauperate samples obtained at 200 m. Note that the 1 m depth sample obtained from Station 38
is also grouped in Cluster B, due to only two taxa at limited densities being recorded from this
sampling site.
Analysis of Similarity (ANOSIM) is used to test for variation with depth on fourth root transformed
data. A significant difference between the communities at different depths is observed (Global R =
0.539, P = 2.9%). Note that due to the number of samples obtained at each depth and the
subsequent limited number of data permutations to construct the null distribution of the ANOSIM
test statistic, the maximum significance of the statistic will never be less than 10%. Pairwise
comparisons reveal that the greatest difference is between 100 m and 200 m depth (R = 1,
P=10%). These results are consistent with the univariate analysis which also suggested zonation
of phytoplankton within the water column.
Figure 4-58
4.7.2
Dendrogram of Bray Curtis similarity of phytoplankton community structure
Zooplankton
Zooplankton samples are collected at three stations (Stations 38, 46, and 50) using a 120 μm codend plankton net. A single vertical trawl is completed at each station. Zooplankton data are derived
from taxonomic analysis of the samples. Individuals of planktonic taxa are identified, enumerate
and expressed as density per m3 (ind.m-3) by dividing the total number of individuals obtained in
the samples by the volume of water that passes through the net. The full zooplankton dataset is
presented in the annex B2.8 Plankton- Zooplankton Analysis.
To ensure zooplankton community data are suitable for the analysis, the data are standardised to
remove extraneous data (i.e. taxa of little relevance to the analysis) and ensure that all taxa are
mutually exclusive. Larvae of benthic invertebrates form a proportion of the zooplankton (termed
meroplankton) and as such, unlike in the macrofaunal analysis, juvenile specimens are retained for
the zooplankton data analyses. As with phytoplankton, zooplankton communities vary seasonally
and, therefore, the current assessment represents the state of the zooplankton at the time of
sampling only.
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General Description and Diversity
Zooplankton communities can be split into: holoplankton, those organisms which are permanent
residents in the water column; and meroplankon, organisms that reside in the plankton for part of
their life cycle (i.e. larval and juvenile invertebrates and fish). In total, 132 discrete taxonomic
groups are identified from the analysis, although this is likely to be an underestimation of the true
diversity since many species are identified to a low level of taxonomic resolution.
The majority of species and individuals recorded in the samples are holoplankton, in particular
Copepoda and other Crustacea (Table 4.32). In terms of density, the Copepoda dominate the
holoplankton, containing 65.0% of all individuals. Other crustaceans (i.e. Crustacea with Copepoda
removed) make up 16.2% of the total density and comprised 38 different identified taxa. In
addition, 7 crustacean taxa are also included within the meroplankton ‘other’ grouping. A group
comprising several ‘other’ holoplankton taxa contains the greatest number of taxa (40.2%), but only
contributes 7.5% to total density; this group containsd members of the Annelida, Crustacea,
Cephalorhyncha, Chordata, Cnidaria and Phoronida.
Meroplankton are comparatively rare in the samples constituting 4.0% of the total density (Table
4.32 and Figure 4-59). Fish eggs (Ichthyoplankton) are also relatively scarce with a percentage
density of 0.4%.
Results from this survey are broadly consistent with results from the previous Jubilee survey which
also shows a dominance of copepods within the zooplankton trawls (ERM, 2009). Results are also
comparable to the data from the Phase 2&4 survey.
Table 4.32
Number of Taxa and Density of Zooplankton Taxonomic Groups
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Figure 4-59 Number of Taxa and Density of Zooplankton Taxonomic Groups (Note: *Other
Holoplankton include Annelida, Chaetognatha, Cnidaria, Ctenophora, Foraminifera,
Mollusca, Myzozoa, Nemertea, Radiozoa, Sipuncula and Animalia. **Other Meroplankton
include Annelida, Crustacea, Cephalorhyncha, Chordata, Cnidaria andPhoronida)
Primary variables
Due to the low level of samples (a total of three trawls) and the inconsistent taxonomic resolution,
with many taxa being identified to phylum level, and some being identified further, statistical
analysis (univariate/multivariate) is not deemed appropriate. Primary variables are given in Table
4.33 of the community observed at each station.
The number of discrete taxa identified in each sample is slightly higher at Station 46, at 96 taxa,
relative to 62 and 65 taxa (Stations 38 and 50, respectively). The total zooplankton density is
higher at the shallow stations (1892 ind.m-3 at Station 46 and 1758 ind.m-3 at Station 50) than at
the deeper Station 38 (211 ind.m-3). Total density is lower than levels from the Phase 2&4 survey
suggesting that zooplankton communities are richer in the shallower water, possibly due to
increased nutrient supply from coastal upwells and terrestrial run-off.
The relative proportions of copepods and meroplankton in the samples appears to follow a similar
trend to the total density with higher percentages at the two shallow sites (Table 4.33). Over 94%
of the density of the deeper Station 38 is copepods and only 0.3% is meroplankton.
Table 4.33
Primary Variables of Zooplankton
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4.8.1
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BENTHIC ORGANISMS
Data treatment
A total of 12 stations are sampled for macrofauna using a 0.1 m2 dual van Veen grab (see Figure
4-61). Two replicate grab samples are obtained for macrofaunal analysis (denoted FA and FB) at
all stations, resulting in a total of 24 grab samples for macrofaunal analysis. All macrofauna (>1
mm) are analyzed, identified, and enumerated. Abundances are expressed as numbers of
individuals per 0.1 m2.
To prevent spurious results, data underwent a rationalisation process. This involved combining
juvenile taxa with the parent taxon so as to prevent artificial inflation of taxon numbers. A total of
269 adults, 35 juveniles and 7 damaged individuals are recorded. Twelve individuals of juvenile
Maldanidae are recorded; this family is ranked seventh in abundance. Newly settled juveniles of
benthic species may at times dominate the macrofauna, but due to heavy post-settlement
mortality, in many cases they should be considered an ephemeral component and not
representative of prevailing bottom conditions (OSPAR Commission, 2004). When juveniles are
ranked in abundance in the top 10 taxa, OSPAR (2004) recommends that statistical analysis is
conducted both with and without juveniles in order to evaluate their ecological importance to the
dataset and hence their need for inclusion/exclusion. However, the juveniles are identified to a low
level of taxonomic resolution.
Since the number of adult species and individuals in the dataset is also low, the inclusion of
juveniles would potentially result in spurious results due to a doubling up of taxa identified to
different levels of taxonomic resolution. It is therefore considered appropriate to exclude the
juveniles. In addition, based on the same rationale, the seven damaged individuals are also
excluded.
Meiofaunal taxa were also recorded, however they are under recorded on a 1 mm sieve size. In
addition, they are not considered part of the macrobenthos and were removed from the calculation
of macrobenthic community indices and multivariate analysis of community structure (OSPAR,
2004).
4.8.2
Phyletic Composition
A total of 91 macrofaunal taxa from 8 phyla are recorded during the course of the survey, excluding
the 18 juvenile, 7 damaged, 3 meiofaunal and 1 pelagic taxon removed from the data set for
taxonomic rationalisation (annex B2.9
Benthic Organisms- Macrofauna Analysis). Of these 91
taxa, 54 (59.3%) were annelids, 14 (15.4%) were arthropods, 13 (14.3%) were molluscs, 4 (4.4%)
were sipunculids, and 3 (3.3%) were echinoderms (Table 4.34 and Figure 4-60). Cnidarians,
nemerteans and echiura comprised the remaining 3 taxa and are included in the ‘Other’ group
(3.3% of the total).
In terms of abundance, annelids are dominant, representing half (50.9%) of the 269 individuals
recorded. Arthropods, molluscs and echinoderms represent 10.4%, 13.4%, and 1.1% of the total
abundance, respectively. Other taxa make up 10.0% of the total abundance, of which echiura sp.
A. contributed 6.7%. Mean macrofaunal density per sample is 11.2 individuals per 0.1 m2 ±10.4
(S.D.), indicating that abundance is highly variable between samples.
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Table 4.34
Abundance of Major Taxonomic Groups
Figure 4-60
Abundance of major taxonomic groups
4.8.3
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Rank Abundance and Dominance
The ten most abundant taxa recorded from the grab sampling survey are presented in Table 4.35,
alongside mean abundance, frequency of occurrence and rank dominance. By ranking the taxa
recorded for each sample in terms of abundance and summing the rank scores for all samples to
give the overall rank dominance for each taxon, it is possible to examine which species are
consistently dominant throughout the survey route. This method is less susceptible to bias toward
species which may occur in higher densities at a smaller proportion of stations. In an area from
which a single community is found, few notable disparities would be expected between dominance
and abundance ranks.
In general, the abundance of macrofauna is low, a maximum of 18 individuals in total recorded for
any single species/taxon from the 22 samples obtained across 11 stations. The most abundant
species are the sipunculid Onchnesoma steenstrupii and ECHIURA sp. A. (18 individuals, ranked
joint first in abundance), both occurring at 9.5% of stations surveyed (Table 4.35). All individuals of
O. steenstrupii are recorded from two samples obtained from a single station (49FA: ten
individuals; 49FB: eight individuals). Similarly, all individuals of echiura sp. A. are also obtained
from a single station (47FA: 3 individuals; 47FB: 15 individuals). Ranked joint third in abundance
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are the sipunculid Apionsoma sp. and the bivalve Medicula ferrigunosa. These two species contain
a similar number of individuals (17 individuals) but are more widely distributed at approximately
24% and 33% of all stations, respectively. Other species which are relatively abundant include the
eunicid polychaete Aponuphis sp. A., and the terebellid polychaete Monticellina sp. (14 individuals
each, ranked joint fifth in abundance). In terms of rank dominance, Monticellina sp. is ranked first,
due to relatively high number of individuals and the high frequency of occurrence (38%). Ranked
second and third are M. ferrigunosa and Aponuphis sp. A., respectively. The most abundant
species, O. steenstrupii and echiura sp. A., are ranked fifth and tenth in dominance, respectively,
the difference in rank caused by the greater between sample (within station) variability in the
abundance for echiura sp. A. (3 and 15 individuals: Station 49), compared to O. steenstrupii (10
and 8 individuals: Station 47). In addition to the taxa already mentioned, Aricidea sp. is the most
observed taxon, occurring at 38% of the stations surveyed, with 10 individuals recorded.
The marked difference between the abundance ranks and dominance ranks, and low frequency of
occurrence of relatively abundant taxa indicates that the benthic community is spatially variable.
This is possibly a function of differing community assemblages between stations or possibly a
result of the very low abundance, resulting in very few characterising taxa per station making it
difficult to resolve similarities or differences in the community structure.
Table 4.35
4.8.4
Dominant Taxa and Dominance Rank for All Samples [0.1 m2]
Primary Variables and Univariate Analysis
The primary variables, numbers of taxa (S) and abundance (N), have been calculated together with
the univariate measures richness (D), evenness (J′), dominance (1-λ) and Shannon-Wiener
diversity using the PRIMER v6.1.15 DIVERSE procedure (Clarke and Gorley, 2006). Margalef’s
richness (D) is a simple measure calculated from the number of taxa and abundance. Pielou’s
evenness (J′) and the reciprocal of Simpson’s dominance (1-λ) are measures of equitability (i.e.
how evenly the individuals are distributed among different species); low evenness indicates that a
sample is dominated by one or a few highly abundant species whereas high evenness means that
total abundance is spread more evenly among the constituent species. The Shannon-Wiener index
(H′) (Shannon and Weaver, 1949) combines both the components of species richness and
evenness to calculate a measure of diversity. See Magurran (1988) for further discussion of these
indices. Further details on the univariate measures analysed are available in Annex B1.8.
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Sample Data [0.1m2]
The mean number of taxa per sample is 7.1 per 0.1 m2 ±5.4 (S.D.), and ranged from 0 in samples
40FA, 40FB and 41FB, to 23 in sample 44FA. The mean number of individuals per sample is 12.2
±10.3 (S.D.), ranging from 0 individuals in samples 40FA, 40FB and 41FB to 37 individuals in
sample 44FA. The number of taxa is significantly positively correlated with the number of species
(P<0.001); stations with a relatively high number of taxa have a relatively high number of
individuals, and conversely, those with a low number of taxa have a low number of individuals.
Stations with low numbers of both taxa and individuals included 38FA, 38FB, 41FA, and 42FA,
whereas stations with high numbers of both taxa and individuals included 44FA, 44FB, 49FA, and
49FB. Stations where no individuals are recorded included 40FA, 40FB, and 41FB. Coefficients of
variation (standard deviation expressed as percentage) reveal that abundance is slightly more
variable than the number of taxa (92.72 and 75.33, respectively). The average number of taxa per
station and average abundance per station are illustrated on Figure 4-61 and Figure 4-62.
Both the sum of the taxa and the total number of species at each station are negatively correlated
with depth and the proportion of sediment fines (P<0.05) (annex B2.10 Benthic
OrganismsCorrelations). This suggests benthic communities may be richer in shallower waters; however it
should be noted that this may be a function of sediment differences in shallower water and not
directly related to water depth.
Mean Margalef’s species richness is 3.0 ±1.0 (S.D.), ranging from 1.2 to 6.1. Mean ShannonWiener diversity is 1.5 ±0.8 (S.D.), but ranged from 0 to 2.9, suggesting that at some stations
diversity is low (e.g. 38FA, 38FB, 40FA, 40FB, 41FA, 41FB and 42FA) whereas at other stations it
is relatively high (e.g. 44FB, 49FB and 44FA).
Pielou’s evenness ranged from 0.6 to 1.0, revealing that at some stations the abundance is
dominated by only a few species (e.g. 47FB), whilst at other stations the abundance is evenly
spread across the species (e.g. 39FB, 41FA, 42FA, 43FA and 46FA). However, evenness
averaged 0.9 ±0.1 (S.D.) revealing that the predominant trend is for abundance to be evenly
spread between the occurring taxa; this is largely due to a low number of individuals spread across
a limited number of taxa at several stations. Simpson’s dominance index ranged from 0.0 to 0.9
and averaged 0.8 ±0.2 (S.D.), again demonstrating the general evenness of the community and
relatively low dominance.
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Table 4.36
Primary and Univariate Parameters by Sample [0.1 m2]
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Figure 4-61
Spatial distribution of average number of taxa (S) [per 0.1 m2]
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Figure 4-62
Spatial distribution of abundance (N) [per 0.1 m2]
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Species Accumulation and Richness Estimation
The species accumulation plot displayed in Figure 4-63 is generated using untransformed sample
data (0.1 m2) in PRIMER v6.1.15. The observed number of taxa obtained through repeated
sampling (Sobs) are cumulatively plotted, as are richness estimates from repeated sampling as
calculated by the Chao1, Chao2, Jacknife1 and Jacknife2 formulae (see Chao (2005) for further
discussion of these indices). All of the displayed curves are smoothed (by random permutation of
the data points) to aid interpretation.
The observed species accumulation curve (Sobs) is of reasonably constant slope and appeared
unlikely to be close to reaching its asymptote; this suggests that a number of taxa present in the
survey area has not been detected by the sampling undertaken. The richness estimators also
suggested that the survey area has not been fully described, with estimates for the total
macrofaunal diversity of the area ranging from 140 taxa (Jacknife 1) to 165 taxa (Jacknife 2), in
comparison to the 91 taxa observed. These estimates suggest that only a moderate proportion
(55% to 65%) of the area’s total faunal diversity had been detected by the sampling undertaken.
Nevertheless, the main keystone species should have been captured by the sampling campaign,
although increased replication at each station would have captured a greater proportion of the
diversity at each station.
Similarly, more stations would have facilitated an enhanced analysis of spatial differences in
benthic community structure within the survey area.
Figure 4-63
4.8.7
Species accumulation plot
Multivariate analysis of data allows a more thorough examination of differences between samples
that cannot be achieved by examination of univariate measures alone. Multivariate analysis
preserves the identity of species when calculating similarities between sample data, whereas this
information is lost when computing univariate measures.
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Analyses are undertaken using the PRIMER v6.1.15 statistical package (Clarke and Gorley, 2006).
Two techniques have been used to illustrate and identify differences in the data; cluster analysis,
which outputs a dendrogram displaying the relationship between data based on the Bray-Curtis
Similarity measure; and non-metric multi-dimensional scaling (nMDS) in which station data are
ordinated as a 2-dimensional map. No transformation is applied to the data before analyses, due to
the low abundances of taxa at all survey stations. This low abundance or lack of fauna at each
station is considered to be for the same reasons (i.e. no location is identified a likely to be depurate
because of disturbance or contamination), and therefore Bray-Curtis similarity coefficients are
constructed with a dummy variable (see Clarke and Gorley, 2006; Clarke et al., 2006). The
insertion of a dummy variable enables samples with denuded communities to be placed near to
one another in multivariate space, under the assumption that the lack of individuals between two
statistically similar samples is for the same reason.
The dendrogram (Figure 4-64) shows patterns in sample data similarities. The similarity profiling
(SIMPROF) algorithm is used to identify statistically significant (P=0.01) differences between
samples, with significant splits shown as black lines and non-significant splits as red lines.
The probability level is set at 1% (P=0.01) since at the lower probability of 5% (P=0.05) an
increased number of groups are differentiated which are considered to be artefacts of the
clustering of data with very low internal variability. Using a higher significance level increases the
likelihood that observed clusters represent genuine differences in the data.
A key characteristic of the data is the low level of similarity in community structure between
replicate samples obtained from the same station, such as Station 49, where the similarity between
replicates is approximately 39% (Figure 4-64). In addition, several sample replicates from the same
station are placed in different clusters, such as samples 45FA and 45FB (Figure 4-64). This
indicates that the macrofaunal communities are patchy over the relatively small spatial scales
between replicate samples taken within the survey area. (Note, however, that several stations in
Cluster F display high similarity due to a complete lack of fauna, and hence are classified as 100%
similar to one another).
In total, seven cluster groups are identified. A 2-dimensional nMDS plot is presented in Figure
4-65.
The grouping of stations into clusters in part reflects variations in community structure according to
station depth. Cluster A represents the shallowest stations occurring at depths of 219 m and 220
m, while Cluster C includes stations at a deeper depth of 327 m and 427 m. The remaining clusters
occur at depths of between 519 m and 1122 m.
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Figure 4-64
Dendrogram of benthic macrofaunal data (Bray Curtis similarity) with SIMPROF
testing (P=0.01)
Figure 4-65
nMDS ordination Bray Curtis similarity of benthic macrofaunal data
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Figure 4-66
Spatial distribution of macrofaunal multivariate clusters
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The PRIMER similarity percentage analysis (SIMPER) routine is run on the benthic macrofaunal
dataset to identify the taxa which contribute to the top 90% of within group similarity (Table 4.37).
Within group similarity is consistently low, ranging from 16.46% for Cluster G to 36.67% for Cluster
A. This demonstrates that the grouping of samples together is achieved with only limited
similarities. As already discussed each sample has only a small number of taxa and low
abundance so and number of individuals from which to draw similarities between is low limiting the
ability of the tests to resolve assemblage differences.
In Clusters A, D and E, a maximum of three taxa contribute the bulk of the contributions to the
within cluster similarity, suggesting that these clusters are characterised by the share occurrence
of a small number of individual taxa between the samples. In Cluster C, the number of taxa
comprising the bulk of the within-group contributions is increased to five, although the top two taxa
(Apionodma sp. and Monticellina sp.) still contribute over 60% to the group’s similarity Table 4.37).
Cluster A is located at a depth of 219 m. Sediments at stations in this cluster had the largest mean
grain size (221 μm). This cluster is characterised predominantly by the sipunculid Onchnesoma
steenstrupii, which contribute more than 70% to within cluster similarity. Other characteristic taxa
included the phylodocid polychaete Goniada sp. and the eunicid polychaete Lumbrineris sp. C.
Cluster B is located at 561 m in very poorly sorted very fine sand. This cluster containes only
Station 47FB and is typified by Echiura sp. A.
Cluster C is found at stations at 327 m and 427 m (Stations 44FA, 44FB, 48FA, and 48FB).
Sediments vary between these stations, including very poorly sorted very fine sand at Station 44
and very poorly sorted medium silt at Station 48. The main characterising taxa are the sipunculid
Apionsoma sp., the cirratulid polychaete Monticellina sp., and the eunicid polychaete Aponuphis
sp. A.
Cluster D is located at depths ranging from 833 m to 1111 m (Stations 39FB, 42FB, 43FB, and
45FA). Sediments contain a high proportion of fine material and are classified as very poorly sorted
fine or medium silts. Over 90% of within group similarity is contributed by two polychaete taxa,
Aricidea sp. and Prionospio sp.
Cluster F is found at five stations (38FA, 40FA, 40FB, 41FB, and 42FA), ranging from 519 m to
1122 m deep, and represents impoverished or denuded samples. Stations 38FA and 42FA contain
only a single individual and four individuals, respectively, while all other samples are devoid of
fauna, and consequently no taxa characterizes this cluster.
Cluster G is found at six stations (38FB, 39FA, 45FB, 46FA, 46FB and 47FA) ranging from 561 m
to 1122 m deep. Station sediments are all very poorly sorted and ranged from fine silt, to medium
silt to very fine sand. A high degree of variability in community structure between stations in this
cluster is apparent, as evident by the between station distances on the MDS plot (Figure 4-65) and
low within cluster similarity (Table 4.37). The predominant taxa which typified this cluster includes
Nemertea and the bivalve Mendicula ferruginosa.
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Table 4.37
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SIMPER Analysis Showing Characterising Taxa for Clusters
The abundance in each sample from each individual station is also summed by station to remove
within station heterogeneity (see Somerfield et al., 1995), thus potentially enabling any spatial
trends to be more easily observed. However, no spatial differences can be resolved because of the
very low numbers of taxa and individuals observed (Figure 4-65). Although it may be true that a
single benthic community is apparent across the whole survey area, the clustering of a single
group at very low similarity levels (Figure 4-65) indicates that there is limited data from which to
draw statistical conclusions from. Increased replication or additional stations may have identified
more taxa, potentially enabling any apparent spatial trends identified.
Since no structure in the macrofaunal assemblages across the survey area is able to be assessed,
it is deemed inappropriate to try to find the best explanatory variables which match the
(nonexistent) structure of the macrofauna to the patterns in the abiotic data (i.e BIOENV algorithm).
For this reason the PRIMER BEST routine has not been utilised to calculate correlations between
environmental variables, and any observed patterns in community structure.
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Figure 4-67
(P=0.05)
4.9
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Dendrogram of Bray Curtis similarity of benthic macrofauna with SIMPROF testing
CORAL REEF
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Coral
reefs are colonies of tiny animals found in marine waters that contain few nutrients. Most coral
reefs are built from stony corals, which in turn consist of polyps that cluster in groups. The polyps
belong to a group of animals known as Cnidaria, which also includes sea anemones and jellyfish.
Unlike sea anemones, coral polyps secrete hard carbonate exoskeletons which support and
protect their bodies. Reefs grow best in warm, shallow, clear, sunny and agitated waters.
Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection. However,
coral reefs are fragile ecosystems, partly because they are very sensitive to water temperature.
They are under threat from climate change, oceanic acidification, blast fishing, cyanide fishing for
aquarium fish, overuse of reef resources, and harmful land-use practices, including urban and
agricultural runoff and water pollution, which can harm reefs by encouraging excess algal growth.
4.9.1
Coral reef location
Generally corals exist both in temperate and tropical waters but shallow-water reefs form only in a
zone extending from 30° N to 30° S of the equator. Tropical corals do not grow at depths of over
50 meters. The optimum temperature for most coral reefs is 26–27 °C, and few reefs exist in
waters below 18 °C (Achituv, Y. and Dubinsky, Z. 1990. Evolution and Zoogeography of Coral
Reefs Ecosystems of the World. Vol. 25:1–8).
However, reefs in the Persian Gulf have adapted to temperatures of 13 °C in winter and 38 °C (100
°F) in summer (Wells, Sue; Hanna, Nick (1992). Greenpeace Book of Coral Reefs. Sterling
Publishing Company. ISBN 0-8069-8795-2)
There are 37 species of scleractinian corals identified in such harsh environment around Larak
Island (island off the coast of Iran in the Persian Gulf). (Vajed Samiei, J.; Dab K.; Ghezellou P.;
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Shirvani A. (3). "Some Scleractinian Corals (Class: Anthozoa) of Larak Island, Persian Gulf".
Zootaxa 3636 (1): 101–143.)
Coral reefs are rare along the west coasts of the Americas and Africa, due primarily to upwelling
and strong cold coastal currents that reduce water temperatures in these areas (respectively the
Peru, Benguela and Canary streams) (Nybakken, James. 1997. Marine Biology: An Ecological
Approach. 4th ed. Menlo Park, CA) (Figure 4-68, Figure 4-69).
Figure 4-68
Boundary for 20 °C isotherms. Most corals live within this boundary. Note the cooler
waters caused by upwelling on the southwest coast of Africa and off the coast of Peru. (map adapted
from PDF world map at CIA World Fact Book)
Corals are seldom found along the coastline of South Asia—from the eastern tip of India (Madras)
to the Bangladesh and Myanmar borders (Spalding, Mark, Corinna Ravilious, and Edmund Green
(2001). World Atlas of Coral Reefs. Berkeley, CA: University of California Press and UNEP/WCMC
ISBN 0520232550)—as well as along the coasts of northeastern South America and Bangladesh,
due to the freshwater release from the Amazon and Ganges Rivers respectively.
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Figure 4-69
Locations of Available Coral Reef Data -- This image depicts all of the areas that the
Millenium Coral Reef Landsat Archive covers. Red dots indicate coral reef data at the website:
http://seawifs.gsfc.nasa.gov/cgi/landsat.pl
4.9.2
Coral Reef nearshore
The continental shelf of Ghana’s western region is traversed by a belt of dead madreporarian coral
from 75 m depth. Beyond this coral belt, the bottom falls sharply, marking the transition from the
continental shelf to the slope (Figure 4-70)
Soft sediment (mud and sandy mud) predominates along the coast and offshore of the coral belt.
The central part of the continental shelf has extensive hard bottom areas, which are widest off
Takoradi and Cape Coast and extend eastward. They consist of flat rocks and shoals and are
covered by gorgonians, branched corals, and bryozoans (Rijavec, 1980). Mixed gravel and pebble
bottoms, on the other hand, are usually covered with corallinaceous algae (Figure 4-71)
Figure 4-70
Map of southern Ghana showing the location of dead madreporian corals
Figure 4-71
Distribution of seafloor types offshore Ghana, West Africa (From: Martos et al., 1991)
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According to Ghana Environmental Protection Agency there is the evidence of the existence of live
coral reef s along Ghanaian coastline.
The Ghana’s EPA published on its website an article that refers: “….Mr. Daniel Amlalo, the
Executive Director of the Agency thanked the Norwegian experts for accepting to train his staff. He
said we are privileged to have the Norwegians to train our staff’. Explaining the outcome of the
marine environmental survey undertaken by the Norwegian research vessel Dr Fridtjof Nansen and
officers of the Agency along the entire coastline of Ghana, he said ‘during the survey of the marine
ecosystem along the Ghanaian coastline live coral reefs were discovered. These discoveries are
interesting and the reefs should be protected because it has immense ecological benefits for the
country’”
The cruise report (in this report cited as EAF Nansen, 2010) “2009 MARINE ENVIRONMENTAL
SURVEY OF BOTTOM SEDIMENTS IN GHANA”- Cruise report No 5/2009 – May 2009” that
involved Institute of Marine Research – IMR (Norway), Uni Research AS, SAM-Marin Norway,
Environmental Protection Agency (EPA Ghana), University of Ghana Legon, Ghana, University of
Cape Coast (UCC) Ghana, Survey Department Ghana, Tullow Oil Ghana, put in evidence the
presence of two individuals of Hexacorallia Class at GP1 station (28 meters depth).
Analyzing TDI-Brooks surveys (TDI Brooks, 2008) individuals of Anthozoa Order (Phylum:
Cnidaria-Class: Anthozoa-Order: Actiniaria and Phylum: Cnidaria-Class: Anthozoa-Order:
Pennatulacea) occur in three sapling points EBS:E2_SS, EBS:E3 R_SS, EBS:T6_SS (respectively
at 64.5 m, 50 m, 51.9 m depth), while considering Fugro report on Phase 2&4 surveys individuals
of Actiniaria Order occur in two sapling points ENV09 and ENV29 (respectively at 51 m, 15 m
depth).
Figure 4-72 shows the localizations of sampling point GP1 of the EAF Nansen 2010 (red dot), the
environmental sampling points realized by Fugro during the survey offshore for the phase 1 (green
square with black text on white background labels), the sampling points ENV09 and ENV29
realized by Fugro during the survey for the phases 2 and 4 (violet rhombus with violet txt on white
background labels) and the sampling points EBS:E2_SS, EBS:E3 R_SS, EBS:T6_SS realized by
TDI-Brooks surveys of 2008 year (yellow square with black text on yellow background labels)..
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Figure 4-72
Localization of sampling points
Overall considering the 4 surveys cited above, an evidence of coral along Ghanaian coastline is
found only in the nearshore sampling points mentioned above..
The ReefBase database (accessed on 25 February 2014 http://www.reefbase.org/main.aspx)
shows the offshore band of dead coral, but does not identify any active coral reefs offshore Ghana.
In fact querying reef locations dataset, that are taken from the original ReefBase database, that
provides point data on the approximate location of coral reefs environments, no data are found
about Ghana (Table 4.38).
Table 4.38
Table extracts from
http://www.reefbase.org/main.aspx)
I
D
RE
GIO
N
SUBR
EGIO
N
COU
NTR
Y
83
44
Afri
ca
West
Africa
83
43
Afri
ca
West
Africa
LOC
ATIO
N
ReefBase
LA
T
LO
N
REEF_S
YSTEM
Ghan
a
4.4
333
3
1.7
166
7
Cape
Three
Points
Ghan
a
7.1
333
3
1.1
833
3
Ghana
database
REEF
_TYP
E
Nonreef
coral
comm
unity
Nonreef
coral
comm
unity
(accessed
on
25
February
2014
PROT
ECTE
D
TOU
RIS
M
COUNTR
Y_CODE
Cape
Three
Points
0
0
GHA
Ghana
0
0
GHA
REEF_
NAME
WATER
_DEPTH
ISLAND
_NAME
Table 4.38 Attribute Data:
Records in the Place Name dataset include the following attribute data:
Eni S.p.A.
Field name
Description
ID
Region
Subregion
Country
Location
Lat
Lon
Reef_system
Reef_type
Reef_name
Water_depth
Island_name
Protected
- ReefBase GIS ID
- Regional name
- Sub regional name
- Country name
- Name of place
- Latitude of reef
- Longitude of reef
- Reef system name (larger system where reef is part of)
- Type of reef
- Reef name
- Sea water depth level
- Name of Island where reef is located
- Is protected area
0 - No
1 - Yes
- Is tourism area
0 - No
1 - Yes
- ReefBase country code
Tourism
Country_code
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An internet search indicates several named reefs in nearshore waters (e.g., Bosum Accra reef,
Kassa reef, Pompendi reef, Roani bank, Suchu reef, and Takoradi reef [SatelliteViews, 2009]
http://www.satelliteviews.net/cgi-bin/w.cgi/?c=gh&DG=RF).
This last two considerations are reported also in the “Preliminary Environmental Report – West
Cape Three Points, 2011 Exploration and Appraisal Program Offshore Ghana”.
4.9.3
Coral reef – Deep Water Corals
According to NOAA's Coral Reef Information System (CoRIS) updated in 2004
(http://www.coris.noaa.gov/about/deep/) in addition to coral reefs that thrive in shallow, well lighted,
clear, warm tropical waters, corals also grow in the deep, cold sea. Although the existence of some
of these deep-sea coral thickets has been known for several centuries, initially from pieces of
broken corals brought up with fishing gear, scientists know little about their distribution, biology,
behavior, and function as essential habitats for fishes and invertebrates.
Some deep-water corals (also called cold-water corals) do not form reefs exactly like those in
tropical waters. Often, they form colonial aggregations called patches, mounds, banks, bioherms,
massifs, thickets or groves. These aggregations are often still referred to as “reefs.” While there
are nearly as many species of deep–water corals as there are shallow-water species, only a few
deep-water species develop “reefs.”
Three main groups of corals make up deep-water coral communities: hard (stony) corals of the
Order Scleractinia, which form hard, ahermatypic reefs; black and horny corals of the Order
Antipatharia; and soft corals of the order Alcyonacea, which includes the gorgonians (sea fans)
(Williams, 2001). Deep-water corals are similar in some ways to the more familiar corals of
shallow, tropical seas. Like their tropical equivalents, the hard corals develop sizeable reef
structures that host rich and varied invertebrate and fish fauna. However, unlike the tropical ones,
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which are typically found in waters above 70m depth and at temperatures between 23° and 29° C,
deep-water corals live at depths just beneath the surface to the abyss (2000 m), where water
temperatures may be as cold as 4° C and utter darkness prevails.
At these depths, corals lack zooxanthellae. These symbiotic algae provide food for many shallowwater corals through photosynthesis. They also assist in the formation of the calcareous skeleton,
and give most tropical corals their coloration. By contrast, the polyps of deep-water corals appear
to be suspension feeders. They capture and consume organic detritus and plankton that are
transported by strong, deep-sea currents. These corals are commonly found along bathymetric
highs such as seamounts, ridges, pinnacles and mounds.
Deep-water corals are found globally, from coastal Antarctica to the Arctic Circle. In northern
Atlantic waters, the principal coral species that contribute to reef formation are Lophelia pertusa,
Oculina varicosa, Madrepora oculata, Desmophyllum cristagalli, Enallopsammia rostrata,
Solenosmilia variabilis, and Goniocorella dumosa. Four of those genera (Lophelia, Desmophyllum,
Solenosmilia, and Goniocorella) constitute the majority of known deep-water coral banks at depths
of 400 to 700 m (Cairns and Stanley, 1982).
Two of the more significant deep-sea coral species are Lophelia pertusa and Oculina varicosa.
These species form extensive deep-water communities that attract commercially important species
of fishes, making them susceptible to destructive bottom trawling practices (Reed, 2002a).
Lophelia pertusa is the most common aggregate-forming deep-water coral. Typically, it is found at
depths between 200 and 1,000 m in the northeast Atlantic, the Mediterranean Sea, along the midAtlantic Ridge, the West African and Brazilian coasts, and along the eastern shores of North
America (e.g., Nova Scotia, Blake Plateau, Florida Straits, Gulf of Mexico) as well as in parts of the
Indian and Pacific Oceans (Figure 4-73
Global distribution of Lophelia pertusa. Image:
Southampton Oceanography Centre, UK)
Figure 4-73
UK
Global distribution of Lophelia pertusa. Image: Southampton Oceanography Centre,
Oculina varicosa is a branching ivory coral that forms giant but slow-growing, bushy thickets on
pinnacles up to 30 m in height. The Oculina Banks, so named because they consist mostly of
Oculina varicosa, exist in 50 to 100 m of water along the continental shelf edge about 26 to 50 km
off of Florida's central east coast.
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In summary NOAA's Coral Reef Information System and other document as the report “Cold-water
coral reefs - Out of sight – no longer out of mind” supported by the Governments of Ireland,
Norway and the United Kingdom, as well as the World Wide Fund for Nature (WWF) and the
United Nations Environment Programme (UNEP) confirm the potential presence of deep water
corals also in the project area but neither Fugro’s Environmental surveys nor the other surveys
taken into considerations revealed the presence of any kind of deep water corals.
The sum of all evidence gathered would indicate that no coral reefs occur in the deep waters of
Ghana.
4.10 CHEMOSYNTHETIC ORGANISMS
Chemosynthesis is the biological conversion of one or more carbon molecules and nutrients into
organic matter using the oxidation of inorganic molecules (eg hydrogen sulphide) or methane as a
source of energy, rather than sunlight, as used in photosynthesis. In water depths where there is
no light penetration and where seepage of hydrocarbons, venting of hydrothermal fluids or other
geological processes supply abundant reduced compounds, microorganisms can use
chemosynthesis to produce biomass and can become the dominant component of the ecosystem.
Chemosynthetic communities can have unusually high biomass (MacDonald, 2002).
The three main sources of energy and nutrients for deep sea communities are marine snow, whale
falls, and chemosynthesis at hydrothermal vents and cold seeps.
The first type of organism to take advantage of this deep-sea energy source is bacteria that
metabolize methane and hydrogen sulfide. Other organisms that rely with this type of bacteria are
bivalves, mussels and tubeworms.
Recently seep communities have been discovered in the eastern Atlantic, on a giant pockmark
cluster in the Gulf of Guinea near the Congo deep channel, also on other pockmarks of the Congo
margin, Gabon margin and Nigeria margin (Olu K., Cordes E. E., Fisher C. R., Brooks J. M., Sibuet
M. & Desbruyères D. (2010). "Biogeography and Potential Exchanges Among the Atlantic
Equatorial Belt Cold-Seep Faunas". PLoS ONE 5(8): e11967. doi:10.1371/journal.pone.0011967).
These cold seeps are within the Atlantic Equatorial Belt (AEB), that extends from the Gulf of
Mexico to the Gulf of Guinea, that was one focus of the Census of Marine Life ChEss
(Chemosynthetic Ecosystems) program to study biogeography of seep and vent fauna (Figure
4-74).
Figure 4-74
Atlantic Equatorial Belt- Priority field program area. A) AEB: (1) Equatorial MAR and
fracture zones; (2) Mid-Cayman Rise; (3) Gulf of Mexico; (4) Barbados Accretionary Prism; (5) NW
African margin; (6), Costa Rica margin
The Figure 4-75, and the Table 4.39 show the sampling sites and the list for deep-sea
Bathymodiolus mussels evidencing the presence of these species in the proximity of the project
area.
(Jun-Ichi Miyazaki, Leonardo de Oliveira Martins, Yuko Fujita, Hiroto Matsumoto, Yoshihiro
Fujiwara
(2010)
“Evolutionary
Process
of
Deep-Sea
Bathymodiolus
Mussels”
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010363)
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Figure 4-75
Sampling sites for deep-sea Bathymodiolus mussels
Table 4.39
Sample list for deep-sea Bathymodiolus mussels
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Other research program and studies put in evidence results that could confirm the presence of
chemosynthetic communities in the proximity of the project area.
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The Environmental Baseline Survey explained in GHANA JUBILEE FIELD PHASE 1
DEVELOPMENT reports two examples of research with some findings:
-Brooks and Bernard (2006) found two sites with chemosynthetic communities using coring
samplers over small mounds associated with presumed deeper faulting in water depths of between
1,600 and 2,200 m offshore Nigeria. The communities comprised a high density of mussels and
associated tubeworms, clams, shrimps, limpets, crabs, brittle stars, heart urchins and sponges.
-Nibbelink and Huggard (2002) in a study of submarine canyons offshore the Volta River Delta in
Ghana, noted evidence of gas seeps on seismic data and oil slicks on radar images. They
interpreted the flat floors of the canyons as carbonate formed by chemosynthetic communities that
feed on hydrocarbons seeping from the depleted free gas zones below the canyons.
Regarding the results and the research programs cited above in the project area potentially exist
chemosynthetic communities but neither Fugro survey nor The Environmental Baseline Survey of
GHANA JUBILEE FIELD PHASE 1 DEVELOPMENT, indicate the presence of any chemosynthetic
communities in their survey area
4.11 MARINE MAMMALS
The following paragraphs show the results of our desktop studies about the populations of marine
mammals which pass through or live permanently/seasonally in the area of the project.
Considering the physiological and ecological characteristics of these animals, data for distribution
of the mammals and their use of habitats has not always been available. Many aspects of their life
are still relatively undocumented and our knowledge of their geographical distribution, behaviour
and other characteristics is constantly evolving. Descriptions of marine mammals derive almost
exclusively from dead specimens, beached or killed by whalers and fishermen.
Towards the end of the century Jefferson et al. have already undertaken a census of sightings of
odontoceti (toothed whales) and pinnipeds (seals and sea-lions) in the area between the Straits of
Gibraltar and the mouth of the river Congo. Since the year 2000 studies have been carried out on
the presence and distribution of marine mammals in the Gulf of Guinea area.
The ecological significance of Ghana’s coastal waters for dolphins and whales has only recently
become the subject of scientific studies, which partially explains the lack of population abundance
estimates and why their natural history remains largely unknown. The conditions created by the
seasonal upwelling in the northern Gulf of Guinea is likely to create conditions favourable for
marine mammals as well as for fisheries.
Small cetaceans of Ghana are documented to suffer considerable pressure from frequent bycatches in mostly drift gillnet fisheries and perhaps also in industrial purse-seine fisheries although
the latter remain largely unmonitored. While total mortality is unknown, it is significant and
potentially increasing with intensifying fishing effort. Monitoring of landings over a few years has
shown the presence of at least 17 different species of dolphins and small whales and all are
affected to varying degrees.
Researchers at the University of Ghana at Legon and the Wildlife Department have pressed for the
adoption of conservation strategies for marine mammals offshore Ghana.
In 2008, the Conference of the Parties of the Convention for the Conservation of Migratory Species
(CMS/UNEP) included the West African population of Clymene dolphin (Stenella clymene)
(Ghana’s
principal
dolphin
species)
on
its
Appendix
II
(http://www.cms.int/bodies/COP/cop9/Proposals/Appendix_I_&_II_Proposals.pdf), thus formally
recognising its vulnerable status. The Atlantic humpback dolphin, a species endemic to West
Africa, has not yet been found in Ghana even though good habitat exists. Rudimentary knowledge
of the presence of large whales in Ghana waters may result equally problematic as potential
conservation issues may also go unrecognised. For instance, the Gulf of Guinea humpback whale
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population occupies Ghana’s shelf zone as a calving and breeding area, i.e. during a period when
they are most vulnerable to disturbance. The global threat of large ships colliding with whales and
killing or injuring them is well-documented. Shipping is known to affect at least humpback whales
and Bryde’s whales worldwide but also in West Africa and especially near large ports. In West
Africa, a number of unexplained whale deaths are suspected to be due to ship strikes.
Together with these deaths is important to consider the washing ashore of whales carcass. A total
of 20 dead whales have been discovered along Ghana's coastline in the last four years (starting
from 2009) including at least eight since September 2013.
Current knowledge of the distribution, natural history, population structure and ecology of dolphins
and whales in the Gulf of Guinea is rudimentary and fragmentary in the scientific literature. All
information on cetaceans in Ghana is the result of land-based field research, mainly monitoring of
fishing port for landings of small cetacean by-catches as well as the study of stranded animals.
Capture locations and thus habitat (neritic, slope, pelagic) are unknown, as fishermen may operate
both shorewards and offshore of Ghana’s continental shelf and operate at considerable distances
to the east or west of the ports where they landed catches. No shipboard surveys for marine
mammals have been implemented so far, therefore it is not presently possible to provide
distribution maps for Ghana or adjacent states. Scientists who study aquatic mammals are based
at the University of Ghana at Legon and the Faculty of Sciences at the University of Cape Coast.
Figure 4-76 shows artisanal fishing ports and fish landing beaches where cetaceans have been
landed (Van Waerebeek et al, 2009). Specimens derived from by-catches and stranding shows
that the cetacean fauna of Ghana is moderately diverse, essentially tropical and predominantly
pelagic. It comprises 18 species belonging to 5 families: 14 species of Delphinidae (dolphins) and
one species each of families Ziphiidae (beaked whales), Physeteridae (sperm whales), Kogiidae
(pygmy sperm whales) and Balaenopteridae (rorquals).
Figure 4-76
Fishing Ports on the Ghanaian Coast
References to cetaceans in West Africa include Wilson et al (1987) for a striped dolphin Stenella
coeruleoalba record from Côte d’Ivoire, but no voucher material is identifiable. However, striped
dolphins are not uncommon offshore Angola (Weir, 2007) and this delphinid and the short-snouted
common dolphin Delphinus delphis are expected to occur in the Gulf in deep waters. Among
beaked whales, the Gervais’ beaked whale Mesoplodon europaeus has been documented from
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Ascension and Guinea-Bissau (Rice, 1998), so may also be present offshore, as well as Blainville’s
beaked whale Mesoplodon densirostris which is a pantropical cetacean. Another widely distributed
(sub)tropical cetacean that may be present within the survey area is the pygmy sperm whale Kogia
breviceps. All these species have a pelagic distribution in common and may be present in the Gulf.
The presence of long- snouted common dolphin in Ghana, Côte d’Ivoire (Cadenat, 1959) and
Gabon (Van Waerebeek, 1997) puts in evidence a wide distribution in the Gulf, perhaps partly
related to the seasonal upwelling over the continental shelf (Adamec and O’Brien, 1978). The
listing of D. delphis in Ofori-Danson et al (2003) was premature, but the species may be present
offshore. The skull of a confirmed D. delphis was collected in Mayoumba, Gabon (van Bree and
Purves, 1972; Van Waerebeek, 1997).
Among baleen whales, pictures of Bryde’s whales Balaenoptera brydei/edeni were taken as far
north as Gabon (Ruud,1952) and it is likely that Bryde’s whale occurs in Ghana’s Exclusive
Economic Zone (EEZ) waters. B. brydei was originally described from South Africa (Olsen 1913)
and is the most likely species involved. Other rorquals (Balaenoptera spp.) could also occur. No
Atlantic humpback dolphins (Sousa teuszii) have so far been confirmed in Côte d’Ivoire, Ghana,
Togo, Benin or Nigeria (Debrah, 2000; Ofori-Danson et al, 2003; Van Waerebeek et al, 2004,
2009; Perrin and Van Waerebeek, 2007), despite suitable coastal habitat. Also, since the holotype
was collected in the port of Douala (Kükenthal, 1892), it has not been reported again from
Cameroon. Possible explanations may include local extirpation through intense pressure from
coastal fisheries (by-catch), disturbance and other habitat encroachment or insufficient research
effort.
There are unconfirmed fishermen’s reports that humpback dolphins may occasionally be seen
between the Volta River delta and Lomé, Togo. In recent years, Atlantic humpback dolphins have
been encountered with some regularity in Gabon (Schepers and Marteijn, 1993; Collins et al, 2004;
Van Waerebeek et al, 2004). In 2008, the species was listed on Appendix I of CMS reflecting
mounting international concern about its population status. Other rorquals such as minke whales
(Balaenoptera acutorostrata), sei whales (Balaenoptera borealis), blue whales (Balaenoptera
musculus) and fin whales (Balaenoptera physalus) have very wide distributions globally. Of these,
the blue, fin and sei whales are classified as Endangered on the IUCN’s Red Data List. The
primary and secondary ranges of blue whales and the secondary ranges of fin whales potentially
extend into the Gulf of Guinea, although there are no records of blue whales in Ghanaian waters.
Sei whale are not generally found in equatorial waters as they occupy areas northern and southern
oceans (Jefferson et al, 2008).
Regular landings in several Ghana ports of Clymene dolphin, pantropical spotted dolphin, common
bottlenose dolphin and, to a lesser degree, short- finned pilot whale, Risso’s dolphin, Atlantic
spotted dolphin, rough-toothed dolphin and melon-headed whale suggest that these species are
not rare in the northern Gulf of Guinea, although any estimate of population abundance is lacking.
Rarely captured species may be characterised by a lower abundance in the areas that are near the
continental shelf and slope. Landed cetaceans are often used as ‘marine bush meat (Clapham and
Van Waerebeek 2007), which is defined as meat and other edible parts derived from wild-caught
marine mammals, sea turtles and seabirds.
4.11.1
Common bottlenose dolphin (Tursiops truncatus)
The bottlenose dolphin (family Delphinidae) is one of the best documented species of marine
mammals. It is found in all temperate and tropical oceans and seas. Its distribution seems to be
correlated to temperature, directly or indirectly, via availability of prey (Wells & Scott, 2002). Areal
distribution varies as there is a wide range of behaviour patterns: seasonal migration, annual
changes of the area of residence, periodic residence, combinations of long range migrations and
residence in the same area. The species therefore has a large variety of marine habitats, also
including estuary areas, although it does favour shallow coastal waters. It is thought that this
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species includes two types (ecotypes), one coastal, which is smaller in size, and one pelagic, with
a more robust body. The coastal ecotype is migratory, the open sea type is generally sedentary.
The bottlenose is highly social, it congregates in schools formed by females and their young, the
males form associations, also with other species (IUCN Red List of Threatened Species accessed
on 20 November 2013 from www.iucnredlist.org).
Bottlenose dolphins have been recorded landed at Jamestown, Senya Beraku (05°23’N,00°29’W)
and Tema. A small group has been recorded foraging around artisanal encircling gillnets set in
nearshore waters west of Cotonou, Benin. Four bottlenose dolphins of an undetermined
population, possibly offshore, were taken 10-16nm south of Vridi (ca. 05°14.5’N, 04°02.3’W), Ivory
Coast, in 1957-1958 (Cadenat and Lassarat, 1959a). Both inshore and offshore populations occur
off Angola year-round (Weir, 2007), as well as off western South Africa and Namibia (Ross,1977;
Findlay et al, 1992).
Bottlenose dolphin is the third-most frequently (15.5%) landed small cetacean in Ghana (OforiDanson et al, 2003). The location of the usual drift-gillnetting grounds suggests an offshore
population, although this has not been confirmed. A total of 11 live-capture attempts were made in
Walvis Bay, Namibia, in 1975, 1976 and 1983 (Findlay et al, 1992). Best and Ross (1984) warned
against capture operations on small coastal populations on South Africa’s west coast as ‘potentially
of more consequence’.
Figure 4-77
Spatial distribution of Tursiops truncates
Source: http://maps.iucnredlist.org/map.html?id=22563 accessed on 20 November 2013
4.11.2
Clymene dolphin (Stenella clymene)
The clymene dolphin is highly similar to the spinner, so much so that for many years it was
considered a variant type, until 1981 when it was reclassified as a separate species. It is very
commonly found in deep tropical and subtropical waters of the Atlantic. It is thought to frequent the
entire tropical coastline of western Africa (Perrin & Mead, 1994). It is pelagic, favouring deep
waters, including depths of over 5000m. It is gregarious and forms schools ranging from some
individuals to thousands, and is often found in association with the spinner dolphin S. longirostris
and short-beaked common dolphin Delphinus delphis (Perrin & Mead, 1994).
(IUCN Red List of Threatened Species accessed on 20 November 2013 from www.iucnredlist.org).
Robineau et al (1994) provided a first review of the presence of Clymene dolphin in West Africa,
but did not indicate records for Ghana. Ghanaian fishermen however are most familiar with the
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Clymene dolphin, some calling it ‘true dolphin’ or ‘Etsui Papa’ because the species is so frequently
found entangled in fishing gear. Many specimens have been landed at Keta (05°55' N, 00°59' E),
Winneba, Apam and Dixcove (Debrah, 2000; Ofori-Danson et al, 2003). A sighting was registered
in deep oceanic water at 02°10'N,02°30'W, some 160nm south of the Ghana coast (Perrin et al,
1981). From temporal distribution of captures, Clymene dolphins seem to be present year-round in
Ghanaian waters. South of the Gulf, credible sightings were reported from Congo and Angola
(Weir, 2006a, 2007). Being a tropical species, it is absent from the cool Benguela system off
southwestern Africa (Findlay et al, 1992).
Some 34.5 percent of captured cetaceans have been Clymene dolphins, more than of any other
species (Ofori-Danson et al, 2003). Most catches were by drift-gillnet fishermen operating out of
Apam and Dixcove. The COREWAM-Ghana database holds photographic evidence for at least 35
net-entangled specimens. In 2007, concern about the observed take led the CMS Scientific
Council to unanimously endorse an Appendix II listing proposal for the West African population
(Van Waerebeek, 2007). The population was added to Appendix II by the Conference of the
Parties in December 2008.
Figure 4-78
Spatial distribution of Stenella clymene
4.11.3
Spinner dolphin (Stenella longirostris)
The spinner dolphin is a small, toothed mammal of the Delphinidae family. It is commonly found in
tropical and temperate warm waters all over the world, its presence in the African Atlantic offshore
is poorly documented. Although it generally prefers the open seas it does at times frequent coastal
waters. The spinner is a social animal, forming pods ranging from just a few individuals to some
thousands.
Spinner dolphins have been offloaded at Dixcove and Axim in 2000. Skulls exist from specimens
collected at Abidjan, Côte d’Ivoire (van Bree, 1971) and in Liberia. (Broekema, 1983).
Weir (2007) reported sightings in deep pelagic areas off Angola. Spinner dolphins, typically wideranging and oceanic, are likely to occur throughout the deeper waters of the study area and the
entire eastern tropical Atlantic.
Morphology points to the pantropical subspecies S. longirostris longirostris (see Perrin, 1990).
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Conservation status is unknown. Spinner dolphins are only infrequently captured (3.5% of dolphin
takes) by Ghana’s artisanal fishermen (Ofori-Danson et al, 2003). The claim that tuna- dolphin
associations are rare in this ocean province and tuna purse-seiners rarely set upon dolphins is not
properly supported and stands in sharp contrast with the situation in the eastern tropical Pacific
(e.g. Perrin, 2004). If the captures by small-scale drift-gillnet boats in Ghana are any indication,
several species of tuna, billfish and sharks are habitually taken with dolphins in the same nets
(Debrah, 2000; Ofori-Danson et al, 2003).
Figure 4-79
Spatial distribution of Stenella longirostris
4.11.4
Pantropical spotted dolphin (Stenella attenuata)
The pantropical spotted dolphin is found in tropical and subtropical seas and oceans and
temperate warm waters all over the world, although sightings along the western coasts of Africa
are rare. Weir (2007a) reports 5 sightings in Angola bertween 2003 and 2006, in deep waters
beyond the continental slope, all located in northern Angolan waters in July.
The first supported record in Ghana was a juvenile examined at Apam in 1998; since then many
more have been collected from the main study sites. The species has been documented from Côte
d’Ivoire (Cadenat and Lassarat, 1959b; van Bree, 1971), Gabon (Fraser, 1950a) and offshore
waters of the eastern tropical Atlantic (Perrin et al, 1987). No records exist from the Atlantic coast
of South Africa (Findlay et al, 1992). A group was encountered off Pointe Pongara, southern shore
of the Gabon River estuary (Fraser, 1950a).
An high percentage (17.2%) of small cetaceans offloaded in Ghana ports were pantropical spotted
dolphins, making it the second-most frequently captured species (Ofori-Danson et al, 2003).
Spinner and pantropical spotted dolphins are the main marine mammal indicator species for the
presence of tuna in the eastern tropical Pacific (Perrin, 2004). For tuna fisheries in the eastern
Atlantic such associations have not yet been studied. Information on levels of incidental dolphin
mortality in these fisheries is scarce and of questionable credibility.
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Spatial distribution of Stenella attenuata
4.11.5
Atlantic spotted dolphin (Stenella frontalis)
The Atlantic spotted dolphin is commonly found in tropical and warm temperate waters of the
Atlantic ocean. Its presence is well documented at equatorial African latitudes (Guinea and Ivory
Coast; Perrin et al., 1994a) but there is little detailed information on distribution along the entire
western coast of Africa. The species is thought to include two ecotypes, a coastal type, more
spotted and larger in size, and a pelagic type, less spotted and smaller (Perrin et al., 1994b). The
former populates continental shelf areas (<200m), the latter deeper waters near the continental
slope.
Atlantic spotted dolphin is endemic to the eastern and western tropical Atlantic (Perrin et al, 1987).
The earliest reports of Atlantic spotted dolphin in Ghana refer to two bycatch victims at Dixcove,
one in 2000 and another in 2003. Two specimens were captured off Vridi, Côte d’Ivoire, in 1958
(Cadenat and Lassarat, 1959b). Off Benin, a group of 10 individuals was sighted in coastal waters
(Van Waerebeek, 2003). Gabon has also been cited as a range state (Perrin and Van Waerebeek,
2007). Atlantic spotted dolphin is reported from Angola (Weir, 2008), but the species avoids the
cold Benguela Current off Namibia and western South Africa (Findlay et al, 1992). As noted above,
the spotted dolphin collected off Gabon and reported by Fraser (1950a) as Stenella frontalis was
actually a pantropical spotted dolphin.
In Ghana in 1998-2000, Atlantic spotted dolphins accounted for 5.2 percent of the small cetacean
bycatch (Ofori-Danson et al, 2003). Two specimens were captured for research in Côte d’Ivoire
(Cadenat, 1959). The largest recorded mortality was attributed to fisheries in Mauritania involving
140 stranded dolphins of which at least 125 died (Nieri et al, 1999). Off Angola, Weir (2008)
detected negative responses in Atlantic spotted dolphins to seismic surveying off Angola.
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Spatial distribution of Stenella frontalis
4.11.6
Long-beaked common dolphin (Delphinus capensis)
Long-beaked common dolphins inhabit tropical and warm-temperate waters of all three major
oceans. D. capensis seems to prefer shallower and warmer water and occurs generally closer to
the coast than does D. delphis (Perrin 2002). It is found mostly over continental shelf water depths
(< 180 m), and generally does not occur around oceanic islands far from mainland coasts
(Jefferson and Van Waerebeek 2002). It sometimes associate with other species of cetaceans.
Long-beaked common dolphins generally occur within about 180 km of the coast. The overall
distribution of this species remains imperfectly known, because until 1994, all common dolphins
around the world were classified as a single species: D. delphis (Heyning and Perrin 1994).
There are two subspecies recognized:
 D. c. capensis – This subspecies appears to be found in distinct areas and apparentlydisjunct subpopulations are known from the east coast of South America, West Africa,
southern Japan, Korea and northern Taiwan (and possibly China), central California to
southern Mexico, Peru, and South Africa.
 D. c. tropicalis – This subspecies ranges in the Indo-Pacific from at least the Red
Sea/Somalia to western Taiwan/southern China and Indonesia, and including the Persian
Gulf and Gulf of Thailand (Jefferson and Van Waerebeek 2002).
This species is often confused with the short-beaked common dolphin D. delphis. Fishermen
landed two long-beaked common dolphins at Dixcove in 1999 and a third was landed at Axim in
2000. For the Gulf, Cadenat (1959) provided body measurements for 24 long-beaked common
dolphins from Côte d’Ivoire. Van Waerebeek (1997) re-examined nine West African dolphin skulls
considered D. delphis (van Bree and Purves, 1972) but assigned only two specimens to D. delphis,
one from Mayoumba, Gabon and another from Angola. Four skulls from Gabon, two from Angola
and one from Congo were assigned to D. capensis. Most common dolphins occurring within the
200-m isobath shelf in South African waters are D. capensis.
Common dolphin records, perhaps of both species, exist as far north as Walvis Bay, Namibia
(Findlay et al, 1992). Photographs off Gabon (in Rosenbaum and Collins, 2004) show a colouration
pattern consistent with that of D. capensis. It supports an earlier claim that long- beaked common
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dolphins are widely distributed in the Gulf of Guinea as well as off central Africa (Van Waerebeek,
1997).
Long-beaked common dolphins are avid bowriders and can easily be targeted with hand-held
harpoons. However, so far only a few have been recorded landed in Ghana ports. Simmons (1968)
reported the take of ‘common dolphins’ with tuna in the Gulf of Guinea.
Figure 4-82
Spatial distribution of Delphinus capensis
4.11.7
Fraser's dolphin (Lagenodelphis hosei)
It is an oceanic species that prefers deep offshore waters, but it can be seen near shore in some
areas where deep water approaches the coast (such as the Philippines, Taiwan, and some islands
of the Caribbean and the Indo-Malay archipelago) (Perrin et al. 1994).
In the eastern tropical Pacific, it occurs more often in Equatorial - southern subtropical surface
water and other waters typified by upwelling and generally more variable conditions (Au and
Perryman 1985). Off South Africa, records are associated with the warm Agulhas Current that
moves south in the summer (Perrin et al. 1994).
Fraser's Dolphins feed on midwater fish (especially myctophids), squid, and crustaceans (Dolar et
al. 2003). Physiological studies indicate that Fraser’s are capable of quite deep diving (and it is
thought that they do most of their feeding deep in the water column – in waters up to 600 m deep),
but they have been observed to feed near the surface as well (Watkins et al. 1994).
The exact distribution of this species is poorly known. Fraser's Dolphin has a pantropical
distribution, largely between 30°N and 30°S in all three major oceans (Jefferson and Leatherwood
1994, Dolar 2002). Strandings in temperate areas (Victoria in Australia, Brittany and Uruguay) may
represent extralimital forays connected with temporary oceanographic anomalies such as the
world-wide El Niño phenomenon in 1983–84, during which a mass stranding occurred in France
(Perrin et al. 1994). Bones et al. (1998) reported on a stranding on the coast of Scotland.
Records of Fraser’s dolphin in West Africa were recently reviewed (Weir et al, 2008). For Ghana,
only bycatch specimens are known: one in Axim in 2000 (Ofori-Danson et al, 2003), three at
Dixcove and Axim in 2000 (Debrah, 2000). One probable sighting is known from Nigeria and two
confirmed sightings from Angola (Weir et al, 2008). To the west, the closest record is Ile de
Sangomar (13°50'N, 16°46'W), Senegal (Van Waerebeek et al, 2000). However, Fraser’s dolphin
may be widely distributed in deep waters of the Gulf and the tropical SE Atlantic Ocean. In South
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Africa all records are from the warm Agulhas Current-influenced SE coast (Ross, 1984; Findlay et
al, 1992).
Of unknown status, Fraser’s dolphin is only occasionally taken in Ghana’s artisanal fisheries,
explainable by its preference for far offshore waters. The potential of bycatches by large pelagic or
foreign fishing vessels remains to be assessed.
Figure 4-83
Spatial distribution of Lagenodelphis hosei
4.11.8
Rough-toothed dolphin (Steno bredanensis)
The rough-toothed dolphin is a large mammal found in warm waters all over the world, although
with low abundance. It is typically an open sea mammal, preferring tropical and subtropical waters
of considerable depth. It is gregarious, often forming schools of some tens of individuals and has
been observed in association with the bottlenose dolphin Tursiops truncatus (in Gabon) and pilot
whale Globicephala macrorhynchus (in Angola).
Jefferson et al (1997) reported two undocumented sightings ‘off Ghana’ in 1972. At least four
catches are recorded in Ghana at Apam: one in 1999, two in 1998, and another one in 2002
(Debrah, 2000; Van Waerebeek et al, 1999). Rough-toothed dolphins are confirmed from Côte
d’Ivoire when 3 were taken 15-18nm south of Vridi in 1958 (Cadenat, 1959), a fourth (a skull) with
reported origin ‘Abidjan’ is at the US National Museum of Natural History. Only one specimen
record exists for Namibia (Möwe Bay, 19°20S,12°35’E) in 1986 (Findlay et al, 1992). Roughtoothed dolphins plausibly range in deep waters throughout the eastern tropical Atlantic.
In Ghana, rough-toothed dolphins are occasional victims of gillnet entanglement (3.5% of cetacean
catches). Apparently the Vridi specimens (Cadenat, 1959) were taken for research purposes. Little
else is known on the species’ status in the eastern tropical Atlantic.
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Spatial distribution of Steno bredanensis
4.11.9
Risso's dolphin (Grampus griseus)
Risso's dolphin is a cosmopolitan species of the Delphinidae family, absent only from high latitude
seas. It frequents all temperate and tropical waters with temperatures above 10°C (Notarbartolo di
Sciara, 2002). It favours the deep waters near continental escarpments and particularly zones
where the slope is most steep, as well as submarine canyons, also approaching the coast if the
seabed is sufficiently deep. However it is not uncommon to find it also near coasts (sightings in
platform zones in Gabon in 2004). It is usually observed in groups comprising 1 to 15-18
individuals (Weir, 2007a).
Ghana’s Fante fishermen have long been familiar with the Risso’s dolphin and call it ‘Eko tui’, the
parrot dolphin, in reference to its peculiar head shape. Confirmed landings are known at Apam in
1999, at Dixcove in 2000, and one at Axim in 2000 (Ofori-Danson et al , 2003). A crew chased a
small group of Risso's dolphins ca. 25nm off Côte d’Ivoire in 1958, in a failed harpooning attempt
(Cadenat, 1959). The species almost certainly occurs throughout the Gulf, but Ghana and Côte
d’Ivoire are the only confirmed range states.
The Risso’s dolphin inhabits tropical to cool-temperate waters which is in concordance with its
presence off Angola (Weir, 2007), Namibia and South Africa where it is associated with the shelf
edge and pelagic waters (Findlay et al, 1992).
Risso's dolphins are regularly captured (6.9% of catches) in Ghana’s artisanal fisheries (OforiDanson et al, 2003), but we know little else on the species’ status.
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Spatial distribution of Grampus griseus
4.11.10 Melon-headed whale (Peponocephala electra)
Most sightings are from the continental shelf seaward, and around oceanic islands; they are rarely
found in temperate waters. However, they do occur in some nearshore areas where deep water
approaches the coast (see Watkins et al. 1997; Wang et al. 2001a, b). In the eastern tropical
Pacific, the distribution of reported sightings suggests that the oceanic habitat of this species is
primarily in the upwelling modified and equatorial waters (Perryman et al. 1994).
Little is known of the diet of this species, though they are known to feed on several species of
squid, shrimp and small fish.
Melon-headed whales have a pantropical distribution (Perryman 2002). The distribution coincides
almost exactly with that of the pygmy killer whale in tropical/subtropical oceanic waters between
about 40°N and 35°S (Jefferson and Barros 1997). A few high-latitude strandings are thought to be
extralimital records, and are generally associated with incursions of warm water. These include
specimens from Cornwall in England, Cape Province in South Africa, and Maryland, USA
(Perryman et al. 1994; Rice 1998).
The melon-headed whale is known in the Gulf solely from bycatches in Ghana. Geographically
most adjacent records are, to the northwest, a skull from Guinea-Bissau (van Bree and Cadenat,
1968) and, to the south, three sightings in deep oceanic waters off Angola (Weir, 2007) plus a
stranding at Hout Bay (34°03' S,18°21'E), South Africa (Best and Shaughnessy, 1981).
Nonetheless, melon-headed whale may be widely distributed in the eastern tropical Atlantic but it is
probably fairly rare.
Melon-headed whales are accidentally netted with some regularity in Ghana waters. Specimens
have been landed in Shama in 1994 and at least four in Dixcove in 2000 and 2002. No other
information is available.
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Spatial distribution of Peponocephala electra
4.11.11 Pygmy killer whale (Feresa attenuata)
The pygmy killer whale occurs in deep, warm waters, generally beyond the edge of the continental
shelf, and rarely close to shore (except near some oceanic island groups where the water is deep
and clear). This species is mainly tropical, but occasionally strays into warm temperate regions.
Little is known of the diet of this species, although it is known to eat fish and squid. It has
occasionally been recorded attacking dolphins, at least those involved in tuna fishery interactions
in the eastern tropical Pacific (Perryman and Foster 1980).
This is a tropical/subtropical species that inhabits oceanic waters around the globe generally
between 40°N and 35°S. It does not generally approach close to shore, except in some areas
where deep, clear waters are very close to the coast (such as around oceanic archipelagos like
Hawaii). Reports of its occurrence in the Mediterranean Sea, while common in the literature, are
not supported by authenticated records. It is also doubtful whether it occurs regularly in the Red
Sea or Persian Gulf (Leatherwood et al. 1991). A few high-latitude strandings and sightings are
thought to be extralimital records, and are generally associated with incursions of warm water
(Ross and Leatherwood 1994; Donohue and Perryman 2002; Williams et al. 2002).
An adult-sized pygmy killer whale landed at Dixcove in 2007 is the first and only documented
record in the Gulf of Guinea. Records to the south from Annobon Island (01°24.2'S,05°36.8' E)
were reported by Tormosov et al (1980) however there is no voucher information and the records
cannot be verified. Indeed, confusion with melon-headed whales is very common. Off
southwestern Africa, pygmy killer whales have stranded in Cape Town and as far north as 23°S,
Namibia (Best, 1970; Findlay et al, 1992). Best (1970) documented in great detail four animals
stranded at Lüderitz Lagoon, but little other information is published.
An adult-sized pygmy killer whale was landed at Dixcove in December 2007, the only case
detected during our port monitoring (Van Waerebeek et al, 2009). Status is unknown but, as
elsewhere, pygmy killer whales are probably rare.
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Spatial distribution of Feresa attenuata
4.11.12 Short-finned pilot whale (Globicephala macrorhynchus)
The short-finned pilot whale Globicephala macrorhynchus is one of the two species of marine
mammals of the genus Globicephala, family Delphinidae. It is widely distributed in all seas but
mainly found in warm waters. It is a gregarious species and forms pods of tens or even hundreds
of individuals. Weir (2007a) reports that between 2003 and 2006 there were twenty two sightings of
pods, with from 4 to 200 animals. The sightings were made in open seas beyond the continental
shelf, in waters of average depth of 2000m, and throughout the entire year.
The other species in the genus is Globicephala melas (long-finned pilot whale). It is commonly
found in sub-polar temperate waters of oceans and seas that have a temperature range between
0°C and 25°C (Martin 1994). An open sea mammal with a gregarious temperament, it favours
deep waters, far from the coast. The species forms pods of large numbers.
Differentiating between the two species of the genus is difficult at sea. They are distinguished by
the length of the fins, G. macrorhynchus has short fins, G. melas long
Short-finned pilot whales seem to be fairly common in Ghana waters, and also occur off Côte
d’Ivoire (Cadenat, 1959). Pilot whales are also reported off Cap López, Gabon (Walsh et al, 2000).
Fraser (1950b) summarized the morphology of pilot whales in NW Africa. Distribution boundaries
to the south and SE are unclear. On South Africa’s Atlantic coast the cool-water- adapted longfinned pilot whale G. melas edwardii is found but no short-finned pilot whales have been recorded
(van Bree et al, 1978; Findlay et al, 1992).
Short-finned pilot whales are irregular bycatch victims in drift gillnets off Ghana (3.5% of cetacean
catches, Ofori-Danson et al, 2003) and have been landed at Shama, Axim and Dixcove.
Most specimens are too big to haul onboard artisanal fishing boats and are towed to port. The Vridi
specimen was harpooned for research purposes (Cadenat, 1959). A significant conservation
problem exists around the Canary Islands where animals are frequently hit by small boat propellers
during whale-watching (Heimlich-Boran,1990; Carwardine, 1994; Van Waerebeek et al, 2007).
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Spatial distribution of Globicephala macrorhynchus
4.11.13 Killer whale (Orcinus orca)
The orca or killer whale is a marine mammal belonging to the Delphinidae family, suborder
Odontoceti. It is extremely common in all oceans, from polar to tropical waters, although as a
general rule it prefers the cold waters of the poles, at times migrating to the equator. Its habitats
are highly varied, from open seas to shallow waters, including very low depths and sometimes
even the mouths of rivers. It is a highly social animal, typically congregating in pods with an
average of 15 individuals, usually composed of a female, her young, older females and one adult
male.
A single skeletal specimen is known for Ghana, possibly collected in 1956. A killer whale was
harpooned some 15-20nm south of Abidjan in 1958 but the animal sank. Cadenat (1959) claimed
that killer whales are regularly present in the region. Observers on industrial tuna purse-seiners
reported a few sightings off the coast of Liberia, Ivory Coast and Ghana (Hammond and Lockyer,
1988). Other sighting reports exist for Gabon (Reeves and Mitchell, 1988; Jefferson et al, 1997;
Rosenbaum and Collins, 2004). The presence of humpback whales with calves in many areas of
the Gulf may attract killer whales to prey on them.
The status in the region is unknown but no conservation problems have been identified. The only
killer whale reported taken in the Gulf was in 1958 (Cadenat, 1959).
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Spatial distribution of Orcinus orca
4.11.14 False killer whale (Pseudorca crassidens)
False killer whales occur in tropical and temperate waters worldwide (Stacey et al. 1994; Odell and
McClune 1999), generally in relatively deep, offshore waters. However, some animals may move
into shallow and higher latitude waters, on occasion (including some semi-enclosed seas such as
the Red Sea and the Mediterranean). The species seems to prefer warmer water temperatures. Off
Hawaii, this species is found in both shallow (less than 200 m) and deep water (greater than 2000
m) habitats (Baird et al. 2008).
Although false killer whales eat primarily fish and cephalopods, they also have been known to
attack small cetaceans, humpback whales, and sperm whales. They eat some large species of
fish, such as mahi-mahi (also called dorado or dolphinfish), tunas (Alonso et al. 1999) and sailfish.
In Hawaiian waters observational studies suggest that large game fish (mahi-mahi, tunas, billfish)
may form the majority of their diet (Baird et al. 2008).
False killer whales are found in tropical to warm temperate zones, generally in relatively deep,
offshore waters of all three major oceans. They do not generally range into latitudes higher than
50° in either hemisphere. However, some animals occasionally move into higher latitude waters.
They are found in many semi-enclosed seas and bays (including the Sea of Japan, Bohai/Yellow
Sea, Red Sea, and Persian Gulf), but they only occasionally occur in the Mediterranean Sea
(Leatherwood et al. 1989). There are a few records for the Baltic Sea, which are considered
extralimital. There are also records of false killer whales being found far into large rivers in China.
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The first record in Ghana comprises three false killer whales landed at Apam in 2003. Skulls were
collected from a false killer whale stranded near Assini (05°07'25"N, 03°06'40"W), Côte d’Ivoire, in
1970 (van Bree, 1972) and from a specimen in Benin (Van Waerebeek et al, 2001; Tchibozo and
Van Waerebeek, 2007). An animal live-stranded at Cap Esterias (00°37’N, 09°29’E), Gabon, in
1992 (Van Waerebeek and De Smet, 1996). Mörzer-Bruyns (1969) described a group of 30 off
Liberia at 04°48’N,11°24’W in 1961.
Nine sightings off Angola, in eight months of the year, were all located over deep-water areas
seaward of 1467m (Weir, 2007) in accordance with the species’ usual habitat elsewhere. Findlay et
al (1992) reported a mass stranding near Lüderitz, Namibia.
The conservation status of false killer whale in the Gulf is unknown. In Ghana, the species is
infrequently captured in drift gillnets. The animal that live-stranded in Gabon was butchered for
food (Van Waerebeek and De Smet, 1996).
Figure 4-90
Spatial distribution of Pseudorca crassidens
4.11.15 Cuvier's beaked whale (Ziphius cavirostris)
A toothed whale belonging to the family Ziphiidae, the beaked whale is named for its elongated
beak, typical of the family. It is commonly found in all oceans, in temperate and tropical waters. It is
typically an open sea mammal, rarely found near coastal and continental shelf waters. It favours
deep waters beyond continental slopes, with a marked preference for zones over submarine
canyons. In general it is solitary or congregates in small pods (2-4 individuals). Although present in
practically all seas, it seems to have a low abundance and is also poorly documented.
Cuvier's beaked whale is a cosmopolitan ziphiid found in pelagic tropical to warm temperate
waters. A juvenile landed at Axim in 1994 is the first documented beaked whale in the Gulf of
Guinea. Weir (2006b) described a group of 3 Cuvier’s beaked whales SW of Luanda, Angola, at
07°15.84’S,11°07.79’E, and reported a group of 3-4 ‘likely Cuvier’s beaked whales’ NW of Luanda.
Four other beaked whale sightings off Angola were not identified, but Cuvier’s beaked whale was
possible in three cases. The fourth was a Mesoplodon sp.
All encounters were over deep water seaward of the continental shelf (Weir, 2006b). Three
stranded Cuvier’s beaked whales are known from Namibia (21°-23°S) and another two from the
Atlantic coast of South Africa (Findlay et al, 1992).
The status of Cuvier’s beaked whale is unknown, but no threats are identified. The single capture
in Ghana among hundreds of other small cetaceans (Debrah, 2000; Ofori-Danson et al, 2003)
suggests that impact from bycatch is probably negligible.
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Spatial distribution of Ziphius cavirostris
4.11.16 Dwarf sperm whale (Kogia sima)
A relative of the sperm whale, this species is also known as the dwarf sperm whale due to its much
smaller size. It is one of the three species of Odontoceti of the family Physeteridae. Commonly
found in tropical and subtropical ocean waters, it seems to favour deep waters beyond the
continental shelf. The dwarf sperm whale is usually solitary but has occasionally been seen in
small pods.
In Ghana, a dwarf sperm whale was taken by fishermen from Apam in 1998. Two unidentified
Kogia sp. were landed, one at Shama in 1994 and another at Apam in 2003. No sightings exist for
the Gulf. In South Africa dwarf sperm whale distribution is limited to the South Coast between
Cape Columbine and c. 28°E. Stranded dwarf sperm whale specimens are recorded north to at
least 22°S at Cape Cross, Namibia (Ross 1984, Findlay et al 1992). Maigret and Robineau (1981)
reviewed the genus Kogia in Senegal and West Africa.
Although all three kogiid specimens, one K. sima and two Kogia sp. were captured in drift gillnets,
impact of fisheries cannot yet be evaluated. While entanglement rate seems low, populations may
also be small.
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Spatial distribution of Kogia sima
4.11.17 Sperm whale (Physeter macrocephalus)
Belonging to the suborder of Odontoceti, family Physeteridae, the sperm whale is found in oceans
worldwide, from the equator to cold water seas, with a marked preference for deep waters. It is a
typical open sea mammal, capable of diving to over 2500m. It prefers continental slope and canyon
areas, approaching the coast only where the seabed is particularly steep. Spatial distribution varies
according to age and gender: females and their young frequent temperate and tropical waters,
while males leave these nurseries in puberty and migrate to higher latitudes or even as far as polar
waters (Best, 1974). The social structure of the sperm whale is also determined by gender:
females are highly social, they congregate in pods of about a dozen individuals and their young;
males, once they have left the nursery, form pods of bachelors with other males of similar age and
size, becoming solitary in later life.
Hardly any information is available on sperm whales in the Gulf of Guinea, however at least
females and juveniles are thought to be present year-round beyond the continental shelf. In
Ghana, two dead sperm whales washed ashore, one near Accra in 1994 and a second at Dixcove
in 2002. Off Gabon, sperm whales were hunted from August till October (Slijper et al, 1964). Off
Angola, their density peaked between January and May (Weir, 2007a). As expected, sperm whales
were sighted exclusively seaward of the shelf break.
A notable cluster occurred west of the Congo River mouth. Natural history information is available
only for sperm whales off the southwest coast of South Africa (e.g. Best 1967, 1969, 1970). Sperm
whales are ‘Vulnerable’ according to the 2008 IUCN Red List and are listed in Appendix I of CMS.
Long-line fishermen targeting tuna and sharks in equatorial waters of the Gulf and farther south
complain about regular predation of hooked fish by sperm whales.
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Spatial distribution of Physeter macrocephalus
4.11.18 Humpback whale (Megaptera novaeangliae)
With few exceptions, such as the Arabian Sea population, humpback whales undertake long
migrations between breeding grounds in tropical coastal waters in winter to feeding grounds in
middle and high latitudes, mainly in continental shelf waters (Clapham 2002).
In the Southern Hemisphere, humpbacks appear to feed mainly in the Antarctic, where the diet
consists almost exclusively of krill (Euphausia superba) (Mackintosh 1970), although some feeding
in the Benguela Current ecosystem on the migration route west of South Africa has been observed
(Best et al. 1995; suspected prey species are: E. lucens and Themisto gaudichaudii).
The Humpback Whale is a cosmopolitan species found in all the major ocean basins (Clapham
and Mead 1999), and all but one of the subpopulations (that of the Arabian Sea) migrate between
mating and calving grounds in tropical waters, usually near continental coastlines or island groups,
and productive colder waters in temperate and high latitudes.
Humpbacks in the North Atlantic range in summer from the Gulf of Maine in the west and Ireland in
the east, and up to but not into the pack ice in the north; the northern extent of the humpback's
range includes the Barents Sea, Greenland Sea and Davis Strait, but not the Canadian Arctic.
They occur mainly in specific feeding areas, as noted below. In the winter the great majority of
whales migrate to wintering grounds in the West Indies, and an apparently small number use
breeding areas around the Cape Verde Islands.
In the North Pacific their summer range covers shelf waters from southern California, to the Gulf of
Alaska, Bering Sea and southern Chukchi Sea, the Aleutian chain and Kamchatka, Kurile Islands,
Okhotsk Sea and northeastern Japan. Wintering grounds are off the coasts of Mexico and Central
America, around the Hawaiian Islands, the Bonin Islands, Ryukyu Islands and the northern
Philippines, and possibly around additional island groups in the western North Pacific.
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Humpbacks are abundant throughout the Antarctic in summer south to the ice edge, but not within
the pack ice zone. In the winter, Southern Hemisphere whales aggregate into specific nearshore
breeding areas in the Atlantic, Indian Ocean and Pacific, two of which extend north of the equator,
i.e. off Colombia in the eastern Pacific and in the Bight of Benin in the Atlantic. Some wintering
grounds are fairly localized, e.g. around island groups, and some are more diffuse, e.g. along the
western coast of southern Africa and the southern coast of West Africa.
There is a resident year-round population in the Arabian Sea, which is genetically distinct from that
of the southern Indian Ocean.
Humpbacks rarely enter the Mediterranean and are considered only visitors there (Reeves and
Notarbartolo di Sciara 2006).
Irvine (1947) recorded a possible humpback whale at Prampram in September 1938. Van
Waerebeek and Ofori-Danson (1999) first confirmed the species from Ghana based on a fresh
neonate stranded at Ada (05°48.5’N,00°38'E) in September 1997. An adult-sized humpback whale
stranded at Ada Foah (05°46’33”N,0°36’58”E) in October 2006. Humpback whales are regularly
sighted inshore, e.g. from the Dixcove castle, from September till December. A neonate stranded
in Lomé, Togo, in August 2005 (Tchibozo and Van Waerebeek, 2007). Rasmussen et al (2007)
encountered several pods including a mother and possible newborn calf in Ghanaian waters in
October 2006.
From the presence of humpback whales exclusively from early August till late November, and the
frequent observations of neonates and ‘competitive groups’, it is evident that the continental shelf
of Benin, Togo, Ghana, and western Nigeria hosts a breeding/calving population with a Southern
Hemisphere seasonality (Van Waerebeek et al, 2001; Van Waerebeek, 2003), referred to as the
‘Gulf of Guinea stock’. Its parapatric distribution suggests it may be related to the IWC- defined
breeding stock ‘B’ from central-west Africa (IWC, 1997, 2006). Mother/calf pairs have been sighted
exclusively nearshore in Benin, sometimes just beyond the surf-zone. The westernmost
authenticated record is a stranding at Assini Mafia (05°7’25”N, 03°16’40”W), eastern Côte d’Ivoire
in August 2007 (Van Waerebeek et al, 2007). For many years, small-scale, seasonal humpback
whale-watching sorties have been conducted from the ports of Sekondi- Takoradi, Lomé and
Cotonou (Van Waerebeek et al, 2001). The breeding stock off Gabon and Angola is the subject of
long-tem dedicated studies (e.g. Best et al, 1999; Walsh et al 2000; Rosenbaum and Collins,
2004).
No abundance estimate is available for the Bight of Benin population, but encounter rate in
October 2000 was 0.109 humpback whales/nautical mile surveyed (Van Waerebeek et al, 2001).
The reported neonates stranded in unknown circumstances, both natural and anthropogenic
causes are possible. At least some humpback whale strandings in the area are thought to be
animals killed in vessel collisions, which may be far more common in African waters than scarce
reports suggest (Félix and Van Waerebeek, 2005; Van Waerebeek et al, 2007). Humpback whales
near Cotonou’s harbour entrance and crossing the main shipping lanes, incur obvious risk. The
individual that stranded at Assini Mafia was reported with external trauma consistent with a
propeller hit (see Van Waerebeek et al, 2007).
Table 4.40
Threatened Marine Mammals Species in Ghanaian Waters (IUCN Red List of
Threatened Species accessed on 20 November 2013 from www.iucnredlist.org) (IUCN Red List Status
CR=Critically Endagered; EN=Endagered; DD=Data deficient; LC=Least Concern; NT=Near
Threatened; VU=Vulnerable)
Scientific name
Globicephala macrorhynchus
Common name
Short-finned Pilot Whale
Red List Category
DD
Population
trend
Unknown
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Scientific name
Common name
Red List Category
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Population
trend
Grampus griseus
Risso's Dolphin
LC
Unknown
Kogia breviceps
Pygmy Sperm Whale
DD
Unknown
Kogia sima
Dwarf Sperm Whale
DD
Unknown
Lagenodelphis hosei
Fraser's Dolphin
LC
Unknown
Orcinus orca
Killer Whale
DD
Unknown
Stenella attenuata
Pantropical Spotted Dolphin
LC
Unknown
Stenella clymene
Clymene Dolphin
DD
Unknown
Stenella frontalis
Atlantic Spotted Dolphin
DD
Unknown
Stenella longirostris
Spinner Dolphin
DD
Unknown
Steno bredanensis
Rough-toothed Dolphin
LC
Unknown
Tursiops truncatus
Common Bottlenose Dolphin
LC
Unknown
Delphinus capensis
Long-beaked common dolphin
DD
Unknown
Peponocephala electra
Melon-headed whale
LC
Unknown
Pseudorca crassidens
False killer whale
DD
Unknown
Zipihius cavirostris
Cuvier’s beaked whale
This taxon has not yet
been assessed for the
IUCN Red List, and also
is not in the Catalogue of
Life.
N.A.
Physeter macrocephalus
Sperm whale
VU
Unknown
Megaptera novaengliae
Humpback whale
This taxon has not yet
been assessed for the
IUCN Red List, and also
is not in the Catalogue of
Life.
N.A.
4.12 SEA BIRDS
The west coast of Africa forms an important section of the East Atlantic Flyway (Figure 4-94), an
internationally-important migration route for a range of bird species, especially shore birds and
seabirds (Boere et al, 2006, Flegg 2004). A number of species breed in higher northern latitudes
winter along the West African coast and many fly along the coast on migration. Seabirds known to
follow this migration route include a number of tern species (Sterna sp.), skuas (Stercorarius and
Catharacta spp.) and petrels (Hydrobatidae).
The distance of the migration routes of these species from the shore depends on prey distribution
and availability (eg the abundance and distribution of shoals of anchovies or sardines) (Flegg
2004). Species of waders known to migrate along the flyway include sanderling (Calidris alba) and
knott (Calidris canuta). The highest concentrations of seabirds are experienced during the spring
and autumn migrations, around March and April, and September and October. Waders are present
during the winter months between October and March. The marine birds of Ghana include storm
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petrels (Oceanodroma castro) and Ascension frigatebirds (Fregata aquila). Records dating back to
the 1960s reveal only limited sightings of a few species (Elgood et al, 1994). The rarity of oceanic
birds may be attributable to the absence of suitable breeding sites (eg remote islands and rocky
cliffs) off the Ghana coast and in the Gulf of Guinea.
During the environmental baseline studies for the West African Gas Pipeline (WAGP, 2004) in
2002/2003, the survey crew recorded several sightings of black tern (Chlidonias niger), White
winged black tern (Chlidonias leucopterus), royal tern (Sterna maxima), common tern (Sterna
hirundo), sandwich tern (Sterna sandvicensis), great black-back gull (Larus marinus), lesser blackback gull (Larus fuscus), pomarine skua (Stercorarius pomarinus) and great skua (Catharacta
skua). The two species of skua are predominant in the Western offshore environment. Black terns
were mainly recorded at nearshore locations close to estuaries and/or lagoons. These species
leave the onshore areas to feed at sea during the afternoon. The general low diversity of marine
birds may be ascribed to lack of suitable habitats and availability of food resources in the offshore
area. There are 40 Important Bird Areas (IBAs) designated by Birdlife International within Ghana
(BirdLife
International
(2013)
Country
profile:
Ghana.
Available
from:
http://www.birdlife.org/datazone/country/ghana accessed on 20 November 2013). Six IBAs are
located along the coastline of Ghana, namely:






Amansuri wetland;
Densu Delta Ramsar Site;
Keta Lagoon Complex Ramsar Site;
Muni-Pomadze Ramsar Site;
Sakumo Ramsar Site; and
Songor Ramsar Site.
According to BirdLife International (2013) in Ghana there are a total of 676 species of birds divided
in Landbirds (555 species), Migratory (211 species), Seabirds (15 species) and Waterbirds (120
species).
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Figure 4-94
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Representation of East Atlantic Flyway (Boere et al, 2006, Flegg 2004)
Overall the IUCN red List Status of bird species in Ghana is shown in Figure 4-95 while the list of
seabirds species is shown in Table 4.41.
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Figure 4-95
Overall IUCN Red List Status of bird species in Ghana (BirdLife International (2013)
Country profile: Ghana. Available from: http://www.birdlife.org/datazone/country/ghana accessed on
20 November 2013)
Table 4.41
Seabirds Species List in Ghana (BirdLife International (2013) Country profile: Ghana.
Available from: http://www.birdlife.org/datazone/country/ghana accessed on 20 November 2013)
(IUCN Red List Status CR=Critically Endagered; EN=Endagered; DD=Data deficient; LC=Least
Concern; NT=Near Threatened; VU=Vulnerable)
Species
Sterna balaenarum
Phalacrocorax carbo
Pelecanus onocrotalus
Stercorarius
pomarinus
Larus fuscus
Larus ridibundus
Sterna nilotica
Sterna caspia
Sterna maxima
Sterna sandvicensis
Sterna hirundo
CommonName
Damara Tern
Great Cormorant
Great White Pelican
IUCN
Category
NT
LC
LC
Pomarine Jaeger
Lesser Black-backed Gull
Black-headed Gull
Gull-billed Tern
Caspian Tern
Royal Tern
Sandwich Tern
Common Tern
LC
LC
LC
LC
LC
LC
LC
LC
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Species
Sterna paradisaea
Sterna albifrons
Chlidonias niger
Sterna dougallii
CommonName
Arctic Tern
Little Tern
Black Tern
Roseate Tern
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IUCN
Category
LC
LC
LC
LC
4.13 SEA TURTLES
The Gulf of Guinea serves as an important migration route, feeding ground, and nesting site for
sea turtles. Five species of sea turtles have been confirmed for Ghana, namely the loggerhead
(Caretta caretta), the olive ridley (Lepidochelys olivacea), the hawksbill (Erectmochelys imbricata),
the green turtle (Chelonia mydas), and the leatherback (Dermochelys coriacea) (Armah et al, 1997,
Fretey, 2001). All five species of sea turtles are listed by the CITES and National Wildlife
Conservation Regulations under Schedule I. The olive ridley is listed by the World Conservation
Union (IUCN) as vulnerable while the loggerhead and green turtles are listed as endangered. The
hawksbill and the leatherback are listed as critically endangered.
All species except the hawksbill are captured with some regularity in fishing nets set off Ghana.
Although fully protected by national and international legislation, sea turtles that are landed are
sold locally for human consumption.
The EEZ waters of Ghana constitute a known feeding area for at least the green turtle. However,
there is no published information on the spatial and temporal distribution of turtles in both
nearshore and offshore waters. Recent sea turtle telemetry tagging undertaken by a team from the
Department of Oceanography and Fisheries, University of Ghana and Galathea II team from
Denmark indicated that sea turtles from Ghana migrate as far west as the inshore areas of Liberia.
Marine turtles spend most of their life at sea, but during the breeding season they go ashore and
lay their eggs on sandy beaches. The beaches of Ghana from Keta to Half-Assini are important
nesting areas for sea turtle species.
Approximately 70 percent of Ghana’s coastline is found suitable as nesting habitat for sea turtles,
and three species; the green turtle, olive ridley and leatherback turtles are actually known to nest
(Armah et al, 1997; Amiteye, 2002). The olive ridley is the most abundant turtle species in Ghana.
Population estimates from four previous surveys of these turtle species are provided in Table 4.42.
The nesting period stretches from July to December, with a peak in November (Armah et al, 1997).
In Ghana, the majority nests observed (86.3 percent) are those of the olive ridley.
Table 4.42
Population of the three sea turtle species that nest on the beaches of Ghana
In the Western region, the beaches at Kengen, Metika Lagoon, Elonyi, Anochi, Atuabo and Benyin
are important nesting sites for sea turtles. The prime nesting sites have been identified as the
coastline from Prampram (about 10 to 15 km east of Tema) to Ada and the areas beyond the Volta
estuary to Denu, in the Volta region. It is also evident that moderate nesting occurs from Winneba
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through Bortianor and on some beaches around Accra such as Gbegbeyise and Sakumono
(Amiteye, 2002). These nesting sites are located along the eastern coast of Ghana.
Despite their protected status, marine turtles continue to face various forms of threat on Ghanaian
beaches. The major threat to marine turtle population in Ghana is predation on eggs and juveniles
by domestic animals especially pigs and dogs (Billes, 2003). Human exploitation also contributes
significantly to the decline in turtle population in Ghana. Female turtles which come to the beaches
to lay eggs are normally ambushed and killed as soon as they start laying because they become
weak and hence easy to capture. Where the female succeeds to complete laying the eggs, the
local people walk the beaches at dawn to look for the tracks and dig up the eggs. Special fishing
nets are used by local fishermen for capturing the turtles. The turtle meat and eggs obtained by the
above methods are eaten or traded for cash income.
The Ghana Wildlife Society has been carrying out sea turtle research and monitoring activities,
conservation education and enforcement of legislation since 1995. The marine turtle conservation
project is a contribution towards the achievement of Ghana’s national goal of sustainable
management of coastal resources and wetland habitats. The objective of the project is to promote
the socio-economic development of coastal communities through marine turtle conservation.
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Figure 4-96
Sea turtle habitats/sites/nesting, Africa (Source: Ocean Biogeographic Information
System - Spatial Ecological Analysis of Megavertebrate Populations (OBIS-SEAMAP) website)
Figure 4-97
Sea turtle habitats/sites/nesting, Gulf of Guinea (Source: Ocean Biogeographic
Information System - Spatial Ecological Analysis of Megavertebrate Populations (OBIS-SEAMAP)
website)
4.13.1
Olive Ridley (Lepidochelys olivacea)
The Olive Ridley sea turtle has a circumtropical distribution, with nesting occurring throughout
tropical waters (except the Gulf of Mexico) and migratory circuits in tropical and some subtropical
areas (Atlantic Ocean – eastern central, northeast, northwest, southeast, southwest, western
central; Indian Ocean – eastern, western; Pacific Ocean – eastern central, northwest, southwest,
western central) (Pritchard 1969). Nesting occurs in nearly 60 countries worldwide. Migratory
movements are less well studied than other marine turtle species but are known to involve coastal
waters of over 80 countries. With very few exceptions they are not known to move between ocean
basins or to cross from one ocean border to the other. Within a region, Olive Ridleys may move
between the oceanic and neritic zones (Plotkin et al. 1995, Shanker et al. 2003) or just occupy
neritic waters (Pritchard 1976, Reichart 1993).
Like most other sea turtles, Olive Ridleys display a complex life cycle, which requires a range of
geographically separated localities and multiple habitats (Márquez 1990). Females lay their nests
on coastal sandy beaches from which neonates emerge and enter the marine environment to
continue their development. They remain in a pelagic phase, drifting passively with major currents
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that disperse far from their natal sites, with juveniles sharing some of the adults’ habitats (Kopitsky
et al. 2000) until sexual maturity is reached (Musick and Limpus 1997). Reproductively active
males and females migrate toward coastal zones and concentrate near nesting beaches. However,
some males appear to remain in oceanic waters and mate with females en route to their nesting
beaches (Plotkin et al. 1996, Kopitsky et al. 2000). Their post-breeding migrations are complex,
with pathways varying annually (Plotkin 1994) and with no apparent migratory corridors, swimming
hundreds or thousands of kilometers over large ocean expanses (Morreale et al. 2007), commonly
within the 20°C isotherms (Márquez 1990). In the East Pacific, they are present from 30°N to 15°S
and often seen within 1,200 nautical miles from shore although they have been sighted as far as
140°W (IATTC 2004). Western Atlantic Olive Ridleys appear to remain in neritic waters after
breeding (Pritchard 1976, Reichart 1993).
Size: Adult Length 60-70 cm Mass up to 70 kg/ Hatchlings Length 25 mm. Mass 15-20 g
Distribution: Circumglobal.Nesting areas in tropical to sub-tropical regions.Non-nesting range
extends to temperate regions.
Reproduction: Reproduce every 1-3 years. Lay 1-3 clutches of eggs per season. Lay 90-130 eggs
per clutch. Ping-pong ball size eggs weigh approximately 30 grams each. Incubation period
approximately 60 days long.
(IUCN Marine Turtle Specialist Group accessed on 20 November 2013 http://iucn-mtsg.org)
4.13.2
Green Turtle (Chelonia mydas)
The Green Turtle has a circumglobal distribution, occurring throughout tropical and, to a lesser
extent, subtropical waters (Atlantic Ocean – eastern central, northeast, northwest, southeast,
southwest, western central; Indian Ocean – eastern, western; Mediterranean Sea; Pacific Ocean –
eastern central, northwest, southwest, western central). Green turtles are highly migratory and they
undertake complex movements and migrations through geographically disparate habitats. Nesting
occurs in more than 80 countries worldwide (Hirth 1997). Their movements within the marine
environment are less understood but it is believed that green turtles inhabit coastal waters of over
140 countries (Groombridge and Luxmoore 1989).
Like most sea turtles, green turtles are highly migratory and use a wide range of broadly separated
localities and habitats during their lifetimes (for review see Hirth 1997). Upon leaving the nesting
beach, it has been hypothesized that hatchlings begin an oceanic phase (Carr 1987), perhaps
floating passively in major current systems (gyres) that serve as open-ocean developmental
grounds (Carr and Meylan 1980, Witham 1991). After a number of years in the oceanic zone, these
turtles recruit to neritic developmental areas rich in seagrass and/or marine algae where they
forage and grow until maturity (Musick and Limpus 1997). Upon attaining sexual maturity green
turtles commence breeding migrations between foraging grounds and nesting areas that are
undertaken every few years (Hirth 1997). Migrations are carried out by both males and females
and may traverse oceanic zones, often spanning thousands of kilometers (Carr 1986, Mortimer
and Portier 1989). During non-breeding periods adults reside at coastal neritic feeding areas that
sometimes coincide with juvenile developmental habitats (e.g., Limpus et al. 1994, Seminoff et al.
2003).
Size: Adult Length 80-120 cm. Mass up to 300 kg/ Hatchlings Length 30-40 mm. Mass 25-30 g
Distribution: Nesting areas throughout tropical regions are often on islands and coral atolls in
addition to mainland beaches. Non-nesting range extends to temperate regions during immature
stages.
per clutch. Large ball size eggs weigh approximately 40-50 grams. Incubation period approximately
60 days long. Can take 20-40 years to reach sexual maturity
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4.13.3
Leatherback Turtle (Dermochelys coriacea)
The Leatherback turtle has a worldwide distribution. It is found from tropical to sub-polar oceans;
nests on tropical (rarely subtropical) beaches. Very little is known about the distribution of posthatchlings and juveniles. Leatherbacks smaller than 100 cm curved carapace length seem limited
to regions warmer than 26°C. Sightings of turtles less than 145 cm show that some juveniles
remain near to the coast in St. Lucia, E. Trop. Pacific, Mexico, Barbados, USA (east and west
coast-Georgia, S. Carolina, Texas, Rhode Island, California) Puerto Rico, Amer. Samoa, Bonaire,
Chile, Spain, Venezuela, Scotland, and England (Eckert 1999).
Main Habitats are nest on sandy beaches. The juveniles may remain in tropical waters warmer
than 26°C, near the coast, until they exceed 100 cm in curved carapace length. When adults, they
are pelagic and live in open ocean, sometimes in temperatures below 10°C. There are very few
sighting of males near the coast during the breeding season, only the females are near to the coast
during the breeding season and go to the beach to nest.
Size: Adult Length 140-160 cm Mass 300-1000 kg/ Hatchlings Length 50 mm Mass 40-50 g
Distribution: Present in all world’s oceans except Arctic and Antarctic. Nesting areas in tropics.
Non-nesting range extends to sub-polar regions
per clutch. Billiard ball size eggs weigh roughly 80 grams. Incubation period is approximately 60
days long.
4.13.4
Hawksbill Turtle (Eretmochelys imbricate)
The Hawksbill has a circumglobal distribution throughout tropical and, to a lesser extent,
subtropical waters of the Atlantic Ocean, Indian Ocean, and Pacific Ocean. Hawksbills are
migratory and individuals undertake complex movements through geographically disparate habitats
during their lifetimes. Hawksbill nesting occurs in at least 70 countries, although much of it now
only at low densities. Their movements within the marine environment are less understood, but
Hawksbills are believed to inhabit coastal waters in more than 108 countries (Groombridge and
Luxmoore 1989, Baillie and Groombridge 1996).
Hawksbills nest on insular and mainland sandy beaches throughout the tropics and subtropics.
They are highly migratory and use a wide range of broadly separated localities and habitats during
their lifetimes (for review see Witzell 1983). Available data indicate that newly emerged hatchlings
enter the sea and are carried by offshore currents into major gyre systems where they remain until
reaching a carapace length of some 20 to 30 cm. At that point they recruit into a neritic
developmental foraging habitat that may comprise coral reefs or other hard bottom habitats, sea
grass, algal beds, or mangrove bays and creeks (Musick and Limpus 1997) or mud flats (R. von
Brandis unpubl. data). As they increase in size, immature Hawksbills typically inhabit a series of
developmental habitats, with some tendency for larger turtles to inhabit deeper sites (van Dam and
Diez 1997, Bowen et al. 2007). Once sexually mature, they undertake breeding migrations
between foraging grounds and breeding areas at intervals of several years (Witzell 1983, Dobbs et
al. 1999, Mortimer and Bresson 1999). Global population genetic studies have demonstrated the
tendency of female sea turtles to return to breed at their natal rookery (Bowen and Karl 1997),
even though as juveniles they may have foraged at developmental habitats located hundreds or
thousands of kilometers from the natal beach. While Hawksbills undertake long migrations, some
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portion of immature animals may settle into foraging habitats near their beaches of origin (Bowen
et al. 2007).
Size: Adult Length 75-90 cm. Mass up to 150 kg/ Hatchlings: Length 30 mm. Mass 5 g
Distribution: Nesting areas in tropics. Non-nesting range is generally restricted to tropical regions,
although during immature stages it extends to sub-tropical regions.
per clutch. Ping-pong ball size eggs with approximately 25-30. Incubation period is approximately
60 days long.
(IUCN Marine Turtle Specialist Group accessed on 20 November 2013 http://iucn-mtsg.org).
4.13.5
Loggerhead Turtle (Caretta caretta)
Loggerhead sea turtles are found in coastal tropical and subtropical waters often extending to
temperate waters in search of food. Found in the Atlantic Ocean from Argentina to Nova Scotia.
The highest populations in North America are found on barrier islands from North Carolina to the
Florida Keys. These Florida loggerheads migrate to the Bahamas in the winter. Small populations
of the Atlantic loggerhead are also found on barrier islands off of the Texas coast. Primary habitat
is in southeastern United States ranging southward to South America and extending eastward to
Africa and the Mediterranean as well as areas of the western Pacific and Indian Oceans.
Hatchling habitat is primarily in warm ocean currents among flotsam such as sargassum mats.
Adult habitat includes rock outcroppings and reefs near shore as well as in brackish lagoons and
the mouths of inlets. Long migrations often occur, especially to return to nesting beaches.
(MarineBio accessed on 20 November 2013 http://marinebio.org)
Size: Adult Length 70-100 cm. Mass up to 200 kg/ Hatchlings: Length 25 mm. Mass 15-20 g
Distribution: Nesting areas in tropical to sub-tropical regions; Non-nesting range extends to
temperate regions. Loggerheads exhibit trans-oceanic developmental migrations from nesting
beaches to immature foraging areas on opposite sides of ocean basins.
per clutch. Large ping-pong ball size eggs weigh 30-40 grams. Can take 20-30 years to reach
sexual maturity.
4.13.6
Kemp's ridley sea turtle (Lepidochelys kempii)
Kemp’s ridley turtles have an extremely restricted range; found mainly in the Gulf of Mexico and
some way up the eastern seaboard of the United States. The epicenter of nesting is a 20 kilometre
beach at Rancho Nuevo in Northeast Mexico, with most nesting in the Mexican state of
Tamaulipas. Nesting has also been documented in Veracruz and Campeche, Mexico, as well as in
various U.S. states. Most U.S. nesting occurs in Texas, with nesting coastwide, but concentrated in
the southern part of the state.
Adults inhabit crab-rich shallow inshore waters near the coast. Juveniles are also found in shallow
waters, often where there are eelgrass beds and areas of sand, gravel and mud.
(Arkive accessed on 20 November 2013 http://www.arkive.org)
Size: Adults: Length 60-70 cm; mass up to 60 kg/ Hatchlings: Length 25 mm. Mass 15 to 20 g
Distribution: Most restricted geographic range of all sea turtle species. Only nesting areas in
Rancho Nuevo, Tamaulipas, Mexico, and in Texas, U.S. Non-nesting range extends between the
Northwest Atlantic Ocean, the Gulf of Mexico, and the Caribbean.
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per clutch. Ping-pong ball size eggs weigh approximately 30 grams each. Incubation period is
approximately 60 days long. Takes 10-15 years to reach sexual maturity.
On the 15th June 2009 the Nature Conservation Research Centre (NCRC) and Beyin Beach
Resort commissioned a back ground study on the Sea Turtle on the West Coast of Ghana. This
study (due for completion on 1st November 2009) has identified a strong interest from resorts and
fishing village communities to better understand sea turtle populations and ecology and build on
efforts already seen at the local scale by Green Turtle Lodge and Beyin Beach Resort.
Figure 4-98
Beyin Beach Sea Turtle Conservation Program Area (from interviews during eni OCTP
Block Site Selection June 2012 survey)
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Figure 4-99
Beyin Beach and Green Turtle Lodge Sea Turtle Conservation Program Areas (from
interviews during eni OCTP Block Site Selection June 2012 survey)
According to the Sea Turtle Conservation on the West Coast of Ghana - A Background Report
(October 2009) the population of sea turtles on Ghana’s West Coast is without a doubt declining.
All coastal communities consistently reported observing less of all species of sea turtles now than
ever before.
Sea turtles move into Ghanaian West Coast water to mate and prepare for nesting primarily
between the months of August and April, with a peak in activity during October, November and
December.
Most sea turtles prefer to nest near where the vegetation line meets the first sand dune. Lights,
noise and physical obstacles that are usually associated with West Coast development prevent
nesting in this area.
The list of sea turtle species and their possible observation is reported in the Table 4.43.
Table 4.43
Sea turtle species and likelihood of being observed on west coast of Ghana
Since 2007 Beyin Beach Resort in collaboration with local villagers have been collecting data for
both the Olive Ridley and Green turtles nesting.
Where nests were discovered, the clutches were transferred to the Beyin Beach Turtle Hatchery,
because of the threats, primarily due to human predation. The percentage of relocated clutches
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that hatched within the hatchery at Beyin Beach Resort since August 2008 was 79 percent. Other
results such as hatchling success, incubation period and clutch size are summarised in the Table
4.44 below
Table 4.44
Results of Beyin Beach Sea Turtle Conservation Program
The data also indicates that the most active months that the Olive Ridley and Green Turtles nest at
Beyin are September, October and November and also between the months of August to April.
The total number of eggs relocated along the 10kms of beach at Beyin for the period of August
2008 to May 2009 was 5998.
Table 4.45
Threatened Sea Turtles Species (IUCN Red List of Threatened Species accessed on 20
November 2013 from www.iucnredlist.org) (IUCN Red List Status CR=Critically Endagered;
EN=Endagered; DD=Data deficient; LC=Least Concern; NT=Near Threatened; VU=Vulnerable)
Scientific name
Lepidochelys olivacea
Chelonia mydas
Dermochelys coriacea
Eretmochelys imbricate
Caretta caretta
Lepidochelys kempii
Common name
Olive Ridley
Green Turtle
Leatherback Turtle
Hawksbill Turtle
Loggerhead
Kemps Ridley Turtle
Red List Category
VU
EN
CR
CR
Population trend
criteria
Decreasing
Atlantic easter and central/Terrestrial
Marine system/Oceanic
habitat/assessment year 2008
Decreasing
Decreasing
Decreasing
EN
CR
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4.14 FISH ECOLOGY
The composition and distribution of fish species found in Ghanaian waters, and the wider Gulf of
Guinea, is influenced by the seasonal upwelling that occurs between Nigeria and the Ivory Coast
mainly in July to September and to a lesser extent in December to February.The rising of colder,
dense and nutrient-rich deep waters stimulate high levels of primary production (phytoplankton)
and consequently this will increases the production of zooplankton and fish.
The fish species find in Ghanaian waters belong to four groups:
 small pelagic species;
 large pelagic species (tuna and billfish);
 demersal (bottom dwelling) species; and
 deep sea species
4.14.1
Small pelagic species
The pelagic fish assemblage consists of a number of species that are exploited commercially but
are also important members of the pelagic ecosystem, providing food for a number of large
predators, particularly large pelagic fish such as tuna, billfish and sharks. The most important
pelagic fish species find in the coastal and offshore waters of Ghana are:
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round sardinella (Sardinella aurita);
flat sardinella (S. maderensis);
European anchovy (Engraulis encrasicolus); and
chub mackerel (Scomber japonicus).
These species are important commercially as they represent approximately 80 percent of the total
catch landed in the country.
Acoustic surveys have shown that the two sardinella species and the European anchovy represent
almost 60percent of the total biomass in Ghanaian waters (FAO & UNDP, 2006).
Sardinella
Both sardinella species are found throughout Ghanaian coastal waters and the local population is
part of the Central Upwelling Zone stock which is one of three stocks along the West African coast.
The eggs and larvae of the sardinellas are found all year but distinct peaks in spawning are seen
between July and August during the upwelling periods. The eggs are planktonic and found in the
upper mixed layer and upon hatching the larvae feed on plankton in the upper layers. Adults exhibit
seasonal migration towards the shore (see Figure 4-100). Juveniles remain in shallow water until
maturation when they migrate into deeper shelf waters to join the adult stock.
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Migratory Pattern of the Sardinellas
European Anchovy
The European anchovy is found throughout European waters and all along the West African coast
as far as Angola. European anchovy are mainly a coastal marine species but they can tolerates a
wide range of salinities and may be found in lagoons, estuaries and lakes, especially during
spawning. This species shows a tendency to extend into more waters further north in summer
where it moves into the surface water layers. During the winter the populations retreat and
descend to deeper water where they can be found as deep as 400 m in West Africa and deeper in
more northerly areas. This species forms large schools and feeds on planktonic organisms,
especially copepods and mollusc larvae and the eggs and larvae of fish. Spawning takes place
over an extended period from April to November with peaks usually in the warmest months.
Chub Mackerel
Chub mackerel are a cosmopolitan species and inhabit the warm and temperate transition waters
of the Atlantic, Indian and Pacific oceans and adjacent seas. They are primarily coastal pelagic
species and are found from the surface down to depths of 300 m. However, they may extend into
the epipelagic(1) (to 200 m) or mesopelagic (200 to 1,000 m) waters over the continental slope.
Seasonal migrations may be very extended, with entire populations in the northern hemisphere
moving further northward with increased summer temperatures and southwards for overwintering
and spawning. In Ghanaian waters spawning, in common with most pelagic species, coincides with
the seasonal upwelling. The chub mackerel is an opportunistic and non-selective predator, feeding
on copepods and other crustaceans, fish and squid. Its predators include tuna, billfish and other
fishes, as well as sharks and pelicans.
Other Pelagic Species
Other pelagic species found in Ghanaian water:
 horse mackerel (Trachurus sp.);
 little tunny (Euthynnus alletteratus);
 bonga shad (Ethmalosa fimbriata);
 African moonfish (Selene dorsalis);
 West African Ilisha (Ilisha africana);
 largehead hairtail (Triciurus lepturus);
 crevalle jack (Caranx hippos);
 Atlantic bumper (Chloroscombrus chrysurus); and
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Barracuda (Sphyraena sp.).
Large Pelagic Species
Large pelagic fish stocks off the coast of Ghana include tuna and billfish. These species are highly
migratory and occupy the surface waters of the entire tropical and sub-tropical Atlantic Ocean.
They are important species in the ecosystem as both predators and prey for sharks, other tuna and
cetaceans as well as providing an important commercial resource for industrial fisheries.
The tuna species are:
 skipjack tuna (Katsuwonus pelamis);
 yellowfin tuna (Thunnus albacares); and
 bigeye tuna (Thunnus obesus).
Billfish species occur in much lower numbers and comprise:
 swordfish (Xiphias gladius);
 Atlantic blue marlin (Makaira nigricans); and
 Atlantic sailfish (Istiophorus albicans).
Skipjack Tuna
Skipjack tuna is a cosmopolitan species found in schools in tropical and subtropical waters. This
wide distribution accounts for the number and variety of fisheries that have developed all around
the world.
The species is epipelagic generally inhabiting open waters with aggregations associated with
convergences, boundaries between cold and warm water masses, and other hydrographic
discontinuities. Depth distribution ranges from the surface to about 260 m during the day, however,
they remain close to the surface during the night.
In the Eastern Atlantic skipjack tuna spawn over a wide area on either side of the equator, from the
Gulf of Guinea to 20º to 30ºW. Spawning seasons differ according to the zone, in the southern part
of their range (Liberia, Ivory Coast, Ghana and Cape Lopez) spawning mainly takes place during
the first and fourth quarters of the year (Cayré and Farrugio, 1986).
In common with other tuna species, skipjack tuna is an opportunistic predator with the principal
prey being fish (mainly mackerels and pilchards), cephalopods and crustaceans.
Yellowfin Tuna. Yellowfin are found in open waters of tropical and subtropical seas worldwide
where they are generally confined to the upper 100 m of the water column with their vertical
distribution being influenced by the thermal structure of the water column.
Yellowfin tuna found in Ghana form part of an Atlantic population which spawns off Brazil and in
the Gulf of Guinea and migrates to the Equatorial East Atlantic in the austral summer. The Gulf of
Guinea is one of the most important areas for yellowfin tuna in the Atlantic population and large
aggregations are found in near-surface waters, often associated with floating debris. Yellowfin tuna
feed near the surface, mainly on epipelagic fish.
Bigeye Tuna
Bigeye tuna form part of an Eastern Atlantic population whose core distribution extends from northwest Africa to southern Angola.
Generally this species is epipelagic and mesopelagic in oceanic waters, occurring from the surface
to about 250 m in depth. Vertical distribution is influenced by water temperature and thermocline
depth, although their range differs from yellowfin tuna.
Spawning takes place throughout the year in a vast zone in the vicinity of the equator with
temperatures above 24ºC. The Gulf of Guinea is one of the most important spawning areas for this
species.
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The diet of bigeye tuna includes a variety of fish species, cephalopods and crustaceans, however,
they forage over a greater vertical range and feed on a wider range of fish and cephalopod species
than yellowfin tuna, due to the latter’s more narrow temperature range.
Atlantic Blue Marlin
Atlantic blue marlin is an epipelagic oceanic species, found in wide open waters. Adults spends
over 80% of their time in the surface water, however, they undergo frequent, short duration dives to
depths of between 100 and 200 m. Blue marlin display extensive migratory patterns, making transequatorial movements between the eastern and western Atlantic, although they are less abundant
in the eastern Atlantic than the western Atlantic. Off the west coast of Africa they mostly occur
between 25°N and 25°S, with important concentrations being found within the Gulf of Guinea.
Spawning takes place during austral spring-summer and boreal summer. Most spawning takes
place in the western Atlantic. Blue marlin feed near the surface and in deep water where they feed
opportunistically on schooling stocks of flyingfish, small tunas, dolphinfish and squid.
Swordfish
Swordfish are a cosmopolitan species found in tropical, temperate and sometimes cold waters of
all oceans, including the Mediterranean Sea.
They are mainly found in open oceanic waters but may occasionally be found in coastal waters,
generally above the thermocline (Colette, 1995). Migrations consist of movements toward
temperate or cold waters for feeding in summer, and back to warm waters in autumn for spawning
and overwintering.
Swordfish spawning grounds are known to be present in the western Atlantic and the
Mediterranean and spawning takes place throughout the year in the western Atlantic with a peak
from April to September.
Adult swordfish are opportunistic feeders. Over deep water, they feed primarily on pelagic fish,
including tuna, dolphinfish, flyingfish, barracuda and pelagic squid. In shallower waters their diet
consists mainly of mackerel, herring, anchovy, sardines and needlefish. Large adults often make
feeding trips to the bottom to feed on demersal fish including hake, redfish and lanternfish.
Sailfish
Sailfish are found throughout the tropical and temperate Atlantic Ocean. In the eastern Atlantic its
distribution extends from the Bay of Biscay to the Cape of Good Hope. It is an epipelagic and
coastal to oceanic species, often found above the thermocline, although it is known to frequently
make short dives to depths of up to 250 m.
Sailfish spawning areas in the Atlantic are mainly found in the tropical areas of both hemispheres.
In the eastern Atlantic, spawning has been observed in West African shelf waters throughout the
year. Sailfish migration routes are not fully understood, however, it is thought that most adults
remain in the same location and there are few, if any, trans-Atlantic migrations. Adult sailfish feed
opportunistically on schooling stocks of halfbeaks, jacks, small tunas, and cephalopods. Larvae
sailfish feed on copepods.
Juveniles and small adults of skipjack, yellowfin and bigeye tuna school at the surface either in
mono-species groups or together and these schools are often associated with floating objects such
as floating seaweed, pieces of wood and stationary, anchored or drifting vessels (Røstad,
Kaartvedt, Klevjer and Melle, 2006). The attraction is likely to be linked to predator avoidance and
a focus of aggregation behaviour. Marlin, swordfish and sailfish are also attracted to floating
objects probably for the same reason as tuna but also to feed on readily available prey that is
attracted to floating objects. Fishermen exploit this by using floating aggregation devices (FADs) to
attract schools of tuna.
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Demersal Species
Demersal fish are widespread on the continental shelf along the entire length of the Ghanaian
coastline. Species composition is a typical tropical assemblage including the following families:
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Three Porgies or seabreams (Sparidae), eg Pagellus bellottii, Pagrus caeruleostictus,
Dentex canariensis, Dentex gibbosus, Dentex angolensis and Dentex congoensis;
Two Grunts (Haemulidae), eg Pomadasys incisus, P. jubelini and Brachydeuterus auritus;
One Croakers or drums (Sciaenidae), eg Pseudotolithus senegalensis;
Goatfishes (Mullidae), eg Pseudupeneus prayensis;
Snappers (Lutjanidae), eg Lutjanus fulgens and L. goreensis;
Groupers (Serranidae), eg Epinephelus aeneus;
Threadfins (Polynemidae), eg Galeoides decadactylus; and
Emperors (Lethrinidae), eg Lethrinus atlanticus.
The seasonal upwelling of cold and saline waters over the Ghanaian shelf provokes changes in the
geographical distribution of many of the demersal fish species. During the upwelling season, the
bathymetric extension of the croakers is reduced to a minimum, while the deep water porgies are
found nearer the coast than at other times of the year.
The demersal species that are most important commercially are cassava croaker (Pseudotolithus
senegalensis), bigeye grunt (Brachydeuterus auritus), red pandora (Pellagus bellottii), Angola
dentex (Dentex angolensis), Congo dentex (Dentex congoensis) and West African Goatfish
(Pseudupeneus prayensis).
Cassava croaker (Pseudotolithus senegalensis)
Cassava croaker is considered to be the most economically important demersal fish in West
African waters, although it is reported (Froese and Pauly, 2009) that in recent years in Ghana their
importance has declined. They are distributed along the west coast of Africa as far south as
Namibia and as far north as Morocco. They are a demersal species occupying both marine and
brackish water down to a depth of 70 m.
They are mainly found in coastal waters over muddy, sandy or rocky bottoms. Smaller individuals
are found in shallow waters, occasionally entering estuaries. Their diet includes fish, shrimps and
crabs. Spawning in the Gulf of Guinea takes place between November and March in waters of 22
to 25°C.
Big eye grunt (Brachydeuterus auritus)
Big eye grunt are common along the coast of West Africa and may also extend into the waters of
Morocco. In Ghana, big eye grunt inhabit coastal waters with sandy and / or muddy bottoms at
depths of between 10 and 100 m, but are mostly found between 30 and 50 m. This species
remains near the bottom during the day and migrates vertically at night, feeding on invertebrates
and small fishes. Other important grunt species of this group include sompat grunt (Pomadasys
jubelini) and the bastard grunt (Pomadasys incisus).
Red pandora (Pellagus bellottii)
Red pandora are found along the west African coast from the Canaries to Angola. They are mainly
benthopelagic (they usually live just above seabed) but demonstrate demersal behaviour. Red
Pandora inhabit inshore waters, with hard or sandy bottoms, to a depth of 250 m, with their
preferred depth being greater than 120 m. Their diet is omnivorous, with benthic invertebrates,
cephalopods, small fish, amphioxus (lancelets) and worms dominating. Once fish are mature (at 1
to 4 years) they migrate to the coast and intermittent spawning occurs between May and
November.
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Angola dentex (Dentex angolensis)
Angola dentex occur along the West Coast of Africa from Morocco to Angola. In common with the
large eye dentex, this species is benthopelagic with a predominantly demersal behaviour. They are
found on varied substrates but mainly occupy sandy mud substrates on the shelf and upper slope
between 15 and 700 m. Adults feed predominantly on crustaceans, but fish, molluscs and worms
also form part of their diet.
Congo dentex (Dentex congoensis)
Congo dentex are distributed along the West African coastline from Senegal to Angola. Congo
dentex is a benthopelagic species that inhabits various bottoms types on the continental shelf and
upper slope, to a depth of at least 200 m. The species is carnivorous feeding chiefly on fish, and to
a lesser extent on tunicates and molluscs.
West African goatfish
West African goatfish are distributed along the West African coast between Morocco and Angola.
They inhabit the coastal waters of the continental shelf, over sandy and muddy bottoms, where
they feed on benthic invertebrates such as amphipods and polychaetes.
4.14.4
Deep Sea Species
Froese and Pauly (2009) lists over 180 species of deep-sea fish, including 51 bathydemersal
species that are associated with the bottom and a further 106 are listed as bathypelagic (1000 to
4000 m). The remaining species are generally considered to occupy depths to 1000 m (ie
epipelagic or mesopelagic) but may venture into deeper water during part of their lifecycle.
Froese and Pauly (2009) lists 89 species from 28 families that are likely to be found in Ghanaian
waters within the depth range 1,100 and 1,700 m.
Table 4.46 provides a list of the families and representative species that potentially occur on the
seabed in the project area.
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Deep Water Fish Families Potentially Present in the Project Area
Maintenance of deep-sea fish communities depends on the presence of large fish to break up the
bulk of the carrion falls, allowing the majority of fish species to access a vital food source and the
presence of small amphipods (small crustaceans) at the basis of the food chain that support many
of the larger fish.
4.14.5
Protected or Endangered Species
The sensitive species in Ghanaian waters according to the IUCN red list (IUCN, 2013) are
presented in Table 4.47. Of these only the tuna and swordfish species are likely to occur in the
water depths found in the project field area.
A number of these species are commercially important and are subjected to heavy exploitation,
particularly Albacore tuna and swordfish. It should be noted that Albacore catches in Ghanaian
waters are not currently recorded (ICCAT Fishstat data). Of the listed species, bigeye tuna,
yellowfin tuna and swordfish are recorded as being present in the project area. These species are
all found within the surface waters of the area (the first 100 m below the surface). Swordfish and
bigeye may also be found at depths up to 250 m.
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In the global context there is concern about the bigeye tuna stocks. The International Commission
for the Conservation of Atlantic Tunas (ICCAT) has listed it as the species of greatest concern,
after the bluefin, in terms of its population status and the unsustainable levels of exploitation
exacted on this species.
Table 4.47
Threatened Fish Species in Ghanaian Waters (IUCN Red List of Threatened Species
accessed on 20 November 2013 from www.iucnredlist.org) (IUCN Red List Status CR=Critically
Endagered; EN=Endagered; DD=Data deficient; LC=Least Concern; NT=Near Threatened;
VU=Vulnerable)
Scientific name
Common name
Red List Category
Population trend
Epinephelus itajara
Atlantic Goliath Grouper
CR
unknown
Squatina aculeata
Sawback Angelshark
CR
Decreasing
Squatina oculata
Smoothback Angel Shark
CR
Decreasing
Epinephelus marginatus
Dusky Grouper
EN
Decreasing
Rostroraja alba
Bottlenose Skate
EN
Decreasing
Sphyrna lewini
Scalloped Hammerhead
EN
unknown
Sphyrna mokarran
Squat-headed Hammerhead Shark
EN
Decreasing
Bathyplotes natans
LC
stable
Bathyplotes pourtalesii
LC
stable
criteria
Atlantic easter and
central/marine
system/Oceanic
habitat/assessment year
2011
Atlantic easter and
central/marine
system/Oceanic
2007
Atlantic easter and
central/marine
system/Oceanic
2007
Atlantic easter and
central/marine
system/Oceanic
2004
Atlantic easter and
central/marine
system/Oceanic
2006
Atlantic easter and
central/marine
system/deep benthic
2007
Atlantic easter and
central/marine
system/Oceanic
2007
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/deep benthic
2013
LC
unknown
Atlantic easter and
central/marine
Grampus griseus
Risso's Dolphin
Eni S.p.A.
Scientific name
Common name
Red List Category
Population trend
LC
unknown
LC
unknown
Mesothuria lactea
LC
unknown
Mesothuria rugosa
LC
unknown
Molpadiodemas villosus
LC
unknown
Parastichopus regalis
LC
unknown
Holothuria lentiginosa
Lagenodelphis hosei
Fraser's Dolphin
Spirula spirula
Ram's Horn Squid
LC
unknown
Stenella attenuata
Pantropical Spotted Dolphin
LC
unknown
Steno bredanensis
LC
unknown
LC
unknown
LC
unknown
Synallactes crucifera
Tursiops truncatus
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criteria
system/Oceanic
2012
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/Oceanic
2012
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/Oceanic
2012
Atlantic easter and
central/marine
system/Oceanic
2012
Atlantic easter and
central/marine
system/Oceanic
2012
Atlantic easter and
central/marine
system/deep benthic
2013
Atlantic easter and
central/marine
system/Oceanic
2012
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Scientific name
Common name
Red List Category
Population trend
Carcharhinus falciformis
Silky Shark
NT
Decreasing
Dalatias licha
Kitefin Shark
NT
unknown
Galeocerdo cuvier
Tiger Shark
NT
unknown
Negaprion brevirostris
Lemon Shark
NT
unknown
Prionace glauca
Blue Shark
NT
Decreasing
Raja clavata
Thornback Skate
NT
Decreasing
Thunnus alalunga
Albacore Tuna
NT
Decreasing
Thunnus albacares
Yellowfin Tuna
NT
Decreasing
Alopias superciliosus
Bigeye Thresher Shark
VU
Decreasing
Alopias vulpinus
Common Thresher Shark
VU
Decreasing
Carcharhinus longimanus
Whitetip Oceanic Shark
VU
Decreasing
criteria
Atlantic easter and
central/marine
system/Oceanic and deep
benthic
2009
Atlantic easter and
central/marine
system/deep benthic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/deep benthic
2005
Atlantic easter and
central/marine
system/Oceanic
2011
Atlantic easter and
central/marine
system/Oceanic
2011
Atlantic easter and
central/marine
system/Oceanic
2006
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2006
Carcharias taurus
Sand Tiger
VU
unknown
Atlantic easter and
central/marine
Eni S.p.A.
Scientific name
Common name
Red List Category
Population trend
Carcharodon carcharias
Great White Shark
VU
unknown
Centrophorus lusitanicus
Lowfin Gulper Shark
VU
unknown
Galeorhinus galeus
Whithound
VU
Decreasing
Isurus oxyrinchus
Shortfin Mako
VU
Decreasing
Isurus paucus
Longfin Mako
VU
Decreasing
Kajikia albida
White Marlin
VU
Decreasing
Lepidochelys olivacea
Olive Ridley
VU
Decreasing
Makaira nigricans
Blue Marlin
VU
Decreasing
Manta alfredi
Reef Manta Ray
VU
Decreasing
Manta birostris
Giant Manta Ray
VU
Decreasing
Mobula rochebrunei
Lesser Guinean Devil Ray
VU
Decreasing
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criteria
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/deep benthic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2009
Atlantic easter and
central/marine
system/Oceanic
2006
Atlantic easter and
central/marine
system/Oceanic
2011
Atlantic easter and
central/marine
system/Oceanic
2008
Atlantic easter and
central/marine
system/Oceanic
2011
Atlantic easter and
central/marine
benthic
2011
Atlantic easter and
central/marine
benthic
2011
Atlantic easter and
central/marine
system/Oceanic
Eni S.p.A.
Scientific name
Thunnus obesus
Common name
Bigeye Tuna
Red List Category
VU
Population trend
Decreasing
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criteria
2009
Atlantic easter and
central/marine
system/Oceanic
2011
4.15 MARINE HABITATS AND PROTECTED AREAS
In the marine area affected by the project operations no protected or restricted areas have been
highlighted by the desktop study. Ghana has not declared any marine protected area with the
exception of Ramsar sites that are all located onshore.
4.16 BIOPHYSICAL BASELINE CONCLUSION
4.16.1
Sediment remarks
Sediment granulometry in the survey area is very poorly sorted and ranged from fine sand to fine
silt. Silt is the dominant sediment component at the majority of stations. In general, the proportion
of silt increases and the proportion of sand decreases with increasing water depth.
Considering chemistry there are some salient issues.
Total hydrocarbons are low at most stations but are considerably elevated at Station 41. Station 41
is located approximately 340 m west-northwest of the ENI Ghana Gye Nyame-1 well where new
hydrocarbon resources were discovered in July 2011. Side scan sonar of drill spoil at the Sankofa
2A/2AST well, located approximately 16 km west-northwest of Gye Nyame-1, is observed to
extend approximately 500 m west-northwest of the well. Thus it is likely that the high readings at
Station 41 are related to local anthropogenic activities, and petrogenic contamination.
Total PAHs are low at all stations apart from Station 41. At Station 41 they are considerably
elevated, with a dominance of NPD 2-3 ring PAHs. Elevated PAHs at station 41 support the
assertion of drilling related sediment contamination from the nearby Gye Nyame-1 well.
CPI ratios at most stations suggest a dominance of biogenic/terrestrial n-alkanes. In contrast, the
signature at Station 41 indicates that the n-alkanes within the sediments are probably of
anthropogenic sources. Station 41 is dominated by short chain alkanes, indicating petrogenic
contamination. The GC trace at Station 41 is indicative of well weathered low-toxicity based drilling
muds. Pristane and phytane concentrations are also markedly elevated at Station 41.
Metal concentrations are generally low, although arsenic, chromium and nickel are found to exceed
respective NOAA ERL values at Stations 41, 44 and 48. Barium, used as a weighting agent in
drilling muds, has marginally elevated levels due to general drilling activities in the region, and
higher level at station 41 that indicates direct drilling related contamination.
4.16.2
Benthic macrofauna remarks
The macrofauna are characterized by low abundance and low diversity assemblages, with
numbers of individuals and species consistently low at all stations. At some stations no
macrofauna are recorded.
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As previously enlighten station 41 is characterized by contaminated sediment but considering the
paucity of fauna and the general lack of abundance at all stations surveyed it is not possible to
determine if the faunal composition has been affected. Furthermore, no increase in density of
opportunistic or pollution tolerant fauna is observed at Station 41.
The same kind of conclusion can be done considering that all stations are found to contain
sediments with concentrations of arsenic, chromium and/or nickel above their respective ERL level
4.16.3
Coral reef remarks
As reported in chapter 4.9, in the project area there is no findings of deep coral reefs (coldwater
corals), while some evidences of corals are found in nearshore areas.
NOAA's Coral Reef Information System (CoRIS) and NOAA Coral Reef conservation Program
websites give us an overview on coral threats and future scenarios.
Coral reefs face numerous hazards and threats. As human populations and coastal pressures
increase, reef resources are more heavily exploited, and many coral habitats continue to decline.
Current estimates note that 10 percent of all coral reefs are degraded beyond recovery. Thirty
percent are in critical condition and may die within 10 to 20 years. Experts predict that if current
pressures are allowed to continue unabated, 60 percent of the world's coral reefs may die
completely by 2050 (CRTF, 2000). Reef degradation occurs in response to both natural and
anthropogenic (human-caused) stresses. Threats to coral reefs can be also classified as either
local or global: local threats include overfishing, destructive fishing practices, nutrient runoff,
sedimentation, and coral disease while global threats include mass coral bleaching produced by
rising sea surface temperature (worsened by climate change), and ocean acidification. Together,
these
represent
some
of
the
greatest
threats
to
coral
reefs.
(http://www.coris.noaa.gov/about/hazards/)
Coral reef threats often do not occur in isolation, but together, having cumulative effects on the
reefs and decreasing its overall resiliency. Following destructive natural events such as hurricanes,
cyclones or disease outbreaks, reefs can be damaged or weakened, but healthy ones generally
are resilient and eventually recover. In many cases, however, natural disturbances are
exacerbated by anthropogenic stresses, such as pollution, sedimentation and overfishing, which
can further weaken coral systems and compromise their ability to recover from disturbances.
Conversely, a reef directly or indirectly affected by anthropogenic stresses may be too weak to
withstand a natural event. In addition, many scientists believe that human activities intensify natural
disturbances, subjecting coral reefs to stronger, more frequent storms, disease outbreaks and
other natural events. (http://www.coris.noaa.gov/about/hazards/)
Furthermore, even if little is known about deep water coral (coldwater corals), during the annual
meeting of the American Association for the Advancement of Science in Seattle, United States, in
February 2004 was stated that documented and potential sources of threats to coldwater corals
are:







commercial bottom trawling and other bottom fishing
hydrocarbon exploration and production
cable and pipeline placement
bioprospecting and destructive scientific sampling
other pollution
waste disposal and dumping
coral exploitation and trade
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4.16.4
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upcoming threats: sequestration of CO2, other mineral exploration and increased
atmospheric CO2.
Water remarks
Water profiling identifies a stratified water column with a discontinuity layer occurring between 25
m and 75 m where the greatest rate of change in water temperature, salinity, dissolved oxygen and
pH is recorded.
Nutrients, total dissolved solids, biochemical oxygen demand, phenol index, cyanide and faecal
coliforms are low at all stations and depths. All heavy and trace metals in all water samples are
below detection limits or at very low levels and were below the chronic ‘Ambient Water Quality
Criteria’ benchmark.
In contrast, total hydrocarbon concentrations are elevated compared to previous studies, in
particular high concentrations of the shorter chained nC12-20 alkanes are recorded at all stations
and depths, suggesting hydrocarbons from petrochemical sources probably from shipping activities
in the region or a dispersed effect arising from the numerous wells in the area.
The phytoplankton community is dominated by microflagellates and diatoms. Phytoplankton
abundance is generally greater at 1 m and 100 m sample depths and denuded at 200 m.
Zooplankton community is dominated by copepods. Zooplankton dynamics are closely linked to
phytoplankton production The difference in zooplankton densities between the onshore and
offshore surveys may be explained by the much greater densities of phytoplankton, and hence
food resources for zooplankton, nearer shore compared to the offshore stations. The decrease in
phytoplankton at the offshore sites may be due to the lower phosphate concentrations, compared
to the inshore sites. Phosphate is known to be a limiting nutrient of phytoplankton growth, and
hence the lowered concentrations offshore may partly explain the lower densities in this region.
4.16.5
Marine mammals remarks
As reported in paragraph 4.10 the knowledge about distribution, natural history, population
structure and ecology of dolphins and whales in the Gulf of Guinea is rudimentary and fragmentary
in the scientific literature.
The most important remarks about marine mammals concern the threats.
The main threats are:
 Collision with ships
 pressure from frequent by-catches in mostly drift gillnet fisheries and perhaps also in
industrial purse-seine fisheries
 water pollution
 seismic activity related to hydrocarbon exploitation activities
Among the causes of the beaching of cetaceans the seismic activity and the use of sonar are
surely recognized, while the events of washing ashore of whales carcass remain without a
definitely explanation.
Is important to underline that in some opinions, the washing ashore of whales carcass along
western Ghana's coastline has been associated with the offshore activity for oil production. The
discovering of the 20 dead whales along Ghana's coastline started in 2009 when oil exploitation
activities intensified offshore Cape Three Points and continued with the production of oil. However,
this association is not shared by all researchers belonging to this field of studies. Indeed, so far,
there is no scientific evidence of direct correlation between activities of the extractive sector in
Ghana and whale beaching events. This was also mentioned by researchers of the University of
Ghana.
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Sea turtles remarks
As reported in paragraph 4.12 the Gulf of Guinea serves as an important migration route, feeding
ground, and nesting site for sea turtles, approximately 70 percent of Ghana’s coastline is found
suitable as nesting habitat for sea turtles and in particular In the Western region, the beaches at
Kengen, Metika Lagoon, Elonyi, Anochi, Atuabo and Benyin are important nesting sites.
In general but also considering the area of interest of the project, the principal threats must be
underlined:
 Unsustainable harvest of Sea Turtles and their eggs for human consumption
 Unsustainable harvest of fish stocks and improper management of by-catch
 Loss of habitats
 Deteriorating water quality and increased sea debris
(“Sea Turtle Conservation on the West Coast of Ghana A Background Report” 2009)
The first two points are related because the depleting of fish stock is negative for sea turtle
(considering fish as their food) and because induces the changing of human opportunistic
consumption of sea turtles meat and eggs, in something more frequent.
Considering the habitats is important to consider all five different habitat types that Sea turtles use
at different stages of their lives. These are: the natal beach; mating areas; inter-nesting habitat;
feeding areas; and pelagic waters (Environment Australia, 2003).
Considering the deteriorating of water quality, the report puts in evidence that the presence of oil
based pollutants such as coal tar and engine fuel were frequent. These pollutants can originate
from test extractions at oil deposits only 70 km off the west coast of Ghana but are more likely
spills from local and commercial fishing vessels or the flushing of cargo ship bilge tanks (“Sea
Turtle Conservation on the West Coast of Ghana A Background Report” 2009).
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5
SOCIO-CULTURAL BASELINE
There are 10 administrative regions in Ghana, same as in 1984. The coast and the sea are very
important for the people of Ghana and for the Country’s economy. The main economic activities
practiced in the coastal zone are fishing, farming, manufacturing, salt production, oil and gas
extraction and tourism.
The Western region covers an area of approximately 23,921 square kilometres, which is about 10
per cent of Ghana’s total land area and some 75% of its vegetation is classifiable as high forest
area. It lies in the equatorial climatic zone that is characterized by moderate temperatures and is
also the wettest part of Ghana with an average rainfall of 1,600mm per annum. The southernmost
part of Ghana lies in this region, at Cape Three Points near Busua, in the Ahanta West District.
Table 5.1 Districts in the study area coastal zone with relative population, surface area and shoreline
length
Region
Western
5.1
District
Jomoro
Nzema East & Ellembele
Ahanta West
Population
Area (sq. km)
Coastline (km)
150,107
148,329
106,215
1,350
2,088
568
55
51
57
ADMINISTRATIVE STRUCTURE
The government structure in Ghana is made up of ten administrative regions subdivided into 170
metropolitan, municipal and districts areas, each with an administrative assembly comprised of a
combination of appointed (a third) and elected (two-thirds) officials. Ghana changed from the local
authorities system of administration to the district assembly system in 1988. The country was
demarcated into 138 districts out of the existing 140 local authorities. The boundaries of the
districts do not necessarily conform to the boundaries of the local authorities but are coterminous
with regional boundaries.
The Western Region was once a single vast province covering the present Western and Central
Regions, and known as the Western Province, with its capital in Cape Coast, until the country
achieved republican status in 1960. The Region, as presently constituted, became a separate
administration in July 1960, with Sekondi as its capital, when the Central Region was carved out of
the erstwhile province. Present day urbanised settings have made Sekondi and Takoradi one big
metropolis.
The Western Region (the Region closest to the project) currently comprises 14 Districts, two
Municipalities, and one Metropolis, the latter being STM. The Districts and their District capitals are
presented in Table 5.2. Six of the 14 districts constitute the coastal districts of the Western Region;
Jomoro, Nzema East, Ellembele, Ahanta West, Shama and Sekondi-Takoradi.
The Nzema East Municipal was once somewhat larger but after the creation in its more westerly
area of first Jomoro and then Ellembelle, now covers a distinctly smaller surface area. Its capital is
Axim. The Jomoro District (which used to be part of the then Nzema East Municipal) was created
by Legislative Instrument 1394 in 1988, and lies on the Country’s border with Cote d’Ivoire, to the
West. The District’s capital is Half Assini. The Ellembelle District was carved out of the then
Nzema East District in December 2007 by (LI) 1918 and inaugurated in February 2008, with
Nkroful as the District Administrative seat or Capital. Shama District was created in 2005.
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There is very little published data available for these newly created Districts; much information still
refers to the previous administrative subdivision of the Region and most of the information
presented here for the new Districts is derived from the interviews with District officials.
Table 5.2
Districts and Capitals of the Western Region
Districts
Jomoro
Nzema East
Shama
Sekondi-Takoradi
Ellembele
Ahanta West
Tarkwa Nsuaem (Wassa West)
Wassa Amenfi West
Aowin-Suaman
Juabeso
Sefwi-Wiawso
Bibiani-Anhwiaso-Bekwai
Bia
Wassa-Amenfi East
Pristea Huni Valley
Sefwi Akontombra
Mpohor-Wassa-East
Administration Type
Capitals
District
Municipality
District
Metropolis
District
District
Municipality
District
District
District
District
District
District
District
District
District
District
Half Assini
Axim
Shama
Sekondi
Nkroful
Agona Nkwanta
Tarkwa
Asankragua
Enchi
Juabeso
Sefwi-Wiawso
Bibiani
Essam
Wassa Akropong
Bogoso
Sefwi Akontombra
Daboase
The Regional Coordinating Council (RCC), which is the highest decision-making body, comprises
the Regional Minister who is also its Chairperson, District Chief Executives, Presiding Members of
the various District Assemblies and two Paramount Chiefs nominated by the Regional House of
Chiefs. There is also a Regional Coordinating Director, who is the Secretary to the RCC and the
head of the civil administration of the region.
Each District has a District Chief Executive (DCE) who heads the local assembly. The DCE is
nominated by the President of the country and is confirmed by the assembly through balloting. The
local government is made up of the Regional Coordinating Council (RCC), four-tier Metropolitan
and three-tier Municipal/District Assemblies with Urban/ Town/ Area/ Zonal Councils. Each
Electoral Area (EA) is represented at the assembly by an elected assembly member and has a
Unit Committee.
The District Assemblies constitute:
 the pivot of administrative and developmental decision-making in the district and the basic
unit of government administration.
 the Administrative entity assigned with deliberative, legislative as well as executive
functions.
 The monolithic structure assigned the responsibility of the totality of government to bring
about integration of political, administrative and development support needed to achieve a
more equitable allocation of power, wealth, and geographically dispersed development in
Ghana.
 the Planning Authority for the District.
Meanwhile, Paramountcies constitute the expression of traditional authorities and hierarchical
structures of Ghana, and carry great influence. This monarchical authority ensures the
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maintenance of law and order among the traditional hierarchies and the people, handles all affairs
pertaining to stools, and mediates in chieftaincy disputes.
In Jomoro District there is just one Paramountcy, the Western Nzema Traditional Council, with its
capital at Beyin. Ellembelle District too has only one Paramountcy, the Eastern Nzema Traditional
Council, situated at Atuabo. While Nzema East Municipal, though largely reduced in size over the
years, has five Paramountcies, which are:
 Lower Axim Traditional Council -Axim
 Upper Axim Traditional Council - Axim
 Nsein Traditional Council - Nsein
 Ajomoro Traditional Council - Apataim
 Gwira Traditional Council - Bamiankor
All the Traditional Councils, in the three Districts of Nzema East, Ellembelle and Jomoro, constitute
the Nzema Manle Council (District House of Chiefs), with headquarters at Esiama. Finally, there
are three Paramountcies in Ahanta West, namely Busua, Upper Dixcove and Lower Dixcove with
the Ahantahene (Omanhene) at Busua.
5.2
HISTORY AND CULTURE
The Western Region comprises five major indigenous ethnic groups. These groupings exhibit a
high degree of cultural homogeneity, especially in the areas of lineage, inheritance and
succession, marriage and religion. The location occupied by the five major ethnic groups in the
region cannot be clearly and unambiguously defined, as their boundaries overlap.
The Ahantas, who form about 6%, and the Nzemas (including the Evalues) 11% of Ghanaians by
birth in the region, occupy the entire coastline from Shama on the east to the western border of
Ghana.
The Wassa people, who form about 12 per cent of Ghanaians by birth in the region, can be found
further inland off the coast towards the interior. However, the people of Essiama in the Ellembelle
district also trace their lineage to the Wassa people who first settled along the coast.
The Sefwis who represent about 11% and the Aowins who constitute about 3% of Ghanaians by
birth in the region are in the northern part of the region.
There yet other indigenous minorities present in the region, among these the Pepesa.
Although not indigenous to the Region, about 18% of Ghanaians by birth in the region are Fantes;
settlers who migrated several years go from the Central Region, and have since then fully
integrated themselves into the indigenous populations. Apart from the Fantes, other ethnic
groups who have migrated into the region are the Asantes (7.3%), Ewes (5.9%), Brongs (3.4%)
and Kusasis (2.9%). Most of the region’s inhabitants are either Ghanaians by birth (92.2%) or by
naturalisation (4.1%), with a few immigrants from other neighbouring West African countries.
The languages/dialects of the Sefwis and Aowins are very similar to each other, as well as to the
Ahanta and Nzema languages. The four groups can converse with each other in their own peculiar
dialects or languages and still understand one another.
It is worth noting that although Ahanta, Nzema, Wassa, Sefwi and Brossa (Aowin) are the
languages spoken by the indigenes of this region, Fante is widely spoken as a second language in
the southern part of the region. It is in fact the school language and medium of instruction in lower
primary classes in many of the basic schools. Twi is more widely spoken in the Sefwi and Bibiani
areas even though Fante is also widely spoken in the same areas. The only other language used
as a school language/medium of instruction is Nzema, even though Ahanta has now also become
a written language.
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There is complete freedom of religious belief in the region, however the major religious
denominations are Christian (81%) (Pentecostals (21.6%), Protestants (19.5%), Methodists,
Catholics (19.4%), Christ’s Church) and other Charismatic churches. Muslims (8.5%) and
traditionalists (1.5%) follow suit.
Though Western Christian religions are widely embraced, most of the local communities tend to
adapt their Christian faith to the practice of local traditions. In fact the local populations are in
practice largely traditionalists with a high commitment to traditional beliefs and practices. Most
communities have their own ‘fetish priest or priestess’. Most rituals or ‘fetishes’ nowadays consist
in animal sacrifices to the chief god and other smaller gods. The essence of most rituals is to seek
for peace and unity as well as development of the community. Given this manifest attachment to
traditional practices the Western Region is naturally littered with cemeteries and royal cemeteries
(mausoleums), sacred spots, shrines and other cultural sites. Moreover, there are diverse taboo
practices in place; in many of the coastal fishing communities any activity in the lagoon is
prohibited on Wednesdays, fishing is not undertaken on the seas on Tuesdays and Thursdays are
taboo days for farming.
The major festival among the Ahanta and the Nzema people of the Western Region of Ghana is
the Kundum festival, and is held in all the major traditional chiefdoms/paramountcies of the study
area. The festival is celebrated between September and October, more or less coinciding with the
harvest period, and constitutes an important expression of culture, social cohesion and politics of
the Ahanta and Nzema people. During Kundum ‘food’ is offered to the gods and is an occasion for:










Thanks giving and paying of homage;
Honouring ancestors;
Socialization;
Unity and peace (rekindling the sense of community);
Reconciliation;
Calibration of life of existing citizens;
Pour of libation for protection and long life;
Settlement of disputes among citizens and family members;
Instilling of moral values (humility and fairness) among the youth;
Food security.
Other festivals of cultural importance to the local populations are the Odwira (Yam Festival)
celebrated by the Gwira Traditional Area (in Nzema East), the new Clan Festival – a colourful and
educative socio-economic development festival – which takes place from December 26th to
January 1st, as well as several other town-based festivals.
5.3
DEMOGRAPHICS AND GEOPOLITICS
The population of Ghana is approximately 23 million (July 2008 estimate) with the Western Region
having approximately 2.5 million people (Government of Ghana 2010). The Western Region has
average population density of 80.5 persons per square kilometre, making it the sixth densest
region out of the ten regions in the country, and has experienced accelerated population growth
over the years. Between 1960 and 1970, the population grew by 23 percent, between 1970 and
1984 it more than doubled, while between 1984 and 2000, it increased by 66 percent.
The rapid population growth registered between 1970 and 1984 (high in comparison with the
national average) may be attributable to several factors, including an increase in the birth rate and
a decrease in the mortality rate over the period. The growth would also have been linked to inmigration resulting from increased economic activity, particularly between 1984 and 2000, when
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the region experienced a boom in both the mining and the cocoa industries (Population and
Housing Census, 2000).
Migration (both in and out) in the region has been affected by geographical and economic factors
over the years. The region has the highest rainfall in the country, with the Axim area and the
Ankobra and lower Tano river basins having the highest rainfall in the whole country. The high
rainfall makes the region suitable for the cultivation of rain-fed forest area cash crops such as
cocoa, coconut palm, oil palm, rubber, and a small amount of coffee. The region has the highest
production figures for all these four economic crops. This might have attracted people from other
regions, notably Brong Ahafo and Ashanti, to the farming areas In 1970, 35% of the inhabitants of
the region were born outside the region. This figure declined to 29.3 per cent in 2000.
Nowadays, migration by the large takes place in the fishing industry. Very large proportions of
fishermen in the Region emigrate from the northern parts, moving towards the coastal area during
the major fishing season, which is normally between July and September. During this period,
fishing-related migration also occurs within and between the shorefront communities all along the
coast. The fishing migrants are hosted by the resident coastal communities in their homes, free of
charge or at most for token fees.
Another form of migration present in the Region is that associated to refugees, currently mainly
originating from Ivory Coast. In Ghana, as of October 2011, there were about 18,000 Ivorian
refugees.
The Krisan Refugee Camp situated in the study area is a melting-pot of cultures, religion, and
languages; it is home to 1,700 refugees from several African nations; Burundi, Democratic
Republic of the Congo, Côte d'Ivoire, Liberia, Republic of Congo, Rwanda, Sierra Leone, Somalia,
Sudan and Togo. The camp is well planned in terms of structures and the people though from
different countries seem at peace with one another. Nevertheless, the camp’s population are in
need of improved livelihood resources and livelihood stability.
Population density (standing at 111 persons/km2 in Jomoro, 73 persons/km2 in Ellembelle and
Nzema East combined, and 167 persons/km2 in Ahanta West) would indicate no great pressure of
population on the land tout-court. However, the same cannot be said of pressure on resources and
existing infrastructure. For example, settlements or growth points such as Esiama and Aiyinasi in
Ellembelle District, though urbanised areas, have been experiencing relatively higher population
densities with corresponding pressure being exerted on existing and limited infrastructural facilities.
The head of the household is the one who is identified as the head by members of the household
and not necessarily the one who maintains the household. The Region is characterised by 72%
male-headed households against 28% female-headed households. Other relatives and
grandchildren, who are an extension of the nuclear family, make up 26% of the household
structure. According to the 2000 Census, there are 410,412 households in the region, occupying
259,874 housing units, which give an average of 1.6 households per house. Comparable past
averages are 2.2 for 1970 and 2.0 for 1984. This may be the result of increases in supply of
houses or a slow-down in the formation of new households.
The average household size, that is, the average number of persons in a household, has been on
the increase since 1960, when 3.8 was recorded. This increased to 4.0 in 1970 and to 4.4 in 1984.
The average number of persons per household for 2000 is 4.7. Notwithstanding the constant
increase over the years, the household size in the region is still below the national average of 5.1.
The observed large household sizes over the years may be the result of the high fertility rate (4.4
per woman) prevailing in the region and the practice of adult children with offspring, staying with
their parents.
The number of houses in the region increased from 61,103 in 1960 to 127,427 in 1984, and further
to 259,874 in 2000. This constitutes a percentage increase in housing stock of about 103.9 during
the 16-year period. However, the increase in housing stock has lagged behind population growth
as reflected in the number of people per house in the region, which is still considered too high,
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notwithstanding its steady decline from 10.2 in 1970 to 9.0 in 1984, and further to 7.4 in 2000.
Household members or relatives own more than half of the houses in the region; and generally
make them available to other relatives either for a token rent or free of charge. Most of the houses,
particularly in the rural areas, are constructed with sun-dried mud bricks with cemented floors and
corrugated metal roofing materials.
Over one third (36%) of the Western Region is urbanised and the remaining 64% is rural (the
rural/urban classification of localities is population based, with a population size of 5,000 or more
being urban and less than 5,000 being rural). With regards to age distribution, the Western
The population of the Western Region is relatively young, with approximately 43 percent of the
population falling between the ages of 0 and 15 years while 5% of the population are more than 64
years old . A summary of the age characteristics by District is provided in Table 5.3. The new
Districts of STM and Shama have reported separate data, however, for the Former Nzema East
District there is no separate data for Nzema East Municipality and Ellembelle District. STM has the
lowest proportion of people between 0 and 15 years (38 percent) compared with the other Districts
with between 42 percent and 44 percent. Nearly five percent of the population in the Region are
older than 64 years. The age structure follows the known trend of a developing economy with a
broad base (many young people) that gradually tapers off with increasing age. STM has the largest
proportion of the population (58 percent) in the working age group (15-64 years) in the Region.
Jomoro (53 percent) also has a significant proportion of the population in this age group. These
figures may be due to migration of young adults to the commercial and mining towns in these
Districts.
Table 5.3
Age Characteristic by District
Age
Characteristics
All Districts
Jomoro
Nzema East
& Ellembele
Ahanta
West
STM
Shama
0-14
15-64
65+
Dependency ratio
18+ (% Adult Pop.)
42.4
53.1
4.5
88.3
51.7
41.3
53.4
5.3
87.1
52.9
43.1
51.2
5.7
95.1
51.4
43.2
51.8
5.0
93.2
51.1
37.7
57.6
4.7
93.6
55.8
44.8
51.9
3.3
92.7
n.a.
Source: * 2000 Population and Housing Census Western Region; ** 2009 Shama District Profile
There is a relatively high dependency ratio in the Region. This is attributable to the high proportion
of the population who are not economically active; primarily due to age (younger than 15 years or
older than 64 years) and high levels of unemployment. This dependency places a heavy burden on
the economically active sector of the population in the District and can lead to low standards of
living.
Gender distribution within the populations of each District are illustrated in Table 5.4.
Table 5.4
Population by District and Gender
Geographical Area
Ghana
Western Region
Jomoro
Ellembelle
Nzema East
Ahanta West
Total
24658823
2376021
150107
87501
60828
106215
Sex
Male
12024845
1187774
73561
42317
29947
50999
Female
12633978
1188247
76546
45184
30881
55216
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STM
Shama
559548
81966
273436
38704
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286112
43262
Source: Ghana Statistical Service, 2010
An overview of the population characteristics for the six coastal Districts that form part of the study
is hereby provided.
Jomoro District. The District has a total population of 111,348 and a population growth rate of 3.2
percent. The District is mainly rural (29.6percent urban) with only four settlements having
populations in excess of 5,000. The major settlements with larger populations are Bonyere, Elubo,
Half Assini and Tikobo No.1. Population density has increased over recent years with 2000 figures
being 82.8 persons per km2. Almost 15.8 percent of the population are immigrants, mainly settled
in the northern part of the District. About 53 percent of immigrants are male and 58percent are in
the age group of 18 - 35 years.
Nzema East Municipality. Available population figures for the area are for the former Nzema East
District which included the new Ellembelle District. The population of the Nzema East District was
142,871 in the year 2000 with annual growth rate of 2.7 percent. The population density was 65.1
per km2. The area is largely rural (26.6 percent urban) with most communities having a population
of less than 5,000. However, a steady rural to urban migration has seen an increase in the urban
populations in recent years. According to the municipal planning office, migrations tend to be
seasonal with persons migrating to farming areas during the farming season and to the coast
during the fishing season. There is, however, no data to indicate whether there has been an
increased migration into the District recently.
Ellembele District. District specific population figures are not available at present as these have
not been separated from the former Nzema East District figures. According to the District planning
office, it can be estimated that half the population of the Nzema East District (i.e. approximately
70,000) resides in Ellembelle. The District is mainly rural with only 26 percent of the population
living in urban centres.
Ahanta West District. A population of 95,140 was reported for this District in 2000 with a
population growth rate of 3.2 percent. Based on this growth rate, the population was projected to
be 122,817 by the end of 2008. The District is characterised by a high population density of
141/km2 in 2000 compared with regional population density of 51 per km2. The high population
density of the District indicates population pressure on land and other limited facilities and services
within various settlements. Approximately 80 percent of the population lives in rural settlements
making Ahanta West a rural District.
Sekondi-Takoradi Metropolis (STM). The population of STM was 369,166 in 2000 and projected
to 492,378 in 2009. It is the most populated area in the Western Region and comprised about 15
percent of the regions total population in 2000. Population density is 1,022 people per km2. The
STM has 49 communities and approximately 14 of these settlements have a population exceeding
7,000. The major settlements are Takoradi, Effia-Kwesimintsim, Effiakuma, and Sekondi. Built up
areas in the Metropolis can be classified into urban and rural settings. The urban portions
constitute about 32 percent of the land area and accommodate close to 70 percent of the
population. Sekondi-Takoradi, serves as a destination as well as transit point for approximately
80,000 migrants mostly from rural portions of the country that commute to the area in for work. This
has resulted in the increased development of slums in the city.
Shama District. The population of the District was reported as 68,642 in the 2000 census. The
projected 2008 population is 88,314. The population growth rate of 3.5 percent in 2000 was higher
than the regional and national averages of 3.2 percent and 2.7 percent respectively. According to
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the District planner, the District experiences emigration of economically active people in search of
employment in major urban centres.
5.4
LOCAL ECONOMY AND LIVELIHOOD RESOURCES
Ghana’s domestic economy currently revolves around agriculture (which includes fishing). This
accounts for about 45 to 50 percent of GDP and employs about 55 percent of the work force,
mainly small landholders and fishers. Other major sources of employment include mining and
quarrying (employing approximately 15 percent of the population), and manufacturing, employing
approximately 11 percent of the population.
Ghana also has a wide range of natural, cultural and historical attractions, which provides the basis
for the growing tourism industry. Indeed, according to the Ghana Investment Promotion Centre
(2010), Ghana’s tourism sector is expected to grow at an average rate of 4.1 percent per annum
over the next two decades. Since the late 1980s tourism has received considerable attention in the
economic development strategy of Ghana. The number of tourist arrivals and amount of tourists’
expenditure has steadily increased, while both public and private investment activity in various
tourism subsectors have expanded (GIPC, 2010).
5.4.1
Regional Economic Activities
The Western Region is endowed with considerable natural resources, which give it a significant
economic importance within the context of national development potential. It is in fact one the
largest producer of cocoa, rubber and coconut, and one of the major producers of vegetable oils
as a result of the extensive oil palm and coconut plantations. The Benso Oil Palm Plantation,
owned by Unilever Ghana Limited, is one of the largest in the country. The region also has the
largest and only economically viable rubber plantation in the country, stretching from Agona
Junction to Bonsa on the Tarkwa road, from Agona Junction to Dadwen on the Axim road, and
Baamiangor in the Dwira traditional area on the Esaaman to Dominase/Enibil road. The plantations
used to support the erstwhile but still potentially viable Firestone tyre factory at Bonsa, but now
support only the rubber-processing factory at Agona Junction, which processes rubber into a
semi-finished product for export. Moreover, the rich tropical forest makes the Region one of the
largest producers of raw and sawn timber as well as processed wood products, while a wide
variety of minerals, including gold, bauxite, iron, diamonds and manganese are either being
exploited or are potentially exploitable. The region’s total geological profile and mineral potential
are yet to be fully determined. Large potential deposits of gas and crude oil that are nearest to
possible economic exploitation can be found in the Tano Basin and offshore in the Jomoro
(Western Nzema) District. The same district has high quality limestone and fine sand deposits
upon which the country’s cement and glass industries can rely. Finally, some salt production is
practiced in the coastal Districts of the Western Region.
The major industrial activities in the region are consequentially agriculture, excluding fishing but
including forestry and hunting (58.1%), mining and quarrying (2.4%), manufacturing (10.2%) and
wholesale and retail trade (10.3%), while the four major employment sectors in the region are
agriculture including fishing, animal husbandry and hunting (58.1%), production and transport work
(14.5%), sales work (10.2%) and professional and technical work (5.4%).
The economically active population in all the districts (except the Shama-Ahanta East
metropolitan area) exceeds 70%. However, more than two-thirds of the economically active
population in all the districts of the region are made up of self-employed persons with no
employees, i.e. involved in mainly subsistence activities.
Subsistence farming, including fishing, is in fact the most widely practiced economic activity by the
Region’s population. Food crops produced are mainly cassava, maize, rice, cocoyam, plantain,
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pepper and tomatoes; rice is grown in some low-lying areas. Fishing shall be dealt with in greater
detail further on in the Report.
The tourism potential in the Western Region is related to the number and extent of pristine
tropical beaches as well as wildlife parks and forest and game reserves featuring tropical
rainforests, inland lakes and rivers. Some of the most popular recreational beaches along the
western coastline are located at Biriwa, Brenu Akyinim, Busua, Butre, Cape Coast, Egyembra,
Elmina, Komeda, Sekondi and Takoradi (Ghana Tourism Bureau, 2010). Hotels are generally
located at popular beach destinations and at commercial centres. There are a total of only 28
waterfront hotels (approximately 1000 beds) along the whole Ghanaian coast officially registered at
the Tourist Board of Ghana.
5.4.2
Economic Activities at Coastal Districts
Similarly to the Region at large, economic activities within the study area include small-scale
agriculture, processing of coconut oil, fishing, trading and petty-trading, coastal salt production,
some forestry, as well as more formal sources of employment (teaching, health care, etc.).
Fisheries, small-holder farming and tourism are the three most important activities in relation to the
study area; the importance of fishing as an economic activity is discussed in further detail in Error!
Reference source not found..
The agricultural activities within the coastal districts of the Western Region reflect those typical of
the Western Region overall. There is evidence of agricultural activities throughout the coastal area,
including small plots where coconuts, cassava, palm-nut, plantain, corn and vegetables are grown.
Some livestock herding is also practiced along the coastal road. According to an assessment of
critical coastal habitats of the Western Region of Ghana, implemented by the Coastal Resources
Center - University of Rhode Island in 2010-2011, the following crops can be found in the referral
coastal districts (see Table 5.5). It is evident that most resources are used both for subsistence
and sale; in fact the general rule among subsistence farming and fishing communities is that in
presence of surplus, resources are taken to the nearest market place for sale. Table 5.5 also
highlights community participation in resource use by gender and age group.
Table 5.5
Agricultural Resources Use in the coastal districts of Western Region (source:
“Assessment of Critical Coastal Habitats of the Western Region, Ghana, University of Rhode island &
USAID, July 2011)
Resource
Cassava
Cocoyam
Mushroom
Pepper
Plantain
Tomatoes
Vegetables
Yam
Use
d
s
d
s
d
s
d
s
d
s
d
s
d
s
d
Amansuri
(macroareas 1-4)
m
x
x
w
x
x
c
x
x
Ankobra
m
x
x
x
x
w
x
x
x
x
c
x
x
x
x
Cape Three
Points
(macroareas 6-7)
m
w
c
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
Princestown
(macroareas 5-6)
m
x
x
w
x
x
c
x
x
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s
Medicinal
herbs
Coconut
Palm nuts
d
x
x
x
s
d
s
d
s
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
d=domestic, s=sale, m=men, w=women, c=children.
Tourism in the region has been described as the country’s sleeping giant. Even though the Central
Region often comes to mind when tourism is discussed, the sheer mass of the tourism potential of
the Western Region is yet to be properly assessed and exploited. The region has the second
largest concentration of forts and castles in the country, accounting for seven out of the country’s
fifteen selected tourist forts under the Museums and Monuments Board. Fort St. Anthony in Axim is
the second oldest Fort and European settlement in Ghana. Others are Fort Apollonia in Beyin, Fort
Gross-Friedrichsburg at Princestown, and Fort Metal Cross at Dixcove.
Table 5.6
Historical Monuments situated along the Ghana Western Coastline
Town/Location
Beyin
Sawoma
Axim
Princess Town
Akoda
Dixcove
Butre
Sekondi
Shama
Komeda
Elmina
Cape Coast
Moree
Anamabo
Abandze
Monuments
Fort Appolonia built in 1770 by Britain
Monument
Fort Antonio built in 1515 by the Portuguese
Fort Gross Fredericksburg built in 1683 by Brandenburg-Prussians
Ruins of and old Fort Dorothea
Fort Metal Cross built in 1692 by the British
Fort Batenstein built in 1656 by the Dutch
Fort of Orange built in 1656 by the Dutch
Fort St. Sebastian built in 1523 by the Portuguese
Ruins of Fort Vredenburg built by the Dutch in 1682
Fort English built by the Dutch in 1687
Elmina Castle (St. George’s Castle) built in 1482 by the Dutch
Fort St. Jago built in 1665 by the Portuguese
Cape Coast Castle built in 1653 by the Dutch
Fort Nassau built in 1612 by the Dutch
Fort Charles built in 1630 by the Dutch
Fort Amsterdam built in 1631 by the British
Source: Environmental Sensitivity Map for the Coastal Areas of Ghana, 2004
The area has a substantial eco-tourism potential which is yet to be fully exploited. There is the
southernmost part of Ghana at Cape Three Points near Busua in Ahanta West, a part of which is
already a classified forest reserve, which is destined to be enlarged extending down towards the
coastline. Wildlife and nature reserves in the Western Region include ANkasa Conservation Area
including Nini-Suhein Natinal Park, Amansuri Conservatin Area (the wetlands which include the
internationally recognised bird sanctuary, located in Nzema East), and Bia National Park. There
can also be found the famous Nzulezo village built on stilts on water in Jomoro, as well as the sea
turtle conservation area at Krisan near Eikwe, in the same district.
Moreover, there are clean and still unspoilt coconut palm-lined beaches, well-preserved wildlife
parks and forest and game reserves. Some of the more popular recreational beaches along the
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western coastline are located at Biriwa, Brenu Akyinim, Busua, Butre, Cape Coast, Egyembra,
Elmina, Komeda, Sekondi and Takoradi.
With regards to tourism infrastructure the area still requires great investment. The region has some
good, moderately priced hotels and eco-tourism hotels dotted around the beaches and nearby
areas. In fact, hotels are generally located at the popular beach destinations and at commercial
centres.
In recent years, tourism in Ghana has become a major socio-economic activity and one of the most
important and fastest growing sectors of the Ghanaian economy. The number of tourist arrivals
and amount of tourists’ expenditure has steadily increased, while both public and private
investment activity in various tourism sub-sectors have expanded. In 2004, the sector attracted
more than 500,000 foreign tourists with the corresponding tourist receipts of US$640 million. No
wonder economists have predicted that the economic survival of Ghana will depend on what
Governments will do to treat and manage the tourism sector. In the meantime the Government of
Ghana has expressed its intentions to use tourism as an alternative development strategy to help
address broad national issues. Indeed, discussions on tourism during eni site selection field survey
meetings with the District Assemblies of Jomoro, Ellembele, Nzema East and Ahanta West (June
2012), all revealed clear plans to invest in the districts’ tourism development.
5.4.3
Economic Activities by District
Jomoro District
The economy of Jomoro District consists of a large traditional agricultural sector made up of mostly
small-scale farmers, a growing sector of small informal traders, artisans and technicians, and a
small processing and manufacturing sector. Approximately 54 percent of the population is engaged
in the agricultural sector, comprised of 39 percent farming and 15 percent fishing. Major crops
grown are cassava (40.5%), coconut (16 %), maize (15%), cocoa (9.4%), and plantain (9.4%). The
use of traditional farming methods, which include slash and burn and the extraction of wood fuel, is
resulting in deforestation. Both inland and sea fishing is another major economic activity and is
characterised by the use of canoes with out-board motors and dragnets. The District has extensive
rainforest and wood harvesting takes place around Mpataba, Nuba, Ankasa, Tikobo No.1, Ellenda
and Anwiafutu area. There are, however, no established timber processing companies in the
District. Larger industries in the District include the Wienco factory which manufactures erosion
control mats from coconut husks. There is also the Effasu Power Plant which the District planner
reported was due to be recommissioned in the near future.
Nzema East Municipality and Ellembelle District
Information on economic activities in the area is only available for the former Nzema East District
which included both Nzema East Municipality and Ellembelle District. Sixty percent of the
population in this area is involved in agriculture and agro-processing. The major tree crops grown
are coconut, oil palm, rubber and cocoa with cassava and plantain being the major food crops.
Vegetables are also cultivated among other crops and rice is grown in some low-lying areas like
Asanta, Kikam, Esiama and Kamgbunli. Food crops such as cassava, maize, rice, cocoyam and
plantain are grown extensively both for subsistence and for cash. Coconut is grown extensively in
the District especially in the southern part while cocoa is grown commercially in the northern parts
of the area. In recent years, Cape St. Paul’s Wilt Disease has devastated about half of the coconut
plantations in this area. This has seriously affected the economic livelihoods of people in these
areas, leading to low incomes and increased unemployment. Fishing is a key economic activity in
the area. The District has the second highest marine fish production in Ghana and approximately
nine percent of the population is involved in the fishing sector. According to the Ellembelle District
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planning officer, the area also has economic minerals such as kaolin, silica and gold; the latter
which is currently being exploited by the Adamus Resources Limited.
Ahanta West District
Approximately 65 percent of the active population in Ahanta West is directly involved in agricultural
production. Farming is the major economic activity in the District. Other economic activities include
informal trading, processing of agricultural produce mainly oil palm, cassava, rubber and other
trades like hairdressing, dressmaking, carpentry, block-making, auto-electricians, fitting, car-body
spraying, refrigeration mechanics or repairers and others. Oil palm and rubber are the major cash
crops, however, farming is mainly subsistence in nature. Apart from rubber and oil palm, food
crops such as cassava, maize, plantain, vegetables are also cultivated in the District. Significant
timber and sawmills in the Western Region are located in the District. These companies are the
major sources of employment and economic activity in the District. NORPALM and Ghana Rubber
Estates Limited (GREL) are the two major companies with extensive oil palm and rubber
plantations respectively. These companies employ considerable numbers of people in the District.
Fishing is an important economic activity for the people of the coastal areas. Dixcove is noted all
over the Western Region for its sharks, tuna and lobsters catches. Other important fishing
communities include Funkoe, Butre, Aketekyi, Akwidaa, Adjua, Egyambra and Cape Three Points.
Sekondi-Takoradi Metropolis (STM)
The major economic activities in STM are related to the port. The area is the third largest
industrialised centre in the country and there are significant industrial and commercial activities in
the manufacturing sector (food processing, spirits production, textiles, metal fabrication) and
resources sector (timber, clay). STM has a large food and goods market which is a centre for small
and medium sized trading. The manufacturing industry includes cement, household utilities, cocoa
processing and wood processing. The major food items processed are fish, cassava and palm
kernel. Fish is mostly smoked at areas like New Takoradi and Amanful. In STM, 19 percent of the
population is employed in the agricultural sector. Crop production is practiced at a small scale.
Fishing is the predominant occupation category of the agriculture sector, with up to 1,800 people
engaged in fishing along the coastline from Takoradi to Ngyeresia. Commercial livestock and
poultry farming is largely non-existent in the Metropolis, however, many urban dwellers keep
sheep, goats and poultry on free range and household level.
Shama District
Farming and fishing are the main economic activities in the District, employing about 78 percent of
the population. Main crops include cassava, plantain, cocoyam, maze rice, oil palm and
vegetables. According to the District planning officer, coconut palm was extensively grown in the
District until the 1990s when Wilt Disease exterminated most of the trees. The main fishing
communities in the District are Abuesi, Shama and Aboadze. These occupy about seventy percent
of the coastline of the District. The three communities have about 1,500 registered seaworthy
canoes and a catch of about 30,000 t is recovered annually. Large quantities of Birimian rock
deposits have been revealed in the District. Small and medium scale quarry firms have started
mining the rock reserves. There are no major industries in Shama except for the 550 MW Takoradi
Thermal Power Station at Aboadze.
5.5
LAND TENURE
The ownership of land in Ghana is based on the fundamental principle that land is owned by the
community or group. Under the existing arrangement, traditional land-owning authorities (stool
chiefs, clan heads and skins) hold allodial (absolute ownership) title to land on behalf of their
people. Thus outright ownership of land is still a rare form of land tenure in Ghana. Leases and
rentals over a satisfactory period of time for economic/commercial activities are possible and
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involve permission by the allodial titleholders to use the land. However, the land must revert to the
community or the allodial titleholder at the end of the lease or at cessation of the activity for which
the lease was granted.
The land tenure system in Ghana makes it easier for rural households to acquire and own land
than those living in urban areas. The fact that building houses in rural areas is easier than in urban
areas also contributes to making house ownership more prevalent in the rural areas. People living
and working in urban areas tend to rent houses in the area close to where they work, and then
build their own houses in their home towns or villages where they either visit every weekend, or
expect to retire. Districts with high migrant labour have a high number of people renting dwelling
units as opposed to owning houses. Rent-free housing is common, due to the extended family
system; this happens in situations where the owners of these houses may have moved to live in
the city to work and may allow relatives to stay in their houses for free.
The 2000 Population and Housing Census gives the number of dwelling units, including vacant
units, in the Western Region as 430,180. Compound houses constitute the greater number of
dwelling units. Flats or apartments are common in Sekondi Takoradi whereas huts and other types
are common in many rural Districts. Other types of dwellings include uncompleted or temporary
shelter or farm houses constructed with coconut branches or clay, which are used seasonally.
5.6
WELFARE
5.6.1
Poverty
Table 5.7 illustrates the poverty profile in Ghana. The poverty incidence in the Western Region of
Ghana ranked third highest in the country and contributed about 6.5% to the national poverty level.
The levels of unemployment in the Western Region are also considered to be high.
Table 5.7
Poverty Profile in Ghana 2005-2006
Age
Characteristics
Western
Central
Gt. Accra
Volta
Eastern
Ashanti
Brong Ahafo
Northern
Upper East
Upper West
Pop. Share (%)
Avg. income (000’s cedis)
Poverty Incidence (%)
10.1
8.8
13.9
7.5
13.4
16.8
9.2
12.2
4.8
3.6
7,813.3
8,394.3
10,871.2.2
9,590.9
7,805.7
8,284.9
6,718.2
4,779.8
3,409.3
2,354.4
18.4
19.9
11.8
31.4
15.1
20.3
29.5
52.3
70.4
87.9
Source: Etsey, Y.K.A 2009
5.6.2
Education
Ghana has a free basic education system that is compulsory up to age 15. There are six years of
primary education, three years junior secondary school education, three years of secondary
education and four years of tertiary level education.
The level of literacy in the Western region is 58.2% (population of Ghana above 15 years of age
literate in either English or a major Ghanaian language), compared to a national average of 57.9%.
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The level of literacy for females (47.9%) in the region is low compared to males (68.0%). Moreover,
the highest educational attainment level by females (42.4%) in the region is primary, while for
males (42.4%) it is middle/junior secondary school (JSS).This low literacy level for females could
be linked to the low level of educational attainment in the region. In fact, nearly two-thirds
(64.3%) of those currently in school are at the primary level, while only 21.3% are in junior
secondary school. There is therefore a very high attrition rate between primary and junior
secondary school levels. Several reasons account for the high dropout during the transition from
primary to junior secondary. These include the unavailability of junior secondary schools within
many rural localities, resulting in pupils having to travel 10 kilometres or more to the nearest junior
secondary school. Other important factors are affordability and poor infra-structural facilities. In
recent years, however, there have been efforts to improve both quality and quantity of
infrastructural facilities of primary and junior secondary schools. At any rate these figures depict
low educational and literacy levels and distinct gender disparity in access to education and basic
school enrolment.
In the Western Region, Shama Ahanta East has the highest number of teaching staff.
Approximately, 15 percent of teaching staff is based in this District because of the high number of
schools and pupils. The lowest number of primary teaching staff was recorded in Ahanta West
District and the lowest numbers for secondary teaching staff occur in Juaboso.
There are a broad range of educational facilities in all of the Districts, including pre-schools,
primary schools, junior high schools, senior high schools and tertiary institutions. These facilities
fall into public and private categories that are run by the government, individuals or religious
organisations. There are 1,320 primary schools in the Region, 1,240 of these are public and 80 are
private schools. There are half as many junior secondary schools as there are primary schools,
which indicates that access to these schools would be more difficult for some children in the
Region. Consequently, as aforementioned, children living in localities where junior secondary
schools are not within reasonable distances are likely to drop out of school after primary school
(Ghana Districts, 2009). Access to senior secondary school in the Region is poor compared to
access to primary schools and junior secondary schools. There are 42 senior secondary schools in
the Region, with most concentrated in the Sekondi-Takoradi area. An overview of educational
facilities for the Districts is provided below.
Jomoro District
The District has 68 primary schools, 53 junior secondary schools and two senior secondary
schools. The District has focused on the provision of infrastructure such as classroom blocks and
provision of furniture; however, many school blocks are in poor condition and need major
rehabilitation.
Nzema East Municipality and Ellembele District
Educational infrastructure in the area is in fairly good condition. However, some facilities require
renovation. Numbers of educational facilities are only available for the former Nzema East District.
The following facilities were available: 132 pre-schools, 138 primary schools, 67 junior secondary
schools, four senior secondary schools and three tertiary level institutions, namely Kikam Technical
Institute, Esiama Public Health Nursing School and Asanta Teacher Training.
The District has private and public educational facilities including 90 pre-schools, 86 primary
schools, 54 junior secondary schools, three senior secondary schools and a vocational/technical
school.
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Sekondi-Takoradi Metropolis and Shama District
There are 177 pre-schools in STM, 161 primary schools, 144 junior high schools, 19 secondary
high schools, four technical/vocational schools and nursing and teacher training colleges under
public management. School facilities within the area are evenly distributed, so there is easy access
to these facilities and children travel short distances to attend school.
5.7
SOCIAL INFRASTRUCTURE AND SERVICES
5.7.1
Water
There are three major sources of drinking water namely, piped (inside, outside, tanker supply), well
(well, borehole) and natural (spring, river, stream, lakes, rainwater, dugout). In the western region
only 32 percent of houses have access to treated piped water with 8.5 percent having this
available within their dwelling places. The highly urbanised Districts have almost 100 percent
availability of, or accessibility to piped water. This is in contrast to rural Districts where over 60
percent of households rely mainly on surface waters such as rivers, streams, dugouts, shallow
hand-dug wells, spring or rain water as their main source of water, with only approximately 9
percent having access to processed piped water. A few have access to deep boreholes and
relatively shallow but clean water wells. An overview of the water sources is presented in Table
5.8.
Table 5.8
Overview of Water Resources
Water Access Type
Total Households
Piped Outside
Piped Inside
Tanker Supply
Well
Borehole
River / Stream
Spring / Rain
Dugout
Other
All Districts
Jomoro
Nzema East
Ahanta West
Shama Ahanta East
409,282
23.2%
8.5%
0.7%
23.2%
14.2%
24.1%
4.4%
1.5%
0.2%
22,137
15.5%
1.3%
0.5%
32.9%
14.8%
31.2%
3.1%
0.7%
0.0%
29,591
10.6%
2.2%
0.3%
23.1%
14.5%
36.3%
3.4%
0.6%
0.0%
23,064
14.4%
2.9%
2.2%
28.5%
28.6%
16.0%
5.7%
1.5%
0.1%
86,511
59.7%
27.3%
0.7%
7.8%
1.2%
1.3%
1.4%
0.3%
0.3%
Source: Population and Housing Census, 2000
Note: Statistics unavailable for newly created Districts
Potable water is in fact gradually being made available to rural communities through the sinking of
deeper boreholes. Table 5.9 lists the sampling results of some of the wells encountered during the
field survey, June 2012. Results reveal that water tends to be somewhat salty when wells are
located close to the coast and only lightly mineralized once wells are located further inland (behind
the coast road); none of the wells sampled contain oligomineral water.
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Sampling of a few wells in Study Area (eni site selection survey, June 2012)
Town/Location
pH
Conductivity
(Microsiemens/
cm)
Metika (Macroarea 1)
6.8
1.650
ESIAMA 1 (Macroarea 5)
7.3
5
2.400
ESIAMA - Chief Fisherman’s private well
(Macroarea 5)
7.4
5
1.870
Photo
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ASAMKO aqueduct
6.3
473
Egyan inland well (Macroarea 6)
6.4
860
Egyan town well (Macroarea 6)
AKONU (Macroarea 6)
6.4
6.5
557
840
No photo (raining heavily)
287 of 425
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ASANTA (Macroarea 5)
5.7.2
6.7
5
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1.885
Electricity
Electricity and kerosene lamps are used as the main sources of lighting in the Western Region,
providing about 99 percent of the lighting needs of households. In the urban areas, the majority of
households use electricity while in the rural Districts, kerosene lamps are the main source of
lighting. Rural households are also gradually gaining access to electricity through a rural
electrification programme, even though this programme has as yet only touched a few
communities located fairly close to urban centres. An overview of access to electricity for the
Districts is provided below.
Jomoro District
A large portion of the population in Jomoro (55%) does not have electricity. The large towns in the
District such as Half Assini, Elubo, Tikobo 1, Jaway Wharf and Mpataba have all been connected
to the national grid; however, settlements on the south western part of the District such as
Newtown, Nzimtianu and other parts in the north, have no power. Those with power experience
voltage fluctuations and frequent power interruptions.
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Households in the urban areas have access to electricity, while a large number of peri-urban and
rural households are also gradually gaining access to electricity through the rural electrification
programme, even though this programme has a very long way to go and benefited only a few
communities which are fairly close to urban centres.
Electricity services have been expanded to include communities such as Media, Boakrom, Aboadi,
Kubekor, Aboagyekrom, Enmokanwo, Boekrom, Ellobankanta and others under Self Help
Electrification Project (SHEP). Most people have access to electricity, however, regular power
outages are common due to inadequate infrastructure such as transformers.
Almost 90% of the Metropolis has been connected to the electricity grid through the SHEP. Street
lighting is, however, a problem in the Metro. A number of communities in the metropolis are without
electricity, these include newly schemed areas. The Metro, as a whole, experiences frequent
power outages. In Shama, almost the entire (95 %) District is connected to the national electricity
grid.
Fuel for cooking is instead principally charcoal and firewood in the Region, even for quite a
sizeable number of urban dwellers. Coconut husks are also used. Liquid petroleum gas is used for
cooking in some homes, particularly in the big cities and towns. The use of electricity for cooking is
minimal, being limited to Sekondi-Takoradi with its highly urbanised status and access to
electricity.
The Takoradi Thermal Power Plant lies on the coast approximately 17 km east of SekondiTakoradi, and relies on marine water for cooling purposes. The Thermal Plant started operation in
1997, and was initiated by the Volta River Authority to complement the existing Hydro Plant at
Akosombo and Kpong. The Takoradi Thermal Power Plant is therefore a facility of strategic
importance for meeting Ghana’s energy needs (Volta River Authority, 2006). The plant has
historically been fuelled by crude or fuel oil but conversion to use of natural gas from the West
Africa Gas Pipeline (WAGP) occurred in 2008 though initial flows have been intermittent.
There are two existing bulk fuel storage facilities in STM, namely the Shell and GOIL depots
located between Poasi and New Takoradi. According to the STMA planning officer, a third bulk fuel
facility is planned by Cirrus in the same area. Takoradi Port also has dedicated oil berthing
facilities. Fuel is distributed via road tanker to filling stations in the coastal District either from Tema
or Takoradi. Other than the effects of intermittent national fuel shortages, none of the Districts
experience problems with fuel availability.
5.7.3
Telecommunications
Two main types of telephone systems are in operation in the country. These are the fixed line
telephones and the mobile telephone systems. Other systems being operated are wireless, radio
telephone and satellite communication systems. Vodafone Ghana Telecom Company operates
over 95 percent of the fixed line telephones in the country. Teledensity of fixed line telephones in
the Western Region is 0.3 telephones per 100 persons, which is below the national average of 0.7.
Of the 12,985 fixed lines the Region recorded in the year 2000, 11,046 or 86 percent served the
Sekondi Takoradi metropolis. The Western Region is extensively covered by the following mobile
telephone operators: MTN, Vodafone, Ghana operators of Vodafone, Tigo, Kasapa and Zain. The
Region has the second highest locality coverage by MTN, which is the largest mobile telephone
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system in the country. Mobile telephone coverage is poor in the northern part of Nzema East
Municipality and in Jomoro District.
5.7.4
Police Services
Police services in the Region are those offered by the Ghana Police Service. Most communities
have a Police Station and every District capital has a District Police Headquarter with a Regional
Police Headquarter in the regional capital. The Western Region Command of the Ghana Police
Service is located in Takoradi. Apart from the Police Service, chiefs and elders in the communities
are responsible for settling disputes.
5.7.5
Fire Services
Fire response capability in Takoradi exists through the National Fire Service and the Ghana Ports
and Harbours Authority Fire Service Department. There are reportedly a total of five fire tenders at
the National Fire Station’s disposal in case of emergencies. The port has two fire tenders and the
airport, one.
5.8
5.8.1
TRANSPORT INFRASTRUCTURE
Roads
The Ghana Private Road Transport Union (GPRTU) and other transport organisations provide
transport services within the Districts in the Region. The most common means of transport is by
road where there are privately owned or state owned buses. The state owned buses usually
operate within the urban areas. In the villages, private taxis and small buses owned by private
individuals are operational. The road network in the Western Region is limited and the conditions of
the roads can be very poor, particularly in the rainy season. Goods such as bauxite, manganese,
timber and timber products and cocoa are transported by rail on the Western Line which runs from
Takoradi to Kumasi and Awaso.
An overview of transport and road infrastructure present in the relevant Districts is hereby
provided.
Jomoro District
Thirty-six percent of roads in Jomoro are trunk roads while the remaining 64 percent are feeder
roads. The roads tend to be generally muddy and slippery during the wet season and sometimes
become inaccessible. An exception is the trunk road which traverses the District in an east-west
direction to Takoradi and which forms part of the Trans- West African Highway. In 2007 and 2008
there were major improvements in road rehabilitation. Boats are an important mode of transport for
goods and passengers in Jomoro District. There are communities along the Juan Lagoon and
other river bodies which can only be accessed by boat.
The former Nzema East District has a total of 154 km of trunk roads, of which 64 km are metalled.
The metalled trunk roads form part of the Trans-West Africa Highway. The rest of the trunk roads
are gravel or earth-surfaced. Apart from the trunk roads, the District has a total of 253 km of feeder
roads, of which 40 percent are in poor condition. Over 70 percent of these feeder roads are in the
southern half of the District.
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The road networks (mostly feeder roads) have been improved by 10%. This has opened up the
District for easy access to farming communities and market centres. In 2006, for example, 14
feeder roads underwent maintenance. Due to the poor condition of some of the feeder roads, some
parts of the District are not easily accessible, especially during the rainy season.
Most of the roads in the STM, particularly those within the urban centers have been over stretched.
There is rapid development taking place in the hinterland and a significant proportion of these
areas is without access roads. The condition of the road network in the Metropolis stands at 51.6%
good, 28.2% fair and 19.6% poor. The total length of all-weather roads in the Metropolis has been
extended from 330 km in 1996 to over 400 km in 2006.
5.8.2
Ports and Harbours
The Port of Takoradi was built as the first commercial port of Ghana in 1928 to handle imports and
exports to and from the country. The port currently has a covered storage area of 140,000 m2 and
has an open storage area of 250,000m2. It has a wide range of vessels supporting its operations
including tugboats, lighter tugs, a water barge and a patrol boat. The Port handles both domestic
nd transit cargoes and currently handles about 600 vessels annually, which is 37 percent of the
total national seaborne traffic, 62 percent of total national export and 20 percent of total national
imports annually. Almost 160,000 tonnes of cargo are handled annually at the port. The Port of
Takoradi also has a fishing harbour located at Sekondi, which has an ice plant that can
accommodate vessels with up to 3 m draft. Other ship traffic in the area is associated with ports
such as Abidjan (Côte d’Ivoire) and Lagos (Nigeria).
5.8.3
Airports
The Takoradi Airport is the only civilian airport in the Western Region. The airport has one runway.
Ghana Air Force also has a base at the airport. At least one scheduled domestic flight lands and
takes off from this airport daily.
5.9
WASTE AND SANITATION
The indiscriminate disposal of solid waste in gutters, open spaces and the sea has led to
unsanitary conditions in some Districts. Added to this is the unavailability of toilet facilities with over
40 percent of dwellings in the Western Region having either no toilet facilities or having to use a
public toilet. The environs of these public toilets are being turned into solid waste dumps with
serious health hazards in many of the urban and peri-urban localities (Population and Housing
Census, 2000). Where facilities do exist in the region, the most common types are Kumasi
Ventilated-Improved Pit (KVIP), pit latrine or a bucket/pan system. Where no facilities exist, people
are forced to make use of the beaches, outlying bushes and gutters.
Waste management is a serious issue in the Western Region like many others in Ghana. The
predominant means of waste disposal is either by dumping; this may be at specified sites; or
indiscriminately burning or burying. Approximately 60 percent of all households in all the Districts
use a specified public dump while an additional 29 percent use unauthorised dump sites to dispose
of waste. The waste from these open dumps washes into streams and rivers which often serve as
sources of water for local communities. Collection and disposal of waste by the local authorities
accounts for only about 2 percent of all households. Households in Sekondi Takoradi, more than
any other District, use collection agencies and public dumping sites. A site visit of the existing
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waste handling facilities was undertaken in May 2009 to determine the suitability of these facilities
for the wastes from the Jubilee Project.
5.10 COOPERATION AND DEVELOPMENT
In Ghana, ODA (Official Development Assistance) is channelled through technical assistance
projects and through a budget support mechanism, named Multi-Donor Budgetary Support which
serves as the main framework for poverty-reduction interventions, financed by both domestic and
external resources. The scheme is said to have reduced competing demands on the Government
of Ghana. It has also wiped out any reference to external interventions in the districts with the
exception of international NGOs. Non-governmental organizations that can be found in the coastal
districts are depicted in Table 5.10.
Table 5.10
NGOs operating in the coastal districts of the study area
District
NGO
Intervention Areas
COSPE (co-operation for the
development
of
emerging
countries)
Developing of small scale and
income generating activities.
SNV
Land tenure issues, ownership of
resources on land, sustainable
management of resources
Ghana wildlife Society
Conservation of biodiversity,
wildlife, migratory birds.
COLANDEF
Land
governance,
natural
resource management, gender,
local governance
Ellembele
COLANDEF
Land
governance,
natural
local governance
Nzema East
Care International
Land tenure issues, ownership of
resources on land, sustainable
management of resources
Friends of the Nation
Environmental conservation
SNV
Sanitation
improvement
programme for Axim
COLANDEF
Land
governance,
natural
local governance
COSPE
Income generating activities
Conservation Foundation
Environment, gender equity,
water and sanitation, health
Ricerca e Co-operazione
Conservation of biodiversity
World Vision International
Water and Sanitation, education,
health, child protection
Friends of the Nation
Natural Resources Management,
Community Development,
Enterprise Development
Eagle’s Eye Charity Foundation
Basic
Education,
Vocational
Training, Youth and Women
Jomoro
Ahanta West
Sekondi-Takoradi
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Empowerment, Advocacy, Health
Relief, Community Development,
Human Rights
Friends of Women
Women and girls empowerment
Jomelos Save Life Organisation
Food, education and health
services for orphans, longdistance adoption
Mehran Foundation
Health and education
Safe Blood Ghana
Youth Health Awareness on
HIV/AIDS,
Child
Support
Programme through micro-credit
loans
Local NGOs/CBO are active in STMA and the District of Shama; that is outside the 4 districts of the
study area but within Western Region, and should therefore still be considered for stakeholder
identification and consultation.
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HEALTH BASELINE
In 2011 eni Ghana undertook to conduct an Environmental, Social and Health (ESH) Baseline
Study in order to provide a broad preliminary analysis of the sensitive aspects and areas existing
throughout the country in general, and secondly and in particular regard to those specific areas
potentially affected by current and future company operations (defined as the six fringe coastal
districts of Ahanta West, Sekondi-Takoradi, Shama, Nzema East, Ellembele and Jomoro, in the
Western Region of Ghana). The regional and district level health data collected through the survey
carried out is here-in used to provide an overview of the health status in the Region and in the six
referral coastal districts.
6.1
REGIONAL HEALTH STATUS
Infant mortality rate is one of the measures of development of a country and it is of prime
importance to every nation, of which Ghana is no exception. Figure 6-1 displays the trend in Under
5 Mortality, Neonatal Mortality, and Peri-natal Mortality and Rates of Under-5 Malnourished. Infant
mortality rate in the region fell from 76.9 in 1988 to 51 in 2008. Under-5 mortality rate also fell
sharply from 151.2 to 60 within the same twenty-year period in the region. On the other hand,
neonatal mortality rate fell initially from 47 in 1993 to 38.3 and 37 in 1998 and 2003 respectively.
However, in 2008, the records show that it has started to rise from 37 to 40. Peri-natal Mortality
Rate in contrast has increased dramatically between 1998 and 2003; from 44.7 to 66.0. The Under
5 Malnourished situation also shows signs of some improvement from 33.1 in 1993 to only 10.3 as
at 2008.
Figure 6-1
Trend of Western Region performance in some key child health indicators
Source: Ghana Health Service (GHS) 2009
The Western Region of Ghana had been recording unacceptably high maternal deaths in the past
few years. A review of the records showed that over 57% of the deaths were due to haemorrhage
and eclampsia. Although the major delays leading to maternal deaths (and new born deaths) are
well known, it is believed that not much has been done to address the delays especially on the part
of the health workers.
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According to a Ghana Health Service 2009 Report, the death rate among infants was 51.8 for 2008
and 45.2 in 2009, showing a decrease of 6.6. The under 5 death rate was lower than that of the
infants, 31.9 and 24.2 for 2008 and 2009 respectively. This also shows a decrease of 7.7. Lastly,
those above five years had the overall lowest mortality rate of 25.9 and 23.1 for the two referral
years.
Top ten causes of hospital reported deaths in the Western Region are shown in. During the period
2008-2009, the top ten causes of reported deaths accounted for 54.9% of all causes of deaths with
malaria and anaemia taking the 1st and 2nd positions respectively. Malaria contributed 20.2%
which showed an increase from the previous year 2009 (16.2%) during the same period. This is a
source of concern because of the many ITNs that have been distributed and IPT given to pregnant
women. There is need to investigate the cause for these deaths and address them appropriately.
Table 6.1
Top ten causes of hospital reported deaths in Western Region, 2008-2010
2008
2009
N° of
cases
%
Malaria
198
16.2
Anaemia
94
HIV/AIDS
2010
N° of
cases
%
N° of
cases
%
Malaria
171
16.2
Malaria
218
20.2
7.7
Anaemia
110
10.4
Anaemia
99
9.2
59
4.8
HIV/AIDS
54
5.1
HIV/AIDS
55
5.1
Hypertension
58
4.8
Hypertension
42
4
Hypertension
48
4.4
CVA
52
4.3
CVA
40
3.8
CVA
37
3.4
Pneumonia
44
3.6
Pneumonia
37
3.5
Pneumonia
31
2.9
Septicaemia
41
3.4
Septicaemia
25
2.4
Septicaemia
31
2.9
Diabetes
36
3
Diabetes
25
2.4
Diabetes
29
2.7
Meningitis
25
2.1
Meningitis
24
2.3
Meningitis
24
2.2
Cellulitis
24
2
Cellulitis
19
1.8
Cellulitis
21
1.9
All other
diseases
588
48.2
All other
diseases
506
48.1
All other
diseases
488
45.1
Total Cases
1219
100
Total Cases
1,053
100
Total Cases
1081
100
Condition
Condition
Condition
Source: GHS, 2010
The picture of ten top causes of morbidity in the Western Region is displayed in Table 6.2. Malaria
continues to be the number one cause of OPD morbidity, contributing 44.6% to all new reported
cases during the study period. Acute Respiratory infections have been the second cause of OPD
cases from 2008 to 2010, contributing 9.5% in 2010. Diarrhoeal Diseases and Skin Diseases have
been interchanging the third and fourth positions during the same three year period.
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Table 6.2
Top ten causes of morbidity in Western Region, 2008-2010
2008
2009
N° of
cases
%
Malaria
330,996
42.5
*Other ARIA
63,673
Skin
diseases &
ulcers
2010
N° of
cases
%
N° of
cases
%
Malaria
458,563
45.2
Malaria
515,082
44.6
8.2
*Other ARIA
75,386
7.4
*Other ARIA
109,326
9.5
36,757
4.7
Skin
diseases &
ulcers
43,980
4.3
Skin
diseases &
ulcers
53,801
4.7
Diarrhoeal
diseases
33,917
4.4
Diarrhoeal
diseases
40,639
4
Diarrhoeal
diseases
49,678
4.3
Pregnancyrelated
complications
19,483
2.5
Pregnancyrelated
complications
26,295
2.6
Pregnancyrelated
complications
33,333
2.9
Rheumatism
& joint pains
18,689
2.4
Rheumatism
& joint pains
22,957
2.3
Rheumatism
& joint pains
22,650
2.0
Hypertension
17,158
2.2
Hypertension
21,095
2.1
Hypertension
19,543
1.7
Acute eye
infection
14,173
1.8
Acute eye
infection
19,160
1.9
Acute eye
infection
17,710
1.5
Intestinal
worms
12,481
1.6
Intestinal
worms
18,286
1.8
Intestinal
worms
16,770
1.5
Chicken pox
10,318
1.3
Chicken pox
12,326
1.2
Chicken pox
12,879
1.1
All other
diseases
221,603
28.4
All other
diseases
276,465
27.2
All other
diseases
303,166
26.3
Total Cases
779,608
100
Total Cases
1,015,152
100
Total Cases
1,153,935
100
Condition
Condition
Condition
Source: GHS, 2010
6.2
HEALTH STATUS IN COASTAL DISTRICTS
This section discusses the major hospital-reported diseases in the six coastal districts of Shama,
Sekondi-Takoradi, Ahanta West, Nzema East, Ellembele and Jomoro.
According to GHS data (see Table 6.3), Malaria ranks first among the top ten causes of morbidity
in the district of Shama, accounting for 43.66% and 46.63% in 2008 and 2009 respectively;
showing an increase of almost 3%. The next three diseases in the same two-year period were
respiratory tract infections, skin diseases and ulcers, and diarrhoeal diseases.
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Table 6.3
Top ten causes of morbidity in Shama District, 2008-2009
2008
Disease
2009
N°
%
Malaria
22,769
43.66
Acute respiratory
tract infection
7,275
Skin diseases &
ulcers
N°
%
Malaria
39,287
46.63
13.95
Acute respiratory
tract infection
11,132
13.21
4,379
8.40
Skin diseases &
ulcers
6,388
7.21
Diarrhoeal diseases
2,539
4.87
Diarrhoeal diseases
3,321
3.94
Intestinal worm
infestation
1,387
2.66
Rheumatism & joint
pains
3,070
3.64
Rheumatism & joint
pains
1,203
2.31
Intestinal worm
infestation
2,489
2.95
Hypertension
941
1.80
Anaemia
1,192
1.42
Anaemia
713
1.37
Hypertension
1,071
1.27
Vaginal discharges
491
0.94
Home accidents and
injuries
982
1.16
Home accidents and
injuries
424
0.81
Acute Eye Infection
903
1.07
10,019
19.22
Others
14,404
17.10
Others
Disease
Source: GHS, 2009
Malaria also ranks first among the top ten causes of morbidity in the Sekondi-Takoradi Metropolis;
it constituted 41.7% of all cases in 2010 as compared to 37.37.% in 2009. Hypertension, intestinal
worms, skin diseases and ulcers and acute eye infection showed an increase in morbidity whiles
anaemia showed reduction.
Table 6.4
Top ten diseases in the Sekondi-Takoradi Metropolis, 2009-2010
2009
Disease/Condition
2010
N°
%
Malaria
146,059
37.37
Other ARI (acute)
32,895
Acute Eye Infection
Disease/Condition
N°
%
Malaria
170,409
41.7
8.42
Other ARI (acute)
47,662
11.7
19,272
4.93
Skin diseases &
ulcers
21,048
5.1
Diarrhoeal diseases
17,487
4.47
Diarrhoeal diseases
18,635
4.6
Skin diseases &
ulcers
15,016
3.84
Acute Eye Infection
13,467
3.3
Rheumatism & joint
pains
9,982
2.55
Rheumatism & joint
pains
8,819
2.2
Anaemia
9,323
2.39
Hypertension
7,368
1.8
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Hypertension
7,212
1.85
Anaemia
6,997
1.7
Acute Urinary Tract
4,358
1.12
Intestinal worms
5,855
1.4
Intestinal worms
4,182
1.07
Vaginal discharges
4,245
1.0
Other diseases
125,024
31.99
Other diseases
104,281
25.5
Source: GHS Health Sector Review, 2010
The predominant disease in Ahanta West district is again malaria, accounting for about 46 percent
of the OPD cases. This is a clear reflection of the poor sanitary conditions in the district. Other
diseases according to the district health report are depicted in Table 6.5.
Table 6.5
Top ten diseases in Ahanta West District
2009
Disease
N° of OPD cases
Malaria
44,948
Acute Respiratory Infection
8,785
Skin diseases & ulcers
6,933
Diarrhoeal diseases
4,681
Pregnancy-related complications
3,636
Intestinal worms
2,978
Rheumatism & joint pains
1,817
Home accidents and injuries
1,643
Hypertension
1,365
Acute eye infection
1,267
Others
20,657
Source: DHMT, 2009
Unlike the other districts, Nzema East district reported five top causes of disease, instead of the
usual top ten. Malaria has been identified as the major disease in the. Other common diseases
reported are pregnancy related, diarrhoea, hypertension and other ARI. Table 6.6 shows the trends
in the top five diseases reported in 2008 and 2009.
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Table 6.6
Top five diseases Nzema East District, 2008-2009
2008
2009
Disease
N°
%
Malaria
36,442
72.0
Pregnancy-related
complications
4,351
Diarrhoeal diseases
Disease
N°
%
Malaria
34,847
70.0
8.5
Pregnancy-related
complications
3,724
7.5
3,312
6.5
Diarrhoeal diseases
2,010
4.5
Other ARI
2,390
3.9
Hypertension
1,898
4.2
Hypertension
2,169
3.6
Other ARI
1,743
3.5
Source: Nzema East District Development Plan, 2009
Due to poor sanitation and frequent rain falls Malaria is the number one endemic disease in
Ellembele district. It is most always the number one cause of OPD attendance in all the health
facilities and among all age groups. It also accounts for most of the admissions and deaths
especially among children at the only hospital in the district, St Martin de Pores at Eikwe. TB and
HIV are also diseases which are commonly detected at the hospital. However, one cannot tell the
magnitude of the situation in the district at present, since most of the cases of Eikwe Hospital are
attributable to patients from neighbouring districts and Ivory Coast. Other diseases like Yaws and
Schistosomiasis are found to be common among school children (Ellembele Development Plan,
2008).
Table 6.7
Top ten diseases of OPD attendants in Ellembele District, 2009
2009
Disease/Condition
N°
%
Malaria
67,778
42.6
Acute Respiratory Infections
13,769
8.6
Skin diseases and ulcers
8,492
5.3
Diarrhoeal diseases
8,330
5.2
Pregnancy-related complications
8,219
5.2
Rheumatism & joint pains
6,626
2.2
Hypertension
3,571
1.5
Gynaecological conditions
2,455
1.4
Anaemia
2,287
1.2
Intestinal worms
1,848
1.2
All other diseases
35,184
22.5
Source: Ellembele District Development Plan, 2009
Malaria ranks the first of the top 10 diseases in Jomoro district. The number of cases reported
were 32,134 and 40,952 in 2009 and 2010 respectively. The results show that malaria infection
has been on the increase in the reported period. Other major diseases apart from malaria were
other ARI. Intestinal worm cases were reduced from 5524 (second position in 2009) to 3000 in
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2010. On the other hand skin diseases rose from the third position to second in 2010. There were
no new diseases entering the top ten between 2009 and 2010.
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Table 6.8
Top ten diseases in Jomoro District, 2009-2010
2009
Disease/Condition
2010
N°
%
Malaria
32,134
46.9
Other ARI (acute)
7,889
Intestinal worms
Disease/Condition
N°
%
Malaria
40,952
46.3
11.5
Other ARI (acute)
10,321
11.2
5,524
8.0
4,014
4.5
3,602
5.3
Diarrhoeal diseases
3,624
4.1
Diarrhoeal diseases
2,895
4.2
Rheumatism & joint
pains
3,464
4.0
Rheumatism & joint
pains
2,816
4.1
Pregnancy-related
complications
3,248
3.7
Pregnancy-related
complications
2,720
4.0
Intestinal worms
3,000
3.4
Typhoid Fever
2,479
3.6
Typhoid Fever
2,700
3.1
Hypertension
2,207
3.2
Hypertension
1,917
2.2
Anaemia
1,227
1.8
Gynaecological
disorders
1,567
2.0
Other diseases
5,092
7.4
Other diseases
13,671
15.5
Source: GHS District Report, 2010
6.2.1
HIV/AIDS and Tuberculosis
HIV prevalence rate based on the sample of all those tested at health institutions and other
services available are presented in
Table 6.9. Jomoro district reported the highest proportion (10.4%) of HIV cases, followed by
Ellembele (9.1%) and Nzema East (8.3%), with Shama district reporting the lowest prevalence rate
of 1.2%. On the other hand, Ellembele reported the largest number of people receiving ART
treatment (247), followed by Sekondi-Takoradi (147), Nzema East (53), Jomoro (17), while none
received treatment in Shama and Ahanta West Districts.
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Table 6.9
District-level Control Indicators of HIV/AIDS
District
N° of
institutions
offering
HIV/TB
counselling
N° of
ART
Centres
N° of ART
Centres
with CD4
machines
Cumulative
N° of HIV
patients
receiving
ART in
2009
HIV
prevalence
among all
tested at
health
institution
HIV
prevalence
(%) during
“know your
status”
campaign
2009
Shama
1
0
0
0
1.2
1
Sekondi-Takoradi
1
4
3
147
5.7
6.1
Ahanta West
1
0
0
0
3.7
3.3
Nzema East
1
1
1
53
8.3
4.0
Ellembele
1
1
1
248
9.1
1.3
Jomoro
1
0
1
17
10.4
3.3
Source: GHS, 2010
Table 6.10Table 6.11show the cure and success rate of those diagnosed with TB in the six referral
coastal districts. Nzema East District was the best among the six districts achieving 100% cure rate
in 2009. It is followed by Sekondi-Takoradi (77%), Ellembele (72%), and Shama (71%). The
remaining two districts need to step up their effort in increasing their cure rate. However, it should
be noted that apart from Nzema East District that exceeded the 80% target, all the other districts
fell below the set target.
Table 6.10
TB Control – TB cure rates (%) (Target – 80%)
District
2009 half yr cohort
2008 cohort
2007 cohort
2006 cohort
Shama
71
0
0
0
Sekondi-Takoradi
77
78.2
76.2
64
Ahanta West
45
73.3
70.7
58
Nzema East
100
91.5
75.5
72
Ellembele
72
0
0
0
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Jomoro
53
84.4
64.6
52
Source: GHS, 2009
With regards to TB success rate Nzema East District still tops the list, exceeding the target set in
achieving a 100% success rate. However, two other districts (Ellembele and Jomoro) met the
success rate target of 90%. The other three districts – Shama (89%), Sekondi-Takoradi (87%), and
Ahanta West (82%) were also close to the set target.
Table 6.11
TB Control – TB Treatment Success Rates (%) (Target – 90%)
District
2009 half yr cohort
2008 cohort
2007 cohort
2006 cohort
Shama
89
0
0
0
Sekondi-Takoradi
87
78.2
86.9
80
Ahanta West
82
86.6
86.2
79
Nzema East
100
97.2
89.8
84
Ellembele
92
0
0
0
Jomoro
90
89
82.3
72
Source: GHS, 2009
6.3
HEALTH FACILITIES IN COASTAL DISTRICTS
The Ghanaian public health service is offered through a hierarchy of hospitals, health centres,
maternity homes and clinics including Community-based Health Planning and Services (CHPS)
compounds. Services are run on a three-tier system of care; from primary through secondary to
tertiary services organized at five levels: community, sub district, district, regional and national.
Community and sub-district levels provide primary care, with district and regional hospitals
providing secondary health care. The teaching hospitals are at the apex providing tertiary services
and responsible for the most specialised clinical and maternity care and also provide the highest
level of academic and practical training and research in medicine and related health fields. The
public health sector is complemented by the private health sector, which provides about 42 per
cent of Ghana’s health care services (Arhinful, 2009).
The Public Health Division of the Western Region has a key function of coordinating all public
health and Clinical activities in the region to ensure a steady improvement in the health status of
the region and in the country.
The structure of the health referral system in the Western region is a shadow of the national
structure. Health system in the region is dominated by facilities in tiers one and two. The highest
referral system in the region is Effia Nkwanta Regional Hospital, which falls in the tier-III, thus
secondary health. Besides this, all the remaining systems are either within tier-1 or tier-2.
The official national norm is that no citizen should be more than 8 kilometres away from the
nearest health facility. There are a total of 354 health facilities in the region made up of 28
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Hospitals, 54 Health Centres (HC), 102 Clinics, 130 functional CHPS compounds and 36 maternity
homes (MH). The breakdown of health facilities are shown in Table 6.12.
Table 6.12
Ownership
Health facilities by ownership and type – Western Region
Hospital
HC
Clinic
CHPS
MH
Total
Gov’t
14
54
35
130
0
233
Mission
4
2
18
0
0
24
Quasi-gov’t
3
0
2
0
0
5
Private
5
0
47
0
36
89
Industrial
2
0
0
0
0
2
Total
28
57
102
130
36
354
Source: Ghana Health Service, Western Region, 2010
There is one hospital, three health centres, six clinics, five CHPS, and no maternity home in the
Ahanta West District as displayed in Table 6.13
Table 6.13
Ownership
Health facilities by ownership and type – Ahanta West District
Hospital
HC
Clinic
CHPS
MH
Total
Gov’t
1
3
6
5
-
13
Mission
-
-
-
-
-
-
Private
-
-
-
-
-
-
Industrial
-
-
-
-
-
-
Total
1
3
6
5
-
13
Expectedly, the Sekondi-Takoradi metropolis had the highest number of health facilities among
districts in the region. Overall, there were twenty-one health facilities in the metropolis, comprising
five hospitals (2 public and three private). Shama is the district with least (8) number of health
facilities as shown in Table 6.14 - Table 6.18.
Table 6.14
Ownership
Health facilities by ownership and type – Sekondi-Takoradi District
Hospital
HC
Polyclinic
Clinic
CHPS
MH
Total
Gov’t
2
5
1
2
-
-
10
Mission
-
-
-
3
-
-
3
Private
3
-
-
-
-
5
8
Industrial
-
-
-
-
-
-
-
Total
5
5
1
5
-
5
21
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As shown in Table 6.15, Shama district, one of the newly created districts has one hospital, two
health centres, four clinics, two CHPS, and no maternity home. There are five government, two
private and one industrial health facilities in the district.
Table 6.15
Ownership
Health facilities by ownership and type –Shama District
Hospital
HC
Clinic
CHPS
MH
Total
Gov’t
-
2
1
2
-
5
Mission
-
-
-
-
-
-
Private
-
-
2
-
-
2
Industrial
1
-
-
-
-
1
Total
1
2
3
2
-
8
Of the 12 facilities in the Nzema East District, all are owned by the government (see Table 6.16).
Table 6.16
Ownership
Health facilities by ownership and type – Nzema East District
Hospital
HC
Clinic
CHPS
MH
Total
Gov’t
2
6
1
3
-
12
Mission
-
-
-
-
-
-
Private
-
-
-
-
-
-
Industrial
-
-
-
-
-
-
Total
2
6
1
3
-
12
As shown in Table 6.17, all health facilities (12) in Ellembele are owned by the government. These
are made up of one hospital, three health centres, four clinics, four CHPS, and no maternity home.
Table 6.17
Ownership
Health facilities by ownership and type – Ellembele District
Hospital
Health
Centre
Clinic
CHPS
Maternity
Home
Total
Gov’t
1
3
4
4
-
12
Mission
-
-
-
-
-
-
Private
-
-
-
-
-
-
Industrial
-
-
-
-
-
-
Total
1
3
4
4
-
12
Unlike the previous two districts where all the health facilities are fully government-owned, in
Jomoro district, out of the total 11 facilities, six are owned by the government and the other five are
privately owned. As shown in Table 6.18, there are three health centres, one clinic, and two CHPS
owned by the government. One hospital and four clinics are privately owned.
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Table 6.18
Ownership
Health facilities by ownership and type – Jomoro District
Hospital
Health
Centre
Clinic
CHPS
Maternity
Home
Total
Gov’t
-
3
1
2
-
6
Mission
-
-
-
-
-
-
Private
1
-
4
-
-
5
Industrial
-
-
-
-
-
-
Total
1
3
5
4
-
11
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IMPACT IDENTIFICATION AND ASSESSMENT
7.1
ASSESSMENT METHODOLOGY
The present chapter analyses the associated and potential impacts that the proposed Ghana
OCTP Block Phase 1 Development Project activities could have on the biophysical and anthropic
environment. As described in Chapters 2 (Project Description), the project essentially involves
installation of the drilling rig, drilling, production testing and well completion. The salient features
involve the well drilling operations, to be performed using a “Semisubmersible Drilling Unit”,
Installation, operation and removal of well heads; Laying and operation of Transport Systems
(flowlines); and Installation and operation of FPSO and mooring systems.
The chapter describes the impact identification and assessment methodology, identifies the
potential impacts and assesses the significance of the identified potential impacts on the various
environmental, social and health components. The assessment approach generally involves
matching the various activities of the proposed project (as described in this report) with the
components of the existing biophysical and anthropic environment (Baseline Analyses chapters 46).
7.1.1
Potential Impacts Identification and Characterisation
The environmental, social and health impacts potentially generated by the development of the
project were identified via the elaboration of impact pathways. An impact pathway is substantially a
process tool which allows for the identification of the main impacts on the surrounding physical
environment and the host communities’ society, economy and health, induced during the execution
of the project, from the initial phase, through to Operation and Production, and ultimately
Decommissioning.
The process begins with an impact identification matrix, which involves the listing of the main
project activities carried out during the various project phase on one side and the baseline
biophysical and anthropic profile components (i.e. environmental, socio-economic and health
components) on the other, so as to highlight the relationships between project activities and
potential direct impacts. In some cases the components are expressible by means of specific
indicator parameters (see next paragraph).
Characterisation refers to the types of impact generated by the Project; i.e. any project can
generate a wide range of potential impacts, some of which will be direct, whilst others will be more
complex and difficult to identify (see box below).
Types of impact:
Direct (or primary)
Indirect
Cumulative
Perceived
Impacts that result from a direct interaction between a planned project
activity and the receiving natural or socio-economic environment.
Impacts that follow on from the primary interactions between the
project and its natural and socio-economic environment as a result of
subsequent interactions.
Impacts that act together with other impacts (including those from
concurrent or planned future third party activities) to affect the same
resources and/or receptors as the project.
Changes that may be unconnected to, but blamed on, the project.
These are usually identified and assessed through stakeholder
engagement and consultation.
Therefore, once the direct impacts are established, the next step is to complete the impact
pathway by determining the indirect impacts of these direct changes to the environmental, social
and health components, as well as any subsequent cumulative and perceived impacts.
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Potential Impacts Indicator Parameters
The next step in the impact assessment methodology consists in selecting the
parameters/indicators of each ESH component that are “sensitive” to the changes triggered by the
potential impacts identified. Their sensitivity renders them capable of describing and/or quantifying
the potential impacts caused by project activities, as well as providing a clear picture of the
potential impacts’ boundaries and characteristics.
The identification of indicator parameters therefore serves the purpose of translating the identified
potential impacts into measurable (qualitatively and/or quantitatively) terms, in order to proceed to
their evaluation via the qualitative assessment method hereby described and/or specific ad hoc
modelling/simulation techniques
7.1.3
Impacts Evaluation
Once identified, the significance of the potential impacts must be assessed in order to determine
requirements for impact mitigation (or enhancement of benefits) and management measures to be
implemented during the project.
Where feasible, in relation to certain components the potential impacts identified were assessed
quantitatively via modelling techniques. These modelling techniques put into correlation the values
of the single indicator parameters of each component before and after the project’s activities, thus
allowing to quantify their relative potential disturbing effect.
In the case of other components the assessment is solely qualitative and is limited to a series of
considerations on the possible natural and/or anthropic sources of disturbance, their status within
the marine environment and their effects on the biophysical and/or anthropic ecosystems. Here, in
assessing the significance of each potential impact (positive or negative), the following criteria of
consequence were applied:

Duration: The temporal scale of the effect, ranging from 1 year or less to 10 years or
more (potentially irreversible);

Extent: The geographical scope of the impact, ranging from local scale (the proposed
operating area and immediate environs) through to international transboundary scale
effects;

Magnitude: This is composed of three elements, namely:
- extent of the change induced with respect to the baseline,
- sensitivity/resilience of the receptor, i.e. its ability to recover or adapt to the
change induced (1 implies good adaptability/resilience or low sensitivity while 4
means poor adaptability/capacity to recover or high sensitivity),
- importance/persistence of cumulative effects derived from the impact;

No. of Elements: includes individuals, households, enterprises, species and habitats
that could be affected by the impact.
Each criterion is assigned a rating, and the consequence (severity) score is the sum total of the
criteria ratings (ranging from 4 to 16) (see Table 7.1)
Table 7.1
Ranking of evaluation criteria.
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Evaluation Criteria
Importance / resilience
Extent
of receptor / resource
Low value/sensitivity of
Local scale: the
receptors or resources,
proposed operating
able to recover or adapt to
site and its immediate
the change without
environs
interventions
No. of elements
involved
Affecting small no. of
Less than 1
individuals,
Low
year /
households, individual
1
Temporary
enterprises and/or
small no. of species
Affecting small number
Regional scale: as
Moderate value/sensitivity
of individuals,
determined by
of receptors or resources,
Medium Between 1
communities or
country’s
able to adapt with some
2
and 5 years
administrative and/or
administrative
difficulty and which may
higher no. of species
boundaries
require interventions
and habitats
Affecting great no. of
High value/sensitivity of
individuals, households
receptors or resources,
High
Between 5
National scale: Entire
and/or medium/large
poorly able to adapt to
3
and 10 years country
enterprises and/or
changes with strong
habitats and
interventions
ecosystems
Affecting huge no. of
Extreme value/sensitivity individuals, households
Over 10
Critical
International scale:
of receptors or resources, and/or large
years /
4
trans-boundary
resulting in permanent
enterprises and/or
Irreversible
changes
habitats structure and
ecosystems functions
Score
1–4
1–4
1–4
1–4
Duration
Alongside impact consequence, it is necessary to establish the impact’s probability of occurrence.
Probability is divided into four, almost equally weighted, categories:
 Unlikely: Unlikely to occur in normal operating conditions but may occur in exceptional
circumstances;
 Possible: May occur under normal operating conditions, but not likely;
 Probable: Likely to occur under normal operating conditions; and
 Definite: Will occur under normal operating conditions.
Once consequence and probability have been established, the significance (Low, Medium or High)
can be determined (see Table 7.2). Consequence and probability can be established quantitatively
or qualitatively, on the basis of an analysis of the information contained in the baseline data report,
project data and other relevant (international) literature.
Table 7.2
Significance ratings
Consequence
Score
4–6
7–9
10 – 12
13 – 16
Unlikely
Low
Low
Low
Low
Probability
Possible
Probable
Low
Low
Low
Medium
Medium
Medium
Medium
High
Definite
Low
Medium
High
Critical
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POTENTIAL IMPACT IDENTIFICATION AND CHARACTERISATION
As mentioned in order to identify all of the potential impacts of a project, all proposed project
activities must be analysed in relation to the environmental, social and health components of the
natural and socio-economic environment that may be affected by the project.
The procedure applied for the impact analysis of the project and the analysis of the environment
conducted in the study has involved the breakdown of the project into operating stages:
 Mobilization and rig installation, wells drilling;
 Production tests
 Well completion and installation/removal of well heads;
 SURF (Subsea Umbilical, Riser, Flowline) installation/operation,
 Installation/removal of FPSO and mooring system
 FPSO process commissioning/operation
 Decommissioning
 Overhead (i.e. comprises activities which are cross-cutting to all stages, affecting the socioeconomic and health components)
Next, for each individual project stage considered, different project sublevels have been identified
leading to identification of the project actions. (see Table 7.5 Table 7.10)
While the environmental, social and health components considered were:
 Atmosphere
 Water environment (characteristics of the water column)
 Sea bed and marine subsoil (characteristics of the sea bed sediments)
 Vegetation, flora and fauna (characteristics of the animal and plant associations of the
water column, sea bed and avifauna)
 Coastal economic resources
 Local economy
 Community health and safety
 Community relations
For each individual project stage considered, different project sublevels have been identified
leading to identification of the project actions with clearly defined interactions with the
environmental components listed above, in some cases expressible by means of parameters.
For each project action, it has been thus possible to identify the Potential Impacts and make a
qualitative estimate of the potential impacts on the various environmental components, through the
identification of appropriate parameters.
The list of Potential Impacts has been drawn up on the basis of the characteristics of the
environmental parameters and with a view to subsequent definition of the interactions between the
project and the marine environment.
The selection of the Potential Impacts highlights the parameters of greatest significance in relation
to the project, and is the outcome of multidisciplinary studies and experience, an in-depth survey of
the bibliography, and data and information obtained from scientific research: the parameters were
also chosen on the basis of the specific characteristics of the environment concerned.
In order to identify the parameters potentially affected by the execution of the planned project
activities, the project actions were examined in depth to produce the graph of ACTIONS against
POTENTIAL IMPACTS shown below (Table 7.3), which clearly reveals that, directly or indirectly,
each action included in the project may lead, in quality terms, to specific forms of impact.
The graph underlines the relationship of cause and effect between the operations related to the
project and the impacts on the various environmental components generated in the different
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contexts. This has been followed by a thorough examination of the impacts of the various
operations, the different types of effect, and the processes which might potentially be triggered.
The Potential Impacts selected are those potentially capable of shifting the balances of
environmental systems in the marine context, or interacting with on-going environmental
processes. The factors highlighted are those considered to be of significance, on the basis of the
knowledge acquired, for the purposes of providing a complete description of the project under
examination and a clear definition of its impacts.
For example, the project action “use of support vessels”, which takes place during installation of
the sub-sea well heads and laying of the flowlines, has the corresponding Potential Impact of the
emission of atmospheric pollutants arising from the generators installed on board the craft.
Table 7.3 details, for each of the operations, the Potential Impact which generate significant
environmental alteration, leaving aside forms of impact which lead to changes to the environment
which, although not negligible, are often of slight or very slight extent.
The impacts deriving from activities of water reinjection into the reservoir have been preliminarily
evaluated and found negligible with respect to ground water contamination; impacts on surface
environment of the said activities, such as atmospheric and noise emissions, are part of the
considerations included in the present chapter.
The following assessments includes a description of the impacts deriving from the discharge into
the sea of the civil sewage produced during the proposed project, after physical-chemical
treatment.
The project envisages the total reinjection of the production water after mixing with seawater,
process cooling water and test water; nevertheless, in the present document potential impacts
deriving from discharge of the production water into the sea are described. In that case, production
water will be discharged after treatment to reduce the oil content in line with applicable regulation
and best practices.
Table 7.3
Relationships between Project Actions and Potential Impacts
STAGE
ACTIVITY
Drilling activities
WELLS
DRILLING
Drilling support
ACTION
Drilling system
installation and
removal
Drilling system
operation
POTENTIAL IMPACTS
damages to morphological structures and benthic
biocenoses
mobilisation and resuspension of sediments
emission of pollutants into the atmosphere
generation of noise in the water
damages to benthic biocenoses
Production test
Use of support
vessels
Installation/removal
activities
WELL HEADS
INSTALLATION
AND REMOVAL
Well heads
installation and
removal
Use of support
vessels
release of pollutants and metals in solution
discharge of engine cooling water, hot waste water
discharge of nutrients and organic matter from civil
sewage
biocenoses
sewage
WELL HEADS
Normal
Presence of
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STAGE
OPERATION
ACTIVITY
operating
procedures
ACTION
production structures
Protection of
structures against
corrosion (anodes)
Production
support,
maintenance
use of support
vessels
mooring system
installation activities
Installation
activities
use of support
vessels
FPSO –
MOORING
SYSTEM
INSTALLATION
protection of
structures against
corrosion (anodes)
Structures
normal
operating
conditions
presence of mooring
system
use of support
vessels
Commissioning
FPSO PROCESS
COMMISSIONING
AND
OPERATION
Process normal
operating
conditions
POTENTIAL IMPACTS
Increased availability of organic matter
physical presence of structures
sewage
biocenoses
sewage
Increased availability of organic matter
physical presence of structures
sewage
commissioning
procedures, hydrotest
release of pollutants and biocides in solution
process operation
discharge of cooling water, hot waste water
production water
discharge
offloading activities
Production
support,
maintenance
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use of support
vessels
The Potential impacts are briefly listed in Table 7.4.
sewage
sewage
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List of Potential Impacts identified
Emission of pollutants into the atmosphere
Generation of noise in the water
Discharge of cooling water into the sea Hot waste Water
Discharge/availability of Nutrients and Organic Matter
Damages to morphological structures and benthic biocenoses
Mobilisation and Resuspension of sediments
Physical Presence of Structures
Release of pollutants, biocides and metals in Solution
The Activity/Potential Impacts table shows which Potential Impacts are caused by the various
project activities.
Our scrutiny of the project’s characteristics arising from the available technical design, thus
enabled us to identify and select the main Potential Impacts potentially capable of creating
interferences with the marine, coastal and anthropic environment and the relative components
identified.
The interactions between project actions and ESH components affected result in the following
impact identification matrices, organised by Project Stage:
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Table 7.5
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Matrix to identify potential environmental, socio-economic and health impacts – Well Drilling Stage
Drilling system
installation and
removal
Drilling activities
Drilling system
operation
Disturbance to
marine & fishing
resources
Impact on health due
to emission of
pollutants into the
atmosphere
Disturbance to
marine & fishing
resources
Emission of pollutants
into the atmosphere
Damages to
morphological
structures and
benthic biocenoses
Drilling cuttings
discharge
Damages to
morphological
structures and
benthic biocenoses
WELLS DRILLING
Production test
Drilling support
Use of support
vessels
to emission of
pollutants into the
atmosphere
to emission of
pollutants into the
atmosphere
into the atmosphere
into the atmosphere
Discharge of nutrients
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Release of pollutants
and metals in solution
Discharge of cooling
engine water into the
sea – Hot waste
water
engine water into the
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
Increase in marine
traffic
Community
Relations
Community
Health &
Safety
Damages to
morphological
structures and
benthic biocenoses
Mobilisation and
resuspension of
sediments
Local/national
economy
Mobilisation and
resuspension of
sediments
Damages to
morphological
structures and
benthic biocenoses
Mobilisation and
resuspension of
sediments
Coastal
economic
resources
Vegetation,
Flora, Fauna
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
ENVIRONMENTAL, SOCIAL AND HEALTH COMPONENTS
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Table 7.6
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Matrix to identify potential environmental, socio-economic and health impacts – Well Heads Installation, Operation and Removal Stages
Well heads
installation and
removal
into the atmosphere
Use of support
vessels
Normal operating
procedures
Presence of
production structures
Protection of
structures against
corrosion (anodes)
WELL HEADS
OPERATION
into the atmosphere
Production, support,
maintenance
Use of support
vessels
Mobilisation and
resuspension of
sediments
Damages to
morphological
structures and
benthic biocenoses
Mobilisation and
resuspension of
sediments
Damages to
morphological
structures and
benthic biocenoses
Generation of noise
in the water
Disturbance to
marine & fishing
resources
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
cooling water into the
sea – Hot waste
water
Increase in marine
traffic
Mobilisation and
resuspension of
sediments
Increased availability
of organic matter
Mobilisation and
resuspension of
sediments
of organic matter
Physical presence of
structures
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Mobilisation and
resuspension of
sediments
of organic matter
structures
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
sea – Hot waste
water
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
Disturbance to
marine & fishing
resources
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
Community
Relations
Community
Health &
Safety
Local/national
economy
Coastal
economic
resources
Mobilisation and
resuspension of
sediments
Installation/removal
activities
WELL HEADS
INSTALLATION AND
REMOVAL
Vegetation,
Flora, Fauna
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
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Matrix to identify potential environmental, socio-economic and health impacts – Transport Systems Construction and Operation Stages
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
sea – Hot waste
water
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
Mobilisation and
resuspension of
sediments
of organic matter
Mobilisation and
resuspension of
sediments
of organic matter
structures
Mobilisation and
resuspension of
sediments
of organic matter
structures
Laying of flowlines
TRANSPORT
SYSTEMS
CONSTRUCTION
into the atmosphere
Laying of flowlines
Use of support
vessels
Protection of
structures against
corrosion (anodes)
TRANSPORT
SYSTEMS
OPERATION
Flowlines operations
Presence of flowlines
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
Community
Relations
Mobilisation and
resuspension of
sediments
Damages to
morphological
structures and
benthic biocenoses
Community
Health &
Safety
Mobilisation and
resuspension of
sediments
Damages to
morphological
structures and
benthic biocenoses
Local/national
economy
Mobilisation and
resuspension of
sediments
Coastal
economic
resources
Vegetation,
Flora, Fauna
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
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Matrix to identify potential environmental, socio-economic and health impacts –FPSO Mooring System Installation Stage
into the atmosphere
Installation activities
Use of support
vessels
Protection of
structures against
corrosion (anodes)
Presence of mooring
system
Structures normal
operating conditions
into the atmosphere
Use of support
vessels
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
sea – Hot waste
water
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
Mobilisation and
resuspension of
sediments
of organic matter
Mobilisation and
resuspension of
sediments
of organic matter
structures
Mobilisation and
resuspension of
sediments
of organic matter
structures
Disturbance to
marine & fishing
resources
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
sea – Hot waste
water
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
Community
Relations
Community
Health &
Safety
Local/national
economy
Disturbance to
marine & fishing
resources
Mooring system
installation activities
FPSO MOORING
SYSTEM
INSTALLATION
Coastal
economic
resources
Vegetation,
Flora, Fauna
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
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Table 7.9
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Matrix to identify potential environmental, socio-economic and health impacts –FPSO Process Commissioning and Operation Stage
Commissioning
procedures, hydrotest
into the atmosphere
Process operation
FPSO MOORING
SYSTEM
INSTALLATION
into the atmosphere
Off-loading activities
into the atmosphere
Production support,
maintenance
Use of support
vessels
and biocides in
solution
and biocides in
solution
to emission of
pollutants into the
atmosphere
water – Hot waste
water
and biocides in
solution
to emission of
pollutants into the
atmosphere
Release of metals
and pollutants in
solution
Release of metals
and pollutants in
solution
Release of metals
and pollutants in
solution
and organic matter
from civil sewage
Discharge of engine
sea – Hot waste
water
and organic matter
from civil sewage
and organic matter
from civil sewage
Discharge of engine
sea – Hot waste
water
and organic matter
from civil sewage
and organic matter
from civil sewage
and organic matter
from civil sewage
Disturbance to
marine & fishing
resources
Discharge of engine
sea – Hot waste
water
Discharge of engine
sea – Hot waste
water
Generation of noise
in the water
Increase in marine
traffic
to emission of
pollutants into the
atmosphere
Increase in marine
traffic
Community
Relations
and biocides in
solution
Community
Health & Safety
and biocides in
solution
Local/national
economy
and biocides in
solution
Coastal
economic
resources
and biocides in
solution
water – Hot waste
water
and biocides in
solution
Production water
discharge
Process normal
operating conditions
Vegetation,
Flora, Fauna
Commissioning
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
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Table 7.10
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Matrix to identify potential environmental, socio-economic and health impacts – Overhead Activities all stages
Employment of
personnel and
contractors
OVERHEAD
Procurement of
goods and services
Payment of taxes,
royalties and fees to
Government
Employment of
personnel and
contractors
Increase in
employment levels
and income
generation
Procurement of
goods and services
Increase in GDP
Increase in
employment levels
and income
generation
Payment of taxes,
royalties and fees to
Government
Increase in
Government
revenues
Increase in GDP
Community
Relations
Community
Health &
Safety
Local/national
economy
Coastal
economic
resources
Vegetation,
Flora, Fauna
ACTION
Seabed &
Marine Subsoil
ACTIVITY
Water
Environment
STAGE
Atmosphere
Alteration in
community
expectations on
employment
opportunities
Alteration in
community
expectations on
socio-economic
development
investments
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Table 7.11 represents, for the different ESH components, the summary list of all the potential direct
impacts caused by the Project, as identified in the Activity/potential Impacts (or Impact
Identification) matrix. The table also allows to represent how each component may be disturbed by
a synergy of potential impacts.
Community Relations
Community Health & Safety
Local economy
Soil - Subsoil
Water environment
Potential Impacts
Atmosphere
Environmental, social & health components
Coastal Economic
Resources
ESH Components/Potential Impacts
Vegetation Flora Fauna
Table 7.11
Discharge of cooling water into the sea - Hot
waste Water
Discharge/availability of Nutrients and Organic
Matter
Damages to morphological structures and
benthic biocenoses
Mobilisation and Resuspension of sediments
Physical Presence of Structures
Release of pollutants, biocides and metals in
Solution
Disturbance to marine and fishing resources
Increased employment levels and income
generation
Increase in marine traffic
Alteration in expectations of local communities
Increase in Government Revenues
Increase in GDP
Impacts on health
Once the direct impacts are established, the next step is to determine the impact pathway to
identify the further socio-economic and health implications (indirect impacts) of these changes, as
well as any subsequent cumulative and perceived effects (Table 7.12).
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Table 7.12
Impact pathway to identify indirect (as well as cumulative and perceived) socioeconomic and health impacts (both positive and negative)
Direct
Indirect
Increased employment
levels and income
generation
Increased capacity to
access services such as
schooling and health
Improved education
levels, health status, etc.
Interruption or
disturbance to fishing
activities
Loss of income and
decreased food security
Biophysical impacts on
marine resources
Hazards to and
disruption of navigation
Cumulative
Potential emergency
situation from vessel
collision
Impacts to local
economy
Alteration in
expectations of local
communities
Risk of unmet
expectations
Company sector
reputational damage
Increase in GDP and
Government revenues
Increased public
investment in
infrastructure & services
provision (education,
health, etc.)
Improved standards of
living
7.3
Perceived
Expectations regarding
new opportunities for
employment and public
services
Marine pollution will
harm fish and coastal
communities, especially
in the case of an oil spill
Conviction that physical
structures and activities
of Project are
responsible for fish
catch reductions
employment, improved
infrastructural conditions
like water, electricity,
public transport, health
centres and schools,
etc.
social and infrastructural
services improvement &
provision
POTENTIAL IMPACTS INDICATOR PARAMETERS
It is possible to express the ESH components by means of specific indicator parameters. (see
Table 7.13). This table of INDICATOR PARAMETERS against POTENTIAL IMPACTS illustrates
which environmental, social and health (ESH) parameters are potentially affected by the Potential
Impacts. The latter modify the parameters more or less significantly, directly and/or indirectly, by
causing a change in the control value of the indicator associated to each parameter before the start
of the project operations.
The chosen Parameters/Indicators are “sensitive” to the changes triggered by the Potential
Impacts, and are therefore capable of describing and quantifying the impacts caused, and
providing a clear picture of their boundaries and characteristics, even where the Potential Impacts
interact with each other to generate more complex forms of environmental/social stress, involving a
variety of interconnected components.
The table is therefore intended as a tool which provides an overview of the environmental, social
and health sensitivity factors and the current or potential criticalities, in relation to the specific, often
synergetic, agents of impact identified and arising from the project operations.
For example, the parameter of the T.O.C. of the sediments and/or water column is clearly
influenced by the discharge of organic effluents, but less explicitly, it is also strongly affected by the
physical presence of a hard substrate in the sea (permanent structure), due to bio-fouling.
Table 7.13
Relationships between Indicator Parameters and Potential Impacts
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Ammoniacal Nitrogen Concentration
Orthophosphate Phosphorus Conc.
Nitrate Concentration
Nitrite Concentration
Total Hydrocarbons
Oxygen Concentration/BOD
Temperature
Transparency
Bioaccumulation of Lead
Bioaccumulation of Aluminium
Bioaccumulation of hydrocarbons (IPA)
Sulphur Dioxide Concentration
Aromatic Hydrocarbon Concentration
Nitrogen Oxide Concentration
Carbon Oxide Concentration
Dust Concentration
Organic Carbon Concentration TOC
Lead Concentration
Aluminium Concentration
Chlorine concentration
Particle Size
Sediment Thickness
Chlorophyll “a”
Fishing Yield
Reduction in Fishing Grounds
Average Number of Species
Specific Diversity Index
Average Low Frequency Noise
Zone Affected by noise
Fish catch trends
Employment levels by sector
staff health & safety accidents/incidents
GDP growth by sector
Social infrastructures availability
Grievance mechanism / Community
relations reports
Increase in GDP and Government revenues
Impact on health and safety
Increased employment levels and income
generation
Disturbance to marine & fishing resources
Release of pollutants, Biocides and Metals in
Solution
Physical Presence of Structure
Mobilisation and resuspension of sediments
Damage to morphological structures
and benthic biocenoses
Discharge of cooling water, hot waste water
PARAMETERS/ Indicators
Discharge of Nutrients and Organic Matter
POTENTIAL IMPACTS
Alteration in expectations of local communities
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Once identified and characterised, potential impacts need to be assessed in order to determine the
significance of each impact, as well as any required mitigation/enhancement and/or management
measures to ensure that impacts are of acceptable levels of significance. The significance of an
impact is qualitatively established on the basis of clearly defined criteria that describe each
impact’s Consequence and Probability, using a methodology developed by eni and defined in the
eni ESHIA Standard (eni doc. no. 1.3.1.47). In relation to some affected components impacts are
also assessed quantitatively through the application of modelling techniques.
This following sections present more detailed discussions on the environmental, social and health
aspects as well as the associated and potential impacts of the proposed projects. As already
indicated in the previous section, these impacts have been assessed (characterized and
evaluated) and the results presented in Table 7.5 toTable 7.10. The discussions presented in this
section are intended to provide insight into the nature and magnitude as well as duration of
identified impacts of the various project activities.
7.4
EVALUATION OF IMPACTS ON THE BIOPHYSICAL ENVIRONMENT
Environmental Effects of Potential Impacts Identified
As previously illustrated in Table 7.11 (ESH Components/Potential Impacts) each environmental
component may be affected by a synergy of potential impacts, which stem one from the other. For
example, the component Seabed and Marine Subsoil is potentially affected by 5 different types of
impact, and these impacts in turn may be generated by one or more project actions. Moving
towards the impact evaluation it is therefore necessary to first provide a description of the
environmental effects of each potential impact, as well as which project actions give rise to the
same potential impact.
The presence of the vessels supporting the installation and operation of the drilling system and the
installation of the sub-sea well heads and the mooring system, the positioning of the FPSO, its
operation and offloading activities, and the support vessels which lay the flowlines linking the subsea well heads and install the connections and protective systems, causes the emission of
pollutants into the atmosphere as a result of operation of the engines and power generators.
However, these emissions are small in quantity, temporary, and partly restricted to the installation
site and partly occurring along the route of the sealines.
The presence of the support vessels necessary for the operations, the drilling operations, subsea
installation and operation activities leads to an increase of the low frequency underwater noise
level which may drive fish species away, although only temporarily and within the small area
where the noise is heard, and may also interfere with the normal physiological functions and
behaviour of some species of mammals and reptiles.
The presence of the support vessels and the operation of FPSO including offloading activities will
also cause the discharge of engine cooling water containing biocides and anticorrosion substances
into the sea; the main effect of the discharge of engine cooling water is a possible local increase
in temperature, with possible consequences for primary production and a light contamination of the
water column.
The discharge of treated sewage from the drilling unit, support vessels, the FPSO and the
offloading vessels involves the discharge both of dissolved substances (e.g. nutrients easily
assimilated into the primary production cycle) and suspended matter (which causes an increase
in turbidity and the consumption of significant amounts of oxygen to degrade the matter through
the affected column of water, also triggering an increase in primary production). In the event that
this discharged material reaches the sea bed (this might not occur in the zone where the water is
very deep) there is an increase in organic matter and thus a reduction in the amount of oxygen at
the interface.
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Treated sewage will be discharged for the time for which the support vessels are required for
drilling operation, well heads installation, FPSO installation and operation, offloading activities and
laying operations, and this will take place in the installation sites and along the route of the
flowlines.
The operations for installation, of the flowlines and anchoring of the lay barge and mooring system
construction may cause small, localised morphological changes, which may lead to interference
with morphological structures (formed by sediments or biological processes) and benthic
biocenoses with potentially damages depending on the vulnerability of involved ecosystems.
Morphological variations of this kind are filled, levelled and returned to their previous conditions by
the currents and hydrodynamics, at varying speeds which depend on the sedimentation rate and
hydrodynamics of the areas where the installation site and flowlines route are located.
During drilling operations, a solid waste processing system will be in operation at the point where
the mud flows out of the well. It will comprise equipment such as a vibrating screen, desilter,
desander, centrifuges, etc., which will separate the mud from the drilling cuttings, which will be
collected after treatment and properly disposed onshore in line with Ghana Regulations.
The drilling fluids used consist of a basic liquid (synthetic oil) rendered colloidal and weighted
through the addition of specific products. The colloidal properties provided by special clays
(bentonite) and enhanced by special compounds such as carboxyl methyl cellulose give the mud
the rheological properties needed to keep the weighting materials and cuttings in suspension, even
when the circulation is at a standstill, with the formation of a gel.
Another consequence of the operations of installing the drilling system and the mooring system,
and of laying the flowlines, is the mobilisation and resuspension of sediments from the sea
bed. This leads to a temporary increase in the turbidity of the water over a small area, the size of
which depends on the local hydrodynamics, and the particle size and cohesiveness of the
sediment. The degree of turbidity decreases as the particle size increases is greater in specific
hydrodynamic conditions, such as where there is stratification of the water column, and leads to a
reduction in the level of light penetration. If this reduction in light levels continues for some time,
there may be a decrease in the amount of oxygen in the water due to a reduction in the rate of
photosynthesis and the activation of degradation/oxidation processes only; primary production is
thus directly affected.
The positioning of the drilling and production structures and their presence leads to burying of the
organisms and benthic biocenoses, and the removal of a small area of habitat; this removal is
temporary in the case of the drilling system and restricted to drilling period and much longer in the
case of well heads and sealines.
The temporary physical presence on the sea bottom of drilling structures and the much longer
presence of the sub-sea well heads, the flowlines and the mooring system, produces an
amplification/modification of the local hydrodynamics and the normal sediment resuspension and
erosion phenomena, with negligible effects on the local particle size and local changes to the
typical percentage of sand, clay and silt, and consequent negligible variations in the numbers and
types of macrobenthic species (especially polychaetes and molluscs), which depend to a
considerable extent on the types of sediment found on the sea bed.
An increase in the organic matter both in suspension and on the sea bed, with a possible reduction
in the amount of oxygen near the sea bed and an increase in the turbidity, with potential direct and
indirect effects on the area’s biology, may arise as a result of the physical presence of the sub-sea
structures (well head, flowlines, FPSO mooring system). These cause an increase in the
availability of the organic matter in the area, thanks to the F.A.D. (Fish Aggregating Device) effect,
creating a new community of fauna different from that typically found in the waters around the well
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heads. This will also have beneficial effects on fishing in the zones close to these sub-sea
structures.
Changes in the trophism (increase in organic matter available during installation due to the treated
sewage discharges, and during normal operation due to the F.A.D. effect) may modify the
concentration of chlorophyll a, linked in turn to the algal biomass.
During normal operation the subsea structure will discharge no nutrients into the sea; the variations
in chlorophyll concentrations derive essentially from the normal seasonal fluctuations, indirectly
influenced by the presence of the offshore structures, which create a microhabitat where biological
activity is amplified compared to the surrounding environment.
There will be a de facto reduction in the area available for commercial fishing due to the
presence of the production structures and the flowlines, or operations related to them. The
operations may also temporarily chase the fish stock available for commercial fishing away from
the involved areas and could partially modify the migratory routes for the young of some species.
However, this will not in any way compromise survival or create any significant impact on
commercial fishing conducted in the vast area.
The fishing performed by coastal communities will not be affected in any way because such fishing
does not involve the area covered by the proposed project which is at a quite some distance from
the coast.
The presence of the vessels needed to lay the flowlines and support installation, operation and
offloading activities may generate an increase in the lead concentration in the water column and
sediments, since this element is present in the fuels used to power the craft.
The quantities of relatively heavy aliphatic compounds (from C10 to C15) and the concentration of
IPA (generally of the order of ppb) can be considered quite low, since the only emission source is
the exhaust water of Diesel-powered vessels used for support activities. The highest levels of
hydrocarbons (and lead) in sediments occur generally along the routes followed by the vessels
which travel to and from the offshore structure, allowing us to assume that their presence is caused
by the passage of the craft.
The resuspension of sediments may trigger a limited release into the water column of pollutants
in the sediments themselves, and in the final analysis indirect effects on the biology of the area
arising from the possible burying of organisms and biocenoses due to the re-sedimentation of
material placed in suspension during operations.
The use of sacrificial anodes to protect the submerged structures against corrosion has negligible
effects on the water column and sediments, and marginally also on the biocenoses. The anodes
(which contain no mercury) shed metals, especially Al, causing a slight increase in the
concentration of these elements in the water column and in the sediment, to which they are
confined, unable to significantly affect the biocenoses.
The bibliography on the effects of the presence of Al in marine sediments or the water column is
very limited. However, there are no reports of cases in which this element has been toxic to
marine organisms, and apparently sea-dwelling filtering organisms are not capable of
bioaccumulating Al.
The project envisages the total reinjection of produced water, nevertheless, in the present
document potential impacts deriving from discharge of the produced water into the sea are
described. In that case, produced water will be discharged after treatment to reduce the oil content
in line with applicable regulation and best practices. The produced water will be discharged into the
sea, after treatment, only in case of unavailability of the water injection system.
Associated with oil and gas deposits, these waters are brought to the surface along with the
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In some cases chemical compounds can be added to the production waters. The amounts of such
additives — e.g. corrosion inhibitors, biocides, de-emulsifiers, etc. — found in production water
does not generally exceed a few parts per million (pm).
The production waters typically contain an inorganic component — essentially composed of
chlorides, bicarbonates and ions of sodium, potassium, calcium, barium and strontium, with
concentrations increasing as depth increases — and an organic component — alkanes from C7 to
C31, aromatic compounds and polycyclic hydrocarbons.
The volatile hydrocarbon liquids (VHLs) — including light aromatics and, in particular, compounds
ranging from benzene to naphthalene of ecotoxicological interest since they are most highly
soluble in water — are those most commonly found in the production water.
The fraction of petroleum insoluble in water is, above all, composed of high molecular weight
aliphatic hydrocarbons (HMW-HC) and cyclical and aromatic hydrocarbons, again with high
molecular weight: only small amounts of polycyclical aromatic hydrocarbons, PAH, are present in
the production waters.
The temperature of the production water increases as the production zone deepens (in shallow
wells the temperature ranges from 30 to 50°C while it can even reach 250°C in the deepest wells).
The solid content suspended in the production water can vary quite significantly; the presence of
major amounts of suspended solids can lead to a significant decrease in the transparency of the
discharge water column. However, that it could have repercussions on the photosynthetic
community on the sea floor is ruled out because of its great depth; thus can be assumed that the
consequence for phytoplankton would be negligible.
In any case, the discharge of volumes of hot water and water (production water, process water)
containing pollutants, biocides and anti-corrosion substances from the production process, FPSO
and flowlines hydrotest into a large and deep basin like the one under consideration may trigger
environmental interferences of negligible intensity.
There is little knowledge of the type and gravity of the consequences of these discharges on the
biological community, which will depend to a large degree on the size of the area affected to
varying extents by the discharge of the cold sea water.
Different environmental scenarios can be considered possible depending on the hydrodynamic
conditions present, whether there is a thermocline with stratification of the temperature gradient
and variation in density at different depths, whether a vertical/horizontal flow is established, etc.
In this context, it is important to consider the limited size of the discharges compared to the volume
of the receptor body and the system and procedures by which the water is discharged along the
water column, in order to ensure a good level of mixing. The extent of the effects of a given impact
varies depending on the stage in the operations, but the processes triggered on the sea bed or
through the water column are generally the same.
The types of change on which attention has been focused have basically been:


anomalies in the morphology, sediments and macro-fauna caused by the physical impact of
installation of drilling structures, mooring system and the well heads, and the presence of the
sub-sea structures (mooring system, well head and flowlines), in terms of both a physical
obstacle interfering with the waves and currents, and occupation of the sea bed;
physical and biological effects (changes in the morphology, sediments, and burying of benthic
organisms) caused by the material suspended as a result of the installation operations and
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subsequently resedimented, and by the treated sewage discharged from the offshore structure
during activities;
 chemical, chemical-physical and biological anomalies in the water column and sea bed caused
by the possible release of any toxic substances or elements present in the sediment disturbed,
with effects on the planktonic and benthic organisms;
 chemical, chemical-physical and biological anomalies of the atmosphere, water column or sea
bed caused by the possible release of any organic and inorganic pollutants and the impacts
caused by the presence of the vessels involved in the activities and by process operation.
To allow a more effective assessment of the impact of the activities on each individual sector, it is
necessary to make a detailed analysis of the project actions, the relative impacts, and the
processes with which they interact. To simplify this analysis, the project actions were subdivided
into groups on the basis of the type of effect induced, and the relative forms of impact, i.e. the ways
in which they interact with and change the environment, were identified for each group.
Table 7.14
Effects of project actions and Potential Impacts identified
Effects of the project actions
Potential Impacts
Modification of primary production and phytoplankton
population density
Discharge of Nutrients and Organic Matter
Increase of organic particulate in suspension
Changes in oxygen
compensation point
consumption
with
variation
in
Variation in the quantity of organic matter in the sediment
Change in the level of microbic decomposition
Actions which may
affect the level of
trophism
Increase in resources of debris-eating animals
Physical presence of structures with increase in
organic matter availability
Discharge of cooling water, hot waste water,
potentially containing hydrocarbons
Modification in thickness of the oxidised layer of the
sediment
Increase in sedimentation of particulate on sea bed
Shifting of sediments and increase in organic particulate in
suspension
Increase in hydrodynamic energy on sea bed
Increase in sedimentary instability of sea bed
Actions which cause
mechanical and
physical disturbance
to the substrate
Damage to morphological structures and benthic
biocenoses from sea bottom activities
Mobilisation, distribution and re-depositing of
sediments
Clogging of breathing surfaces
Physical presence of structures and interference
with the sea bed
Release of metals in solution and their incorporation into
sediments
Release of pollutants and metals in solution from
sacrificial anodes, and as a result of shifting of
any contaminated sediments
Bioaccumulation and biomagnification
Actions causing
inorganic pollution
Discharge of pollutants and biocides
Modification of the physiological functions of organisms
Driving away of fish and breeding stock and interference
with routes used by fry
Attraction of fish species (FAD effect)
Actions which disturb
physical parameters
(not on sea bed)
Physical Presence of Structure
Eutrophying disturbing actions
This first group includes the actions which cause impacts capable of directly or indirectly increasing
the level of nutrients or the level of organic enrichment of the water column and sediment.
This class of impact includes:
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
discharge into the sea of hot water from the cooling of the engines of the vessels present
during installation, operations and offloading activities, and the system power generators;

discharge into the sea of hot production water containing hydrocarbons and salts (the
produced water will be discharged into the sea, after treatment, only in case of
unavailability of the water injection system).

discharge of nitrogen and phosphorus compounds (treated sewage) or other organic
substances, and the actual presence of the sub-sea structures which may indirectly cause
an enrichment of the organic matter due to the variations triggered in the circulation near
the sea bed.

the physical presence of the sub-sea structures causes an increase in the availability of
organic matter due to the colonisation of the structures by filtering bivalves, algae and other
organisms as a result of what is known as the F.A.D. (Fish Aggregating Device) effect, thus
creating a new fauna community different from that typically found on the soft sea beds
around the well heads, with beneficial effects for fishing around the zones close to the subsea structures themselves.
Eutrophying impacts lead to temporary interferences of the kind described, closely correlated to the
increase in primary production, and significant over a limited area, negligible and fading into
nothing along the route of the flowlines in the open sea.
The eutrophying actions cause an increase in the concentration of chlorophyll in the water column,
due to the increase in the densities of the phytoplankton population; the increase of organic
particles in suspension may lead to reduction in the transparency of the water column and a raising
of the depth below which respiration predominates over production, while within the sediment it
may cause an increase in organic matter and thus in the resources for debris-eating animals and
microbic decomposition, causing a rise in oxygen consumption and a reduction in the depth of the
oxidised layer.
Mechanical and physical disturbing actions
This category includes all forms of impact, which, while their impact on the chemical characteristics
of the water column and sea bed is low, have a mainly physical disturbing action, for example by
modifying the hydrodynamics, particle size breakdown and morphology of the sea bed. They
comprise the discharge/leakage of particulate inorganic matter (production water, treated sewage
etc.), movements of sea bed sediments due for example to the laying of the flowlines, burying of
portion of the sea bed, hydrodynamic variations caused mainly by the continuing presence of the
sub-sea structures, which interfere with the waves and currents to cause turbulence and local
erosion-sedimentation, as well as instability of the sedimentation mechanisms.
The presence of the well heads, the mooring system and the flowlines may lead to some level of
distortion of the current field, and local changes of sediment distribution; however, the results of
hydrodynamic models applied to similar structures have revealed that the variation only occurs
over a band just a few metres wide around the structures; moreover, in the case of the flowlines,
the effects will diminish over time as the line gradually becomes covered with sediments.
The interferences caused by mechanical and physical changes to the substrate relate also to the
transparency of the water column and a variation in the sedimentation of the sea bed. The effects
vary depending on the type of the sea bed and the communities to which it is home, and are
particularly severe only on rocky sea beds or organogenic substrates, which are not found in the
areas affected by mooring system, the well heads and laying of the flowlines.
The physical presence of the structures, and the operations which may interact with the sea bed to
cause erosion/resuspension of sediments in general, together with the emission of fine material,
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organic matter and nutrients from the treated sewage from the FPSO and the vessels providing
support for the drilling activities, discharge of production water containing particulate matter, FPSO
operation and offloading and flowlines laying operations, cause a variation in the transparency of
the water and a local alteration in the typical percentages of sand, clay and silt, although this is
limited in both time and space.Although affecting only a limited area, the reduction in transparency
is particularly noticeable in the deepest layers of the water column, due to the movement and
resuspension of the sediments caused by the operations too.
A variation in the average number of polychaete and mollusc species and the specific diversity,
equidistribution and abundance indicators of the benthic biocenoses arises as a result of the
installation and laying of the flowlines, and in general from the operations or activities which affect
the sea bed, although this is of fairly short duration and only occurs in the area immediately around
the operating zones.
The physical presence of the structures and the shifting and re-depositing of the sediments caused
by the operations may lead to habitat loss and changes in the type of the sediment and thus in the
microbiology and in the number and type of the macro-benthic species which depend to a large
extent on the characteristics of the sea bed sediments.
However, it must be remembered that once the flowlines have been laid, its effects will only be felt
for a few metres either side of it, and thus the loss of habitats caused by its presence and that of
the other sub-sea structures is negligible.
Over the long term, the sub-sea structures may encourage colonisation by sessile organisms,
leading to habitat conditions different from those in the surrounding area. There is also the
possibility of species enrichment or the appearance of new species, especially since the
surrounding sea beds are mobile and not hard.
Actions causing inorganic pollution
This is chemical pollution, originating both from the sub-sea structures and the cathodic protection
systems (sacrificial anodes), and from the shifting and resuspension of any sediments containing
pollutants which are thus put back into circulation; the release of ions into the water column by
support vessels is another form of pollution in this category.
The release of hydrocarbons and ions in the sediments and into the water column by the FPSO
(production water) and by support and offloading vessels, and the discharge into the sea of the
biocides or anticorrosion substances (chlorine) contained in the cooling water used during the
production process and in the production water, are other forms of impact in this category. The
potential interaction between these forms of impact and the biological entombment arises from the
bioaccumulation/magnification (incorporation by organisms).
Al is used in the construction of the anodes which protect sub-sea structures from corrosion. This
cathodic protection is provided by applying a certain number of mercury-free strap-on sacrificial
anodes consisting of an alloy containing about 95% aluminium.
The purpose of these anodes is to form batteries with an electromotive force which depends on the
potential difference between the anode and the cathode. They thus wear at a rate calculated on
the basis of a number of environmental parameters, such as the percentage of oxygen, the
exposed surface area, the salinity and the temperature, all factors which affect the normal
corrosion of submerged metal structures.
Apart from Al, the mercury-free anodes contain variable amounts of other elements including Mg,
Mn and Zn, and also In (0.02-0.05 %), Cu (0-0.006%) etc., and during their lifetime, they release
positive ions of these elements.
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The presence of the anodes leads to an increase in the concentration of aluminium in the
sediments around the flowlines, where it remains without causing changes to the biocenoses, and
Al in ionic form in the water column. The presence of Al may lead to co-precipitation with silica (if
concentrations of 0.5 ppm of Al, water temperature of 2° C and 0.5 ppm of Si all occur), and
further to this event zeolitic formations may be deposited on the sea bed in the affected areas.
These substances are not considered harmful or pollutant, and it must also be underlined that Al is
not bioaccumulated by organisms but rather tends to be eliminated by clearance. A slight increase
in the level of the element in filtering organisms may be due to the presence of Al in the
intravalvular liquids.
There may be an increase in the concentration of lead in the water column and sediment as a
result of secondary activities relating to navigation and presence of vessels since it is found in the
fuels used, lead is bioaccumulated by filtering organisms.
From the bibliography available it is clear, that higher lead concentrations are found in sediments
along the routes used by the vessels which visit offshore structures on a regular basis, appearing
to point to an origin linked to the presence of these craft.
Hydrocarbons (IPA in particular) are bioaccumulated by organisms; the data point to negligible
bioaccumulation of hydrocarbons on organisms taken from the legs of offshore structures during
operation (the offshore structure does not discharge IPA), but reveal that mussels are affected by
the presence of the aromatic hydrocarbons derived from the ship traffic.
Some of the chlorine discharged into the sea with the water from the FPSO operation is rapidly
consumed by oxidation reactions with a number of inorganic ions (bromide and ammonium);
another part of this element reacts more slowly, especially with the dissolved organic substances,
but also with the particulate organic matter.
The difference between the chlorine discharged and the residual chlorine is known as the “chlorine
demand”, which depends on the amount of chlorine discharged, the contact time and the
characteristics of the water, which themselves vary depending on the time of year, as a
consequence of the water’s level of oxygenation and phytoplankton blooms. During hypoxic or
anoxic phases, considerable amounts of ammonium are produced and interfere with the chlorine
due to the formation of chloramines, increasing the chlorine demand. Similarly, a larger amount of
plankton in suspension means a higher chlorine demand.
The chlorine discharged into the sea water mainly leads to the formation of organic halogen
compounds (mainly bromine compounds) such as trihalomethanes (especially bromoform),
haloacetic acids, haloacetonytriles and halophenols, compounds with a certain degree of toxicity.
The quantities produced depend on the quantities of chlorine discharged and the concentration of
organic matter present in solution and as particulate; in general terms, it can be assumed that 1%
of the chlorine consumed bonds to the organic matter to form halogen compounds with varying
degrees of toxicity.
Actions which disturb physical parameters
This category includes all physical disturbing actions which do not specifically affect the sea bed,
such as the generation of noise in the water or the discharge into the sea of hot production water,
and hot water used to cool the engines of the vessels operating in the area or during the FPSO
operation process. These impacts, especially those related to water-borne noise emissions, may
cause modifications of organisms’ physiological functions at various levels, or may simply
temporarily drive fish away, up to interfering with the normal physiological functions and behaviour
of some species of mammals and reptiles
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The heat discharged through the production water and the cooling water of the engines of vessels
and the power generators and of the FPSO process is only capable of causing a marginal, local
variation in the temperatures of the zone, since the homoeothermic properties of the open sea
rapidly cool the discharges to the temperature of the surrounding area.
The presence of permanent structures on the sea bed, combined with the relative bans on shipping
and fishing, may cause conflict between the project and fishing activities; the Harbourmaster’s
Office generally establishes protection zones around the well heads, with restrictions on fishing
and mooring.
the coast.
Analysis of Impacts/Effects on Environmental Components
Based on analyses of the previous sections a detailed assessment of the expected impacts on the
individual components of the environment has been carried out; these evaluations are presented in
the following parts of this document.
The estimated values of the impacts produced by the potential impacts, whose behaviour can be
predicted by a simulation model, were obtained through the use of mathematical tools capable of
calculating the variation of the value of a given parameter (e.g. the concentration level of the
metals released from the anodes into the water column) caused by the changes induced by the
specific perturbation considered.
The formulation of reliable and significant quantitative estimates of the disturbing effects caused by
certain activities on selected indicators is not necessarily easy. The difficulties are linked to the
substantial lack of data due to the small number of studies conducted in this sense.
From a statistical point of view, it is therefore necessary to have a consistent data base to obtain
meaningful results. And the use of mathematical simulation models does not solve in a
comprehensive way the existing problems in impact estimation. Especially in cases like this, where
the impacting actions are actually of modest quantitative significance in relation to the quality and
capacity of the receiving body; given that the project area’s water depth is approximately 800-1000
m and about 55 km from nearest landfall, chances that the impacts arising from the project should
affect in any way the sea bed or the coast are very slim. Moreover, the dilution capacity of the
receiving body renders virtually negligible impacts on the water column and on the biological
component.
Despite these limitations, the findings made and the estimates given in this chapter are considered
sufficient to focus on the real extent of the impacts of the project, which overall are very low.
Hereby follows an assessment of the impacts identified, i.e. of the alterations in the indicator
parameters. In more general terms an assessment of the interaction between the Project and the
receptor environment, emphasizing and taking into account:

the characteristics of sensitivity and thus the vulnerability of the environment,

the duration and extent of the potential impacts, as well as,

the number of elements involved.
The sensitivity of the project activities is crucial in influencing the real effect of the impacts
identified.
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Impact on Air Quality
During the proposed project execution, modest levels of emissions will be generated from different
sources such as helicopter movement, sea going and supply vessels and generators. The effects
of the emissions are expected to be low as their effects will be mitigated in addition to atmospheric
dynamics observed in the study area. Under most offshore meteorological (winds, gales, etc.)
conditions, concentration of air quality pollutants would be well below their maximum predicted
values due to the effect of dispersion / dilution leading to very negligible effect.
During well drilling, installation of FPSO, laying of flowlines and well heads installation activities,
atmospheric emissions are essentially linked to exhaust gases from the engines. Other emissions
are related to gas flaring in production tests. Considering that the activities in question are shortlived and that the weather conditions in the open sea present such features as the nearly constant
wind of varying direction and intensity, it is clear that the pollutants in question are disposed of
quite rapidly.
The position of the rig and other facilities allow a greater spread of the plume formed in the
atmosphere, permitting the dispersion due to the higher probability of winds; previous studies of
atmospheric dispersion, show a complete diffusion of pollutant emitted from the fuel combustion.
As regards the atmospheric component, the results reported above indicate that emissions cannot
in any way modify the pre-existing air quality in the offshore area involved in the operations.
Moreover, the project area is located quite far from the coast; so its impact on the shoreline will be
minimal. Therefore, it is possible to underline that the project impacts on the atmosphere due to
emissions produced by the project is totally negligible.
The engineering design approach shall be to minimize emissions to the atmosphere where
practical and economically possible and to apply good engineering practice in the choice of
materials and equipment to minimize fugitive emissions. Where emissions are unavoidable, the
approach shall be for point sources, to provide stacks of adequate height to ensure good
dispersion.
The following sources of atmospheric emissions are considered:
 discharge of exhaust gases from the engines of the drilling unit

discharge of exhaust gases from the engines of the supply vessels

emissions of gas burning during production tests.

Installation of FPSO and mooring system

FPSO operation
The fuel considered for the project activities is diesel, with a sulphur content below 0.2% by weight.
In Table 7.15 data about greenhouse gases (GHG) emissions is reported, calculating the Global
Warming Potentials (GWP) according to IPPC (2007) characterization factor.
Table 7.15
Global Warming Potential of project activities
POLLUTANT
Drilling unit
Supply vessel
Gas flared in production tests
Oil burned in production tests
CO2
CH4
GWP
Kg
kg
Kg CO2 eq.
51.601.204,34
26.182.154,20
2.175.119,15
8.393.647,50
2.794,47
1699,25
222,6285
290,19
51.671.066,19
26.224.635,45
2.180.684,86
8.400.902,25
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TOTAL
88.352.125,19
5.006,54
88.477.288,75
Summary Evaluation
The effects of the emissions are expected to be low as their effects will be mitigated in addition to
atmospheric dynamics observed in the study area. Under most offshore meteorological conditions
(winds, gales, etc.), concentration of air quality pollutants would be well below their maximum
predicted values due to the effect of dispersion / dilution leading to very negligible effect.
During FPSO operation, and well heads activities, atmospheric emissions are essentially linked to
exhaust gases from the engines. Considering that the activities in question produce modest level of
emissions and that the weather conditions in the open sea present such features as the nearly
constant wind of varying direction and intensity, it is clear that the pollutants in question are
dispersed quite rapidly.
The position of the FPSO facilities allow a greater spread of the plume formed in the atmosphere,
permitting the dispersion due to the higher probability of winds; previous studies of atmospheric
dispersion, show a complete diffusion of pollutant emitted from the fuel combustion.
Moreover, the project area is located quite far from the coast; so its impact on the shoreline will be
absent.
The potential impact of air emissions on air quality is therefore assessed to be of low significance.
Table 7.16 Significance of impact of air emissions.
Consequence
Duration
Extent
Magnitude
Medium term
2
Local
1
Low
1
7.4.2
No. of elements
involved
Very small
1
Score
5
Probability
Significance
Definite
LOW -
Impact on Water Quality
During project execution, there will be temporary re-suspension of sediment particles including
organic matter within the water column. This will be low in magnitude and short term hence not
envisaged to have pronounced significant effect on water quality. The following project activities
are likely to contribute to the quality of seawater:
The project’s activities require the presence of some vessels in the surrounding waters to support
the various phases of the work. All vessels have mechanical seals which prevent any leaking of
oily bilge water and thus the physiological hydrocarbon leaks can be deemed negligible. During the
drilling phase, vessels are envisaged to transport personnel and a supply-vessel (for ordinary
maintenance and for loading and unloading other materials).
The presence of naval vessels and the FPSO operation means the emission of hot water as the
engine cooling water is discharged with a local increase in temperature, and possible
consequences for primary production; this water may contain hydrocarbon residues, biocides /
antifouling and trace metals.
The presence of the drilling structure, submerged well-heads, flowlines and FPSO mooring system
may lead to some level of distortion in the current field. However, the results of hydrodynamic
models applied to similar structures have revealed that the variation only affects a very small
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volume of water around the infrastructure and, therefore, its effect can be considered insignificant
as compared to waves and currents motion.
During the drilling and completion phases, the FPSO and well heads installation, and FPSO
operations, effluents from the crew quarters and service areas of the drilling unit, the FPSO and
the vessels, are discharged into the sea after adequate treatment. These discharges contain
nitrogen and phosphorous compounds and organic substances in general, substances which can
raise the BOD level, the level of water trophism and reduce transparency.
The presence of vessels can lead to increases in the lead concentration in the water when leaded
fuels are used. On the other hand, the drilling system and well head are not expected to release
lead into the sea.
The presence of materials suspended in the water column directly reduces transparency (and thus
light penetration) and this can interfere with the variation in euphotic zones and, in turn,
photosynthesis of the plant organisms present, both in the water column and on the sea bed.
Generally, fine materials are a direct result of the increase in particulate substances present in the
sea. However, reduced transparency is often the result of increased numbers of phytoplanktonic
organisms or organic substances present as a result of the increased availability of nutrients.
The use of sacrificial anodes to protect the submerged structures against corrosion has negligible
effects on the water column. The anodes (which contain no mercury) shed metals, especially Al,
causing a slight increase in the concentration of these elements in the water column.
The project envisages the total reinjection of production water, thus in the present
document potential impacts deriving from discharge of the these waters into the sea are
described. The produced water will be discharged into the sea, after treatment the reduce
the oil content in compliance with local legislation and international standards, only in case
of unavailability of the water injection system.
Oily and accidentally oily waters are stored in special drums to be transferred to land to be properly
disposed/treated.
Civil wastes (sewage, water from washbasins, showers, the caboose) are treated, as to achieve
legal concentration limit, with approved systems before being discharged into the sea.
Definition of the Indicator Parameters








Transparency
Temperature
Nutrients
Organic substances, TOC
Chlorophyll “a”
Total Hydrocarbons
Oxygen concentration
Heavy metals.
Potential impacts due to Sewage Waste Discharge
The concentration in the water of a series of characteristic indicators is considered, all of which are
linked to the treated sewage discharged. These indicators are the nitrogen and phosphorous
compounds detected in the water — i.e. ammoniacal nitrogen N-NH3, nitric nitrogen N-NO3,
nitrous nitrogen N-NO2 and phosphorous from orthophosphates P-PO4.
The presence of nutrients directly affects the level of water trophism, making a substrate available
to the primary producers for the synthesis of organic molecules. The phosphates are considered
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the limiting factor in the development of phytoplankton and any significant increase in the water
phosphate concentration can, in some cases, lead to extensive algal bloom. The presence of
organic substances in the sea can indirectly affect the level of trophism since it stimulates
heterotrophic micro-organisms, mineralizing and placing inorganic ions into circulation.
These parameters are linked solely to the sewage discharged from the vessels and platform and
are thus related to the installation and drilling operations. The sewage is treated and it is not
possible to determine the individual nutrient concentrations. An overall estimate of the impact can
be made considering the BOD, the reference parameter for controlling sewage treatment. The
sewage discharges are, in fact, treated so as to achieve a BOD within the 40 mg/l limit.
Evaluation of the dispersion of the treated sewage is performed using the DISP3D model that can
determine the primary dispersion of pollutants and the secondary dispersion due to currents. The
model is a two-stage process: primary dispersion is evaluated using a jet formation while
secondary dispersion is calculated using a 3-D dispersion model that takes the initial concentration
from the primary dispersion model and operates over a rectangular domain; in other words it
applies the approximation that the sea bed is flat and that there are no impediments in the domain
calculation - i.e. structures, coast, etc. The current values must be supplied by the user as input for
the model.
The extent of sewage discharged from the vessels and systems during installation and drilling is
approximately 12 m3/day (100 l x 30 days x 120 pers = 36000 lt/month) which means
approximately 13.9x10-5 m3/s.
During FPSOs operation activities and throughout the entire life cicle of the projected activities it is
estimated that about 60 operatives will be present on the FPSO; on the basis of the data available
in the literature for sites similar to the one under consideration, we can provide an estimate of civil
waste water produced: 100 l x 30 days x 60 pers = 180000 lt/month (6000 l/day)
In subsequent simulations, the emission value of the installation and drilling phase (the higher
value compared with the operation phase), was considered the average emission value but, to
verify the process, a dispersion simulation was also performed considering peak emissions
arbitrarily set at 10 times the average value.
For simulation purposes, current speed was set at 5, 10 and 20 cm/s; low current speeds
correspond to lower pollutant dispersion and thus the concentration will be higher.
The digital simulations were performed over an 800 x 400 m domain, horizontal resolution 20 m,
vertical resolution variable. Since discharges are made near the surface and, in the sea, vertical
exchange is reduced, a rather tight resolution was adopted near sea level – variable from 1 to 4 m
– and was progressively eased toward the bottom.
Figure 7-1 shows the BOD iso-concentration curve calculated with average sewage emissions and
an environmental current of 5 cm/s. The calculation assumed a sewage BOD concentration of 40
mg/l and emission levels were set at approximately 4 m below sea level. The figure refers to the
calculation level falling between 3 and 7 m below the surface, the zone where maximum
concentration was recorded. Digital simulation showed a concentration peak of 1.9 x 10-3 ppm
which was reduced by one order of magnitude at just 100 m from the emission point. Therefore the
values obtained were 2000- 20,000 times lower than the BOD concentration limit of 4 ppm, set as
acceptable.
Similar considerations can be made regarding the results obtained with stationary current levels of
0.10 m/s (Figure 7-2) and 0.20 m/s (Figure 7-3).
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It is worth noting that even assuming peak emission values an order of magnitude higher than the
average emissions (Figure 7-4), the peak concentration —7.0 x 10-3 mg/l — is more than 500
times lower than the above-mentioned limit and it drops to more than 3000 times lower at a
distance of around 200 m from the point of emission.
Therefore we can conclude that the increase in nutrient concentration is negligible, even in the
immediate vicinity of the point of emission.
Figure 7-1
Analysis of the water dispersion of sewage – BOD concentrations (ppm) – V=0.05 m/s
-5
3
– Average emission capacity: 6.94x10 m /s
Figure 7-2
-5
3
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Figure 7-3
-5
3
Figure 7-4
-4
3
In light of the foregoing considerations and the modelling results it is possible to observe that the
impact of wastewater discharge on the quality of the receiving body and on parameter indicators
related to the increased availability of organic matter, will be limited to a restricted area of the water
column, in proximity of the discharge point.
Potential impacts due to Production/Hot Water Discharge
Associated with oil and gas deposits, production waters are brought to the surface along with the
In some cases chemical compounds can be added to the production waters. The amounts of such
additives — e.g. corrosion inhibitors, biocides, de-emulsifiers, etc. — found in production water
does not generally exceed a few parts per million (pm).
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The production waters typically contain i) an inorganic component — essentially composed of
chlorides, bicarbonates and ions of sodium, potassium, calcium, barium and strontium, with
concentrations increasing as depth increases — and ii) an organic component — alkanes from C7
to C31, aromatic compounds and polycyclic hydrocarbons.
The volatile hydrocarbon liquids (VHLs) — including light aromatics and, in particular, compounds
ranging from benzene to naphthalene of ecotoxicological interest since they are most highly
soluble in water — are those most commonly found in the production water.
The fraction of petroleum insoluble in water is, above all, composed of high molecular weight
aliphatic hydrocarbons (HMW-HC) and cyclical and aromatic hydrocarbons, again with high
molecular weight: only small amounts of polycyclical aromatic hydrocarbons, PAH, are present in
the production waters.
The temperature of the production water increases as the production zone deepens (in shallow
wells the temperature ranges from 30 to 50°C while it can even reach 250°C in the deepest wells).
The solid content suspended in the production water can vary quite significantly; the presence of
major amounts of suspended solids can lead to a significant decrease in the transparency of the
discharge water column.
Regarding the temperature trend, the discharge enters the receptor body with a difference with
respect to the ambient temperature of 3°C, however, already in the first few meters, thanks to the
primary dilution, a thermal variance of 2 ° C is recorded 50 -60 m from the point of entry.
The effects of the discharge primary and secondary dispersion determine a rapid attenuation of the
thermal delta between that of the discharge and the receiving environment.
Beyond a 100 m distance, temperature increase settles below + 0.5°C.
Near the entry point temperature delta is greater at the surface, rather than in the rest of the water
column, consistent with the lower density of efflux linked to its higher temperature.
However, that it could have repercussions on the community on the sea floor is ruled out because
of its great depth; thus can be assumed that the consequence for phytoplankton would be
negligible.
Potential impacts due to biocides/antifouling (Chlorine) Discharge
Chlorine compounds are the most commonly used and economical biocides. Sodium Hypochlorite
(NaOCl) can be used.
When added to water the reactions of NaOCl produce HOCl:
NaOCl + H2O  HOCl + NaOH
Hypochlorous acid is a weak acid, only partially dissociating into hydrogen and hypochlorite ions:
HOCl  H+ + ClOThe degree of dissociation of hypochlorous acid is significantly affected by pH and temperature.
With decreasing pH, the degree of dissociation of hypochlorous acid decreases. Below a pH of 5.0,
the dissociation of hypochlorous acid is virtually 0%, regardless of temperature. As temperature
increases or decreases, the dissociation curve shifts along the pH axis, as shown on figure below.
The sum of hypochlorous acid and hypochlorite ion in solution is called “free available chlorine”.
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Dissociation curve of hypochlorous acid as a function of temperature and pH
The effectiveness of chlorine depends on which of these species is present and is therefore a
function of pH. For instance, the killing power of HOCl is much greater than that of ClO-, possibly
because the charged ClO- ion has a more difficult penetrating the cell wall. At typical seawater pH
values (8.1 – 8.2) the chlorine is only 20% active.
However, in waters containing bromide ions, such as seawater that contains nearly 65 g/l of
bromides, chlorine oxidizes the bromide ions to form HOBr, which is still an effective biocide at pH
8-9.
The bromides present in seawater (nearly 65 mg/l) are oxidized into hypobromite and
hypobromous acid according to the reactions:
ClO- + Br-  BrO- + ClHOCl + Br-  HOBr + ClAmmonia-nitrogen is present in seawater as amino groups in amino acids. Further reactions occur
between ammonia-nitrogen and hypochlorous acid to form chloro-amine compounds:
HOCl + NH3  NH2Cl + H2O
(monochloramine)
NH2Cl + HOCl  NHCl2 + H2O
(dichloramine)
NHCl2 + HOCl  NCl3 + H2O
(trichloramine)
and between ammonia-nitrogen and hypobromous acid to form bromo-amines:
HOBr + NH3  NH2Br + H2O
(monobromamine)
NH2Br + HOBr  NHBr2 + H2O
(dibromamine)
NHBr2 + HOBr  NBr3 + H2O
(tribromamine)
All these reactions can occur simultaneously, and it is the physicochemical parameters of the
seawater and the amounts of added oxidizing agent that will determine the prevailing reactions.
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Most of the compounds that are formed oxidize the organic matter in the medium at varying rates
and efficiencies depending on the species and nature of the compounds:
 Hypochlorous acid is some 80 times more effective than hypochlorite ion
 Dissociation of HOBr occurs at a higher pH than HOCl, which makes it more effective in
alkaline environments. As figure below shows, at seawater pH, hypochlorous acid is
80% dissociated while hypobromous acid is 20% dissociated.
 Chloramines are less effective as biocide and no longer react with organic matter
 Bromamines are still effective as biocide and react with organic matter
Figure 7-6
Dissociation of HOBr vs. HOCl – pH effect
The main products present in the medium are hypobromous acid, mono-chloramine, and di- and
tri-bromamine.
The toxicity induced by the presence of chlorinated or brominated products in the medium may
modify the parameters of the local ecosystem (bioaccumulation of toxic products, destruction of
organic matter, etc.)
The degree of toxicity of the different compounds that are formed in seawater depends on a
number of physicochemical parameters and on the compound’s lifetime.
Chloramines are persistent and their effect is detrimental for receiving bodies.
Bromamines are not persistent. Their lifetime is far shorter than that of chloramines as shown on
figure below.
Figure 7-7
Environmental fate of Bromamines vs. Chloramines
Chlorinated or brominated organic compounds are usually more stable than inorganic compounds.
While chlorine compounds are effective in controlling fouling, used in waters with high organic
substances like seawater, they lead to the formation of halogenated organics (in particular,
trihalomethanes) which are released in the environment.
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Sometimes to comply with the limits imposed by legislation for chlorine compound and keep the
system clean it is possible to use a reducing chemical in order to lower the residual chlorine at the
discharge.
The behaviour of discharged waters, with their temperature and content of antifouling and biocides,
after their release into the water column is similar to that of wastewater containing nutrients and
organic matter considered in previous modellings.
In this context, it is also important to consider the limited size of the discharges compared to the
volume of the receptor body, the low concentration of biocides / antifouling and the system and
procedures by which the water is discharged along the water column, in order to ensure a good
level of mixing.
The discharge of volumes of hot water and water containing pollutants, biocides and anticorrosion substances from the FPSO production process and supply vessels engine cooling into
a large and deep basin like the one under consideration may trigger environmental interferences of
negligible intensity.
In light of the foregoing considerations and the modeling results it is possible to observe that the
impact of the discharge of production and cooling water on (i) the temperature of the receiving
body (ii) on indicator parameters relative to temperature and (iii) on those indicator parameters
relative to the presence of biocides and antifouling in the production and cooling water, will be
limited to a restricted area of the water column in the proximity of the discharge point.
Organic substances, TOC
In this case, the organic substance is expressed as the concentration of organic carbon (TOC).
The Total Organic Carbon is the sum of the carbon dissolved (DOC) and the particulate carbon
(POC). The concentration is linked to the natural processes inherent to the biogeochemical cycle of
this element and to any allochthonous sources (transport of solids from rivers, algae and discharge
bloom, sewage).
It is more commonly interpreted as a BOD indicator that quantifies the oxygen demand and thus
provides an indirect measurement of the concentration of organic substances present in the water
directly relating them to the real site conditions. Also see dissolved Oxygen and BOD.
Chlorophyll “a”
This is an indicator of the trophic state of the offshore environment since it is directly linked to the
amount of phytoplankton which, in turn, may increase as a result of sewage discharges.
Total hydrocarbons
The presence of hydrocarbons in the aromatic and aliphatic fractions leads directly to an increase
in their concentration and indirectly to an accumulation in organisms at various points along the
food chain. The aromatic component (PAH — benzene, toluene, xylene, naphthalene,
phenanthrene, etc. general formula: CnH2n-6 with n>6) plays an important environmental role
since it also includes the light aromatic hydrocarbons considered among the most highly toxic
compounds for the environment (the acute effects and toxicity of PAHs with 2- and 3-rings have
been demonstrated while the effects of those with greater numbers of rings has yet to be clarified).
In general, sediments containing the highest concentrations of Polycyclical Aromatic Hydrocarbons
(in particular those with high molecular weight) are relatively more stable in water.
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The sediment PAH level is related to human activities while the concentration of PAHs with a low
number of rings quickly drops in the sediments (since they are highly water soluble).
In general, the presence of consistent levels of 3- and 4-ring compounds indicates that the source
is spent oils, lubricants and crude oil while 4 or more rings indicate that the input is combustion.
The increase in the seaborne hydrocarbon concentration is generally related to shipping traffic, and
this is more intense during installation of the well drilling structures.
The higher molecular weight aliphatic and aromatic hydrocarbons are characterized by low
volatility and low solubility in water and thus tend to accumulate selectively in the biota and marine
sediments.
Considering that the vessel traffic is more intense during the reduced installation and drilling phase
and reduced during the prolonged operation phase, and that in any case the quantities released
are negligible, it is possible to observe that the impact of the activities in their entirety on the
parameter in question is rather negligible.
Water column depth and the volume of the receiving body, distance from the coast and the fact
that the supply vessels are in motion all contribute towards rendering little significant their impact.
Dissolved Oxygen
The amount of oxygen dissolved in the water depends on the solubility of this gas in the aqueous
medium at a given salinity and temperature. It varies on the basis of a complex series of factors,
including in particular, such biotic processes as algal photosynthesis (oxygen production) and
bacterial organic substance mineralization (oxygen consumption). This parameter is affected by
the input of nutrients through sewage discharge, even if the area of influence in open sea is very
narrow.
The variability of this parameter is an indicator of the trophic state of the water and thus depends
mainly on the increase in the autotrophic biomass in suspension. In fact, there is a clear-cut
relationship between the chlorophyll “a” concentration and the fluctuation in dissolved oxygen.
The fluctuations around the value of physical saturation are mainly the result of oxygen derived
from photosynthesis; subsaturation values are seen when the microalgal concentrations increase.
The dissolved oxygen value varies greatly from zone to zone and between surface and deep
waters.
Potential impacts due to Sacrificial anodes on metals content
Alterations in the concentration of heavy metals in the water column are related to their release
from sacrificial anodes and the transiting naval support vessels. Metals considered indicative to
environmental conditions of the area are aluminium and lead. The former, in as much as it is the
main constituent of the sacrificial anodes, the latter given its being the principal substance present
in naval vessel fuel.
Modelling was used to evaluate of the effects of heavy metal dispersion in water, released by the
sacrificial anodes.
The sacrificial anodes are composed of an aluminium-based alloy, which constitutes 95% of the
total composition, as well as of Magnesium, Manganese, Zinc, Indium and Copper.
Considering that the rate of the anodes’ dissolution can be estimated at c. 3kg/Amp/yr. and that
residual current variability can be estimated in an interval of 80-300 mAmp, the release of metals
should result between c. 250g/yr. and 900g/yr.
Nevertheless in the dispersion simulations a notably more conservative approach was opted for,
assuming a release accrual equalling 5kg/yr.
Notwithstanding the notably conservative assumptions, the values calculated for metal release
concentration in the marine environment surrounding the pipeline, prove very low, with a maximal
in immediate proximity of the pipeline of 4 µg/m3.
Furthermore, concentration levels decrease to almost negligible amounts at a 1 metre distance
from the structure; also considering the spacing of the anodes along the structure it is possible to
exclude the juxtaposition of adjoining anodes.
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Figure 7-8 and Figure 7-9 respectively represent the calculation domain and grid adopted for
simulations. The calculation domain is 20 m in length, 3m high and 1m deep, i.e. roughly the
estimated dimension of the anodes. It should be observed that this domain description leads to the
disregard of longitudinal dispersion phenomena, introducing an ulterior element of
conservativeness in the evaluation of metals concentration in the marine environment.
The computational grid’s meshes are subjected to densification in proximity of the seabed so as to
obtain a better description of phenomena associated with the turbulent boundary layer.
Simulations were carried out considering 3 possible scenarios for marine current velocity in
proximity of the seafloor, all assumed to flow perpendicularly to the structure:
 5cm/s current
 10cm/s current
 40cm/s current
The first two cases correspond to climatic conditions with weak currents and therefore reduced
dispersive effects, while the third scenario corresponds to an estimate of expected currents in case
of storms of medium intensity (return period of c. 1 year), and therefore describes a situation
characterised by a greater efficiency of released metals’ dispersion.
Figure 7-8
Calculation domain and grid
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Calculation domain and grid – Detail in proximity of the pipeline
Results
Figure 7-10 illustrates the current velocity calculated around the structure for the undisturbed
current scenario equal to 5cm/s. As foreseeable on the basis of hydrodynamic considerations, the
iso-speed lines substantially highlight 3 regions: a region of flux amplification in correspondence of
the pipeline’s top-side, a limited region of stagnation upstream and a wider region of stagnation
and recirculation downstream. Flux amplification is nevertheless rather contained: maximum
current velocity calculated is only 30% greater to the undisturbed value. Moreover, the effects
caused by the pipeline’s presence in the hydrodynamic field disappear over brief enough
distances; at only 1.5m downstream from the pipeline, the flux resumes its undisturbed conditions.
Figure 7-10
Hydrodynamic field around the pipeline – V=0.05 m/s & velocity scale (m/s)
The iso-concentration curves of released metals (Figure 7-11) indicate rather low values: in
proximity of the pipeline it is possible to observe maximum concentrations of 4µg/m 3, while at only
0.5m from the pipeline values decrease to 1µg/m3 and records completely negligible values at
distances beyond 1m. in order to obtain a metric comparison, the structure + anode system is
represented, for a total diameter of c. 25cm. To this regard it is also possible to observe that
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anodes are spaced at roughly 100-120m intervals along the linear structures. Therefore,
considering that metals release concentration is in fact negligible within a few metres of the
pipeline, phenomena regarding adjoining anodes’ emissions juxtaposition may be ruled out.
Figure 7-11
3
Metals concentration around the pipeline (µg/m ) – V=0.05 m/s
Calculations carried out for undisturbed currents equal to 10 cm/s (Figure 7-12) indicate notably
more extensive downstream phenomena, while again the maximum flux amplification on the topside of the pipeline stands at 30%. A detailed view of the hydrodynamics in proximity of the
pipeline is represented in Figure 7-13. The iso-concentration curves of released metals (Figure
7-14) indicate a greater extension of appreciable concentration zones, even though for extremely
low values as well as lower maximums with respect to the 5cm/s scenario. Indeed, in proximity of
the pipeline maximum values stand at 2µg/m3 with respect to the 4µg/m3 of the previous scenario,
while concentrations decrease to values below 1µg/m3 for distances at 50-60cm from the pipeline.
Figure 7-12
Hydrodynamic field around the pipeline – V=0.10 m/s
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Figure 7-13
Hydrodynamic field around the pipeline – V=0.10 m/s - Detail
Figure 7-14
Metals concentrations around the pipeline (µg/m ) – V=0.10 m/s
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3
The 40cm/s current velocity scenario indicates a greater extension of the area manifesting
conditions of flux disturbance and ulterior amplification of downstream phenomena (Figure 7-15),
which are perceivable up to at least 3.5m from the pipeline. Nevertheless, the greater flux velocity
also entails a greater efficiency in the phenomena of contaminants’ dispersion. Coherently, the isoconcentration curves of released metals indicate extremely low levels of concentration, with
maximums in proximity of the pipeline well below 1µg/m3 (Figure 7-16), and concentration levels
below 0.3µg/m3 at a 0.5m distance from the pipeline.
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Figure 7-15
Hydrodynamic field around the pipeline – V=0.40 m/s
Figure 7-16
Metals concentrations around the pipeline (µg/m ) – V=0.40 m/s
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3
In synthesis the numerical simulations of metals dispersion, consequential to the corrosion of the
submerged structures’ sacrificial anodes, were carried out for 3 scenarios typical of hydrodynamic
conditions. With regards to fractioning of the anodes’ dissolution, notably conservative
assumptions were adopted for the calculations. Nevertheless, values calculated for concentration
levels of metals released into the surrounding marine environment proved to be distinctly low, with
maximums in immediate proximity of the pipeline standing at 4 µg/m3.
Furthermore, concentration levels decrease to almost negligible amounts at distances just over 1m
from the pipeline. Hence, considering the effective spacing of the anodes it is possible to exclude
the effect of emissions juxtaposition between adjoining anodes.
With regards to lead content, given that vessel traffic is more intense during the brief installation
and drilling phase and reduced during the prolonged operation phase, and that the quantities
released into the environment are negligible, it is possible to observe that the impact of the suppply
vessels’ overall activities on lead concentration will be fairly negligible.
Water column depth and volume of the receiving body, distance from the coast and the fact that
the supply vessels are in motion all contribute to rendering little significant their impact.
Summary Evaluation
Changes in sea water quality as a result of installation of the various permanent sub-sea structures
(well-heads, pipelines, flowlines, etc.) and routine operational discharges from the vessels, drilling
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unit and FPSO will be small and limited to the immediate vicinity of the discharge points. The
dynamic nature of the water column environment as a result of waves and currents means that any
pollution resulting from these activities would rapidly disperse in the environment. The potential
impact of changes in sea water quality is therefore assessed to be of low significance (see Table
7.17).
Table 7.17
Significance of impact on sea water quality.
Consequence
Duration
Extent
Magnitude
Medium term
2
Local
1
Low
1
7.4.3
No. of elements
involved
Very small
1
Score
5
Probability
Significance
Definite
LOW -
Impact on Seabed and Marine Subsoil
Most of the impacts on the seabed caused by the project are related to the relatively short
construction phase with the activities related to drilling, installation of the mooring system and the
laying of pipelines.
The impacts resulting from the discharge of production water, civil waste containing organic matter
and nutrients, the release of cooling water containing biocides and antifouling from supply vessels
during the construction phase and during the longer operations phase are not capable of causing
effects on the seabed given the notable water depths and the hydrodynamic conditions which
prevent contaminants from leaving significant traces on the sea floor itself.
The drilling unit has a dynamic positioning system, so the interference between the drilling
structure and the sea bed are limited to the riser. The physical presence of the structures and the
shifting and re-depositing of the sediments caused by the operations, may lead to habitat loss and
changes in the type of the sediment and thus in the number and type of the macro-benthic species
which depend to a large extent on the characteristics of the sea bed sediments.
Over the long term, the flowlines and the sub-sea structures of the well heads and mooring system
may encourage colonisation by sessile organisms, leading to habitat conditions different from
those in the surrounding area. There is also the possibility of species enrichment or the
appearance of new species, especially since the surrounding sea beds are mobile and not hard.
These effects could be qualitatively similar to that of the permanent production structures, but
widely quantitatively lower. Since the sub-sea structures cause a localized variation in the current
field, they indirectly affect the sedimentation process which, in turn, modifies the sea bed
morphology. Nevertheless, this only occurs in a limited area on the sea bed in the immediate
vicinity of the risers.
Likewise emission of the fine material resulting from sewage discharged during drilling can produce
imperceptible variations in the characteristics of the sediments on the sea bed. Discharging
sewage directly emits nutrients and organic substances that can settle on the sea bed. This occurs
during the installation and drilling phases when personnel are present at the site. Of course, this
effect is very displaced because of the water depth.
The effects arising from the presence of sacrificial anodes along the flowlines laid on the sea
bottom and other underwater structures will be limited to the immediate environs of the structures,
affecting a very small volume of the water column and an even smaller volume of sediments.
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The following parameters were used to define the quality and assess the impact the activities have
on the sediments.
 Variation in particle size distribution
 Organic substances - TOC
 Total Hydrocarbons - PAH
 Heavy metals
Variation in particle size distribution
In the absence of any outside disturbance, the particle size characteristics of the site are generally
an index of the hydrodynamics typical of the zone and source of the sediments. Alteration in the
main particle size classes in a limited area can therefore be due to external disturbance.
Interferences present during Project realisation are limited the riser during drilling and the areas
interested by the installation of wellheads, flowlines and FPSO mooring system; these
interferences affecting only small areas (some thousands of square metres) and the potential
alterations of the parameter in question due to Project activities, can therefore be considered
negligible.
Organic substances - TOC
The percentage of organic carbon in the overall weight of the sample is an index of the organic
content of the sediments. Organic substances are a major source of nutrients for the benthic fauna
and can be decomposed by the bacterial flora present in the sediment. However, the presence of
large amounts of organic carbon per unit of surface and the resulting bacterial oxidation leads to
high consumption of oxygen and this, in turn, generally results in hypoxia or oxygen depletion of
the substrate.
The concentrations of organic substances and organic carbon are linked to the particle size
composition of the sediment. In general, the higher the percentage of sand, the lower the carbon
content and thus it is difficult to compare TOC concentrations in sediments with different particle
size distributions.
During the implementation of the project and its operational phase the source of organic matter is
formed by the introduction of civil sewage and the increased productivity of the upper layers of the
column for all the factors aforementioned (release of cooling water, FAD effect, etc.).
In light of modelling results and the above considerations it is possible to observe that the impact of
Project activities on sediment quality and relative indicator parameters, will be limited; the
considerable depth of the water column and the resulting dilution contribute to mitigating the effects
of alterations that occur in marine sediments at their surface.
Total hydrocarbons
The increase in the concentration of hydrocarbons in the water, and thus in the sediments, is
generally related to shipping traffic.
Considering that vessel traffic is more intense during the brief installation and drilling phase and
reduced during the prolonged operation phase, and that in any case the quantities released are
negligible, it is possible to observe that the impact of the activities in their entirety on the parameter
in question is rather negligible.
The considerable depth of the water column and the resulting dilution help to limit the effects of the
alterations that occur in marine sediments at their surface.
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Metals
As previously discussed for the sea environment, lead is deemed most meaningful indicator of
alterations because it is linked to shipping traffic.
Considering that vessel traffic is more intense during the brief installation and drilling phase and
reduced during the prolonged operation phase, and that in any case the quantities released are
negligible, it is possible to observe that the impact of the supply vessels activities in their entirety
on the lead concentration will be rather negligible.
The considerable depth of the water column and volume of the receiving body, distance form coast
and the fact that supply vessels are in constant movement al contribute to rendering little
significant the impact.
The simulations on impact from dissolution of the sacrificial anodes show that the level of heavy
metals introduced into the marine environment is negligible and already at just a few meters from
the anode the metal concentration of the returns to concentration levels existing in nature.
A small increase of Aluminium in sediments can thus derive from the re-deposit on the seabed of
the metals released from sacrificial anodes but the envisaged impact will be negligible.
Summary Evaluation
Changes in sea bed morphology and sediments as a result of installation of the various units and
routine operational discharges from the vessels, drilling unit and FPSO will therefore be small and
limited to the immediate vicinity of the discharge points. The potential impact of changes in seabed
and marine subsoil is therefore assessed to be of low significance (see Table 7.18).
Table 7.18
Significance of impact on sea bed and marine subsoil.
Consequence
Duration
Extent
Magnitude
Long term
3
Local
1
Low
1
7.4.4
No. of elements
involved
Very small
1
Score
6
Probability
Significance
Definite
LOW -
Impacts on vegetation, flora, fauna and ecosystems
The project activities trigger different types of disturbances in the biological environment and they
affect the biological components differently.
The disturbances affect all levels — planktonic, nektonic and benthic — since the systems are
mutually dependent.
The presence of the support vessels necessary for the operations, the drilling operations, subsea
installation and operation activities leads to an increase of the low frequency underwater noise
level which may drive fish species away, although only temporarily and within the small area
where the noise is heard, and may also interfere with the normal physiological functions and
behaviour of some species of mammals and reptiles.
The main effect of the discharge of engine cooling water and production water containing
biocides and anti-corrosion substances is a possible local increase in temperature, with
possible consequences for primary production and a local contamination of the water column.
The discharge of treated sewage containing nutrients easily assimilated into the primary
production cycle and suspended matter causes an increase in turbidity and the consumption of
oxygen to degrade the matter through the column of water and also an increase in primary
production. In the event that this discharged material reaches the sea bed (this might not occur in
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the zone where the water is very deep) there is an increase in organic matter and thus a
reduction in the amount of oxygen at the interface.
Changes in the trophism (increase in organic matter) may modify the concentration of chlorophyll
a, linked in turn to the algal biomass.
The operations for installation, of the flowlines and anchoring of the lay barge and mooring system
may cause small, localised morphological changes, sediments resuspension and risedimentation
which may lead to interference with structures formed by biological processes and benthic
biocenoses with potentially damages depending on the vulnerability of involved ecosystems.
The mobilisation and resuspension of sediments from the sea bed leads to a temporary
increase in the turbidity of the water over a small area and may leads to a reduction in the level of
light penetration. If this reduction in light levels continues for some time, there may be a decrease
in the amount of oxygen in the water due to a reduction in the rate of photosynthesis and the
activation of degradation/oxidation processes only; primary production is thus directly affected.
The positioning of the drilling and production structures and their presence leads to burying of the
organisms and benthic biocenoses, and the removal of a small area of habitat; this removal is
temporary in the case of the drilling system and restricted to drilling period and much longer in the
case of well heads and sealines laying activities.
The temporary physical presence on the sea bottom of the project structures may produces local
changes to the typical percentage of sand, clay and silt, and consequent negligible variations in the
numbers and types of macrobenthic species (especially polychaetes and molluscs), which depend
to a considerable extent on the types of sediment found on the sea bed.
The depth of the water column in the study area and the absence of light at the seabottom do not
allow for the formation of a rich benthic community which, in the area affected by the Project
activities presents itself as poor in species and sparse specimens; for these reasons disturbances
affecting the seabed have negligible effects on benthic biocenoses.
The increase in the availability of the organic matter in the area both in suspension and on the sea
bed, may produce direct effects on the area’s biology, as a result of the physical presence of the
sub-sea structures thanks to the F.A.D. (Fish Aggregating Device) effect, creating a new
community of fauna different from that typically found in the waters around the well heads.
In zones with mobile sea beds, artificial sub-sea structures attract numerous pelagic and demersal
species. The physical presence of the submerged structures in the open sea for relatively long
periods of time (average operation: approx. 20 years) serves to aggregate numerous sea species,
some of which are characteristic of hard substrates which, under normal conditions, would be
absent or poorly represented in the area. These changes could cause an increase in the
availability of organic matter in the water column, promoting the phyto- and zooplankton in the
immediate vicinity of the structures.
During the drilling and installation phases, to ensure operations and safety, the area is lit all night.
Such lighting can attract marine organisms in the surface-most portion of the water column.
The whole process interesting all levels, planktonic, nektonic and benthic, will also have beneficial
effects on fishing in the zones close to these sub-sea structures.
This aggregation ability of submerged structures is lower at great depths where the species
abundance and richness are lower because of the severity of environmental conditions.
There will be a de facto reduction in the area available for commercial fishing due to the
presence of the production structures and the flowlines, or operations related to them. The
operations may also temporarily chase the fish stock available for commercial fishing away from
the involved areas and could partially modify the migratory routes for the young of some species.
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However, this will not in any way compromise survival or create any significant impact on
commercial fishing conducted in the vast area.
the coast.
The sacrificial anodes (which contain no mercury) shed metals, especially Al, causing a slight
increase in the concentration of these elements in the water column and in the sediment, to which
they are confined, unable to significantly affect the biocenoses.
The bibliography on the effects of the presence of Al in marine sediments or the water column is
very limited. However, there are no reports of cases in which this element has been toxic to
marine organisms, and apparently sea-dwelling filtering organisms are not capable of
bioaccumulating Al.
The metal ions (Pb) emitted into the water column by supply vessels can be lightly bioaccumulated
by filter feeding organisms.
The discharge of volumes of hot water, water containing pollutants, nutrients, biocides and
anti-corrosion substances from FPSO operation, supply vessels and offloading activities into a
large and deep basin like the one under consideration may trigger environmental interferences of
negligible intensity.
The type and gravity of the consequences of these discharges on the biological community,
depend to a large degree on the size of the area affected to varying extents by these discharges.
In this context, it is important to consider the limited size of the discharges compared to the volume
of the receptor body and the system and procedures by which the water is discharged along the
water column, in order to ensure a good level of mixing.



Interference with benthic populations
 Average number of species present
 Specific diversity index
Metal bioaccumulation
Bioaccumulation of hydrocarbons (PAH)
The biological world is a complex, dynamic system sensitive to even minimal changes in the
environment. Even under normal conditions, the marine environment is subject to significant
variations linked to the water mass dynamics, the contribution of continental waters, seasonal
variations, etc. Thus it is difficult to establish what parameters are indicators of the disturbance
created and, above all, to identify what contribution each individual form of disturbance makes to
changes in these parameters.
Interference with the benthic populations
The composition of the benthic communities plays a role as biological indicators, understood as
providing indication of the complex environmental conditions ensuing from the interaction of a
multitude of biotic and abiotic parameters that are difficult to measure individually. This type of
approach is based on the concept of biotic community (the series of populations that live in a given
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area or physical habitat and which make up an organized unit the characteristics of which go
above and beyond those of the component individuals and populations) and thus assumes a series
of interactions between organisms and between the organisms and the environment.
Each community presents the so-called homeostasis — i.e. the ability to maintain a steady state by
using feedback control processes to respond to various stimuli. When these stimuli exceed the
homeostasis capacity of the individual organisms, the community is no longer able to return to a
state of equilibrium and its structure undergoes both qualitative and quantitative modifications.
Thus the role of indicator attributed to the community as a whole given its ability to adapt to overall
environmental situations.
Among the zoobenthic communities, the macroinvertebrates (organisms that can be trapped in a 1
mm mesh sieve) have, for various practical reasons, proved to be the best suited to this type of
survey. In the marine benthic communities, the systematic groups (Taxa) most highly represented,
both in terms of number of species and number of individuals, are the Annelids, Molluscs,
Crustacea and Echinoderms. In particular, it has been shown that, since polychaetes occupy
significantly diversified niches in the food chain and are found at various trophic levels in the
macrobenthic communities, they are effective indicators, both functional and structural. Molluscs
have been found to be effective indicators of the overall ecological conditions in coastal marine
ecosystems. On the other hands, the Crustaceans, amphipods particular, have proved to be an
important component of the mobile fauna in various environments.
The average number of species present and the specific diversity index reveal changes in the
population because:
 they reflect both the reduction and survival of the most representative or most resistant
species and
 they show the increase in some species as a result of the variation in environmental
conditions or through repopulation.
The modelling discussed above shows that the interference related to the discharge of nutrients
particulates and contaminants in vicinity of the surface, are not able to affect the seabed given the
considerable depth of the water column.
The same can be said for the discharge of cooling water capable of causing alterations only to a
restricted portion of the water column, without interfering with the seabed.
The release of Al ions will affect a limited portion of the water column and sediments in vicinity of
the submerged structures and flowlines laid on the seabottom.
Finally, it should be remembered that the depth of the water column in the study area and the
absence of light at the seabottom do not allow for the formation of a rich benthic community which,
in the area affected by the Project activities presents itself as poor in species and with sparse
specimens.
For these reasons it is possible to observe that disturbances affecting the seabed have negligible
effects on benthic biocenoses and are not capable of altering the parameter indicators under
examination.
Potential impacts due to biocides/antifouling (Chlorine) Discharge
Several scientific papers regarding impact of chlorinated Cooling Waters CW (Taylor, 2006; Nebot
et al., 2006) indicate the presence of “confounding effects” between the use of hypochlorite as
antifouling and ∆T of wastewaters, making it difficult to discriminate between the effects caused by
the presence of chlorine and CBPs (compounds produced by the reaction of chlorine with
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substances present in seawater are called Chlorination By-Products - CBP’s) and those generated
by the difference in temperatures of wastewater. Also important is the different effects that ∆T
could have on the species (it was found that the juvenile stages of various species of amphipods
can be favoured by increases in temperature, whereas adult populations do not tolerate high
temperatures; Taylor, 2006).
Studies conducted in the 80s and 90s did not identify impacts that can be attributed to residual
chlorine alone; in a dispersive environment such as a non-enclosed sea, where there is a rapid
water discharge, it seems impossible to identify significant impacts in terms of variations in the
distribution, of species, abundance or biomass. Generally, sites in high energy open seas have a
high capacity to dilute and spread chlorinated wastewaters (Lattemann & Höpner, 2008).
Preliminary studies regarding the effects of CW on benthic fauna were conducted by Lewis (1984),
who determined a toxicity limit for Mytilus edulis (L.) for the concentration of total residual chlorine,
under which the chlorination process does not cause the death of this species, but only delays its
growth.
Figure 7-17
Acute toxicity of Mytilus edulis, expressed as forecasted time of death, as a function
of various levels of chlorination, expressed as mg/l of total residual chlorine and various
temperatures of the cooling water circuit (Taylor, 2006).
As shown in Figure 7-17, a concentration of 0.2 mg/l total residual chlorine involves a forecasted
time of death ranging from a little under 100 to 700 days, in a range of temperature of wastewater
from 10 to 25 °C. For lower levels of concentration the mortality is practically null.
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Figure 7-18
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Effect of chlorine vs biofouling concentrations expressed as biomass (Nebot et al.,
Roberts and colleagues (Roberts Jr. et al., 1990) examined the effects of oxidants produced by
chlorination on the settlement of a species of oysters and barnacles, and on the influence of the
settlement’s distance from the water discharge point. No substantial difference was observed in the
number of settled individuals for the mussels and barnacles tested. The growth and larvae survival
experiments performed in the field showed no inhibition for concentrations higher than those that
involved total inhibition to settlement in experiments conducted in the laboratory.
Elliot and colleagues (1993) and Davis (1993) conducted studies on biomarker organisms such as
Dicentrarchus labrax (L., branzino) and on bioindicator organisms such as Mytilus edulis. They
observed the absence of damages to the fish’s liver that could be attributed to exposure to CBPs, a
bioconcentration of bromoforms in the fat of the examined fish species (70-160 times the levels of
concentration in CW) that rapidly disappear when the chlorination process ceases, absence of ecotoxicological stress in the sea bass exposed to CBPs for long periods of time, absence of THMs in
the mussel’s tissues, generation of stress proteins.
Contrarily, other studies (Jenner, 1997) show different CBP toxicity data, indicating greater
concentrations and their effects.
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Table 7.19
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Summary table of available data on CBP Toxicity
Metal bioaccumulation
A part of the metal ions released into the water are bioaccumulated in filter feeding organisms.
Lead is considered the prime indicator because it is linked to shipping and installation activities.
Given their reactivity and the various processes involved in their removal, heavy metals do not
remain in the water column for a long time; they tend to accumulate in the fine sediments and, in
some cases, in the tissues of marine organisms. In this case, they can be detrimental to the
growth, reproduction and species composition of the animal and plant communities (UNESCO,
1980).
Al is not considered harmful or pollutant, and it must also be underlined that Al is not
bioaccumulated by organisms but rather tends to be eliminated by clearance. A slight increase in
the level of the element in filtering organisms may be due to the presence of Al in the intravalvular
liquids.
The bodies tolerate Pb toxicity not only at low concentrations normally found in sea water but also
at higher concentrations; an accumulation in tissues may therefore occur.
If the processes of excretion are not sufficient, the toxic elements can be transformed into nontoxic compounds and stored in the liver and kidneys or in other parts of the body, protecting from
excessive concentration the more sensitive organs.
It is difficult to generalize on Pb toxicity of organisms, since there are considerable differences in
resistance to this pollutant; Mytilus, for example, has a mechanism of purification which allows it to
accumulate Pb in the form of metallic granules that are isolated from its organism.
In the project under review, the volume of the receiving body (water depth is about 1000m) allows
for a rapid dilution of the Pb metal ions released as a result of the activities of supply vessels, thus
limiting their accumulation in benthic organisms as well as those found in the water column.
The simulations presented above allow for the affirmation that the effect of sacrificial anodes on Al
concentration is zero at just a few meters from the anode itself; alteration of the parameter in
question can thus be excluded.
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Hydrocarbon bioaccumulation
The increase in the concentration of hydrocarbons in the water, and thus in the sediments, is
generally related to shipping traffic, and this is particularly intense while the well drilling structures
are being installed. The presence of hydrocarbons and the increase in hydrocarbon concentrations
in the water indirectly leads to bioaccumulation in filter feeding organisms which are highly
sensitive to Polycyclical Aromatic hydrocarbons (PAH - benzene, toluene, xylene, naphthalene,
phenanthrene, etc.), undoubtedly the most highly toxic hydrocarbons.
Many invertebrates tend to concentrate PAH drawn from the water, generally the result of the lipidwater separation balance, thus establishing a direct correlation with the surrounding waters.
The damage to marine organisms can be acute, sub-lethal or chronic since many organisms are
able to concentrate petroleum-based products.
In the project under review, the volume of the receiving body (water depth is about 1000m) allows
for a rapid dilution of hydrocarbons released as a result of the activities of supply vessels, thus
limiting their accumulation in benthic and water column organisms.
Summary evaluation
Changes in the marine biota and ecosystems as a result of the installation and presence of the
subsea structures, drilling unit, well heads and support vessels, as well as normal operation
discharges will be limited to the immediate vicinity of these activities. The potential impact is
assessed to be of low significance and may even be positive if the subsea structures and
exclusion zones attract and provide shelter to a wide variety of species (see Table 7.20).
Table 7.20
Significance of impact on vegetation, flora, fauna and ecosystems.
Consequence
Duration
Extent
Magnitude
Medium term
2
Local
1
Low
1
7.4.5
No. of elements
involved
Very small
1
Score
5
Probability
Significance
Definite
LOW -/+
Underwater noise-generated impacts
Underwater sound allows marine animals to gather information and communicate at great
distances and from all directions. The speed of sound determines the delay between when a sound
is made and when it is heard. The speed of underwater sound is five times faster than sounds
travelling in air, thus marine animals can perceive sound coming from much further distances than
terrestrial animals. Because the sound travels faster, they also receive the sounds after much
shorter delays (for the same distance). It is not a surprise that marine mammals have evolved
many different uses for sounds.
Marine animals rely on sound to acoustically sense their surroundings, communicate, locate food,
and protect themselves underwater. Marine mammals, such as whales, use sound to identify
objects such as food, obstacles, and other whales. By emitting clicks, or short pulses of sound,
marine mammals can listen for echoes and detect prey items, or navigate around objects. This
animal sense functions just like the sonar systems on navy ships. It is clear that producing and
hearing sound is vital to marine mammal survival. Sound is also important to fishes. They produce
various sounds, including grunts, croaks, clicks, and snaps, that are used to attract mates as well
as ward off predators. Marine invertebrates also rely on sound for mating and protection. Little
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research has been done on marine invertebrates that produce sounds, but for those that do, like
shrimp and lobsters, sound is very important for survival against predators.
Sound propagation
Sound is essentially generated when a vibrating object sets molecules in a medium adjacent to
that object into motion. Sound amplitude or what is perceived as loudness is directly related to the
amount of pressure generated by the vibrating object. In a compressible medium, the motion of
molecules produces positive pressure where there is condensation and negative pressure where
there is rarefaction of molecules. The intervals of condensation and rarefaction typically occur in a
cyclical fashion. In a plane progressive wave of sound (when the acoustic pressure is the same in
all planes perpendicular to the direction of propagation), the instantaneous pressure, p, generated
in a compressible fluid can be described by:
p = ρcu
where ρ equals the fluid density, c equals the speed of sound, and u equals the particle velocity.
Acoustic pressure is typically measured as the root-mean-square (RMS) pressure average over
the duration of the sound. For impulsive sound such as pile driving strikes or biosonar clicks, peak
sound pressure (the range from zero to the greatest pressure of the signal) or peak-to-peak sound
pressure (the range of the most positive to the most negative pressure of the signal) are often
reported instead, since it is difficult to define an appropriate duration over which to average the
signal’s pressure (Madsen, 2005). Pressure is typically reported in units of pascals (Pa) or
micropascals (μPa). In a plane progressive wave, sound intensity is described by the sound power
per unit area and is a product of the sound pressure and particle velocity by
I = pu
and substituting u from first equation, intensity of the sound, I, is related to p by
I = p(p/ρc) = p2/ρc
where p is the RMS pressure average over the duration of the sound. Intensity is typically reported
in units of watts per square meter. Sound levels are most often described in units of decibel (dB),
which is traditionally defined as a power or intensity ratio. Sound intensity level in decibels is as
follows:
dB = 10 log10 (I1/I2)
where I is the intensity of the sound of interest and I2 is a reference intensity. In the case of a plane
wave, sound pressure which is typically what is measured by a microphone or hydrophone may
also be used to measure the sound’s magnitude in dB. Because sound intensity is proportional to
pressure squared, sound pressure level (SPL) in dB is given by
dB = 10 log10 (p12)/( p22) = 20 log10 (p1/ p2)
where p1 is the pressure of the sound of interest and p2 is typically the standard reference pressure
for a given medium. In water the reference is usually 1 μPa. SPLs in this document are referenced
to the underwater convention (re 1 μPa) based on RMS measurements unless otherwise noted.
This reference pressure is different from the standard used to measure sound pressure levels in
air. Thus a dB (re 1 μPa) underwater is not equivalent to a dB (re 20 μPa) measured in air. Pulsed
sounds such as explosions, seismic air gun pulses, or pile driving impacts are often measured in
terms of their energy and not just pressure or intensity. Energy measures include time as a
dimension and are also used to quantify sound exposure when both amplitude and duration of
exposure is important. Energy is proportional to the time integral of the pressure squared and in dB
sound exposure levels (SELs) has the units of dB re 1 μPa2s.
Comparison of sound intensities measured in air and water
Direct comparisons of sound intensity levels measured in air and water cannot be made, unless
levels are adjusted to take into account:
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the differences in acoustic impedance between air and water (cwater =1.5x106 and cair
=4.15x102) and
the differences in reference pressures used for air and water (pref water = 1μPa and pref
air = 20μPa).
However, although the physics behind these adjustments is correct it may not reflect the
complexities of marine mammal hearing.
The difference between a Sound Intensity Level measured in water and in air is:
26dB + 36dB = 62dB
Therefore if a SIL is measured in air it has been proposed that its equivalent SIL underwater might
be achieved by adding 62 dB, and, conversely if a SIL is measured in water, subtract 62dB from its
value to get its equivalent value in air.
However, this may be a risky comparison because the mechanisms leading to damage in the ear
underwater may be significantly different to those in the air.
Model description
The acoustic modelling approach is based on the equations of propagation of underwater noise
and the simplistic model published by WDCS in Oceans of noise. The model is called Source Math
Receiver Model.
The basic parameters of this model are:
 Source: the noise source, e.g. ship, sonar etc. Parameter of interest = source level (SL)
 Path or medium: the water column. Parameters of interest include transmission loss
(TL), and ambient noise level (NL)
 Receiver: e.g. whale, hydrophone etc. Parameters of interest include signal to noise
ratio (SNR), received sound intensity level (RL) and detection threshold (DT). A simple
model of sound propagation is:
RL = SL −TL
Where RL is the received level, SL is the source level and TL is the transmission loss.
Model parameters
Transmission Loss (TL)
Transmission loss is the decrease in intensity of a sound as it propagates through a medium, and
is the result of spreading, absorption, scattering, reflection and rarefaction. Transmission loss can
also be estimated by adding the effects of geometrical spreading (TLsp), absorption (TLa) and the
transmission loss anomaly (A). The transmission loss anomaly includes scattering loss and losses
due to reflection and rarefaction at boundary interfaces.
TL  Tlspreading  TLabsorbition  A
For simplicity we'll only deal with spreading (TLsp) and absorption loss (TLa):
TL  Tlspreading  TLabsorbition
Tlspreading
is a major component of transmission loss and is range (distance) dependent. Two forms
of spreading loss are common underwater:

Spherical or Geometrical spreading loss (TLg), and
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Cylindrical spreading loss (TLcy).
Spherical or Geometrical spreading loss (TLg)
Spherical spreading loss assumes a uniform or homogenous environment that is typical of deep
waters (>2000m). Sound from a point source will spread outward as spherical waves, and intensity
varies inversely with the square of the distance from the source:
 R
Tl g  20 log 
 Ro  R  R1
Where R is the range in metres of the receiver from the source and R0 is a reference range,
usually 1m.
With spherical spreading, sound levels decrease by 6dB if distance is doubled and by 20dB when
distance increases by a factor of 10. R1 is the range in metres at which spherical spreading stops
and cylindrical spreading begins.
Figure 7-19
Spherical spreading
Note that for spherical spreading to occur, R1 > R (from Oceans of Noise, WDCS 2004)
Cylindrical spreading loss
Cylindrical spreading is appropriate when the medium is non-homogenous. Non-homogenous
mediums are typical of stratified or shallow coastal waters (<200m), where sound is reflected or
refracted off the sea surface and seabed or off different density layers according to Snell's law.
At a given distance from the source, which is long in comparison to the water depth, various
reflected waves combine constructively to form a cylindrical wave front. Where cylindrical
spreading occurs, sound intensity varies inversely with distance from the source:
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 R
Tlcy  20 log R1  10 log 
 R0 
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R  R1
Cylindrical spreading is applicable where the range of the receiver from the source is greater than
the depth of the water column or density layer, i.e. for R > R1. Where R1 is the range in metres at
which spherical spreading stops and cylindrical spreading begins. For ranges R < R1, TL is
spherical. Spreading loss for cylindrical spreading (R > R1) is less than for spherical spreading (R <
R1), and sound intensity decreases by 3dB if distance doubles and by 10dB when distance
increases by a factor of 10. Therefore, a sound source generated in shallow coastal waters or
estuaries travels twice the distance of an equal sound source in the open ocean.
Figure 7-20
Cylindrical spreading
Note that for cylindrical spreading to occur, R1 < R (from Oceans of Noise, WDCS 2004).
Absorption loss
The model applied considers the following equation for TLabsorbition (Richardson et al. 1995):
TLabsorbition = α R
where α is the absorption coefficient
R is the distance from the source.
α is the result of a complex function of frequency of sound and of salinity, temperature, depth and
pH of water. The following chart shows the trend of the absorption coefficient (in dB/km) as a
function of frequency in typical sea water (Ainslie & McColm 1998).
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Figure 7-21
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Absorption coefficient in sea water depending on frequency
It is clear that the contribution of absorption is negligible at lower frequencies, especially when
compared with spreading loss. Absorption coefficient becomes significant at about 10 kHz,
reaching 1 dB/km, and becomes predominant above 100 kHz, when it reaches 100 dB/km.
Sources definition
The design of the drilling rig and local oceanochartic conditions will affect both the path of the
sound into the water column and how much sound is transmitted.
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Figure 7-22
Sound transmission pathways associated with a fixed platform
Note: (1) Diesel engine/generator exhaust port, (2) Vibration through legs into the water, (3) Vibration through drill string
and casing, (4) Vibration into the seabed, (5) Vibration of drill bit, (6) Noise from helicopters and vessels (Oceans of
noise, WDCS 2004).
The following sources of underwater noise have been identified as potentially important:
 2 support vessel
 1 semisubmersible drilling rig
The present study will simulate noise emissions during the drilling activities considering the ones
generating higher emissions for a defined time period. Data on noise emissions are based on
typical examples of semisubmersible drilling rig (during drilling) and support vessel as described by
P. D. Ward, 2013.
Table 7.21
Construction activities noise sources
Supply ship
Semisubmersible
drilling rig (drilling)
LeqA dB re 1 µPa-m
broadband
1/3 octave band centre frequencies (kHz)
0.1-10
0.05 0.1 0.2 0.5
1
2
4
8
16
32
172
140 158 158 160 157 158 157 155 152 150
170
120
115
105
100
90
85
80
75
70
65
64
146
55
Noise source have been considered in deep waters (1000 meters). These assumptions allow the
use of spherical propagation described above for assessing impacts on receptors located at
distances smaller than the depth of the sea floor (1000 meters from the source), at R < R1. The
spherical model is a better and cautionary approximation also at greater distances, whereas the
cylindrical model is not appropriate at this depth and underestimates impacts when compared with
the spherical one. The spreading loss assumes the trend showed in the following chart (Spence
2006).
Figure 7-23
Spreading loss depending on source distance
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Noise sources have been represented like a unique point source that emits the sum of the single
emissions of the 2 supply ships and the submersible rig during drilling. Table 7.22 shows the level
of the emission sources, and the level assumed for the calculation (logarithmic sum of the levels).
Table 7.22
Level of the noise emission assumed for calculation
Semisubmersible
Supply ship (x2)
Model source
Figure 7-24
broadband
170
172
176.2
0.05
120
140
143
0.1
115
158
161
0.2
105
158
161
0.5
100
160
163
1
90
157
160
2
85
158
161
4
80
157
160
8
75
155
158
16
70
152
155
32
65
150
153
Sources as defined for the simulation
It is clear that the contribution of the semisubmersible rig to the total noise is negligible.
64
55
146
149
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Simulation results
Model results are represented in Figure 7-25 below.
Figure 7-25
Pressure levels versus distance from the source in terms of emissions, for broad
band frequencies, considering spreading loss
Considering broad band emission equal to 176.2 dB re 1 µPa, pressure levels fall below the 100
dB re 1 µPa at about 6 km from the source. This issue, however, is the sum of the contributions of
each frequency over the entire frequency band, and does not take into account the effects of
absorption, which is strongly dependent on frequency. In order to evaluate the impacts on marine
life it is necessary to study the levels of pressure in the frequency range of hearing of the species
analysed.
Figure 7-26 shows the pressure levels versus distance from the source, in terms of emissions for
different frequencies in the band of 1 / 3 octave, considering the attenuation due to absorption.
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Figure 7-26
Pressure levels versus distance from the source in terms of emissions, for each 1/3
octave frequency band, considering spreading loss and absorption loss
An analysis of the chart shows that the decay of pressure over distance from the source is much
faster for higher frequencies. Differences in plots at lower frequencies are mainly due to
differences in starting level of emission from source, but absorption plays an important role at high
frequencies. Levels of 80 dB re 1 µPa are achieved at less than 4000 meters for frequencies
above 16 kHz. In parachart estimation of the impacts, will be addressed further the contribution of
each frequency on the disorder of the main marine species present in the study.
Marine mammal use of and responses to sound
Marine mammals produce a variety of sounds and use hearing for communication, individual
recognition, predator avoidance, prey detection and capture, orientation, navigation, mate
selection, and mother-offspring bonding. At most frequencies, the ear is the most sensitive detector
of acoustic energy although some evidence indicates that humans are affected by low-frequency
sounds below their hearing threshold. In most marine mammals that have been tested, the best
hearing sensitivity appears to correspond to the presumed primordial ocean background noise at
any given frequency. This seems a reasonable limit because greater sensitivity may not convey an
additional advantage. Beluga whales can detect the return of their echolocation signals when they
are only 1 dB above background and grey whales can detect the calls of predatory killer whales at
0 dB above background. Whether anthropogenic sounds are detected at the low levels associated
with detection of prey and predators is not known and likely varies with factors such as species and
habitat. Marine mammals have adapted to varying levels of natural sound, and the adaptive
mechanisms may allow them to function normally in the presence of many anthropogenic sounds.
The key question is when; because of its level, frequency, duration, location, or some other
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characteristic introduced sound exceeds the adaptive capacity of marine mammals, causing
physical injury or eliciting physiological reactions, behavioural responses, masking, or other effects,
and thereby posing a threat to individual animals or their populations.
Richardson et al. (1995) define four zones of noise influences, depending on the distance between
source and receiver. The zone of audibility is defined as the area within which the animal is able to
detect the sound. The zone of responsiveness is the region in which the animal reacts
behaviourally or physiologically. This zone is usually smaller than the zone of audibility. The zone
of masking is highly variable, usually somewhere between audibility and responsiveness and
defines the region within which noise is strong enough to interfere with detection of other sounds,
such as communication signals or echolocation clicks. The zone of hearing loss is the area near
the noise source where the received sound level is high enough to cause tissue damage resulting
in either temporary threshold shift (TTS) or permanent threshold shift (PTS) or even more severe
damage. The different zones are illustrated in Figure 7-27 below:
Figure 7-27
Zones of noise influence (Richardson et al. 1995)
Behavioural responses—At the detection threshold, or at some level above that, sound may
evoke a behavioural response. Examples of behavioural responses include changes in habitat use
to avoid areas of higher sound levels; diving and surfacing patterns or direction of movement; and
vocalization intensity, frequency, repetition and duration (Richardson et al. 1995). Some of these
behavioural responses may affect vital functions (for example, reproduction, feeding). It is often not
clear whether such changes are significant (where significance is defined as having a measurable
impact on either an animal’s reproduction or survival or a population’s status).
Masking—Masking occurs when a sound is more difficult to heard because of added noise
(Southall et al. 2000). In this case, an animal’s behaviour may be affected because it is not able to
detect, interpret, and respond to biologically relevant sounds. Masking may occur at received
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levels less than those required to stimulate observable responses and therefore may affect marine
mammals at greater distances from the sound source than those at which the animal shows a
behavioural response.
Physiological reactions—Exposure to sound energy may result in a range of physiological effects
in marine mammals. The auditory system is thought to be the most sensitive to sound exposure,
but sound exposure also may cause non-auditory physiological effects such as stress and tissue
injury.
Exposure of marine mammals to high intensity sound may cause a temporary threshold shift, or a
temporary loss of hearing sensitivity A reduction in sensitivity is the usual response of a
mammalian sensor exposed to an intense or prolonged stimulus and, within limits, is reversible.
Nonetheless, because of the importance of sound in the daily lives of marine mammals, even
temporary threshold shifts have the potential to increase an animal’s vulnerability to predation,
reduce its foraging efficiency, or impede its communication.
Physical injury—Permanent threshold shifts—or permanent loss of hearing sensitivity—can result
when animals are exposed even briefly to very intense sounds, over a longer duration to
moderately intense sounds, or intermittently but repeatedly to sounds sufficient to cause temporary
threshold shifts. Permanent threshold shifts result in the loss of sensory cells and nerve fibers. In
terrestrial animals, temporary reductions in sensitivity of about 40 dB have been required to cause
permanent threshold shifts. To date, temporary shifts of only about 20 dB have been induced
experimentally in marine mammals, which is much less than required for a permanent shift if
marine mammals respond similarly to terrestrial animals.
Ecological effects—Ecological (indirect) effects may occur if ecologically related species are
affected by anthropogenic sound, thereby changing the nature of their relationship with marine
mammals or the structure of the affected ecosystem. The best-studied indirect effects suggest that,
in some cases, seismic activity may cause a decrease in the number of fish in the survey region. If
and when such effects occur, they may reduce the foraging efficiency of marine mammals,
potentially compromising their growth, condition, reproduction, and survival.
Population effects—The effects of sound on marine mammal populations are uncertain. Sound
has not been considered a factor in several major declines over the past few decades involving
pinnipeds and sea otters, species more easily monitored than cetaceans. Abundance and trends of
cetacean populations often are poorly known and difficult to monitor; many populations could
decline by half without such loss being detected
Cumulative effects—Effects that are individually insignificant may become significant when
repeated over time or combined with the effects of other sound sources. Baleen whales, for
example, use low-frequency sound for communication and therefore may be affected by both
seismic airguns and shipping noise. Similarly, the effects of sound may interact additively or
synergistically with the effects of other risk factors. Beluga whales, for example, may be
compromised in their ability to survive and reproduce if climate change has altered the distribution
and availability of their prey, persistent organochlorine contaminants have altered their immune
function and made them susceptible to disease and parasites, and noise from oil and gas
operations, icebreakers, or commercial vessels has caused them to abandon important habitat.
Effect of the identified sound sources on marine mammals
Odontocetes produce rapid series of whistles and high-frequency clicks. Clicks individuals are
generally used for echolocation, while groups of clicks and whistles are used for communication.
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The sounds are produced by passing air through a structure present in the head, similar to the
human nasal cavity, called the phonic lips. When air passes through this narrow passage, the
membranes of the phonic lips are sucked together, causing the vibration of the surrounding tissues
These vibrations can, like those in the human larynx, be unconsciously controlled with great
sensitivity. The vibrations pass through the fabric of the head to the melon, which shapes and
directs the sound into a ray of sound used for echolocation. All toothed whales except the sperm
whale have two sets of phonic lips and are therefore able to produce two sounds independently.
Once the air is passed through the phonic lips, enters the buccal pouch. Hence the air can be
recycled at the bottom of the complex nasal, ready to be used to produce other sounds, or expelled
through the blowhole (Nedwell et al., 2003). The mysticetes have instead a larynx that appears to
play a major role in the production of sound, but lacking the vocal cords. Scientists therefore
remain uncertain about the exact functioning of the mechanism. The process however, cannot be
completely comparable to that of man, as the baleen whales do not have to breathe out to produce
sounds. It is likely that they recycle the air in the body for this purpose. Even the cranial sinuses
can be used to create the sounds, but again, the researchers cannot explain how.
Odontocetes have a valid biosonar or system of echolocation by which they intercept the prey,
mates and any obstacles in total darkness with the sound being able to feel the presence,
distance, shape, size, texture and direction of movement. Some species can produce sounds of
frequencies up to 300,000 Hz. Mysticetes do not have biosonars but produce signals which are
very intense but with low frequency around 20-100 Hz, similar to the "bellows". The signals keep
individuals in touch with each other even at a distance of tens or hundreds of kilometres.
The threshold of hearing is represented through the audiograms, the track that shows the weakest
sound that can be perceived with varying frequency. Figure 7-28 shows the audiograms of some
species of odontocetes.
Figure 7-28
Audiograms of odontocetes species
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All audiograms exhibit the characteristic U-shape form with relatively high threshold above 1 kHz
and with the area of better perception of ultrasound in the frequency > 20kHz.
Comparing the audiogram values with the emission levels at known distances from the source it is
possible to identify the area of audibility of the source. Table 7.23 shows the results of the model
adopted as the SPL at 1 / 3 octave set at distances from the source.
Table 7.23
source
Results of the model adopted as the SPL at 1/3 octave set at distances from the
Distance (m) Broadband
1
176
100
136
400
124
1000
116
10000
96
30000
87
80000
78
0.05
143
103
91
83
63
53
45
0.1
161
121
109
101
81
71
63
0.2
161
121
109
101
81
71
62
Frequency (kHz)
0.5
1
2
163 160 161
123 120 121
111 108 109
103 100 101
83
79
79
73
67
65
63
54
47
4
160
120
108
100
77
61
38
8
158
118
106
98
73
53
20
16
155
115
103
94
65
35
-
32
153
113
100
90
43
-
64
149
108
93
79
-
The chart below (Figure 7-29) shows the attenuated values of noise produced by sources at
different distances compared with an odontocete audiogram produced from the previous figure
(Figure 7-28).
Figure 7-29
Attenuated values of the noise produced by the noise sources at different distances
compared with an odontocete audiogram
SPL on the source simulated at various distances from the source has been compared with the
odontocete species audiogram. Comparing simulation results and odontocetes audiogram, it is
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gathered that the noise emitted from the source may have an impact on the species because the
levels inputted into the environment are above their threshold of hearing for frequencies of
reference.
From these considerations, we also need to identify the levels at which noise becomes a cause of
disturbance (area response) or even damage (TTS). Several studies describe levels of SPL-related
behavioural responses of different species of cetaceans. In particular Nedwell et al. (2003) define
the threshold of hearing dBht, the value for which are made of behavioural responses in cetaceans
are at a higher level of the threshold of hearing of 75 dB for small responses and 90 for strong
reactions.
Referring to these considerations parameter, you can locate the area of response by adding 75 dB,
and the area of damage by adding 90 dB at the audiogram previously estimated. It should be
emphasized that this analysis is completely deterministic because the threshold for listening dBht
was postulated from studies on humans and fish, and on which the authors have declared a need
for further assessment and analysis, supported by empirical evidence that the time of the study
were not available.
Figure 7-30 shows an indication threshold levels of listening to low noise and high noise according
to the criterion defined by Nedwell et al. (2003) to get the results of the model based on an
evaluation criterion.
Figure 7-30
SPL generated at various distances from sources, compared with threshold levels of
hearing of odontocetes, depending on frequency
An analysis of the figure shows that following the criterion of dBht, 1/3 octave band levels fall below
the mid disturbance threshold of odontocetes outside a radius of 100 m from the source; at
reasonably low distances the hypothesis of damage is therefore skirt.
More information can be deduced by analysing in detail the single species such as bottlenose
truncatus, wide-spread in the Gulf of Guinea. Truncatus bottlenose dolphins, whose audiogram is
shown below, has the ability, typical of dolphins, to perceive the signals covered by a background
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noise The ability of dolphins to detect signals embedded in noise is measured using two
parameters: masking band (MB) and critical ratio (CR).
Figure 7-31
Audiogram of Tursiope truncatus (Johnson, 1967)
MB defines the frequency range able to mask a pure tone. Noise at frequencies outside the MB will
have little effect on the detection of the tone.
The frequencies of communication of bottlenose dolphin (Tursiope truncatus) are shown in Table
7.24 below:
Table 7.24
Dolphin vocalisations (MCIWEM 2006)
Sound type
Barks
Whistles
Clicks
Frequency
range (kHz)
0.20-16.0
0.80-24.0
0.10-300
Dominant
Frequencies (kHz)
Source level
(dB re 1 µPa at 1m)
3.5-14.5
15.0-130
125-173
218-228
CR is a comparison of the signal power required for target detection versus noise power. MBs tend
to be a constant function of the CR throughout an animal’s functional hearing range.
Based on CR and masking bandwidth data, odontocetes, including bottlenose dolphins, are better
than most mammals at detecting signals in noise. Johnson (1968) estimated masking bandwidths
from the CRs of bottlenose dolphins. Between 5 and 100 kHz, MBs appeared to be less than 1/6octave width and rose to approximately 1/3-octave width at 150 kHz. Source noise has the
potential to mask dolphin vocalizations over a significant distance. Both these sounds will attenuate
over distance, and masking will be determined by their levels relative to each other.
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SPL in function of distance compared with Bottlenose dolphin audiogram
Fewer studies have been conducted on the ability of mysticetes to hear sounds than on that of the
odontocetes (Richardson et al., 1991), and therefore there are no reliable audiograms available in
the scientific literature. Erbe (2002) did, in any case, extrapolate information on the hearing
sensitivity of some mysticetes from the available literature. There is evidence of the presence of
mysticetes in waters interested by the project, mainly Bryde’s whale (Balaenoptera brydei) and
humpback whale (Megaptera novaeangliae). Erbe reported an optimal hearing sensitivity
frequency range of 0.07-0.9 kHz for Bryde’s whales and a general sensitivity range of 0.02-10 kHz
(with optimal in range 2-6 kHz) for humpback whales. Similar values apply to other species; clearly,
mysticetes are sensible to much lower frequencies when compared with odontocetes, though
precise audibility and disturbance thresholds are not available.
Malme et al. (1985) showed that individuals of Megaptera novaeangliae exposed to a simulation of
the noise produced by platforms and semi-submergible drilling systems do not show avoidance. In
another study about bowhead whale (Balaena mysticetus), Richardson & Malme (1993) showed
how the noise produced by a drilling platform can be heard from a distance no greater than 2km
from the source, close to the edge of the platform and under typical conditions of low frequency
ambient noise. A later study clarified that the spatial extent of the area avoided by the marine
mammals is between 500m and 1 km and that once the noise source is removed, the marine
mammals return to the area they had previously abandoned. This makes us think that the effects
on their behaviour are reversible (Davis et al., 1987).
Though we lack the data needed to conduct an in-depth study of perceived sound level over
frequencies and distances, by examining case studies we can roughly assume that the disturbance
threshold of mysticetes will not be reached outside a radius of 1 km from the source; at reasonably
low distances the hypothesis of damage is therefore skirt.
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Summary
It is difficult to predict which species will be most vulnerable to man-made noise because of the
wide range of individual and population sensitivities as well as differences in wariness or
motivation. Currently, it may only be possible to make generalizations about the vulnerability of
species groups based on behavioural observations of responses to manmade sounds, habits and
what is known about a species’ auditory sensitivity or vocal range.
The potential impact of underwater noise as a result of the proposed drilling activities on marine
mammals is therefore assessed to be of medium significance (see Table 7.25).
Table 7.25 Significance of impact of underwater noise on marine mammals.
Consequence
Duration
Extent
Magnitude
Medium term
2
Local
1
Medium
2
7.5
No. of elements
involved
Small
2
Score
7
Probability
Significance
Definite
MEDIUM
IMPACTS ON THE SOCIO-ECONOMIC ENVIRONMENT
Given the offshore nature and activities of the Project the main potential social impacts that may be
identified are increased marine traffic, disturbance to fishing activities and the macroeconomic
impact of Government revenue generation. Another likely impact is that local communities develop
perceptions and expectations on the project’s potential to generate economic opportunities; these
are generally far greater than actual opportunities created.
This qualitative identification of potential impacts is based on secondary sources (not directly
commissioned fieldwork), including those data provided in previous environmental, social and
health studies, bibliographic sources, computer databases, GIS data and satellite imagery, etc.
Scope of Assessment and Limitations Encountered
In defining the scope of the impact assessment, there are a few considerations to be made which
influence the elaboration of the assessment of impacts on socio-economic and anthropic activities.
These considerations and limitations are hereby outlined.

Socio-economic and health impacts are not easily objectively measured and therefore
often need to be inferred rather than measured. A combination of insight into social
processes in general and a thorough knowledge of the affected communities are
important in order to draw valid inferences;

Communities are dynamic and often in a continual process of change. The proposed
OCTP Block development project is one factor contributing to this change, but it is often
difficult to identify when an impact is solely attributable to the Project or to other factors
(or a combination thereof);

Human beings are naturally continuously adapting to changes in their environment,
including project impacts. As such, over time these impacts change in significance for
those affected;
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7.5.1

Project operations are located offshore and will therefore imply few direct interactions
with other human activities, exception made for limited numbers of other marine users
operating in the area; among these commercial vessels

Majority of the deepwater offshore infrastructure will be transported to the field by sea
from international locations, and the shore base operations in Ghana will be limited to
routine project support, supply runs, equipment and materials storage, and treated
waste handling;

Information on how the government would use the revenue that would accrue to them is
not defined and is outside the control of the project so the direct socioeconomic benefits
cannot be fully determined in this E(SH)IA;

Finally, social impacts may often prove unavoidable for a given project design or
approach, and as such, mitigation strategies should be regarded as strategies to
manage change rather than as a means to avoid an impact.
Disruption of Economic Livelihood Activities
The presence of exclusions zones in effect around the drilling unit, FPSO, as well as the
movements of supply and support vessels, may impede access to fishing areas and disrupt
navigation by fishing vessels utilising the offshore region in the vicinity of the offshore
development.
Any impacts on the ability of fishing and other vessels to operate normally may lead to a loss of
income or indirect financial costs (in the case of damaged gear) and, for artisanal fisherman in
particular, decreased food security, which is of concern in the region where coastal communities
are reliant on subsistence fishing. Moreover, past interviews with local stakeholders, including
fishing cooperatives, revealed that people have developped the belief that dredging and oil industry
activities already existing in the region lead to decrease in fish catches.
However, considering that local fishing activities are practiced closer to shore with respect to the
FPSO’s offshore position, disturbance to artisanal fishing activities may be considered negligible.
Disturbance is more likely to occur in respect to larger fishing vessels (e.g. Tuna fishing activity).
However, here too the impact may be considered of moderate significance as the safety exclusion
zone around the Project structures constitutes a minor reduction in the available fishing ground
within the Ghanaian EEZ.
The assessment of the impact of disturbance to fishing activities and the consequent disruption of
livelihood resources is further and fully developed in the annexed Fisheries Impact Assessment.
With regards to the other marine related livelihood resource in the AOI, namely tourism,
considering the distance of the OCTP Block from shore and coastal tourism infrastructure, impact
on tourism may be considerable negligible in relation to Phase 1 activities of the project.
Table 7.26
Significance Assessment of disruption of fishing activities
Consequence
Duration
Extent
Magnitude
Long term
3
Local
1
Medium
2
No. of elements
involved
Small
2
Score
8
Probability
Significance
Possible
LOW -
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7.5.2
Increased Government Revenue
Oil and gas production from the proposed OCTP Block Phase 1 project will contribute to Ghana’s
economy through taxes, royalties and other fees that eni Ghana and all other members of the Joint
Venture would have to pay to the government of Ghana. In addition the Government will receive
further revenues through other taxation such as personal income tax and withholding duties on
imported services paid by employees, contractors and supporting services to the Project. This
would all contribute to Ghana’s oil and gas revenue, increase Gross Domestic Product (GDP) and
generally benefit the economy at a national scale.
In turn, these revenues generated by the Project increase finance availability of the Government
and could contribute to the Ghanaian economy directly through reducing the balance of payments
with respect to energy imports as well as facilitate the Government’s investment in the Country’s
socioeconomic development, example the development of much-needed infrastructure such as
road network, power grid water network, and waste management facilities, as well as the provision
of social, education and health services, which would be of great benefit to the local communities.
Revenue from oil and gas depend on the on side on world market prices, on the other on good
fiscal discipline in managing these revenues. Consequently, the benefits of oil and gas revenue will
depend on the policies and actions adopted by the Government of Ghana; the use of revenue
received as a result of projects such as the proposed OCTP Block development is the
responsibility of the Government.
To this regard, the level of revenues from the oil and gas industry and transparency on how it is
used was in fact identified as a key issue during stakeholder consultations.
The positive impact of a contribution to Ghana’s economy as a result of the project is assessed to
be of medium significance.
Table 7.27
Significance assessment of Increased Government Revenue
Consequence
Duration
Extent
Magnitude
Long term
3
National
3
Low
1
7.5.3
No. of elements
involved
Small
2
Score
9
Probability
Significance
Probable
MEDIUM +
Employment Opportunities Generation
An increase in local (Ghanaian) employment, either through direct employment in the project or in
secondary businesses (contractors, suppliers and services providers), has the potential to improve
the socio-economic well-being of employees, their families and their local communities from wages
and other benefits. There will also be minor benefits to the wider economy through income taxes
paid by employees and spending of earnings. In general, the oil industry is not a large employer,
especially after the project installation phase, in relation to the revenues it can generate, therefore,
the spread of money through wages into the wider local economy is less than that experienced for
similar sized industries such as manufacturing or service-based industries. Therefore, although
there are expectations amongst the local communities (as per stakeholder consultations outcomes)
with regards to employment opportunities as a result of the project, it is not anticipated that the
project will result in a significant number of opportunities.
In addition, it is expected that most of the jobs created by the project (in particular direct
employment opportunities) will most probably be skilled/professional level jobs and it is highly
unlikely that these skills will be available in the local community. Despite the fact that the creation
of any employment opportunities in the Western region was stated as highly desirable, the OCTP
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Block project in its offshore phase is not expected to create many new employment opportunities
(direct, indirect or induced) in the Ghana economy.
Therefore, while employment is generally a positive benefit there is the possible negative effect
that due to lack of certain specific skilled labour to meet the particular staff requirements of
offshore development projects and the relatively low numbers of staff required, the Project is
unlikely to meet the high community expectations of employment opportunities (as expressed
during Stakeholder consultations).
Nevertheless, there are other associated positive impacts. The skills developed through training
received and experience gained when employed in the oil and gas sector will be transferred to
other sectors of the economy and will provide positive benefits. It will also make Ghanaians more
competitive in the international market place, facilitating increased opportunities and skills transfer.
Moreover, formal employment is generally speaking more lucrative than many of the economic
activities on which the local communities (particularly in the Soyo region) currently relies and a
reliable regular income would increase financial security and material wealth, and improve the
ability of the employees to better their standards of living, invest in their future and access better
health care and education.
Overall the impacts from direct and indirect employment will be long term, localised and relatively
small scale and therefore assessed as being of Low significance
Table 7.28
Significance assessment of employment opportunities generation
Consequence
Duration
Extent
Magnitude
Long term
3
National
3
Low
1
7.5.4
No. of elements
involved
Very small
1
Score
8
Probability
Significance
Possible
LOW +/-
Procurement of Goods and Services
The majority of the fabrication work for the FPSO will be undertaken with material sourced from
international markets. Installation offshore will be carried out using specialist contractors and
vessels also from sources outside Ghana. During the project lifetime there will, however, be local
procurement of goods and equipment (i.e. food, fuel, chemicals and other consumables), logistics
support (i.e. drivers, supply vessel crew, and plane and helicopter support, pilots and cabin crew),
and services (i.e. onshore administrative support, accommodation staff, security, catering,
cleaning).
Impacts from procurement of goods and services are likely to be positive through stimulating small
and medium sized business development with investments in people (jobs and training) and
generation of profits. Business investment in new and existing enterprises that provide goods and
services can provide the basis for their longer term sustainable growth as they diversify to provide
goods and services to other industries. Secondary wealth generation from the development and
use of local providers of goods and services can be reasonably expected to have a positive impact
through the generation of revenue able to flow into the local economy.
Positive impacts will be long term, but relatively small scale and localised and are assessed as of
Low significance.
Table 7.29
Significance assessment of Procurement of goods and services
Consequence
Duration
Extent
Magnitude
No. of elements
involved
Score
Probability
Significance
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Long term
3
7.5.5
National
3
Low
1
Very small
1
8
Possible
LOW +
Increase in Marine Traffic
Figure 7-33Figure 7-34 present data on current commercial vessel movements (showing general
shipping lanes) and fishing vessel distribution off West Africa and the Ghanaian coast respectively.
Figure 7-33
Shipping Lanes off West Africa
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Figure 7-34
Fishing vessel distribution off coast of Ghana
While the exclusion zones around fixed-position vessels involved in the field development (i.e.
drilling units, FPSO) are intended to prevent collisions and reduce risks, the movement of support
and service vessels associated with the Project could present hazards to other vessels that cross
their paths, increasing the risks of collisions that could cause damage and/or injury, in particular
during the installation of the Project as more significant numbers of vessels will be involved.
Instead, during routine operations just two vessels will sail in and out of Takoradi port on a daily
basis.
Moreover, the exclusion zones and increase in marine traffic associated with the proposed
development, may require that any vessels that usually pass through the area to re-route to avoid
it. This is essential for safety of life at sea, but could marginally affect commercial activities and
livelihoods of vessels utilising the areas in the vicinity of the offshore development.
It is foreseen that established shipping lanes, particularly in approaches to harbour and in heavily
travelled coastal waters, as well as standard vessel navigation and communication equipment will
be used. Moreover, stand-by vessels and offloading tugs shall be present at the FPSO location.
The set-up of these measures guarantees the reduction in collision risk between project vessels
and commercial and fishing vessels. Furthermore, the larger number of vessels is foreseen during
the brief installation phase and only two vessels are foreseen during the longer operations phase.
Given these considerations, the impact from increased marine traffic is considered to be of Low
Significance.
Table 7.30
Significance assessment of Increased Marine Traffic
Consequence
Duration
Extent
Magnitude
Short term
1
Regional
2
Low
1
No. of elements
involved
Small
2
Score
6
Probability
Significance
Probable
LOW -
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7.5.6
Perceptions and Expectations of Local Communities
With most large development projects, and particularly in the case of offshore oil and gas
developments, expectations from local communities with regard to economic opportunities
(employment or business opportunities) typically far exceed the actual opportunities that will be
created by the project. In addition, while local communities usually bear the brunt of the negative
direct and indirect impacts (such as those discussed above) of a project, the socio-economic
benefits (in the form of contribution to the national economy) do not necessarily filter down to
tangible or perceptible socio-economic benefits to the local communities. This may lead to a
negative opinion of a project proponent in the local communities along the coast, and even to
further damaging to the reputation of the oil and gas industry as a whole.
When asked about the principal problems affecting their communities, stakeholders consulted
identified unemployment, negative effects on fishermen’s livelihood due to decline in fishing catch,
rise in cost of living and need for improved social infrastructure including hospital, roads, sanitation
facilities, water supply, as the key concerns of the local communities. As illustrated by the
discussions in this section, projects such as the OCTP Block development can result in impacts
that raise or exacerbate these concerns. Local communities may therefore perceive these
concerns as attributable to the project, whether they can be directly linked to the project or not.
Furthermore, stakeholders consulted for this ESHIA listed employment opportunities, improved
utilities, health and educational infrastructure, as anticipated socio-economic benefits that would
accrue to the local communities as a result of oil and gas development in the region, and the
OCTP Block development in particular.
Overall, it is therefore highly advisable to adequately address stakeholders and their expectations.
The potential negative impacts as a result of perceptions and unmet expectations of local
communities are assessed to be of Medium significance.
Table 7.31
Significance assessment of perceptions and expectations of local communities
Consequence
Duration
Extent
Magnitude
Long term
3
Local
1
Medium
3
7.6
No. of elements
involved
Great
3
Score
8
Probability
Significance
Probable
MEDIUM -
IMPACTS ON HEALTH
Emissions and discharges as a result of project activities may reduce air and water quality and
increase noise levels which may affect the health of employees. In fact during phase 1 where all
activities are forecast offshore, employees on the offshore facilities are most at risk of the effects of
the health impacts discussed above, but the implementation of standard occupation health and
safety standards, including the use of personal protective equipment (PPE), and adequate training
would decidedly reduce these risks.
Usually, any increase in health risks and decline in the health conditions in any region would
increase pressure on the local health care system. Recent health data on Ghana health services
show that local healthcare providers in the Western Ghana coastal communities are currently
under capacity in terms of equipment, facilities, training opportunities and staff. This also implies
that minimal additional pressure on the local health care system as a result of the proposed project
development could reduce local communities’ access to the weak services. However, it is worth
noting that eni is currently involved in the implementation of a health services development project.
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Moreover, given the offshore nature of the Project in this phase it is possible to consider impacts
on health of local community as negligible or absent.
The overall potential negative impacts on health of employees and local communities are
assessed to be of Low significance.
Table 7.32
Significance assessment of Impacts on Health
Consequence
Duration
Extent
Magnitude
Medium term
2
Local
1
Medium
2
7.7
No. of elements
involved
Small
2
Score
Probability
Significance
Possible
LOW -
7
SUMMARY OF IMPACTS
Hereby provided a summary table containing evaluations of the potential environmental, social and
health impacts of the proposed project.
Table 7.33
Potential
Impact
Identified
Impact on Air
quality
component
Impact on
Water quality
component
Impact on
Sea bed and
marine
subsoil
Impact on
sea bed
Ecosystems
and
vegetation,
flora & fauna
Impact on
noise
component
Disruption of
fishing
activities
Increased
Government
revenue
(contribution
to national
economy)
Summary evaluation of ESH impacts of proposed OCTP Block Development Project
Impact
Characterisation
Direct
Direct
Duration
Medium
term
2
Medium
term
2
Significance Evaluation Criteria
Consequence
N° of
Extent
Magnitude
elements
Score
involved
Probability
Impact
Significance
Local
1
Low
1
Very small
1
5
Definite
LOW -
Local
1
Low
1
Very small
1
5
Definite
LOW -
Direct
Long term
3
Local
1
Low
1
Very small
1
6
Definite
LOW -
Direct
Medium
term
2
Local
1
Low
1
Very small
1
5
Definite
LOW -/+
Direct
Medium
term
2
Local
1
Medium
2
Small
2
7
Definite
MEDIUM -
Direct, Indirect,
Perceived
Long term
3
Local
1
Medium
2
Small
2
8
Possible
LOW -
Direct, Indirect,
Cumulative and
Perceived
Long term
3
National
3
Low
1
Small
2
9
Probable
MEDIUM +
Employment
opportunities
Direct
Long term
3
National
3
Low
1
Very small
1
8
Possible
LOW +/-
Procurement
of goods and
Direct
Long term
3
National
3
Low
1
Very small
1
8
Possible
LOW +
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services
Increase in
marine traffic
Perceptions
and
expectations
of local
communities
Community
Health and
Safety
Direct,
Cumulative
Short term
1
Regional
2
Low
1
Small
2
6
Probable
LOW -
Direct,
Perceived
Long term
3
Local
1
Medium
3
Great
3
8
Probable
MEDIUM -
Indirect
Cumulative
Perceived
Medium
term
2
Local
1
Medium
2
Small
2
7
Possible
LOW -
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MITIGATION AND MANAGEMENT MEASURES
Having assessed the potential impacts all impacts identified shall be considered for mitigation and
control through preventive, mitigative and ameliorative measures; appropriate control and
management measures shall be defined and undertaken according to the significance rating of
each impact
These measures shall be incorporated into the proposed project development to minimize or
completely eliminate the key impacts. The approaches to the mitigation measures include
enhancement (for the positive impacts), prevention, reduction, avoidance and compensation (for
the significant negative impacts).
The mitigation measures for each (significant and adverse) impact of the proposed Project
activities are generally identified based on the associated effect to the environment. The
significance of the impact, probability or likelihood that the impact will occur and the severities of its
consequence (as determined from the risk assessment matrix) constitute the indices used for
determining the mitigation requirements as illustrated in Table 8.1 and Figure 8-1.
Subsequently, the specific mitigation measures satisfying the mitigation requirement were
established putting into consideration available resources and competencies, on-site conditions,
public concerns and technology.
Table 8.1
Impact significance, control and management actions.
Ranking Impact level
4–6
Low
7–9
Medium
10 – 12
High
13 – 16
Critical
Control and Management Actions
Actions in the short
Ensure that policy and control measures are
term
adequate to control the impact
Verify that monitoring and reporting activities are
Actions in the long
properly established to guarantee the correct
terms
application of policy and ensure that control
measures remain adequate
Check if current policy and control measures are
adequate, and revise them according to set
term
appropriate objectives for improvement
Develop adequate plans and activities for control
Actions in the long
measures, ensuring that they are approved and
terms
implemented with timescales set and resources
(budget and personnel) allocated.
Plans and activities are implemented to mitigate
the impact as soon as possible. Interim reduction
term
measures are established.
Long-term plans and activities are developed.
parameters and KPIs are set and properly
Actions in the long
measured, monitored, reported and verified.
terms
Targets are set for improvement and feedback
used for corrective actions.
Immediate emergency measures to reduce
impact. Align the current level of control and
implemented measures to best available practices
to address the issue. Parameters and KPIs are
term
measures, monitored, reported and verified.
Targets are set for improvement and feedback
used for continuous improvement.
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Ranking Impact level
Control and Management Actions
The company demonstrates the delivery of
continuously improved performance through
Actions in the long
Research and Development, technology and
terms
innovation, training of the personnel, strategic
partnership and input and feedback from internal
and external stakeholders.
High
Formal
Control
Physical
Control
Avoidance
Training
Formal
Control
Physical
Control
Informal
Control
Training
Formal
Control
Medium
Low
Low
Medium
High
Likelihood of Occurrence
Figure 8-1
Matrix for determination of mitigation measures
The definitions of the various approaches to impact mitigation to be considered are presented
below.
Enhancement: These are measures proffered to ensure that significant beneficial impacts of the
existing facilities and proposed project are encouraged.
Prevention: These are measures proffered to ensure that significant and adverse potential impacts
and risks do not occur.
Reduction: These are measures proffered to ensure that the effects or consequences of those
significant associated and potential impacts that cannot be prevented are reduced to a level as low
as reasonably practicable.
Formal control: This involves the application of documented policy, process or procedure in
mitigating the impacts of the project activities.
Informal Control: This involves the application of sound judgment and best practice in mitigating
the impacts of project activities.
Physical control: This involves the application of physical processes or instruments (pegs, flags,
sign post etc), not necessarily requiring any special technology, in order to mitigate the impacts of
a project or impacts.
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Avoidance: This involves the modification of plans, designs or schedules in order to prevent the
occurrence of an impact or impacts.
Training: This involves personnel awareness in specific / specialized areas.
Management Procedure for Mitigation Measures
The management procedures to be employed for the establishment of mitigation measures for the
identified impacts are presented in Figure 8-2. Mitigation measures are subsequently proffered for
adverse significant potential impacts. These measures (prevention, reduction, control strategies)
shall be developed for the adverse impacts through review of industry experience (past project
experience), consultations and expert discussions with multi-disciplinary team of engineers and
scientists.
Impact Assessment/Evaluation
Is the impact significant?
Considering:

Health & safety of the people

Pollution / deterioration of the
environment

Damage to asset / property

Proponent’s Image &
reputation
Mitigation / Ameliorative Requirements
Impact Mitigation



Prevention strategy
Reduction strategy
Control strategy
Management Plan



Figure 8-2
Management resourcing
& responsibilities
Monitoring plan
Auditing & review
Management Procedure for Mitigation Measures

Eliminate barriers to prevent adverse effect

Control of escalation factors

Recovery preparedness measures

Lessons from past project experience

Consultations with experts
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IMPACT ASSESSMENT RECOMMENDED MITIGATION MEASURES
This section of the report presents the mitigation (preventive, reduction and control) measures and
alternatives considered to ensure that the associated and potential impacts of the proposed well
drilling, completion and production testing, laying of flowlines, installation of FPSO and installation
of well heads and umbilicals on the ecological and socio-economic environment are eliminated or
reduced to as low as reasonably practicable (ALARP), thus preserving the ecological and social
integrity of the existing environment. These cost effective measures have been proffered with
reference to best industry practice and ESH considerations.
Based on the impact assessment matrix in the previous section, the overall ratings of impact
significance High, Medium or Low were established for each identified impact. The proffered
mitigation measures for the identified potential significant impacts are presented in paragraphs
8.1.1 - 8.1.3 below.
8.1.1
Mitigation of Impacts on the Biophysical Environment
Potential Impact
Emission of
pollutants into
atmosphere
Generation of noise
water into the sea –
Hot waste water
Discharge/availability
of nutrients and
organic matter
Damages to
morphological
structures and
benthic biocenoses
Key recommended mitigation measures
 ensure generators, barges etc are maintained at optimal working condition in
accordance with operating manual;
 ensure application of emissions monitoring and control techniques;
 encourage the use of mufflers on equipment manifold where necessary to filter
particulates and thus reduce its emission into the air.
 ensure all noise generating work equipment and vessels are maintained at
optimal conditions as stated in the equipment operating manual
 encourage the use of equipment with low noise ratings
 encourage the use of mufflers on equipment manifold
 discharge of cooling waters only in surface waters
 limit to minimum necessary the amounts of anti-biofouling used in cooling waters
 ENI Ghana shall develop an appropriate Waste Management Plan before project
commencement
 As a minimum all operational waste shall be separated at source to enhance
efficiency in waste handling and disposal
 Also, training on waste management will be conducted for project site personnel
 The pipeline laying technology is such that will reduce bottom sediments
disturbance and possible loss of benthic organisms;
 The procurement of a drilling rig with dynamic positioning and offline activity for
drilling activities will reduce bottom sediments disturbance and possible loss of
benthic organisms
commencement
 ENI Ghana shall treat all effluents (spent mud, cement, cuttings, etc.) in
accordance with regulatory requirements
 The water-depth and density of organisms present in the area are such that
render the impact negligible
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Mobilisation and
resuspension of
sediments
 The pipeline laying technology is such that will reduce bottom sediments
disturbance and possible loss of benthic organisms;
 The water-depth and density of organisms present in the area are such that
render the impact negligible
structures
 ENI Ghana shall ensure that abandoned well head is properly capped
 Post demobilization checks shall be carried out prior to commencement of
development operations in the area to check incidence of well leaks
 Ensure that pipeline is protected

commencement;
 ENI Ghana shall ensure adequate implementation of the Waste Management
Plan;
 Operators shall be trained on safe handling practice;
 ENI Ghana will ensure proper handling of chemicals.
 ENI Ghana shall employ chemicals with lowest toxicity levels in all its operations
 Material safety data sheets (MSDS) shall be provided for chemicals on site
 ENI Ghana shall treat and discharge all effluents (spent mud, cement, cuttings,
etc.) in accordance with regulatory requirements
Release of pollutants,
biocides and metals
in solution
8.1.2
Mitigation of Impacts on the Socio-economic Environment
Potential Impact
Employment and
procurement of
goods and services
 Preferentially employ Ghana nationals to fill available positions in the OCTP
Block project. Give preference to Ghana nationals with the appropriate skills.
Formalise this policy in eni HR guidelines and contractors’ agreements;
 Train Ghana nationals currently employed by eni so that they can eventually
assume positions/functions in the OCTP Block project initially or currently
undertaken by employees of other nationalities;
 Effectively communicate available employment opportunities, required skills and
resources and training programmes to the local communities in the Soyo region.
Procurement of
goods and services
 Preferentially procure goods and services from Ghana sources, where possible
and subject to reasonable financial criteria;
 Procure resources (such as food supplies) at a local level (Western region), if
available. Formalise this policy in eni’s procurement guidelines and contractors’
agreements;
Disruption of fishing
activities
 Develop, in consultation with the relevant coastal communities, a grievance
mechanism through which fishermen can raise concerns with regard to activities
and their grievances can be addressed;
 Implement mechanisms to compensate individuals who can demonstrate loss of
income due to project activities; and
 Implement measures to mitigate the potential negative impacts on the
biophysical environment, particularly impacts that could negatively impact on the
resources targeted by fisheries operating in the area.
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Potential Impact
Increase in marine
traffic and disruption
of offshore navigation
 Inform local fishermen from the coastal communities of coastal Western regions
of the offshore activities, locations, vessel movements routes and timing;
 Inform other users of the sea about the timing and location of offshore activities
through the issuing of Notices to Mariners;
 Comply with international safety standards with regards to offshore navigation
on all project-related vessels;
 Intercept and redirect any vessels potentially entering designated exclusion
zones;
 Ensure potential conflicts between project-related vessels and other users of the
sea are addressed in emergency response planning.
Increase in
Government
revenues
(contribution to
national economy)
Perceptions and
expectation of local
communities
 Implement mitigation measures to maximise employment of Ghana nationals
and procurement of Ghana goods and services; and
 Encourage and lobby for the responsible investment by the government of oilgenerated revenue, particularly in the Western region.
 Develop and implement, in consultation with local authorities, sectoral
institutions and communities, Corporate Social Responsibility (CSR) initiatives
that identify, evaluate and select a range of opportunities to address the key
concerns of the local communities in line with existing sectoral policies and
plans;
 Effectively communicate available employment opportunities, required skills and
resources and training programmes to the local communities in the Western
region; and
 Ensure on-going consultation with local communities with regard to progress
with the project and changing community needs.
 Acknowledge the authority of the local chiefs in all activities, particularly in eni’s
CSR initiatives;
 Ensure a transparent and appropriate grievance mechanism is in place, whereby
local communities communicate incidents with eni personnel and or
contractors/suppliers visiting the communities;
 Work with the local communities and government to identify local infrastructure
needs, including housing, and support initiatives to improve such infrastructure.
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Mitigation of Impacts on Health
Potential Impact
Community health
and safety
For local Communities:
 Develop and implement, in consultation with local communities and relevant
local authorities and as part of Corporate Social Responsibility (CSR), the
needed Community Health (CH) initiatives that identify, evaluate and select a
range of opportunities to support or invest in increasing the capacity of local
health care systems in the Western region through capacity building,
infrastructure revamping, equipment top up and monitoring/evaluating activities;
Within the fence (in-house):
 Monitor the prevalence of communicable diseases among employees and
contractors, and work with local health care providers if additional measures to
deal with the possible increased risk of communicable diseases to local
communities are required;
 Ensure emergency response plans are in place to deal with all potential
emergencies, including support vessel (and helicopter) and offshore facilities
emergency plans; and
 Prevent/Mitigate the potential impacts of pollution as a result of emissions,
discharge of effluent and waste disposal.
 ENI Ghana shall provide and enforce use of appropriate PPE by worksite
personnel at all times.
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ENVIRONMENTAL MANAGEMENT PLAN
This chapter presents the Environmental Management Plan (EMP) developed for the proposed
project activities. An environmental management plan (EMP) is essentially a management tool and
standalone component of an EIA that provides the assurance that the mitigation measures
developed for the significant impacts of a proposed project are implemented and maintained
throughout the project lifecycle. It outlines management strategies for safety, health and
environment stewardship in the proposed project implementation. It states in specific terms how
the project proponent’s commitments will be implemented to ensure sound environmental practice.
9.1
EMP APPROACH
ENI Ghana has designed the EMP of the proposed project in line with its Health, Safety and
Environment (HSE) policy and in accordance with ISO 14001 Environmental Management System
specifications. The EMP for the proposed drilling project, installation of flowlines, installation of
FPSO and installation of well-heads and SURF systems shall be a “live document” which shall be
reviewed periodically with the incorporation of various mitigation measures for potential impacts
and shall form the basis for the actual project implementation.
Compliance with the legal standards on safety and environment is regarded as the minimum
requirement, and must be satisfied during all phases of the Project development. In order to reduce
the risk of an adverse effect on the environment to the lowest level that is reasonably practicable,
an objective of the engineering design will be to apply the ALARP principle. Figure 9-1 illustrates
this principle graphically.
Figure 9-1
9.2
Level of Risk and ALARP
EMP OBJECTIVES
The EMP is designed to:
 ensure that all mitigation measures prescribed in the ESHIA document for eliminating,
minimizing, and enhancing the projects adverse and beneficial impacts are fully
implemented; and
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
provide part of the basis and standards needed for overall planning, monitoring,
auditing and review of environmental and socio-economic performance throughout the
project activities.
This has been developed to manage negative impacts/effects, enhance benefits and ensure good
standards of practice are used throughout the project. These objectives shall be achieved by:
 ensuring compliance with all stipulated legislation on protection of the biophysical and
socio-economic environment and ENI HSE policy;
 integrating environmental and socio-economic issues fully into the project development
and operational philosophies;
 promoting awareness on the management of the biophysical and socio-economic
environment among workers;
 rationalizing and streamlining existing environmental activities to add value to efficiency
and effectiveness;
 ensuring that only environmentally and socially sound procedures are employed during
the project implementation; and
 continuous consultations with the relevant regulatory bodies, community leaders (local
heads/chiefs, clan heads, landlords, etc), youth leaders, community based
organizations (CBOs), and other stakeholders throughout the project lifecycle.
9.3
STRUCTURE AND RESPONSIBILITY
The implementation of the project EMP will be achieved through a management structure
described in the Organizational chart shown in Figure 9-2.
Figure 9-2
9.4
Environmental Management Schematic of OCTP Block Development Project
EMP IMPLEMENTATION FRAMEWORK
The framework for the implementation of this EMP is strongly based on a repeated process of
continuous improvement which comprises of eleven (11) elements, each with underlying principle
and set expectations.
Overview of each of the eleven primary elements is presented as follows.
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Management Leadership, Commitment, and Accountability: Ensures that the workers
understand the goals and management commitment to excellence in safety, health,
environment, and operational integrity.
Risk Assessment and Management: Ensures that risks involved in operations are
recognized so that they can be appropriately addressed through facility design and/or
operating practices.
Facilities Design and Construction: Ensures elements for the protection of people and
the environment are incorporated into the design of facilities and the plans for
installation and operation.
Process and Facilities Information/Documentation: Ensures that the systems designed
to protect people and the environments are appropriately documented.
Personnel and Training: Ensures that personnel understand the systems that are in
place and are appropriately trained to perform required roles with respect to their
functions.
Operations and Maintenance: Ensures that facilities are maintained and operated in
ways that ensure the protection of people and the environment.
Management of Change: Ensures that new personnel are informed of existing systems
that all affected personnel are informed of changes in the systems, and that safety and
environmental aspects are considered when making changes.
Third Party Services: Through contract, oversight and other mechanisms, third party
contractors are held to the same standards as ENI Ghana.
Incident Investigation and Analysis: Seeks to understand the causes of any incidents so
that effective controls or systems can be implemented to prevent recurrence.
Community Awareness and Emergency Preparedness: Though not highly applicable in
offshore project far removed from communities, ensures appropriate outreach and
awareness programmes are implemented to establish effective emergency procedures
and to allay concerns.
Operations Integrity Assessment and Improvement: Ensures that the safety and
environmental performance is monitored against targets to ensure eni Ghana is
meeting its goals to protect people and the environment and seeks the means to
improve the systems and processes, particularly when goals are not being met.
CORE ELEMENTS OF EMP
In line with the objectives summarized in sections 9.1 and 9.2 above, the main elements of this
EMP are:
 overall project organizational chart (including HSE) organogram;
 preliminary EMP guidelines;
 guidelines for waste management;
 overall safety philosophy/guidelines;
 contingency plan for oil spills;
 environmental monitoring plan;
 guidelines for audit and review;
 guidelines on maintenance and facility management; and
 guidelines for decommissioning and abandonment.
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GUIDELINES FOR MITIGATION MEASURES
The guidelines covering the various project phases, activities/aspects and impacts, mitigation
measures and designation of responsibilities for implementation, were presented in chapter five
and give detailed information on waste management, safety, emergency response/contingency. A
detailed environmental monitoring plan, audit and review as well as decommissioning and
abandonment are presented in paragraphs 9.6.1 - 9.6.10.
9.6.1
Roles and Responsibilities
The roles and responsibilities (HSE) for the proposed OCTP Block Development project include:
Resident Engineer
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
HSE management on the project
Provide visible leadership, systems and resources for environmental management
Initiate action to maintain compliance with requirements
Specify and participate in project audits/reviews as required
Assistant Project Manager(s)

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Review procedures for environmental aspects
Follow up actions from project risk assessments and environmental reviews
Be focal point for environmental matters with subcontractors as required
Participate in project audits/review as required
HSE Advisor
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Be pro-active in promoting HSE
Follow-up /monitor requirements with responsible parties
Provide specialist HSE advice
Facilitate project risk assessment as required
Lead/participate in audits, as required
Maintain HSE Activities matrix and monitor close out of Project Environmental Review
Development of Project HSE documentation
Environmental Lead

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
9.6.2
Provide specialist environmental advice
Jointly monitor project Environmental aspects with Project Team
Review relevant project documentation on circulation by Project Team
Facilitate project environmental review
Lead / participate in audits and inspections as required
Review project environmental documentation
Training and Awareness – Site Induction
All Contractor employees and subcontractors involved in the project will be given a comprehensive
induction before they start work. This environmental training will take place in conjunction with
safety awareness training.
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The environmental aspects will include:
 An overview of the Environmental Management Plan, goals and objectives.
 Awareness in relation to the risk, consequences and methods of avoiding noise
pollution, oil/diesel spills, disturbance to wildlife and disturbance to fisher-folk on the
high sea.
 Awareness of individual environmental responsibilities and environmental constraints to
specific jobs.
 Location and sensitivity of the proposed OCTP Block project.
All personnel who have attended the Environmental Induction will sign a Register which will be
kept on the Project Files. Toolbox talks, based on the specific activities being carried out, will be
given to personnel by the nominated project representative. These will be based on the specific
activities being carried out. These talks will take place either on the appropriate off-shore vessel or
on-site and will include environmental issues particular to the proposed OCTP Block Project,
namely:
 Oil/Diesel spill prevention offshore including safe refuelling practice.
 Emergency response procedures used to deal with an oil/diesel spill.
 Minimising disturbance to wildlife such as cetaceans.
9.6.3
Communications
Environmental issues will be communicated to the workforce on a regular basis. Daily project
meetings, which follow a set agenda incorporating Health, Safety and Environmental issues will be
held on-board the project vessels and a daily report will be generated and distributed.
All staff and sub-contractors involved in all phases of the project will be encouraged to report
environmental issues.
Environmental Reporting
The contractor will report the status of project environmental activities to ENI on a regular basis.
These reports will summarize the key environmental issues in the period and identify any nonconformances and the status of corrective actions.
Communication of Initiatives and Project Information
Communication of initiatives and project information will be developed as the project progresses.
Typically, these will include campaigns to raise environmental awareness, circulars to inform staff
of key environmental issues such as lessons learnt from incidents or accidents and the impact of
any new legislation.
Subcontractor Environmental Reporting
All external communications with local interest groups, external agencies and also the response to
any complaints will be conducted by ENI. Contractors shall notify the onsite ENI representative if
any communications are received from external stakeholders.
9.6.4
ENI Environmental Policy Objectives
Operations have a direct impact on the natural and built environment as such environmental
management is an integral part of this project. All project personnel will be accountable for the
environmental performance of the project.
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Environmental performance will be managed, monitored and improved through the implementation
of this Sustainable Environmental Management Plan and associated Operational Control
Procedures in accordance with ISO 14001:2004 standard.
ENI’s environmental policy is personally endorsed by ENI’s Managing Director and is well
documented and circulated within the system and requires all contractors to manage HSE in line
with this policy.
In line with the ENI HSE Policy commitment to ‘Protect the environment’, ENI and their
subcontractors shall ensure that:
 Impact on watercourses, the aquatic environment, terrestrial habitats and all species
therein are minimized.
 Emissions to the atmosphere will be minimized.
 Environmental legislation applicable to activities undertaken is complied with and
contractual obligations are met.
 Performance is monitored and procedures are reviewed to ensure continual
improvement.
 Companywide awareness of environmental issues is raised.
9.6.5
Environmental Control & Monitoring
Environmental Control Procedures
Operational control is required to ensure the management of all operations and activities
associated with significant environmental aspects, policies, objectives and targets. The required
level of control is achieved through the implementation of approved project procedures which
document the methodology for executing the works. As part of the procedures development and
approval, the methodology is subject to peer review and risk assessment processes which
considers environmental impacts and required mitigation measures. The internal audit process will
check that these procedures are being implemented correctly and that they are effective.
Although project procedures, execution plans and method statements represent the most
significant control mechanism, controls also include communication of company requirements
particularly to subcontractors and suppliers, the provision of health, safety and environmental
training, and carrying out effective checking and monitoring. Project procedures will be reviewed
and amended as necessary. The amended procedure will be reviewed to ensure that any new
regulation or training requirements are identified and acted upon.
All activities are required to demonstrate that the Project Team have considered the requirements
of ENI Environmental Policy in the design, construction and installation of the project. The key
environmental goal set for the OCTP Block Development project is that “Discharges and emissions
associated with the development and subsequent production of hydrocarbons from the proposed
OCTP Block project shall be minimized as far as reasonably practicable, and the disturbance to the
environment shall be kept to a minimum”. For the project, this environment goal means minimizing
the impact on Seabed community, marine community (fish, mammals), sensitive uses (fishing etc.),
seawater quality, air quality, etc.
The stated goal shall be achieved primarily through minimizing pollution (‘reduction at source’) by
the effective control of all operations and the monitoring of the potential sources of impact to
ensure that the legislative and regulatory limits are maintained and also to track the progress
towards the environmental targets.
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Monitoring and Reporting
Environmental monitoring is essentially a process aimed at detecting negative impacts of a project
on the environment early enough to take remedial actions. ENI representatives on-board each
Contractors vessel will be responsible for routine day-to-day monitoring of environmental
compliance and shall submit the environmental data for all HSE and community relations aspects.
Environmental Performance Monitoring
The environmental concerns identified will be controlled through adherence to the Environmental
Operational Control Procedures, Method Statements and recommendations. The project will be
monitored by inspections of work activities and internal auditing. The HSE Advisor shall work with
ENI to assess the need for further monitoring.
Monitoring Objectives
The activities of the proposed project have such characteristics:
 The water depth (about 1000 m) make little or non-significant the protocols frequently
used for the physical examination, chemical, biological and sediment monitoring.
 benthic community at those depths is very simplified and uniform and according to both
a temporal and spatial point of view; the distance from the surface and the currents
along the water column (potentially very large and not known) does not ensure that the
benthic community located near the means of drilling is the most affected by the
discharge of water, cuttings or other contaminants.
 Regarding to the water column, an examination of the physico-chemical and biological
parameters do not provide useful assessment of the state nor the quality of the water
column itself (the change is very fast) nor induced impacts from activities project (for the
same reasons described above, the effects could be spread in huge areas currently not
identified).
In addition to the measures that will be defined to monitor possible impacts on the surrounding
environment in particular in relation to the fisheries activities, the post-operation monitoring shall
involve a check of the implementation of the EMP on the environmental performance of facilities
(waste management, wastewater systems, oil consumption and atmospheric emissions, etc.), via
audits and inspections.
Performance Indicators
Table 9.1 shows the parameter monitored in audits and the relative performance indicators are
provided.
Table 9.1
Monitoring Impact Indicators
Parameter
Diesel consumption
Electricity generated
CO2 emission
Unit of measure
Kg
kWh
Kg
CH4 emission
Kg
SOx emissions
Kg
NOx emissions
Kg
Waste generation
Water consumption
Kg
Litre
Performance indicator
Kg diesel / kWh
Kg CO2 / kWh
Kg CH4 / kWh
Kg CO2eq. / kWh (Global
Warming Potential)
Kg SOx / kWh
Kg NOx / kWh
Kg SOx eq. (Acidification
Potential)
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Environmental Audit
eni Ghana shall conduct periodic HSE audits (monthly / quarterly / annually, etc) of the oil wells
activities in OCTP Development project Area in order to ascertain extent of compliance with policy
and regulatory requirements. The audits shall be carried out by certified auditors and in
accordance with ISO 14001 guidelines. The scope of the audits must include the following, as a
minimum:
 compliance with all necessary codes, standards and procedures;
 examine line management systems, plant operations, monitoring practices etc.;
 identify current and potential environmental problems especially during the operational
phase of the project;
 check the predictions in EIA and assure implementations and application of
recommended practices and procedures; and
 make recommendation for the improvement of the management system of the
operation.
 after every audit exercise, the environmental auditor shall produce an Environmental
Audit Report (EAR) which shall be submitted to eni Ghana and the operating contractor.
The audit and inspection frequencies will be established by eni Ghana, and may be increased or
decreased according to the findings and degree of confidence arising from the ongoing audit
program.
All audit findings will be reviewed by the HSE and Community Relations teams and where
corrective actions are deemed necessary, specific plans (with designated responsibility and timing)
will be developed aimed at achieving continuous improvement in performance. In fact, in addition
to assessing operational aspects and monitoring, audits will also assess the effectiveness of the
EMP and its implementation. The EMP will therefore be subject to ongoing review and
development to ensure that it remains appropriate for all aspects of the Project.
9.6.7
Waste Management
Waste Management Strategy
All on-board waste discharge, from vessels, will follow the guidelines from MARPOL 73 / 78 for
domestic waste discharges to the environment.
Solid and Chemical Waste will be treated on-board and recycling will take place wherever
practicable. Incineration of combustible, non-hazardous waste will take place wherever an
approved on-board incinerator is available. Bilge water will be treated on board of vessels in
accordance with MARPOL standards prior to discharge into the sea. All waste discharge will be
monitored & recorded as per vessel procedures. Compliance to this EMP will be monitored
throughout the duration of the project through the project monitoring process.
ENI Policy on waste management
It is the policy of to;
 Adopt effective and responsible measures to minimize the generation of solid and liquid
waste as well as reduce emissions into the air.
 Track and maintain records of the full life cycle of waste streams and provide an
auditable trail as to its management and disposal.
 Manage and dispose all waste in line with relevant regulatory requirements and
environmentally responsible manner.
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Solid Waste Discharge
No solid waste, other than food waste will be disposed of into the sea. Food waste will only be
disposed into the sea, at least 12 nautical miles from the nearest land, after passing through a
dedicated grinder and in accordance with MARPOL 73 78 standards. Any other solid waste that
cannot be incinerated on-board shall be brought to shore for disposal and a record will be kept on
the type and quantities of waste brought to the shore for disposal.
Waste Identification
ENI Marine Wastes Management plan (MWMP) and the Environmental Aspects and Impacts
Register for this project summarize the primary types of waste streams encountered during vessel
operations. Descriptions for typical waste stream, main sources and possible environmentally
significant constituents are also given.
The physical, chemical and toxicological properties of hazardous wastes shall be identified via
Material Safety Data Sheets (MSDS), manufacturer information, process knowledge, and historical
information or lab analysis. Wastes can be grouped according to their health and environmental
hazards.
Waste Minimization
To minimize the quantity of waste to be disposed of onshore, construction vessels where possible,
will be equipped with a food grinder / waste compactor.
On a monthly basis, project vessels will report the amounts of hazardous and non-hazardous
waste generated by the vessels, as per the vessel operators environmental management system.
This data will be used to establish baseline data and targets for improvement.
Onshore Waste Management and Disposal Options
A local contractor / agent will arrange onshore transport and disposal of waste arising from the
project vessels. Any waste that cannot be processed on-board of the vessels will be transported to
the quayside for transport by a permitted waste handler to a permitted/licensed facility, which may
be a Landfill Site or a Transfer Station. Scrap metals and chemical wastes will be transported to
port for reprocessing through approved recycling facilities.
9.6.8
Waste Water Management
Ballast Water Discharge
Ballast tanks will be separated from any hydrocarbon storage areas on board the vessels and no
potentially contaminated drain systems will be routed to the ballast tanks. De-ballasting shall be
undertaken offshore in accordance with IMO guidelines and away from sensitive environmental
areas to prevent introducing marine organisms from outside the project location.
Bilge Water Discharge
All construction vessels will be equipped with oil-water separation systems in accordance with
MARPOL requirements.
Deck Run-Off Water
Any spills on deck will be contained and controlled using absorbing materials.
collected in dedicated drums to avoid contamination of deck run-off water.
This will be
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Sewage Discharge
Vessels and FPSO will be equipped with a sewage treatment system. If a vessel does not have a
sewage treatment system it will have a suitable holding tank, waste water will then be brought back
to shore for treatment by a licensed contractor.
9.6.9
Oil Spill Contingency Plan
Some of ENI’s most important objectives include: Enhancing safety, reducing health risks and
protecting the environment. In light of this, ENI has developed a structured and comprehensive oil
spill contingency plan to cover activities in OCTP Project area.
The oil spill contingency plan outlines coordinated and integrated response actions to be
implemented in the event of an oil spill. It highlights the roles and responsibilities of key personnel
in ENI operations and lists equipment and materials available to combat oil spills. The plan is
designed to cover the control and removal of any oil spill occurring at any of the facilities operated
by ENI. It is a generic plan to be used in conjunction with a separately designed specific
operational annex applicable to the particular project area. The main components of the
contingency plan are namely spill categorization, offshore response action plans, reporting and
notification guidelines.
Pollution Emergency Procedures
On board procedures for pollution prevention and emergency response are laid down in each
vessel Shipboard Oil Pollution and Emergency Plan (SOPEP). Details on project specific (oil)
pollution combat equipment will be available on-board along with locations of equipment,
availability, and contact details for support personnel / services. Each individual vessel will have
regard to ENI Oil Spill Contingency Plan, which contains detailed procedures to be followed in the
event of a pollution emergency.
9.6.10
Safety Philosophy
The Project shall incorporate an Integrated Control and Safety System (ICSS) that shall provide an
integrated monitoring, control, protection and safety system for the entire production, topsides,
marine, and subsea facilities. The safety systems shall be separate from the Process Control
System (PCS).
Fire and Gas Detection
The overall goal of the Fire and Gas System shall be to:
 Continuously monitor all areas of the installation where either a fire hazard may exist or
an accumulation of flammable gas may occur,
 Alert personnel at the CCR to the presence, location and nature of the fire or gas
emergency,
 Alert personnel on board to the hazard via the PA/GA system,
 Automatically activate fixed fire protection systems, and
 Reduce the risk to personnel by implementing executive control actions and/or
shutdown events.
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Lifeboats and Life Rafts
The rig will be provided with life boats on either side of the accommodation having a capacity each
for 100% of the complement. Two 100-persons Totally Enclosed Self Propelled Survival Crafts
(TEMPSC) are installed, one on the port side and the other on the on starboard side. The rig will
also be equipped with a fast rescue boat. The crafts are located and arranged such that boarding
of the units in stowed position will be in accordance with the latest SOLAS requirements. On the
forward main deck area near the turret, on either side, life rafts will be installed in case crew
members cannot return to the accommodation in case of emergency. The number and capacity of
the life rafts will be established by an Escape, Evacuation and Rescue Analysis performed during
detailed design.
Safety Shutdown System
In the event that the primary control system fails to keep the process within specified operating
limits, separate, dedicated safety systems shall be provided for the safe shutdown of equipment
and/or process units. The purpose of these systems shall be; first, to protect personnel from an
abnormal condition; second, to protect the environment and equipment from damage; and third, to
safely isolate problem areas.
Active Fire Protection
The rig shall be sufficiently equipped with fixed automatic, manual and portable fire fighting
equipment. Mechanisms for release of fixed automatic systems shall be:
 Pneumatic fusible plugs for each fire/deluge area;
 F&G input (for inside enclosures);
 Manual buttons in the CCR;
 Manual buttons in local area;
 Remote trips for diesel oil valves, and
 Manual buttons for rotating equipment shutdown and manual released fixed fire fighting
systems.
Accommodation
The living quarters for the rig have a sprinkler system that shall be charged with fresh water and
backup seawater from the ring main.
Helideck
The helideck for the rig shall be provided with two foam hose reels with 0.23 m 3 (60 gallons) of
foam for each reel and deliver foam for a period of 20 minutes.
Electrical Rooms
Rooms containing electrical equipment [transformer room, battery room, high voltage/low voltage
(HV/LV) switchboard rooms and instrument rooms] shall be protected with automatically actuated
non-halon, gaseous fire suppression systems. In addition, portable CO2 extinguishers will be
provided.
Hull Equipment Spaces
None of the hull equipment spaces have oil fuelled machinery and they shall be, therefore, not
‘Category A spaces’ according to safety of life at sea (SOLAS). These compartments shall be
provided with a sufficient number of portable extinguishers and hose reels.
Deluge System
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A pressurized fire water system shall be installed to cover the firewater demand for foam
generation systems, deluge systems and hydrants located throughout the rig.
Water Mist Systems
Fixed self-contained automatic water mist systems shall be used in gas turbine enclosure hoods.
Escape Routes
The general requirement for number and location of escape routes on the rig shall follow the
requirements of specification ‘Facilities Layout and General Operational and Safety Systems. The
EER Analysis contains a more detailed description of the arrangements, which include:
 Main escape routes shall have a minimum height of 2.39 m (7.8’) and a minimum width
of 1.525 m (5’);
 Secondary escape routes shall have a minimum height of 2.1 m and minimum width of
1.0 m (3’-3”);
 Dedicated routes shall be provided to both the helicopter deck and the lifeboats that
allow the transportation of an injured adult on a stretcher from every manned area;
 Two paths of escape shall be provided from every area on the facilities that may be
normally manned. This requirement also applies to enclosed areas and rooms that will
not be continuously manned. However, this does not apply to tanks where normal tank
entry procedure is assigned around tank access. Each tank shall be fitted with a
second access hatch which can be fitted with ladders and access in the event there is
major work required in that space. Smaller rooms/areas where the distance from any
location to the exit will be less than 5 m (16’) may have a single exit, however, all
electrical rooms will have at least two exits; and
 Stairs shall be installed to ensure proper and easy access between all levels of the
facilities. Wherever access shall be needed to a platform or any level below base,
access will, as far as possible, also be performed via stairs.
Means of Evacuation
The primary means of emergency evacuation shall be lifeboats. Escape to sea via life rafts shall be
considered the secondary means of evacuation. If helicopters shall be in the vicinity of the field, it
shall be the decision of the Emergency Incident Coordinator to determine the best means by which
helicopters may be used. The Emergency Incident Coordinator may also instruct the standby
vessel(s) to assist with the evacuation of personnel via the boat landing area or via tertiary means
of evacuation.
Equipment Room Evacuation
Machinery spaces can be evacuated by using the main stairways leading into the space from the
main deck from both the east and west sides. The stairs drop down to the first level of the
machinery space. Escape from the lower levels of each machinery space will also be by stairways.
Deck Escape Routes
There shall be two unobstructed longitudinal escape routes on the main deck. One will be located
on each side of centreline at the outboard edge of the main deck. There shall be also five eastwest or transverse escape routes that join with the longitudinal escape routes at almost equally
spaced intervals. The transverse routes offer at least 7 feet of clearance under the centreline pipe
rack and do not crossover any piping. There shall be one other longitudinal escape route that shall
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be provided on the topsides deck near centreline and can be used for escape along the entire
length of the topsides deck. Stairs shall be provided at intervals along both sides of the deck for
access between the main deck and the process deck.
Personnel caught on deck during a fire can proceed east to west through one of the east-west
escape routes into one of the longitudinal escape routes located farthest away from the fire. The
route taken through the longitudinal escape route shall be either north or south, whichever takes
the trapped persons farther away from the fire or to the closest life boat. Protection against blast
and fire can be provided (for at least 60 minutes) in the North TSR, in the LQ or behind the main
deck blast wall under the LQ.
Each escape route shall be clearly marked, including arrows showing direction of the nearest life
boat.
Muster Areas
The primary muster area on the rig shall have direct access to the life boats and requires a
minimum area of 0.56m2 (6ft2) per person, per specification ‘Facilities Layout and General
Operational and Safety Systems’. Arrangements/location of the muster areas for rig shall be
detailed in the EER Analysis. The study considers the location for the muster area for the rig. The
extent of protection required for personnel mustering will be defined in, based on the hazard
scenarios to which personnel could be exposed; however, the intention will be to use the same
size of lifeboat.
An alternative (backup) muster area will be provided on the rig. The location/size basis will be
based on an analysis of the hazard scenarios for which it may be required. This will be located at
the flare end of the rig. The alternative muster area will be protected from flare radiation and from
the effects of any process hazard scenarios that could impair the muster area.
Based on predicted evacuation times for the rig, primary muster areas will remain intact for a
minimum of 45 minutes in order to allow an orderly evacuation. Protection will be required for this
period from the effects of fire, explosion, un-ignited gas/smoke ingress and excessive heat.
Muster areas will be considered to be impaired if:
 heat radiation exceeds 1.6 kW/m2 (500 BTU/ft2);
 blast overpressure exceeds 0.3 barg;
 smoke levels lead to visibility below 5 m; or
 unignited gas concentrations exceed 50% of the gas lower flammable limit (LFL).
An emergency control centre shall be provided on the rig in close proximity to the primary muster
areas. Telephone and radio communication will be provided to enable coordination of emergency
response actions between the primary and alternative muster areas. The emergency control
centre will be protected to the same extent as the accommodation. The location will be in the
central control room (Rig). It will be possible to initiate ESD from the muster areas.
Life Saving Equipment
Safety and information signs shall be provided in accordance with relevant regulations and
operational requirements.
Helicopter Crash Equipment
Appropriate helicopter crash equipment shall be provided adjacent to the helideck of the rig.
Personnel going offshore shall undergo mandatory helicopter ditching and water survival training.
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Lifeboats/Liferafts
Two (2) lifeboats of the free fall type shall be installed at the Primary Muster Area and one (1) at
the Secondary Muster Area. Each of these free fall lifeboats will be rated for 60 persons minimum.
Sufficient life rafts will be provided to comply with the applicable regulations.
Fast Rescue Boat
A line boat shall be used as the fast rescue craft for the proposed Development Wells Drilling in
Area. This boat shall be mounted on the Westside adjacent to the workshop in Module C on the
process deck. However, this is the windward side for squalls. The boat will be used for rescuing
any personnel who have fallen overboard from the rig, from the export tanker, or if a helicopter
goes down. In a major emergency, the boat can be used to gather and tow life rafts after
launching into the water. The boat can carry up to six persons and will be equipped with a
Hamilton water jet propulsion engine. The engine will be capable of sustaining a speed of twenty
knots. .
Miscellaneous Safety and Lifesaving Equipment
In the accommodation cabins, for each occupant there shall be provided one lifejacket and also a
grab bag containing flashlight, heat resistant gloves and a smoke hood. The provision of additional
equipment items such as safety equipment cabinets, emergency showers and lifejackets will be
determined in detailed design based on the findings of the updated EER Analysis. An emergency
shower will be located adjacent to the chemical usage areas, battery rooms, etc. Self-contained
eye bath bottles and stretchers will be located at strategic points. Emergency response equipment
lockers will be located adjacent to the primary muster area for rig and for other areas will be
determined in detailed design as defined by the updated EER analysis.
Vessel Security
The vessel shall have suitable arrangements to prevent unauthorized personnel access to the
vessel and reduce the risk of sabotage.
Gangway Access
All access ladders on the rig shall have alarms to identify people boarding the ladders and gates at
the top of the ladders.
Riser Support and Protection Security
The riser areas shall have means of preventing unauthorized personnel access to the riser valves
and the vessel. Access ladders to the riser valve platforms will have means to be secured.
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10 DECOMMISSIONING
ENI Ghana shall ensure that all assets (including wells, production facilities, flowlines/risers,
pipelines etc.), which have reached the end of their useful life span, shall be decommissioned and
either dismantled and removed or abandoned, in accordance with statutory requirements and
standards. This will entail the following scope of work.
ENI shall develop a sound and acceptable plan, which will describe how all assets are to be
decommissioned and their planned state after abandonment. The plan will consider all technically
feasible options for decommissioning and abandonment, including alternative uses for the assets,
in accordance with ENI policy and government regulations.
Well suspension or abandonment operations will be carried out in accordance with the regulatory
guidelines and best Industry practice. Once drilling activity has been completed, the well will either
be producing or suspended and may be later abandoned, depending on production. During
abandonment, an abandonment programme will ensure the isolation of the various zones from
each other and from the surface in accord with the regulatory guidelines. Casing and wellhead
equipment will be recovered from the well and the well will be capped at least 3 meters below
seabed.
Following equipment recovery, a recorded site survey will be carried out using an ROV around the
previous wellhead position and a hundred meter radius around the position as debris and dropped
object survey. In the event the well is suspended for future entry for any purpose, down hole
formations will be isolated from each other and from the surface using cement and mechanical
plugs as required. Once the BOP and riser assembly has been removed, corrosion cap will be
installed on the subsea wellhead.
A recorded site survey will be carried out using the ROV as debris and dropped object survey will
be completed over a 50 meter radius around the wellhead locations.
Abandonment Report
ENI shall also prepare final report on condition of all assets abandoned prior to relinquishment. The
Abandonment Report will include as a minimum:
 Operating and Technical Data (data on the asset thorough its operating life; e.g.,
location, repairs, etc.);
 Financial Data on the Abandoned Asset; and
 Final Abandoned Condition.
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SUMMARY AND CONCLUSIONS
The ESHIA of the proposed drilling, Installation/ Operation of FPSO and Mooring System.
Installation and Operation of Well Heads and SURF system in OCTP Block, has been a
combination of data obtained from literature review and existing EIA reports as well as execution of
field studies. The overall goal of the ESHIA is to ensure that potential impacts of the proposed
project are identified, evaluated and adequate mitigation measures are proffered for significant
impacts, while the positive impacts are enhanced. This will consequently provide necessary
data/evidence that will ensure the issuance of an environmental impact statement (EIS) for the
proposed project.
The proposed project may significantly impact the national economy as well as the overall wellbeing of the people. It should also increase Ghana’s total hydrocarbon reserve, production capacity
and ultimately enhance the country’s present image and position in OPEC. It would also result in
the provision of direct and indirect employment opportunities as well as increased derivation funds
to local and state governments and other government agencies/commissions.
The adverse impacts of the project would be in the form of injury/loss of life from operational
accidents/incidents, chronic/acute health condition for onsite personnel due to exposure to
hazardous chemicals and harsh weather, degradation of air quality from emissions from topsides,
degradation of seawater column quality and loss of biodiversity resulting from disturbance of the
seabed, oil spills/leaks, and wastes/effluents disposal. These adverse impacts can be prevented,
reduced or controlled following implementation of the recommended mitigation measures.
Consequently, an EMP has been developed to ensure effective implementation of prescribed
mitigation measures and for proactive environmental management throughout the project’s life
span. The EMP shall be implemented within the framework of ENI’s Environmental Management
System (EMS).
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REFERENCES
Adamec D and O'Brien J J (1978). The seasonal upwelling in the Gulf of Guinea due to remote
forcing. J Phys Oceanog 8: 1050-1060.
Africa Pilot. Volume I Admiralty Charts and Publications, 1982
Ahanta West District Health Management Team, 2009
Alder Jand Sumaila U. Western Africa: a fish basket of Europe past and present. Journal of
Environment and Development 13 (2), 2004
Allotey JA, 2007, Status of biodiversity and impact assessment in Ghana. Environmental
Protection Agency 18pp.
Amiteye B T (2002). Distribution and ecology of nesting sea turtles in Ghana. Unpublished Thesis
University of Ghana.
Anderson DM, Andersen P, Bricelj VM, Cullen JJ, Rensel JEJ (2001). Monitoring and management
strategies for harmful algal blooms in coastal waters. APEC #201-MR-01.1, Asia Pacific Economic
Program, Singapore and Intergovernmental Oceanographic Commission Technical Series No. 59,
Paris.
Andrae MO (1993). Global Distribution of fires seen from space Eos. Transactions of the American
Geophysical Union 74,129-135
Arhinful, D. K. (2009). WHO pharmaceutical situation assessment – LEVEL II –Health Facilities
Survey in Ghana. Ministry of Health.
Armah A K, Biney C, Dahl S O and Povlsen E (2004). Environmental Sensitivity Map for the
Coastal Areas of Ghana Volume II – Coastal Environment. UNOPS/UNDP, Accra. 80p.
Armah A K, Darpaah G A, Wiafe G, Adomako J K, Quartey S Q, Abotchie C, Ansah F and
Fiagbedzi S (1997). Traditional and modern perspectives of marine turtle conservation in Ghana
Biodiversity Conservation: traditional knowledge and modern concepts (eds. Amlalo DS,
Atsiatorme LD and Fiati C), p. 80-87: EPA/MAB/UNESCO.
Armah A. K. and Amlalo DS (1998). Coastal Zone Profile of Ghana. Ministry of Environment,
Science and Technology/Large Marine Ecosystems Project of the Gulf of Guinea. Ghana Ministry
of Environmental Science and Technology, Accra, Ghana.
Assessment of Critical Coastal Habitats of the Western Region, Ghana, University of Rhode island
& USAID, July 2011
Atlantic Coral Ecosystem Study (ACES), 2000. Consortium of European scientists completed an
environmental assessment of the status of Europe’s deep-water corals, available on-line at:
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.cool-corals.de%2F
http://www.coris.noaa.gov/about/deep/#what_are
Avent, R.M., M.E. King, and R.M. Gore. 1977. Topographic and faunal studies of shelf-edge
prominences off the central eastern Florida coast. Int. Revue ges.Hydrobiol. 62:185-208.
Barnes, R. 1987. Invertebrate Zoology. Fort Worth, TX: Harcourt Brace Jovanovich College
Publishers. p. 783.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
407 of 425
Barnes, R. and R. Hughes. 1999. An Introduction to Marine Ecology. Oxford, UK: Blackwell
Science Ltd. pp. 131-133.
Barnes, R.S.K. and Hughes, R.N. 1999. An introduction to marine ecology. Blackwell Science
Limited, London. 286 pp.
Basset A, Galuppo N, Sabetta L, 2006. Transitional Waters Bulletin 1 48-63pp.
Bell, N. and J. Smith. 1999. Coral growing on North Sea oil rigs. Nature 402:601.
Bellona Foundation. 2001. Coral reefs in Norwegian Waters.
http://www.bellona.no/en/b3/biodiversity/coral_reefs/12784.html.
Available
on-line
at
Bernacsek G M (1986). Profile of the marine resources of Ghana CECAF/TECH/71 (En) Food and
Agriculture Organisation (FAO): 118.
Best P B (1967).The sperm whale (Physeter catodon) off the West coast of South Africa. 1.
Ovarian changes and their significance Invesigationt. Rep. Div. Sea Fish. S. Afr. 61: 1-27.
Best P B (1969). The sperm whale (Physeter catodon) off the West coast of South Africa. 4.
Distribution and movements Investigation. Rep. Div. Sea Fish. S. Afr. 78: 1-12.
Best P B (1970). The sperm whale (Physeter catodon) off the West coast of South Africa. 5. Age,
growth and mortality Investigation. Rep. Div. Sea Fish. S. Afr. 61: 1-27.
Best P B and Ross G J B (1977). Exploitation of small cetaceans off Southern Africa Rep. Int.
Whal. Comm. 34: 494-497.
Best P B and Ross G J B (1984). Live-capture fishery for small cetaceans in South African waters.
Rep. Int. Whal. Comm. 34: 615-618.
Best P B, Reeb D, Morais M and Baird A (1999). A préliminaire investigation of humpback whales
off Northern Angola. Paper SC/51/CAWS33 presented to IWC Scientific Committee Grenada 9pp.
Best P. B. 1974. The biology of sperm whale as it relates to stock management. In: Schevill WE
(ed) The Whale Problem: a status report. Harvard University Press, Cambridge, Massachusetts,
USA: 257-293.
Best PB and Shaughnessy PD (1981). First record of the melon-headed whale Peponocephala
electra from South Africa Ann. S. Afr. Mus. 83(3): 33-47.
Best, P.B., and Ross, G.J.B. 1984. Live-capture fishery for small cetaceans in South African
waters. Reports of the International Whaling Commission 34: 615-618.
Billes A, Formia A Tiwari A M Fretey J (2003). Sea turtle conservation along the Atlantic coast of
Africa. Marine Turtle Newsletter 100:33-37.
Biodiversity Threats Assessment for the Western Region of Ghana. Integrated Coastal and
Fisheries Governance Initiative for the Western Region of Ghana, Coastal Resources Center
University of Rhode Island, 2010
Birdlife (2009). http://www.birdlife.org/news/news/2009/10/migratory_bird_decline_proj ect.html
Birdlife International (2011) Birdlife Data Zone – Important Bird Areas.
http://www.birdlife.org/datazone/site/search
Accessed at.
Eni S.p.A.
BirdLife
International
(2013)
Country
http://www.birdlife.org/datazone/country/ghana
profile:
Ghana.
Doc.
000415_DV_CD.HSE.
0208.000_00
408 of 425
Available
from:
Blumer, M. and Snyder, W.D. 1965. Isoprenoid hydrocarbons in recent sediments: presence of
pristane and probably phytane. Science. 150: 1588-1589. Blumer, M. and Snyder, W.D. 1965.
Isoprenoid hydrocarbons in recent sediments: presence of pristane and probably phytane.
Science. 150: 1588-1589.
Boere G C & Stroud D A (2006). The flyway concept: what it is and what it isn’t. Waterbirds around
the world. Eds. Boere G C, Galbraith C A & Stroud D A. The Stationery Office, Edinburgh, UK. pp.
40-47.
Boere G C (2006). The African Eurasian Migratory Waterbird Agreement: a review. Wetlands
International.
Brainard, R.E., C. Birkeland, C.M. Eakin, P. McElhany, M.W. Miller, M. Patterson, and G.A. Piniak.
2011. Status review report of 82 candidate coral species petitioned under the U.S. Endangered
Species Act. U.S. Dep. Commer., NOAA Tech. Memo., NOAA-TM-NMFS-PIFSC-27, 530 p. + 1
Appendix. http://www.nmfs.noaa.gov/stories/2012/05/07_coral_documents_page.html
Bray, J.R. and Curtis, J.T. 1957. An ordination of the upland forest communities of Southern
Wisconsin. Ecol. Monogr. 27: 325-349.
Brodie, J., Fabricius, K., De'ath, G., and Okaji, K. 2005. Are increased nutrient inputs responsible
for more outbreaks of crown-of-thorns starfish? An appraisal of the evidence. Marine Pollution
Bulletin 51: 266-278.
Broekema J W (1983). Catalogue of Cetacea in the collection of the Rijksmuseum van Natuurlijke
Historie, Leiden Zool. Meded. 57: 67-79.
Brooks J M and Bernard B B (2006). Chemosynthetic seep communities along the West Africa
continental margin revealed by surface geochemical exploration studies. Chess Workshop: Atlantic
Equatorial Belt. Barcelona, Spain, 8-10 March 2006.
Brushares JS, Arcese P, Sam MK, Coppolillo PB, Balmford A, 2004. Bushmeat Hunting, Wildlife
Declines, and Fish Supplies in West Africa. Science 306 1180-1183pp.
Bryant, D., L. Burke, J. McManus, and M. Spalding. 1998. Reefs at Risk: A Map-based Indicator of
Threats to the World's Coral Reefs. World Resources Institute. pp. 11-15.
Buchanan J.B. 1984. Sediment Analysis. In Methods for the study of marine benthos, Ed. By
Holme N.A. and McIntyre A.D. Blackwell Scientific Publications, London.
Buchman, M.F. 2008. NOAA Screening Quick reference Tables (SQiRTs), NOAA OR&R Report
08-1.
Burgess N, Küper W, Mutke J, Brown J, Westaway S, Turpie S, Meshack C, Taplin J, McClean C,
Lovett JC, 2005. Major Gaps in the Distribution of Protected Areas for Threatened and Narrow
Range Afrotropical Plants. Biodiversity and Conservation 14 1877-1894 pp.
Burke, L., K. Reytar, M. Spalding, and A. Perry. 2011. Reefs at Risk Revisited. World Resources
Institute.
130
pp.
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.wri.org%2Fpublication%2Freefs-atrisk-revisited
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
409 of 425
Cadenat J (1959). Rapport sur les petits cétacés ouest-Africains. Résultats des recherches
entreprises sur ces animaux jusqu'au mois de mars 1959. Bull. IFAN 21 A(4): 1367-1409.
Cadenat J and Lassarat A (1959a). Notes sur les Delphinidés ouest-africains. III. Notes
complémentaires sur Tursiops truncatus. Bull IFAN 21A (1): 416-419.
Cadenat J and Lassarat A (1959b). Notes sur les Delphinidés ouest-africains. IV. Sur un
Prodelphinus indéterminé de Côte d’Ivoire. BulI. IFAN 21 A(2): 777-786.
Cairns, S. and G. Stanley. 1982. Ahermatypic coral banks: Living and fossil counterparts.
Proceedings of the Fourth International Coral Reef Symposium, Manila (1981), 1: 611-618.
Cairns, S.D. 1982. Antarctic and Subantarctic Scleractinia. Antarctic Research Series 34: 74 pp.
Carwardine M (1994). On the trail of the whale. Thunder Bay Publishing Company Surrey 158pp.
CEFAS 2003. The Use Of Action Levels in The Assessment of Dredged Material Placement at Sea
and in Estuarine Areas under FEPA (II), Defra Project Code AE0258.
CEFAS. 2001. Contaminant Status of the North Sea. A Technical Note produced for the DTI SEA
2.
Chao, A. 2005. Species richness estimation, Pages 7909-7916 in N. Balakrishnan, C. B. Read,
and B. Vidakovic, eds. Encyclopedia of Statistical Sciences. New York, Wiley.
Clapham P and Van Waerebeek K (2007). Bushmeat, the sum of the parts. Mol. Ecol. 16: 26072609.
Clarke, K.R. and Gorley, R.N. 2006. PRIMER v6: User Manual/ Tutorial. PRIMER-E: Plymouth.
Clarke, K.R. and Warwick, R.M.1994. Changes in marine communities: an approach to statistical
analysis and interpretation. Plymouth. Plymouth Marine Laboratory, Natural Environment Research
Council, UK. 144 pp.
Clarke, K.R., Somerfield, P.J. and Chapman, M.G. 2006. On resemblance measures for ecological
studies, including taxonomic dissimilarities and a zero-adjusted Bray-Curtis coefficient for denuded
assemblages. J Exp Mar Biol Ecol 330, 55-80
Clifford, H.T. and Stephenson, W. 1975. An Introduction to numerical classification. Academic
Press, London.
Coles, S. 1996. Corals of Oman: Natural and man-related disturbances to Oman's corals and coral
reefs.
Bernice
Pauahi
Bishop
Museum's
Web
site
at
http://www.bishopmuseum.org/research/pbs/Oman-coral-book/.
Collins T, Ngouessono S and Rosenbaum H C (2004). A note on recent surveys for Atlantic
humpback dolphins, Sousa teuszii (Kükenthal, 1892 in: the coastal waters of Gabon. Paper
SC/56/SM23 presented to International Whaling Commission Annual meeting.
Coral Reef Task Force (CRTF). 2000. The National Action Plan to Conserve Coral Reefs.
Washington, DC: CRTF. p. 3.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
410 of 425
CRC-URI, 2010. Our Coast, Our Future. Western Region of Ghana, Building capacity for adapting
to a rapidly changing coastal zone. H&N Mpoano. Prepared by Coastal resources centre –
University of Rhode Island (CRC-URI) and SustainaMetrix. 66 pp.
Debrah J S (2000). Taxonomy, exploitation and conservation of dolphins in the marine waters of
Ghana Master of Philosophy thesis. Department of Oceanography and Fisheries University of
Ghana 86pp. (unpublished).
Doak, K. Sea turtle conservation on the west coast of Ghana. A background report. Nature
Conservation Research Centre and Benyin Beach Resort, 2009
EAF Nansen Survey (2009). Marine Environmental Survey of Bottom Sediments in Ghana. Norad FAO project GCP/INT/003/NOR cruise reports "Dr. Fridtjof Nansen" EAF N2009/5.
EAF Nansen. 2010. ‘2009 Marine Environmental Survey of Bottom Sediments in Ghana’. NORADFAO
Project
GCP/INT/003/NOR.
Available
from:
http://www.imr.no/filarkiv/2010/07/report_ghana_2009-26_may_2010.pdf/en
Egbert, G.D., and S.Y. Erofeeva, 2002: ‘Efficient inverse modeling of barotropic ocean tides’, J.
Atmos. Oceanic Technol., 19(2), 183-204
Elgood J H, Heigham J B, Moore A M, Nason A M, Sharland R E and Skinner NJ (1994). The birds
of Nigeria (2nd edition) British Ornithologists’ Union Check-list No. 4. British Ornithologists' Union
Tring.
Elgood JH, Heigham JB, Moore AM, Nason AM, Sharland RE and Skinner NJ 1994. The Birds of
Nigeria. Tring: British Ornithologists’ Union.
Ellembele Development Plan, 2008
eni E&P (2008) Community Investment Management System Best Practice, Circular N° 498, 2008.
eni E&P (2010) "Environmental, Social and Health Impact Assessment" HSE Standard - Doc. No.
1.3.1.47 Circular No. 574
eni E&P,(2011). GHANA OCTP BLOCK - Sankofa & Gye Nyame, Preliminary Environmental,
Social and Health Impact Assessment of Geophysical Surveys, Internal report n. 00-BG-E-94750
Rev. 00, -2011.
eni E&P,(2012). GHANA OCTP BLOCK - Sankofa & Gye Nyame, Onshore site selection for
natural gas CPF Internal report - 2012.
ENI GHANA E&P LTD and FUGRO GEOCONSULTING LIMITED Regional Auv Geohazard
Survey Octp Development Area Ghana-VOLUME 2 OF 2: REGIONAL GEOHAZARD
ASSESSMENT REVISED FINAL (19 August 2013)
Entsua-Mensah, M. and Ankudey, N.: “The West African Manatee, Trichechus senegalensis”
Bionews, Newsletter of Ghana Institute of Biology, 1996
Environment Australia and Ierino, T. (2003) “Recovery Plan for Sea Turtles in Australia”. Prepared
by the Sea Species Section Approvals and Wildlife Division, Environment Australia in consultation
with
the
Sea
Turtle
Recovery
Team
http://www.environment.gov.au/system/files/resources/6d26f4aa-751e-4b72-9ab0984a1d6e0fea/files/marine-turtles.pdf
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
411 of 425
Environmental Protection Agency (2010). Guidelines for Environmental Assessment and
Management
in
the
Offshore
Oil
and
Gas
Development.
Available
from
http://www.epa.gov.gh/index.php?option=com_docman&task=cat_view&gid=112& Itemid=73
Environmental Resources Management (ERM). 2009. Jubilee Field EIA, Chapter 4. Available from:
http://www.epa.gov.gh/index.php?option=com_docman&task=cat_view&gid=101&Itemid=116
FAO
(2011).
Ghana
Fishery
Country
profile.
http://www.fao.org/fishery/statistics/cecaf-capture-production/query/en.
Accessed
from:
Félix F and Van Waerebeek K (2005). Whale mortality from ship strikes in Ecuador and West
Africa. LAJAM 4(1): 55-60.
Findlay K P, Best P B, Ross G J B and Cockroft V G (1992). The distribution of small odontocete
cetaceans off the coasts of South Africa and Namibia. S Afr. J Mar. Science 12: 237-270.
Flegg J (2004). Time to Fly. Exploring Bird Migration. BTO, Thetford. Fontaine B, Janicot S and
Roucou P (1999). Coupled ocean-atmosphere surface variability and its climate in the tropical
Atlantic region. Climate Dynamics 15: 451-473.
Flegg J (2004). Time to Fly. Exploring Bird Migration. BTO, Thetford. Boere G C & Stroud D A
(2006). The flyway concept: what it is and what it isn’t. Waterbirds around the world. Eds. Boere G
C, Galbraith C A & Stroud D A. The Stationery Office, Edinburgh, UK. pp. 40-47.
Food and Agriculture Organisation (1995). The state of the World’s fisheries and Aquaculture FAO
Rome.
Food and Agriculture Organisation (2007). Ghana Fishery Country profile (accessed at:
http://www.fao.org/fi/website/FISearch.do?dom=country).
Forrester, A. 1997. The Effects of El Niño on Marine Life. Cambridge Scientific Abstracts Web site.
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.csa.com%2Fdiscoveryguides%2Fa
rchives%2Felnino.php.
Fossa, J.H., P.B. Mortensen, and D.M. Furevic. 2002. The deep-water coral Lophelia pertusa in
Norwegian waters: distribution and fishery impacts. Hydrobiologia 417: 1-12. Available on-line at:
http://www.imr.no/dokumenter/fossa.pdf
Fraser F C (1950a). Description of a dolphin Stenella frontalis (Cuvier) from the coast of French
Equatorial Africa. Atlantide Reports 1: 61-84.
Fraser F C (1950b). Two skulls of Globicephala macrorhyncha (Gray) from Dakar. Atlantide
Reports 1 Copenhagen: 49-60.
Fretey J (2001). Biogeography and Conservation of Marine Turtles of the Atlantic Coast of Africa.
CMS Technical Series Publication 6, UNEP/CMS Secretariat, Bonn, Germany.
Fretey J (2001). Biogeography and conservation of marines turtles of the Altlantic coast of Africa /
Biogéographie et conservation des tortues marines de la cote Atlantique de l’Afrique. CMS
Technical Série Publication No. 6: 209-207.
Froese R and Pauly D (Eds) (2009). FishBase .World Wide Web electronic publication accessed
March 2009 at www.fishbase.org.
Gardline Environmental (2011) Marine Mammal and Turtle Observation Report.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
412 of 425
Ghana Health Service (GHS) (2005). 2005 GHS Annual Report: Western Region
Ghana Health Service (GHS) (2009). 2009 GHS Annual Report: Western Region
Ghana Health Service (GHS) (2009). Health Sector In Ghana: Facts and Figures 2009
Ghana Health Service (GHS) (2010). 2010 Half Year Report: Western Region.
Ghana Health Service (GHS) (2010). Ahanta West District Health Directorate 2010 Performance
Review
Ghana Health Service (GHS) (2010). Ellembelle District 2010 Performance Review
Ghana Health Service (GHS) (2010). Jomoro District Health Directorate 2010 Performance Review
Ghana Health Service (GHS) 2010 Annual Performance Review Nzema East Municipal Health
Administration
Ghana Health Service (GHS) 2010 Annual Performance Review Shama District
Ghana Health Service (GHS) 2010 Health Sector Performance Review Sekondi-Takoradi
Metropolis Health Directorate
Ghana Investment Promotion Centre (GIPC), 2010. Accessed at: http://www.gipcghana.com/
Ghana Jubilee Field Phase 1 Development (2009). Environmental Impact Assessment Report for
Tullow Ghana Limited. Prepared by ESL Consulting and ERM Ltd.
Ghana Tourist Board, 2010. Accessed at: http://www.touringghana.com/investments/index.asp
Ghana Wildlife Society, NKO Magazine, Vol. 12, 2000
Ghanadistricts.com (2006). Accessed at http://www.ghanadistricts.com/home/?_=42.
Government of Ghana (2007). Ghana Statistical Service (GSS) Accra.
Government of Ghana 2010. Website visited December 2013. www.statsghana.gov.gh as
Gray, J.S., Clarke, K.R., Warwick, R.M. and Hobbs, G. 1990. Detection of initial effects of pollution
on marine benthos: an example from the Ekofisk and Eldfisk oilfields, North Sea. Marine Ecology
Progress Series, 66, 285-289.
Hall-Spencer, J. et al. 2002. Trawling damage to Northeast Atlantic ancient coral reefs. Proc. R.
Soc. London B.
Hammond P S and Lockyer C (1988). Distribution of killer whales in the eastern North Atlantic Rit
Fiskideildar 11: 24-35.
Heimlich-Boran S (1990). Pilot study Sonar 4: 6-8.
Hoskin, C.M., J.K. Reed, and D.H. Mook. 1987. Sediments from a living shelf-edge reef and
adjacent area off central eastern Florida. Pp. 42-77, In: F, JMR,Maurrasse (ed.), Symposium on
south Florida geology. Miami Geological Society. Memoirs 3.
HPI, 2009. Takoradi Thermal Power Plant Expansion Project (T3). Environmental Impact
Assessment (EIA) for Volta River Authority. Prepared by HPI. 311 pp.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
413 of 425
ICBP (1984). Status and Conservation of the World’s Seabirds. International Council for Bird
Preservation (ICBP). Technical Publication No.2. 778 pp.
ICCAT (1999). Report of THE ICCAT SCRS Skipjack Stock Assessment Session. SCRS/99/21,
Funchal, Madeira, Portugal, 28 June to 2 July 1999
IFC (2007a). Environmental, Health, and Safety General Guidelines - April 2007.
IFC (2007b). Environmental, Health, and Safety Guidelines for Offshore Oil and Gas Development
- April 2007.
IFC (2012). Performance Standards on Environmental and Social Sustainability, 2012. PS6:
Biodiversity Conservation and Sustainable Management of Living Natural resources - 2012 IFC
IFC, (2007). Stakeholder Engagement: A Good Practice Handbook for Companies Doing Business
in Emerging Markets”.
International Commission for the Conservation of Atlantic Tunas (ICCAT) (2008). Report for the
Biannual period 2006-2007 Part II (2007) - Vol 2 of Standing Committee on Research and
Statistics (SCRS.) International Commission for the Conservation of Atlantic Tunas (ICCAT),
262pp.
International Commission for the Conservation of Atlantic Tunas (ICCAT) (2009). ICCAT Manual.
In:
ICCAT
Publications
[on-line].
Updated
2009.
[Cited
01/27/].
http://www.iccat.int/en/ICCATManual.htm.
International Coral Reef Initiative (ICRI). 1995. The State of the Reefs – ICRI's Major Concern.
ICRI Web site. http://oceanservice.noaa.gov/education/kits/corals/media/icri_stateofreefs.pdf (pdf,
207KB)
International Council for Exploration of the Sea (ICES). 2001a. Marine World, article on deep-sea
coral.
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.ices.dk%2Fmarineworld%2Fdeeps
eacoral.asp
International Council for Exploration of the Sea (ICES). 2001b. Close Europe’s cold-water coral
reefs
to
fishing.
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.ices.dk%2Faboutus%2Fpressrelea
se%2Fcoral.asp
International Council for Exploration of the Sea (ICES). 2001c: Extract of the report of the Advisory
Committee on Ecosystems 2002 on identification of areas where cold-water corals may be affected
by fishing.
International Council for Exploration of the Sea (ICES). 2002. Advisory Committee on Ecosystems.
Report of the study group on mapping the occurrence of cold-water corals: 1-17.
IPIECA (2010). Alien invasive species and the oil and gas industry’.
IPIECA (2011). Ecosystem services guidance”.
IUCN (2011). IUCN Red List of Threatened Species. Available from http://www.iucnredlist.org/
IUCN Red List of Threatened Species accessed on 20 November 2013 from www.iucnredlist.org
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
414 of 425
IWC (1997). Initial alternative hypotheses for the distribution of humpback breeding stocks on the
feeding grounds. Rep. Int. Whal. Comm. 48: 181.
IWC (2006). Annex H: Report of the sub-committee on the other Southern Hemisphere whale
stocks. J. Cet. Res. Manag. (Suppl) 8: 151-170.
Jefferson T A, Curry B E, Leatherwood S and Powell J A (1997). Dolphins and porpoises of West
Africa: a review of records (Cetacea: Delphinidae, Phocoenidae). Mammalia 61: 87-108.
Jefferson T A, Webber M A and Pitman R L (2008). Marine Mammals of the World: A
Comprehensive Guide to their Identification. Academic Press, London.
Jeong, H.J. and M.I. Latz. 1994. Growth and grazing rates of the heterotrophic dinoflagellate,
Protoperidinium, on red tide dinoflagellates. Marine Ecology Progress Series 106: 173-185.
Jun-Ichi Miyazaki, Leonardo de Oliveira Martins, Yuko Fujita, Hiroto Matsumoto, Yoshihiro
Fujiwara
(2010)
“Evolutionary
Process
of
Deep-Sea
Bathymodiolus
Mussels”
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0010363
Karikari AY, Asante KA, Biney CA, 2006. West African Journal of Applied Ecology 10 73-85pp.
Kirby Doak on behalf of Nature Conservation Research Centre and Beyin Beach Resort (2009).
“Sea Turtle Conservation on the West Coast of Ghana A Background Report”
http://www.beyinbeachresort.com/Files/Background%20Report%20%20Sea%20Turtle%20Conservation%20on%20the%20West%20Coast%20of%20Ghana.pdf
Koenig, C., C.F. Coleman, and S. Brooke. Coral restoration in the Experimental Oculina Research
Reserve
of
the
South
Atlantic.
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.bio.fsu.edu%2Fcoleman_lab%2Foc
ulina_research.php
Koranteng K A (1995). The Ghanaian fishery for sardinellas. In Dynamics and Use of Sardinella
Resources from Upwelling off Ghana and Ivory Coast, pp 290–299 Ed by F X Bard and KA
Koranteng. ORSTOM Edition, Paris
Koranteng K A (2001). Structure and dynamics of demersal assemblages on the continental shelf
and upper slope off Ghana, West Africa. Marine Ecology Progress Series, 220: 1-12.
Kükenthal W (1892). Sotalia teuszii n.sp. eine pflanzenfressender Delphin aus Kamerun. Zool.
Jahrbücher Abt. Syst. 6: 442-446.
Laflamme, R.E. and Hites, R.A. 1978. The global distribution of polycyclic aromatic hydrocarbons
in recent sediments. Geochim Cosmochim Acta. 42: 289-303.
Libes, S. M. 1992. An introduction to marine biogeochemistry’. John Wiley and Sons, Inc. US.
Longhurst A R (1969). Species Assemblages in Tropical Demersal Fishes. Proceedings of the
Symposium of the Ocean and Fish Resources of the Tropical Atlantic UNESCO Paris pp 147-168.
MacDonald I R (ed) (2002). Stability and Change in Gulf of Mexico Chemosynthetic Communities.
Volume II: Technical Report. U.S. Department of the Interior, Minerals Management Service, Gulf
of Mexico OCS Region, New Orleans, LA. OCS Study MMS 2002-036. 456 pp.
Magurran, A. E. 1988. Ecological diversity and its measurement. Princeton University Press,
Princeton, New Jersey. 179 pp.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
415 of 425
Maigret, J. and D. Robineau (1981). Le genre Kogia (Cetacea, Physeteridae) sur les côtes du
Sénégal. Mammalia 45:199-204.
Marine Protected Areas of the United States (MPA). 2002. Experimental Oculina Research
Reserve. Available on-line at http://mpa.gov/
Martin A. R. 1994. Globicephala melas. Langflossen-Grindwal. In: Handbuch der Säugetiere
Europas (Niethammer J, Krapp F, Eds) Band 6: Meeressäuger. Teil 1A Wale und Delphine 1. AulaVerlag, Wiesbaden, Germany: 407-421.
Martos A R, Yraola I S, Peralta and Gonzales J F (1991). The “Guinea 90” Survey CECAF/ECAF
SERIES
91/52
FAO
Rome
accessed
June
2009
at
http://www.fao.org/docrep/003/U1509E/U1509e00.htm.
Mayer,
T.
2001.
2000
Years
Under
the
Sea.
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fexn.ca%2FStories%2F2001%2F10%2F1
6%2F52.asp
McDougall, J. 2000. The significance of hydrocarbons in the surficial sediments from Atlantic
Margin regions. in Atlantic Margin Environmental Surveys of the Seafloor, 1996 and 1998. Atlantic
Frontier Environmental Network. CD-Rom.
Mensah M A and Koranteng K A (1988). A review of the oceanography and fisheries resources in
the coastal waters of Ghana 1981-1986. Marine Fisheries Research Report No. 8. Fisheries
Department Ghana.
Merle J and Arnault S (1985). Seasonal variability of the tropical South Atlantic and linkages to the
Pacific Geophysical Research Letters 13: 1039-1092.
Miller, C. B. 2003. Biological Oceanography. Wiley-Blackwell publishing.
Moore, J.W. Ramamoorthy, S. 1984. Organic Chemicals in Natural Waters – Applied Monitoring
and Impact Assessment. Springer Verlag. 308 pp.
Morrisey, D., Howitt, L., Underwood, A.J., and Stark, J.S. 1992. Spatial variation in soft-sediment
benthos. Marine Ecology Progress Series, 81, 197–204.
Mörzer Bruyns W F J (1969). Sight records and notes on the false killer whale, Pseudorca
crassidens (Owen, 1846). Säugetierk. Mitteil. 17: 351-356.
NANSEN-Food and Agriculture Organization (FAO)/United Nation Development Projects (UNDP)
(2005). Surveys of the Fish Resources of the Western Gulf of Guinea (Benin, Togo, Ghana, Cote
d’Ivoire) 3-29 May 2005 NORAD-FAO/UNDP GCP/INT/730/NOR.
National Fisheries Association of Ghana (NAFAG) (2007). National Fisheries Association of Ghana
(accessed in May 2009 at: http://www.nafagfish.org/aboutus.htm).
National Marine Fisheries Service (NMFS). 2001. NMFS Office of Protected Resources Web site.
www.nmfs.noaa.gov/prot_res/PR/.
National
Marine
Sanctuaries
(NMS).
2001.
NMS
Web
sites.
http://www.sanctuaries.nos.noaa.gov/about/ecosystems/coralimpacts.html
National Oceanic and Atmospheric Administration. 1982. Fishery Management Plan for Coral and
Coral Reefs of the Gulf of Mexico and South Atlantic. Gulf of Mexico and South Atlantic Fishery
Management Councils.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
416 of 425
National Oceanic and Atmospheric Administration. 2000. Final Rule, Amendment 4 to the Fishery
Management Plan for Coral, Coral Reefs, and Live/Hard Bottom Habitats of the South Atlantic
Regions (Coral FMP). Federal Register, Vol. 65, No. 115, June 14, 2000.
Neff, J.M., Hart, A.D., Ray, J.P., Limina, J.M., Purcell., T.W., 2005. An Assessment of Seabed
Impacts of Synthetic-Based-Drilling-Mud Cuttings in the Gulf of Mexico. SPE/EPA/DOE Exploration
and Production Environmental Conference, 7-9 March 2005, Galveston, Texas.
Nelson-Smith, A., 1972. Oil pollution and marine ecology. Elek Science, London. 260 pp.
Nibbelink K A and Huggard J D (2002). Radial Canyon System, Volta Fan Fold Belt, Ghana
presented at the Offshore Technology Conference Houston USA 6-9 May 2002.
Nieri M, Grau E, Lamarche B and Aguilar A (1999). Mass mortality of Atlantic spotted dolphins
(Stenella frontalis) caused by a fishing interaction in Mauritania Mar. Mamm. Sci. 15(3): 847-854.
Noble Denton (2008). Offshore Ghana MetOcean data report Report No: L22898/NDC/IGA 45pp.
Notarbartolo di Sciara G. 2002. Cetaceans of the Mediterranean and Black Sea: state of
knowledge and conservation strategies. A report to the ACCOBAMS Secretariat, Monaco.
Nzema East District Development Plan, 2009
O’connor, T. P. 2004. The Sediment Quality Guideline, ERL, Is Not a Chemical Concentration at
the Threshold of Sediment Toxicity." Marine Pollution Bulletin 49.5-6 (2004): 383-85
Oceanweather, Inc. – “West Africa metocean Normals and Extremes (WANE) – Interim reportSept. 2001.
Ofori-Danson P K, Van Waerebeek K and Debrah S (2003). A survey for the conservation of
dolphins in Ghanaian coastal waters. J. Ghana Sci. Assoc. 5(2): 45-54
Olsen O (1913): On the external characteristics and biology of Bryde’s whale (Balaenoptera brydei)
a new rorqual from the coast of South Africa. Proceedings of the Zoological Society of London. Pp.
1073–1090.
Olu K., Cordes E. E., Fisher C. R., Brooks J. M., Sibuet M. & Desbruyères D. (2010).
"Biogeography and Potential Exchanges Among the Atlantic Equatorial Belt Cold-Seep Faunas".
PLoS ONE 5(8): e11967. doi:10.1371/journal.pone.0011967
OSPAR, 2004. Guidelines for Monitoring the Environmental Impact of Offshore Oil and Gas
Activates. OSPAR Commission Reference 2004-11E
Perez-Jimenez, J. R., Young, L. Y., Kerkhof, L. J. 2001. Molecular characterization of
sulphatereducing bacteria in anaerobic hydrocarbon-degrading and pure cultures using the
dissimilatory sulfite reductase (dsrAB) genes. FEMS Microbiol. Ecol 35: 145-150
Perrin W F (1990). Subspecies of Stenella longirostris (Mammalia: Cetacea, Delphinidae) Proc.
Biol. Soc. Wash. 103(2): 453-463.
Perrin W F (2004). Chronological (1941-2001) NOAA Tech. Mem. NMFS- SWFSC 356.
Perrin W F and Van Waerebeek K (2007). The small-cetacean fauna of the west coast of Africa
and Macaronesia: diversity and distribution. UNEP/CMS-WATCH- Inf.6 CMS Bonn.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
417 of 425
Perrin W F, Mitchell E D, Mead J G, Caldwell D K and van Bree P J H (1981). Stenella clymene, a
rediscovered tropical dolphin of the Atlantic. J. Mamm. 62(3): 583-598.
Perrin W F, Mitchell E D, Mead J G, Caldwell D K, Caldwell M C, Vanbree P J H and Dawbin W H
(1987). Revision of the Spotted Dolphins, Stenella Spp, Marine Mammal Science, 3(2):99-170.
Perrin W. F., Caldwell D. K., Caldwell M. C. 1994b. Atlantic spotted dolphin - Stenella frontalis. In:
Ridgway S. H., Harrison S. R. (Eds), Handbook of marine mammals, Academic Press, London,
Volume 6: 173-190.
Perrin W. F., Wilson C. E., Archer F. I. II. 1994a. Striped dolphin Stenella coeruleoalba. In:
Ridgway S. H., Harrison S. R. (Eds), Handbook of marine mammals, Academic Press, London,
Volume 5: 1291-160.
Pielou, E.C. 1969. An introduction to mathematical ecology. Wiley, New York.
Pizzigalli C and Drago M. (2012). OCTP – DEVELOPMEN PROJECT - METOCEAN DESIGN
BASIS – doc n° 350300FORB00010
Powell J A (1996). The distribution and biology of the West African Manatee (Trichechus
senegalensis Link, 1795) UNEP, Regional Seas Programme Nairobi Kenya 61pp.
Quaatey S (1997). Synthesis of recent evaluations undertaken on the major fish stocks in
Ghanaian waters: A Working Document for the Eleventh Session of the Committee for Eastern
Central Atlantic Fisheries (CECAF) Working Party on Resource Evaluation Accra, Ghana. 35pp.
Rasmussen M H, Tougaard J, Eriksen N, Miller L A, Teilmann J, Kyhn L, Wahlberg M (2007).
Sound recordings and sightings of Cetaceans during the Danish round the world "Galathea3"
Expedition Poster presented to The Society for Marine Mammalogy Biennial Conference on the
Biology of Marine Mammals, Cape Town, South Africa.
Reed, J.K. 1981. In Situ growth rates of the scleractinian coral Oculina varicosa occurring with
zooxanthellae on 6-m reefs and without on 80-m banks. pp. 201-206. in: W.J. Richards (ed.),
Proceedings of Marine Recreational Fisheries Symposium.
Reed, J.K. 2002a. Comparison of deep-water coral reefs and lithoherms off southeastern U.S.A.
Hydrobiologia 471: 43-55.
Reed, J.K. 2002b. Deep-water Oculina reefs of Florida: biology, impacts and management.
Hydrobiologia 471:43-55.
Reed, J.K. and C.M. Hoskin. 1984. Studies of geological and biological processes at the shelfedge with use of submersibles. In: Undersea research and technology – Scientific application and
future needs – abstracts, Symposia Series for Undersea Research, Vol. 2, NOAA.
Reed, J.K., R.H. Gore, L.E. Scotto and K.A. Wilson. 1982. Community composition, structure,aerial
and trophic relationships of decapods associated with shallow and deep-water Oculina varicosa
coral reefs. Bull. Mar. Sci. 32:761-786.
ReefBase database accessed on 25 February 2014 http://www.reefbase.org/main.aspx
Reeves R and Mitchell E (1988). Killer whale sightings and takes by American pelagic whalers in
the North Atlantic. Rit Fiskideildar 11: 7-23.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
418 of 425
ReVelle, P. and C. ReVelle. 1988. The Environment: Issues and Choices for Society. 3rd ed.
Jones and Bartlett Publishers. Boston. 749 pp
Rice DW (1998). Marine Mammals of the World. Systematics and Distribution Special Publication
4, The Society for Marine Mammalogy 231pp.
Robineau D, Vély Y M and Maigret J (1994). Stenella clymene (Cetacea, Delphinidae) from the
coast of West Africa. J. Mammalogy 75(3): 766-767.
Rogers, A., M. Le Goff, and B. Stockley. Ecology of deep-water stoney corals (the Darwin
Mounds).
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.soton.ac.uk%2F~merg%2Fcorals.h
tm
Rogers, A.D. 1999. The biology of Lophelia pertusa (Linnaeus 1758) and other deep-water reefforming corals and impacts from human activities. International Review of Hydrobiology 84: 315–
406.
Ross G J B (1977). The taxonomy of bottlenosed dolphins Tursiops species in South African
waters, with notes on their biology. Ann. Cape Prov. Mus. (Natural History) 11(9): 135-194.
Ross G J B (1984). The smaller cetaceans of the southeast coast of southern Africa. Ann. Cape
Prov. Mus. (Nat. Hist.) 15: 173-410.
Roth H H and Waitkuwait E (1986). Répartition et statut des grandes espèces de mammifères en
Côte d’Ivoire. Mammalia 50: 227-242.
Russia’s Weather Server. http://meteo.infospace.ru/main.htm
Schepers F J and Marteijn E C L (eds) (1993). Coastal waterbirds in Gabon, winter 1992:
Foundation Working Group International Wader and Waterfowl Research WlWO-report 41 Zeist
The Netherlands 293 pp.
Shannon, C. E. and Weaver, W. 1949. The mathematical theory of communication. University of
Illinois Press, Urbana. 117 pp.
Simpson, E.H. 1949. Measurement of diversity. Nature 163:688.
Slijper E J, Van Utrecht W L and Naaktgeboren C (1964). Remarks on the distribution and
migration of whales, based on observations from Netherlands ships. Bijdr. Dierk. 34: 3-93.
Snelgrove, P.V.R. and Butman, C.A. 1994. Animal-sediment relationships revisited: cause vs.
effect. Oceanography and Marine Biology: an Annual Review. 32: 111-177.
Somerfield, P. J., Rees, H. L. and Warwick, R. M. 1995. Interrelationships in community structure
between shallow-water marine meiofauna and macrofauna in relation to dredgings disposal.
Marine Ecology Progress Series 127, 103-112.
Southampton Oceanographic Centre. Coral ecosystems in deep water. Available on-line at
http://www.soc.soton.ac.uk/GDD/DEEPSEAS/coralecosystems.html
SUBSEAIQ
2013.
Offshore
field
development
projects.
Available
from:
http://subseaiq.com/(X(1)S(mkjkvqildzzbeg45nytq5o45))/data/Project.aspx?project_id=970&Aspx
AutoDetectCookieSupport=1. Accessed September 2013.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
419 of 425
Sulak, K. and S. Ross. 2001. A profile of the Lophelia reefs. Available on the NOAA Ocean
Explorer
Web
site
at
http://oceanexplorer.noaa.gov/explorations/islands01/background/islands/sup10_lophelia.html.
Tchibozo S and Van Waerebeek K (2007). La baleine à bosse et le lamantin d’Afrique, des
potentielles ressources de tourisme de la nature au Béni Abstract. Presented at the CMS/WATCH
Meeting Adeje Tenerife.
TDI
Brooks.
2008.
Jubilee
Field
EBS
Report.
Available
from:
http://www.epa.gov.gh/index.php?option=com_docman&task=cat_view&gid=101&Itemid=116
Tyler-Walters, H. 2003. Lophelia reefs. Marine Life Information Network: Biology and Sensitivity
Key Information Sub-programme. Plymouth: Marine Biological Association of the United Kingdom.
Available
on-line
at
http://www.coris.noaa.gov/exit.html?url=http%3A%2F%2Fwww.marlin.ac.uk%2Fbiotopes%2Fbio_b
asicinfo_COR.Lop.htm
UNESCO (2009). Marine Spatial Planning Initiative”.
UNESCO
(2012).
World
Heritage
http://whc.unesco.org/en/statesparties/gh.
List
–
Ghana.
Accessed
at
University Of Cape Coast, Environmental, Social and Health Baseline (ESH) Study Report on the
six coastal districts fringing The offshore oil and gas fields In the Western Region of Ghana. (April
2011).
University of the Virgin Islands (UVI). 2001. Threats to Coral Reefs. UVI Web site.
http://www.uvi.edu/coral.reefer/threats.html
Van Bree P J H (1971). On skulls of Stenella longirostris (Gray, 1828) from the eastern Atlantic
(Notes on Cetacea, Delphinoidea IV). Beaufortia 19: 21-25.
Van Bree P J H (1972). Sur la présence de Pseudorca crassidens (Owen, 1846) [Cetacea,
Globicephalinae] au large des côtes d'Afrique occidentale. Bull. IFAN. 34, ser. A, 1: 212-218.
Van Bree P J H and Cadenat J (1968). On a skull of Peponocephala electra (Gray, 1846)
(Cetacea, Globicephalinae) from Senegal. Beaufortia 14: 193- 202.
Van Bree P J H and Purves P E (1972). Remarks on the validity of Delphinus bairdii (Cetacea,
Delphininae) J. Mammal. 53: 372-374.
Van Bree P J H, Best P and Ross G J B (1978). Occurrence of the two species of pilot whales
(genus Globicephala) on the coast of South Africa. Mammalia 42(3): 323-328.
Van Waerebeek K (1997). Long-beaked and short-beaked common dolphins sympatric off centralwest Africa Paper SC/49/SM46 presented to the Scientific Committee of the International Whaling
Commission. 5pp.
Van Waerebeek K (2003). A newly discovered stock of humpback whales in the northern Gulf of
Guinea. CMS Bull. 18: 6-7.
Van Waerebeek K and De Smet W M A (1996). A second confirmed record of the false killer whale
Pseudorca crassidens (Owen, 1846) (Cetacea, Delphinidae) from West Africa Mammalia 60 (2):
319-322.
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
420 of 425
Van Waerebeek K and Ofori-Danson P K (1999). A first checklist of cetaceans of Ghana, Gulf of
Guinea, and a shore-based survey of interactions with coastal fisheries Paper SC/51/SM35
presented to 51st Meeting of the IWC Scientific Committee Grenada 9pp.
Van Waerebeek K, Barnett L, Camara A, Cham A, Diallo M, Djiba A, Jallow AO, Ndiaye E, Samba
Ould Billal AO and Bamy IL (2004). Distribution, status and biology of the Atlantic humpback
dolphin Sousa teuszii (Kükenthal, 1892) Aq. Mamm. 30(1): 56-83.
Van Waerebeek K, Ndiaye E, Djiba A, Diallo M, Murphy P, Jallow A, Camara A, Ndiaye P and
Tous P (2000). A survey of the conservation status of cetaceans in Senegal, The Gambia and
Guinea-Bissau UNEP/CMS Secretariat Bonn Germany 80pp.
Van Waerebeek K, Ofori-Danson P K and Debrah J (2009). The Cetaceans of Ghana: a Validated
Faunal Checklist. West African Journal of Applied Ecology Vol 15
Van Waerebeek K, Tchibozo S, Montcho J, Nobime G, Sohou Z Sohouhoue P and Dossou C
(2001). The Bight of Benin, a North Atlantic breeding ground of a Southern Hemisphere humpback
whale population, likely related to Gabon and Angola substocks. Paper SC/53/IA21 presented to
the Scientific Committee of the International Whaling Commission London 8pp.
Walsh P D, Fay J M, Gulick S and Sounguet P (2000). Humpback whale activity near Cap Lopez
Gabon. J. Cet. Res. Manag. 2(1): 63-67.
Watling, L. 2001. Deep sea coral. Available on the NOAA Ocean Explorer Web site at
http://oceanexplorer.noaa.gov/explorations/deepeast01/background/corals/corals.html.
Weir C R (2006a). First confirmed records of Clymene dolphin Stenella clymene (Gray, 1850) from
Angola and Congo, south-east Atlantic Ocean Afr. Zool. 41(2): 297-300.
Weir C R (2006b). Sightings of beaked whales (Cetacea: Ziphiidae) including first confirmed
Cuvier’s beaked whales Ziphius cavirostris from Angola. Afr. J. Mar. Sci. 28: 173-175.
Weir C R (2007). The distribution and seasonal occurrence of cetaceans off northern Angola. J.
Cet. Res. Manag. 9(3): 225–239.
Weir C R (2008). Overt responses of humpback whales (Megaptera novaeangliae), sperm whales
(Physeter macrocephalus), and Atlantic spotted dolphins (Stenella frontalis) to seismic exploration
off Angola. Aq. Mamm. 34(1): 71-83.
Weir C R, Debrah J, Ofori-Danson P K, Pierpoint C and Van Waerebeek K (2008). Records of
Fraser’s dolphin Lagenodelphis hosei Fraser, 1956 from the Gulf of Guinea and Angola. Afr. J.
Mar. Sci. 30(2): 241-246.
West Africa Gust (WAG) joint industry project – Phase 1. Fugro GEOS Reference No:
C56110/3219/R1. December 2004
West African Gas Pipeline Company (WAGP, 2004), Environmental Impact Assessment for the
West African Gas Pipeline Project.
Wiafe G (2002). Spatial and temporal dynamics of plankton communities in the Gulf of Guinea
ecosystem. PhD Thesis, University of Ghana (Ghana), 200 pp.
Williams, G.C. 2001. Octocoral Research Center
http://www.calacademy.org/research/izg/orc_home.html
Web
Site.
Available
on-line
at
Eni S.p.A.
Doc.
000415_DV_CD.HSE.
0208.000_00
421 of 425
Wilson C E, Perrin W F, Gilpatrick J W Jr and Leatherwood S (1987). Summary of worldwide
locality records of the striped dolphin, Stenella coeruleoalba. US Department of Commerce NOAA
Tech. Mem. NMFS-TM-NMFS-SWFC-90 65pp.
World Bank, 2006. Ghana Country Environmental Analysis (report number: 36985-GH). Prepared
by the Environmentally and Socially Sustainable Development Department (AFTSD) Africa Region
227pp.
World Health Organisation WHO Core health statistics accessed at http://countrystudies.us/ghana/
Yankson K, 1999. EA Obodai. Journal of the Ghana Science Association 2(26) 26-31 pp.
Youngblood, W.W. and Blumer, M. 1975. Polycyclic aromatic hydrocarbons in the environment:
homologous series in soils and recent marine sediments. Geochim. Cosmochim. Acta. 39: 13031314.
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ANNEX 1
COPY OF SCOPING APPROVAL LETTER
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ANNEX 2
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EVIDENCE OF RESPONSE TO GHANA EPA SCOPING REPORT REVIEW COMMENTS
The table below contains a summary presentation which highlights how eni Ghana has given response to Ghana EPA review comments dated 10th
February 2014 to the Scoping Report for the proposed Ghana OCTP Block Phase 1 Field Development Project.
Response to EPA review comments on the Scoping Report for the proposed
Ghana Offshore Cape Three Point (OCTP) Block Phase 1 Field Development Project
Item
EPA Review Comment
Evidence of Responses Provided
Extensive consultations have been done. However the report does not
Stakeholder Engagement (Attachment A to draft E(SH)IA Report)
show how the concerns raised were assessed and used in identifying
duly updated; an issues Matrix has been elaborated.
the key issues of concern. This is the essence of scoping
Consultations
Stakeholder Engagement (Attachment A to draft E(SH)IA Report)
Consider Ghana Gas as one of your major stakeholders and bring any duly updated; eni BID (Background Informaitn Document) was
issue they have on board.
sent to Ghana Gas for their examination and provision of
feedback.
Environmental Assessment Regulations L.I. 1652 of 1999 has not been
Revised (cfr. par. 3.1.3 of draft E(SH)IA Report)
amended.
Legal
Revised and updated (cfr. par. 3.1.12 of draft E(SH)IA Report
Requirements and Local content is now a law, check it out (L.I. 2204)
Policy Framework It is not true that Ghana is not party to the OPRC Convention (page 30).
Revised (cfr. par. 3.2.2 of draft E(SH)IA Report)
Please do check the IMO status again.
Baseline: page 38. Update information on corals. Ghana has a live
The Fridtjoff Nansen baseline information present through the
coral reef in the western part of the country. The Fridtjoff Nansen cruise EPA website has been consulted and referenced in the draft
in 2009 and 2012 revealed this.
E(SH)IA Report (see par. 4.9.2).
Page 80: Primary data: The report talked about a survey. When is the
Baseline
survey going to be carried? Have you considered the Fridtjoff Nansen
Details of survey and dates involved are included in the draft
baseline report to find out whether the data generated would not be
E(SH)IA Report, par. 4.1, pg. 126
adequate for what the intended survey would do so as to avoid
duplication of effort?
The conduct of Fisheries Impact Assessment was raised by the
Has been developed as a separate stand-alone report. FIA report
Impact
Fisheries Commission as a legal requirement and it is important that
structure was agreed upon during discussions held with the
Assessment
ENI responds to this and takes it on board. This is essential given
Fisheries Commission in February 2014.
concerns about the beaching of whales in recent years.
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The effects of having two FPSOs possibly in close proximity should be
considered. This is likely to create conditions for the public particularly
fishermen to complain. It is essential we have enough information
through the assessment to enable us respond adequately.
The environmental matrix on page 63 is not clear. Why should noise be
a potential impact and at same time be an environmental component?
Onshore impacts was not given due attention in the scoping. There are
issues related to offshore waste coming onshore and an increase in
supply base support activities since we would have 2 producing fields.
Some indication of impacts would be useful.
EMP
There are currently no drilling cuttings management facilities onshore
Ghana. Your proposal to bring cuttings ashore for treatment must be
looked at critically. You'll have to convince the Agency that you set up
or has a facility that can treat all the cuttings onshore to the Agency's
satisfaction before permit can be given for such a proposal. The
management of drill cuttings and mud must be given due attention in
your EIA.
424 of 425
Distance from other exploration field in the area is such as not to
have to consider the cumulative impact; shall be specified in the
FIA report.
The environment matrix has been modified; Noise is cited only as
an impact on other environmental components (see Par. 7.2,
tables 7.5 – 7.10, pgs. 313-318).
Waste treatment and disposal by waste type have been described
for each project phase in both Chapter 2 (Project Description) and
Chapter 7 (Impacts). Furthermore, the eni Ghana Waste
Management Plan has been elaborated and included as
Attachment E to the draft E(SH)IA Report.
Important to note that waste treatment occurs offshore.
Drill cuttings shall be treated and discharged offshore, in
accordance with local regulation requirements (see par. 2.7.11)
Local regulation permits the discharge into the sea of drilled
cuttings contaminated by synthetic/pseudo oil based mud system
with a residual oil on cuttings content less than 3% of dry matter if
discharged beyond 500 m water depth (“Ghana EPA Guidelines
for Environmental Assessment and Management in the Offshore
Oil and Gas Development” article 12 and section 7).
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LIST OF ATTACHMENTS TO GHANA OCTP BLOCK PHASE 1 E(SH)IA REPORT
ATTACHMENT A: STAKEHOLDER ENGAGEMENT REPORT
ATTACHMENT B: BASELINE RESULTS
ATTACHMENT C: FISHERIES IMPACT ASSESSMENT (stand alone document to be delivered
directly to the Ghana Fisheries Commission)
ATTACHMENT D: OIL SPILL CONTINGENCY REPORT
ATTACHMENT E: WASTE MANAGEMENT PLAN

Ghana OCTP Block Phase 1 ESHIA

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