Baseline of the Status of the Mesoamerican Barrier Reef Systems

Transcription

PROJECT FOR THE CONSERVATION AND SUSTAINABLE USE
OF THE
MESOAMERICAN BARRIER REEF SYSTEMS
(MBRS)
Baseline of the Status
of the
Mesoamerican Barrier Reef Systems
MBRS / SAM
Results of Synoptic Monitoring
from 2004 and 2005
VOLUME I
December 2006
García-Salgado M., T. Camarena L., G. Gold B., M. Vasquez, G.
Galland, G. Nava M., G. Alarcón D. y V. Ceja M.
Project Coordinating Unit
Coastal Resources Multi-Complex Building
Princess Margaret Drive
P.O. Box 93
Belize City Belize
Tel: (501) 223-3895; 223-4561
Fax: (501) 223-4513
E-mail: [email protected]
Website: http://www.mbrs.org.bz
OF THE
MESOAMERICAN BARRIER REEF SYSTEMS
(MBRS)
Baseline of the Status
of the
Results of Synoptic Monitoring
from 2004 and 2005
VOLUME I
December 2006
García-Salgado M., T. Camarena L., G. Gold B., M. Vasquez, G.
Galland, G. Nava M., G. Alarcón D. y V. Ceja M.
Coastal Resources Multi-Complex Building
Princess Margaret Drive
P.O. Box 93
Belize City Belize
Tel: (501) 223-3895; 223-4561
Fax: (501) 223-4513
E-mail: [email protected]
Website: http://www.mbrs.org.bz
MBRS Technical Document No.18
Baseline of the Status of the Mesoamerican Barrier Reef System
OF THE
MESOAMERICAN BARRIER REEF SYSTEM
(MBRS)
Belize – Guatemala – Honduras – Mexico
Baseline of the Status of the Mesoamerican Barrier Reef Systems
Results of Synoptic Monitoring from 2004 and 2005
Volume 1
García Salgado M.A., T. Camarena L., M. Vasquez, G. Gold
B., G. Galland, G. Nava M., G. Alarcón D., and V. Ceja M.
Synoptic Monitoring Program
2004 and 2005
December-2006
CONTENT
PRESENTATION
ACKNOWLEDGEMENTS
1.
INTRODUCTION .......................................................................................................................................................1
2.
MBRS SYNOPTIC MONITORING PROGRAM....................................................................................................3
2.1 Objectives of the Synoptic Monitoring Program....................................................................................................3
2.2 Selection of the locations and monitoring sites .....................................................................................................3
3.
CORAL REEFS ...........................................................................................................................................................5
3.1 BENTHIC COVER IN THE MBRS..................................................................................................................................7
3.1.1 Scleractinian Coral Cover ...................................................................................................................................7
3.1.2 Algal cover .....................................................................................................................................................17
3.1.3 Gorgonian Cover................................................................................................................................................25
3.1.4 Sponge cover ......................................................................................................................................................29
3.1.5 Encrusting Coralline Algae...............................................................................................................................33
3.1.6 Millepora ............................................................................................................................................................36
REEF HABITATS ................................................................................................................................................................36
3.1.7 Live components of the reef...............................................................................................................................40
3.1.8 Ratio of Main Live Components to Algae .........................................................................................................42
3.2 CONDITION OF CORAL COLONIES IN THE MESOAMERICAN BARRIER REEF SYSTEMS ..........................................47
3.2.1 Species richness of scleractinian corals ............................................................................................................47
3.2.2 Diameter of coral colonies.................................................................................................................................50
3.2.3 Coral Colony Height ..........................................................................................................................................55
3.2.4 Average height of coral colonies by location ....................................................................................................57
3.2.5 Mortality of scleractinian coral colonies...........................................................................................................59
3.2.6 Diseases of the Coral Colonies ..........................................................................................................................64
3.2.7 Bleaching of Scleractinian Coral Colonies.......................................................................................................65
3.3.1 TOTAL FISH DENSITY IN THE MBRS REGION .......................................................................................................66
Total density of adult fish in each location ................................................................................................................68
Map of adult fish density in the reef...........................................................................................................................70
3.3.2 ADULT FISH DENSITY BY FAMILY ...........................................................................................................................72
Average density of fish families by habitat ................................................................................................................72
Density of fish families by location ............................................................................................................................75
3.3.3 SIZE STRUCTURE OF ADULT FISHES .......................................................................................................................76
Reef Habitats...............................................................................................................................................................77
Fish sizes for the locations in the MBRS ...................................................................................................................79
3.3.4 ADULT FISH BIOMASS .............................................................................................................................................81
Reef Habitat ................................................................................................................................................................83
Biomass by location ....................................................................................................................................................84
Map of Herbivorous and Carnivorous Fish Biomass................................................................................................85
3.3.5 DENSITY OF RECRUITS ............................................................................................................................................88
Reef Habitats...............................................................................................................................................................90
Recruits by Location ...................................................................................................................................................91
4 SEAGRASS......................................................................................................................................................................95
4.1. TYPES OF SEAGRASS .................................................................................................................................................95
4.2. IMPORTANCE OF SEAGRASS. ....................................................................................................................................96
4.3. THREATS TO SEAGRASS............................................................................................................................................96
5 MANGROVES...............................................................................................................................................................102
5.1 MANGROVE BIOLOGY .............................................................................................................................................102
5.2 IMPORTANCE OF MANGROVES ................................................................................................................................102
5.3 THREATS TO MANGROVES ......................................................................................................................................102
5.4 CURRENT SITUATION ..............................................................................................................................................103
6 MARINE POLLUTION ...............................................................................................................................................111
6.1 MATERIALS AND METHODS ....................................................................................................................................112
6.2 RESULTS ...................................................................................................................................................................113
6.3 FISH..........................................................................................................................................................................115
6.4 SEDIMENTS...............................................................................................................................................................121
7 WATER QUALITY ......................................................................................................................................................129
7.1 DESCRIPTION ...........................................................................................................................................................129
7.2 RESULTS ...................................................................................................................................................................131
8 DISCUSSION AND CONCLUSIONS.........................................................................................................................134
9 RECOMMENDATIONS ..............................................................................................................................................143
REFERENCES .................................................................................................................................................................146
ANNEXES.........................................................................................................................................................................150
ANNEX I. Indicators of the Status of the Mesoamerican Barrier Reef System ....................................................150
ANNEX II. Fish species studied under the Synoptic Monitoring Program...........................................................155
III Report on the Reef Monitoring Program. Cozumel Reefs National Park 2004-2005 ........................................156
LIST OF ACRONYMS AND ABBREVIATIONS USED
Cholinesterase
Atlantic and Gulf Rapid Reef Assessment
Autoridad para el Manejo Sustentable de la Cuenca Hidrográfica del Lago
de Izabal y Rio Dulce
Analysis of Variance
ANOVA
Amigos de Sian Ka’an, Mexico
ASK
Belize Fisheries Department, Belize
BFD
Bay Islands Conservation Foundation, Honduras
BICA
CARICOMP Caribbean Coastal and Marine Productivity
Comisión Centroamericana de Ambiente and Desarrollo
CCAD
Cuerpos de Conservación Omoa, Honduras
CCO
Centro de Estudios del Mar and Acuacultura, Guatemala
CEMA
Centro de Estudios y Control de Contaminantes
CESCCO
CINVESTAV Centro de Investigación and de Estudios Avanzados del IPN, Mexico
Comisión Nacional de Áreas Naturales Protegidas, Mexico
CONANP
Comisión Nacional de Áreas Protegidas, Guatemala
CONAP
Coastal Zone Management Authority and Institute, Belize
CZMA/I
Diameter at Breast Height
DBH
Dichloro-diphenyl-dichloroetane
DDD
Dichloro-diphenyl-dichloroetilene
DDE
Dichloro-diphenyl-trichloroetane
DDT
Dirección de Biodiversidad, Honduras
DiBio
El Colegio de la Frontera Sur, Unidad Chetumal, Mexico
ECOSUR
Environmental Protection Agency
EPA
Flora and Fauna Protected Area
F.F. P.A.
FUNDAECO Fundación para el Desarrollo and la Conservación, Guatemala
Fundación Mario Dary
FUNDARY
Global Positioning System
GPS
Green Reef, Belize
GR
Hexachlorociclohexane
HCH
Hol Chan Marine Reserve, Belize
HCMR
Total Hydrocarbons
HCs
Leaf Area Ratio
LAR
Ministry of Agriculture, Fisheries and Cooperatives, Belize
MAFC
Ministerio de Ambiente and Recursos Naturales, Guatemala
MARN
Mesoamerican Barrier Reef System Project
MBRS
Main Live Components
MLC
Marine Protected Area
MPA
Most Probable Number
MPN
National Park
N. P.
Non-Governmental Organization
NGO
Amonium
NH4
National Meteorological Service, Belize
NMS
AChE
AGRRA
AMASURLI
NMX-AA-042 Norma Mexicana para el Análisis de Agua No. 042
Nitrite
NO2
Nitrate
NO3
NOAA
OCC
PA
PAHs
PCBs
PCQM
PCU
PEL
PO4
National Oceanographic and Atmospheric Administration, USA
Oficina de Cambio Climático, SERNA, Honduras
Protected Area
Policyclyc Aromatic Hydrocarbons
Polychlorinated Biphenyls
Point-Centered Quarter Method for Mangroves
Probable Effect Levels
Orthophosphate
REIS
RGR
SEMARNAT
SERNA
SICA
SLA
SM-AM
SMP
SS
SWCMR
TASTE
TEL
TIDE
TS
UB
UCM
UGAMPC
UNAH
UNIPESCA
UQROO
USAC
WB
WCS
YSI
Regional Environmental Information System
Relative Growth Rate
Secretaría de Medio Ambiente and Recursos Naturales, Mexico
Secretaría de Recursos Naturales, Honduras
Sistema de la Integración Centroamericana
Specific Leaf Area Ratio
Secretaría de Marina – Armada de Mexico
Synoptic Monitoring Program
Strategic Site
Southwater Caye Marine Reserve, Belize
Toledo Association for Sustainable Tourism and Empowerment, Belize
Threshold Effects Level
Toledo Institute for Development and Environment, Belize
Transboundary Site
University of Belize, Belize
Unresolved Complex Mixture
Unidad de Gestión Ambiental Municipalidad de Puerto Cortés, Honduras
Universidad Nacional Autónoma de Honduras
Unidad de Manejo de la Pesca and Acuicultura, Guatemala
Universidad de Quintana Roo, Mexico
Universidad de San Carlos de Guatemala, Guatemala
World Bank
Wildlife Conservation Society
Yellow Springs Instruments
PRESENTATION
The Mesoamerican Barrier Reef Systems (MBRS) comprise an extensive network of complex
ecosystems, with a high biological diversity. It extends from the northern Yucatan Peninsula in
Mexico, through Belize and Guatemala, to the Bay Islands in Honduras. A large human
population from diverse social and ethnic backgrounds benefit from the marine and coastal
resources through different activities related to fishing, tourism and coastal development. These
activities are continually expanding in the region, generating increased levels of pressure on the
reef ecosystems, coastal lagoons, seagrass beds, mangrove forests, rivers, estuaries and
wetlands in general.
Due to the importance of the coral reefs and related coastal ecosystems in the region, it is
necessary to evaluate the status of the health of these systems in order to improve the
management of marine and coastal resources along the MBRS.
The MBRS Synoptic Monitoring Program (SMP) was designed to provide and apply a series of
standardized monitoring methods in the region. The information obtained is intended to identify
any changes in the status of the marine and coastal components of the MBRS. It is important
that monitoring is continued, on a regular basis, as some of the answers needed for
management require information in the short, medium and long-term.
Due to the changes that occur in the coastal ecosystems, either as a result of natural events or
anthropogenic influences, it is necessary to have a baseline of information, against which
comparisons can be made over time. The information generated during the SMP is being
entered and managed in a regional database, the Regional Environmental Information System
(REIS).
Based on the first data gathered for each site in the years 2004 and 2005, a baseline analysis
was conducted and is presented here. As part of the compilation of the report, two technical
consultations were conducted to discuss data analysis. The first consultation was held in
Chetumal, Mexico in November 2005, with more than 20 regional scientists in attendance. The
second consultation was held in Belize City, in April 2006 and was attended by personnel from
the protected areas and regional agencies. Topics covered during these meetings included:
coral reef ecology, reef fishes, mangrove forests, seagrasses, marine pollution and water
quality.
The description of the marine communities helps to identify the current conditions and the
conservation status of each area. Such studies form a basis for designing management actions
by providing elements for judgment and criteria for the adequate management of the resources
in the region. Furthermore, they serve to identify and select high priority sites for conservation,
or sites that are subject to over exploitation by tourism or fisheries, which work against the
natural processes and the delicate equilibrium of the marine and coastal ecosystems.
This document entitled “Baseline of the Status of the Mesoamerican Barrier Reef
Systems” is an information tool that should foster improved resource management and
environmentally and economically sustainable interactions between the natural resources and
people of the MBRS region.
MBRS Regional Director
Noel Jacobs
MBRS National Coordinators
Mexico. David Gutiérrez, Oscar Alvarez, Alfredo Arellano Guillermo
Belize. Vincent Gillette, Beverly Wade
Guatemala. Carlos Baldetti, Emma L. Díaz, Alba Nidya Pérez H.
Honduras. José A. Fuentes, Sixto Aguilar, Elda Maldonado, Oscar Pinto, Juan P. Suazo.
National Monitoring Coordinators during the different stages.
Mexico. Miguel García, Roberto Landa, Gabriela Nava, José Juan Domínguez
Belize., Isaías Majil, James Azueta
Guatemala. Antonio Salaverría, Lucía Gutiérrez
Honduras. Oscar Torres, David Jaén
Reviewers Spanish version
Héctor Reyes Bonilla.
Pedro Ramírez.
Juan Jacobo Schmitter Soto
José Juan Domínguez
ACKNOWLEDGEMENTS
We would like to extend our deepest appreciation to all the people and institutions that
participated on a daily basis in the actions for management and conservation of the MBRS
marine coastal resources .
Those who conducted training courses for the Synoptic Monitoring program include, Patricia
Almada-Villela, Gerardo Gold, Victor Ceja, Peter Sale, Arturo Zaldívar, Eden García,
Faustino Chi, Roberto Ibarra, Susana Patiño, Alejandro Arrivillaga, Nadia Bood, Miguel
Angel García.
We wish to recognize all those who have made the MBRS Synoptic Monitoring Program a
reality. This baseline report is an achievement benefiting the conservation of our natural
resources.
To all the people in the MBRS…
THANK YOU!!!!!
We also thank all the institutions that have supported the project:
The Global Environment Facility, the World Bank, Central American Commission for
Environment and Development (CCAD), and SUMMIT Foundation.
Participating Institutions:
Mexico
Belize
Amigos de Manatí
Amigos de Sian Ka'an
Centro Ecológico Akumal
CINVESTAV
CONANP
Bacalar Chico Marine Reserve
Caye Caulker Marine Reserve
Coastal Zone Management
Department of the Environment
Fisheries Department
ECOSUR
Friends of Nature
P.N. Arrecifes de Cozumel.
Glovers Reef Marine Reserve
P.N. I. Mujeres, Cancún,
Nizuc.
R.B. Sian Ka'an
R.B. Banco Chinchorro
P.N.. Arrecifes de Xcalak
SM – AM
Univ. de Quintana Roo
F.F.P.A. Yum Balam
Guatemala
Honduras
CEMA / USAC
CONAP
FUNDAECO
FUNDARY
UNIPESCA.
Univ. del Valle de
Guatemala
Punta de
Manabique
BICA - Utila
Cuerpos de Conservación Omoa
CESCCO
DIBIO/SERNA
Fundación Cayos Cochinos
Green Reef
Rio Sarstun
Proyecto Cuenca del Rio Tulian
Hol Chan Marine Reserve
Peace Corps
Port Honduras Marine Reserve
Sapodilla Cayes Marine Reserve
South Water Caye Marine Reserve
TASTE
TIDE
MARN
AMASURLI
SERNA
Universidad Católica
UNAH
Red de Desarrollo Sostenible
Municipalidad de Puerto Cortés
Municipalidad de Roatán
Participating Personnel.
Mexico
Belize
Guatemala
Honduras
Adriana G. Tun
Adriana Zavala
Albert Franquesa
Ann Snook
Arturo Zaldívar
Axayacalt Molina
Daniela Alonzo
Adrián Vernon
Alex Jones
Alicia Eck
Amador Pott
Auriola Samos
Carlos Ramírez
Carren Williams
Christine García
Daniel Arjona
Debbie Wang
Dennis Garbutt
Eden García
Elgar Badillo
Eugene Ariola
Faustino Chi
Gianna Gómez
Gina Young
Godwin Humes, Jr.
Guillermo Paz
Hampton Gamboa
Isani Chan
Jevon Hulse
Jocelyn Finch
Joseph Villafranco
Juan Chub
Kirah Forman
Kyle Koho
Leonardo Castro
Leonel Requena
Linda García
Lisa Carne
Lyndon Rodney
Marlon Williams
Maxine Monsanto
Miguel Alamilla
Nadia Bood
Nerissa Baeza
Neville Smith
Nicole Auil
Nidia Ramírez
Olga Lucía Gallegos
Rennick Jackson
Roberto Carballo
Roger Arana
Saul Vallecillo
Seleem Chan
Servando Valle
Shayne Pech
Sheila Walsh
Tammy Summers
Víctor Alegría
Robert Landolfi
Ana Beatriz Rivas
Ana Giró
Angela Mojica
Antonio Salaverría
Fredy Aguilar
Hugo Hidalgo
Liseth Pérez
Luís F. Fernández
María José González
María Rene Alvarez
Max Ortiz Baldetty
Romeo Leiva
Wendy D. Carrera
Ximena Galán
Adoni Cubas
Alejandro Gallo
Alicia Medina
Amilcar López
Anabel Izaguirre
Antonio Woods
Axcel Sandoval
Calina Zepeda
Carlos Cerrato
David Jaén
Fanny Gómez
Fidel López
Francisco García
Gillian Osorio
Gustavo Cabrera
Italo Bonilla
Jennifer Myton
Karen Escobar
Lidia Medina
Mauricio Casildo
Michelle Fernández
Oscar Torres
Pamela de León
Ramón Salvado
Roselly Vallecillo
Saulo Romero
Tesla Irias
Dolly Espindola
Eulalia Chan
Fabian A. Rodríguez Z.
Felipe Fonseca
Fredy A. Firerol
Gabriela Nava
Gabriela Rodríguez
Gilberto Acosta
Héctor Hernández
Javier González
Jesús Sánchez
Jorge Domínguez
José C. Salgado
José F. Reyes
José Juan Domínguez
Juan Pablo Rodas
Karen Arana
Laura Carrillo
Laura Chanona
Leticia Alpuche
Lucy Gallagher
Miroslava López
Norka Fortuny
Olga Lingard
Paulina Ku
Prócoro Hernández
Rafael Roldán
Raquel Hernández
Raúl A. Medina
Raúl Ucan
Roberto H. Landa
Roberto Ibarra
Rosa María Loreto
Sheryl Shea
Víctor Ceja
Wady Hadad
Wilma Díaz
Yazmín Paredes
1.
INTRODUCTION
The MBRS region extends from the northeast of the Yucatan Peninsula in Mexico,
continuing southwards along the coasts of Belize and Guatemala down to the Bay Islands in
Honduras. It is the second largest barrier reef in the world, approximately 1,000 km long
(Map 1).
The MBRS contributes to the stabilization and protection of the coastal landscapes,
maintains coastal water quality and serves as a feeding and nursery habitat for marine
mammals, reptiles, fish and invertebrates, many of which have great commercial
importance.
The objective of the Project for the Conservation and Sustainable Use of the Mesoamerican
Barrier Reef System is to improve the protection of the vulnerable and unique marine
ecosystems that comprise the MBRS and to support the countries of Mexico, Belize,
Guatemala and Honduras in reinforcing and coordinating national policies, regulations, and
institutional agreements for the conservation and sustainable use of this global public
resource. The Project is part of a long-term plan to ensure the integrity and continuous
productivity of the Reef System. The MBRS Project initiative is being actively promoted by
donors and partners in the region and in the context of the Mesoamerican Biological
Corridor Program.
The MBRS is under increasing pressure from several anthropogenic sources, including:
coastal tourism development, pollution from point and nonpoint sources, excessive
agricultural runoff, coastal aquaculture, pesticides, domestic waste, sedimentation on the
reef, over-fishing, increase in tourism activities, use of ships (fuel spills, anchors and
groundings) and other inappropriate uses of the resources.
Furthermore, it is subject to natural phenomena, including episodes of warmer
temperatures, flooding, bleaching, disease, storms and hurricanes. Human activities may be
compounding the impacts of these phenomena and place additional pressure on these
ecosystems, resulting in their inability to recover from natural events as quickly as they
might have under natural normal conditions.
It becomes more important, therefore, to have baseline information to detect any changes in
the ecosystems and to determine the direction, magnitude and cause of the changes as a
prelude to formulating potential solutions.
There are several studies (Lang, 2003; ICRI, 2002) on coral reefs in the region that have a
similar objective of determining the status of coral reefs. The questions this initiative aims to
answer are: What is the current state of reef conservation in the MBRS region? Are the
reefs and related ecosystems deteriorating? And are current resource management actions
effective in conserving the reefs?
The MBRS Project has established the Synoptic Monitoring Program as a methodology to
monitor the change in the status of the marine and coastal ecosystems, with a view to
improving the management of these natural resources. With this objective in mind, the
Manual of Methods for the MBRS Synoptic Monitoring Program was created, using aspects
of different existing protocols. This manual was the basis for the establishment of
standardized methods of marine and coastal monitoring for the region. In addition, it has
1
served as the basis for training of personnel from participating agencies since 2003. In
2004, data collection was initiated in most of the MBRS sites, and these data, along with
data collected in the year 2005, form the baseline. Permanent monitoring is carried out at
least once a year for all sites.
Map 1. - Mesoamerican Barrier Reef System.
2
2.
MBRS SYNOPTIC MONITORING PROGRAM
2.1 Objectives of the Synoptic Monitoring Program
The MBRS Synoptic Monitoring Program (SMP) is a long-term regional effort that involves
the countries of Belize, Guatemala, Honduras and Mexico with the objective of compiling
data and information about the health of the coral reefs and associated ecosystems as well
as key species in the Mesoamerican Region to provide a solid scientific base of information
for its short, medium and long-term management.
The Project manages the Regional Environmental Information System (REIS), a regional
database where monitoring information is stored. The information recorded in the field is
added to the database via the MBRS Project website. The REIS is a fundamental
component of the SMP.
2.2 Selection of the locations and monitoring sites
For the purpose of the SMP, the monitoring areas were classified in LOCATIONS. Each
LOCATION has one or more ECOSYSTEMS, which in turn have one or more HABITATS in
which selected SITES for monitoring are located. A LOCATION may have ~10-100 km2 of
area, while a SITE (on a scale of ~0.2 km2) is the level where data are collected and
samples taken. These sites are easily accessible from a vessel or from land.
Size, type, and diversity of ecosystems and habitats vary greatly throughout the MBRS
region. The monitoring locations currently identified for the SMP were selected by the
members of the SMP Technical Working Group in Tegucigalpa, Honduras in 2001.
After locations were established, specific monitoring sites were selected, based on the
zoning of the Marine Protected Area (MPA), the areas of use versus non-use, and fishing
grounds which were of particular interest to the MPA managers.
There are some monitoring sites outside of the MPAs that are considered strategic due to
the activities occurring near them or for their connectivity to the reef. This is the case for the
mangrove forests of coastal Honduras (near Cayos Cochinos) and the sites identified for
pollution analysis, including coastal lagoons, river mouths, port developments, shrimp farms,
etc.
Wherever a location contains a reef system, it has been subdivided into three habitats,
which are represented by a typical reef-zoning scheme (Figure 1). The Back Reef is located
in the lagoon before the reef crest. The Shallow Fore-reef is located on the sea side of the
reef crest with approximate depths between 5 and 10 meters, and the Deep Fore-reef is
located further out towards open sea. Monitoring in the Deep Fore-reef is conducted at
depths from approximately 13 to 20 meters.
3
Figure 1. - Reef Profile
Monitoring sites are located in each of these habitats. If the extension and/or number of
reefs (i.e. fringing, patches or barriers) are limited, it may be that one or more of the
previously defined habitats are not present. The depths defined in the monitoring manual
may vary depending on the region.
In the case of the marine pollution and water quality components, which required a network
of sites along the MBRS, some other factors were taken into account to define the layout of
sites. These sites were chosen because they: a) are representative of the area; b) contain a
high biological diversity, in terms of species and ecosystems; c) receive input of critical
levels of contaminants from urban and/or industrial areas; and/or d) are shared by two or
more countries, therefore requiring international cooperation for their prolonged
management.
4
3.
CORAL REEFS
Coral reefs are one of the most biologically important ecosystems, possessing the highest
biodiversity in the ocean. These massive structures are built entirely by tiny living
organisms. The construction and development of the reefs is made possible by the
relationship between the corals and their symbiotic algae.
Coral reefs originally emerged more than 200 million years ago, and some types of corals
that live today first evolved 150 million years ago. To date, 100,000 species have been
named and described out of an estimated total of between 500,000 and 2 million that live on
or in reefs (Spalding et al, 2001).
Corals are sessile, polyp-forming animals, from Phylum Cnidaria, that utilize available
calcium carbonate to form rigid skeletons and live in large colonies. There are more than
seventy species of stony corals (Class Anthozoa) in the Caribbean, whose skeletons form
complex coral structures which are called reefs. Other Cnidarians that are associated with
these reefs are soft corals (Subclass Alcyonaria), some zoantharians (Subclass Zoantharia)
and Millepora or “fire corals” (Class Hydrozoa).
Branching, boulder-forming and encrusting species compete for space on the reef. The reef
structure is made from giant amalgamations of these colonies, along with loose fragments
and calcareous sands, originating from natural breakdown of coral and other calcareous
structures. These rocky structures and their complementary algae, sponges, and other
sessile organisms constitute reefs (Goenaqa, 1986).
Coral polyps are heterotrophic and feed with tentacles, which are used to capture
zooplankton that swim freely in the water column. The most adaptive characteristic of these
polyps, however, is that they have unicellular algae, known as zooxanthellae, living as
endosymbionts inside their tissues. This symbiosis involves an exchange of food for safety,
as the photosynthetic algae provide nutrients for the polyps while being able to live within
the coral skeleton without being digested. Coral reefs sustain high levels of primary
productivity even in the nutrient-poor waters of the tropics (Goenaqa, 1986).
Coral reefs grow in environments with warm temperatures (>21ºC), full salinity, low turbidity,
good wave action, and a low possibility of prolonged emersion. The numerous microhabitats that are formed along the reef provide habitat and shelter to a great number of
organisms, including sponges, worms, mollusks, crustaceans, sea urchins, sea stars,
holothurians and fishes. This complex community of organisms is intimately intertwined as a
result of a long evolutionary history. (Goenaqa, 1986).
Coral reefs provide many important environmental services, such as coastal protection,
animal and plant habitat, breeding sites, and feeding and refuge areas. Economically, coral
reefs are utilized by both the tourism and fishing industries. In some areas, this interest
leads to significant coastal development. Because of these uses by people and the
ecological importance of reefs, they require special attention from scientists and resource
managers to prevent their degradation.
5
There is a constant interconnectedness and mutual dependency between the reef and its
complementary seagrass beds and mangrove forests. The flow of energy and species
between these areas, as well as several other biological, physicochemical, and geological
interactions, create one complete system that should be carefully managed to ensure proper
conservation and sustainable use of resources.
Species composition, live tissue cover, colony size, mortality, disease and bleaching are
examined at a spatial scale throughout the MBRS to give a regional picture of the state of
conservation of the Mesoamerican Barrier Reef Systems.
6
3.1 Benthic Cover in the MBRS
3.1.1 Scleractinian Coral Cover
Stony scleractinian and hydrozoan corals utilize calcium carbonate to create the threedimensional backbone of coral reefs. It is necessary to know the status of these species
when determining which direction to take in successful management. Without these species,
reefs can not recover from natural and anthropogenic disasters (Lang, 2003). The
percentage of hard coral cover is the parameter that is most frequently used by protected
areas managers to estimate the health of the reef. (Hill, 2004)
The MBRS region has an average of 23.47% live coral cover (median 21.01%) with a
standard error of 1.50% (Figure 2). These values fall within a range that is generally
considered to be healthy (Map 2). The standard error is included because it is the statistical
measure that indicates the degree of uncertainty with which an estimation obtained in a
sample approaches the true value of the population.
The highest percentage of cover (49.95%) was observed in South Water Caye (Belize) on
the deep fore-reef. The lowest cover (2.29%) was observed on the shallow fore-reef in
Gladden Spit (Belize). The mean coral cover reported by Kramer (2003) for the Wider
Caribbean, Gulf of Mexico, Bahamas and Brazil is 26%, differing by only 2.53% from this
work.
Figure 2 shows average live coral cover for each site, and the green line represents the
mean cover for the MBRS region as a whole. 52.3% percent of the MBRS sites have values
that are equal to or higher than the mean, indicating good or optimal conditions. Sites with
coral cover values under 20% need to be reanalyzed to include other healthy parameters
such as sponges, Millepora and gorgonians. The coral cover displayed in Figure 2 is
divided into three different colors, each representing one of the reef habitats. The sites are
also grouped by location and by country.
7
Scleractinian Coral Cover
60
Back-reef
Shallow Fore-reef
Deep Fore-reef
Cover (%)
40
23.47
20
Caye Glover's South W.
Caulker
Reef
C.
México
Belize
Gladden Spit
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
F01
D01
D02
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 2. – Mean (+/- standard error) percentages of live coral cover, by site, North to South, for the MBRS region. The green line represents the regional
mean.
8
Coral Reef Habitats
Taking into account the differences that exist in the environmental and hydrological
conditions and the differences in light penetration due to depth, sites were grouped into
three coral reef habitats: back-reef, shallow fore-reef and deep fore-reef.
Table 1 and Figure 3 show similar values for the mean percentages of coral cover in the
different habitats, but the median values seem to show a tendency of increase in cover from
the back-reef out towards the deeper zones.
The maximum value of live coral cover (49.95%) was recorded in the deep fore-reef while
the minimum cover (2.29%) occurred in the shallow fore-reef. All three habitats have means
that indicate healthiness.
Table 1. - Live coral cover by habitat.
Habitat
Mean
Back-reef
Shallow Fore-reef
Deep Fore-reef
24.64
22.09
24.60
Median
20.63
21.23
23.67
Standard
Deviation
13.59
10.19
12.41
Standard
Error
3.04
2.40
2.59
Minimum
Maximum
7.97
2.29
3.33
48.83
34.99
49.95
Scleractinian Coral Cover
MBRS Habitats
30
Good Condition > 20%
Cover (%)
20
10
0
Back-reef
Shallow Fore-reef
Deep Fore-reef
Habitat
Figure 3. – Mean (+/- standard error) coral cover by habitat.
The above analysis narrows the results ecologically (by habitat). The following section
narrows these same findings, geographically, by looking at individual locations and sites.
9
Monitoring Locations
Of the 13 coral monitoring locations along the MBRS, coral cover in seven locations seems
to be in good to optimal condition (>20%). These locations are Cozumel, Banco Chinchorro,
Caye Caulker, Glover’s Reef, South Water Caye, Sapodilla Cayes, Punta de Manabique
and Cayos Cochinos (Table 2).
Most of these locations show good reef development. However, the reef at Punta de
Manabique grows in small patches similar to those that exist on a typical back-reef. Punta
de Manabique exhibits different characteristics than the other locations, such as high
sedimentation, increased fresh water contribution and high levels of pollution.
The most abundant colonies in this location are those that are resistant to sedimentation
(genera Siderastrea, Mycetophyllia, Montastraea and Agaricia). Reef cover is reduced in
this location, and areas of low diversity may exist inside the reef patches.
Table 2. - Live coral cover by MBRS location
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Standard
Deviation
7.15
9.55
9.62
Standard
Error
2.92
3.38
3.93
Median
Standard
Deviation
18.67
11.97
44.58
20.72
18.98
12.92
44.00
17.83
44.25
11.12
28.95
Mean
27.37
26.61
18.85
Median
Minimum
Maximum
15.98
13.33
7.97
34.03
40.24
35.65
Standard
Error
Minimum
Maximum
4.63
2.92
3.09
8.85
2.07
1.46
1.55
5.11
13.65
7.85
41.50
13.67
25.75
14.18
48.83
30.65
45.60
12.92
5.87
5.69
2.62
1.71
34.67
2.29
49.95
19.17
24.66
7.62
4.40
24.44
37.74
29.77
25.84
15.66
Belize
MPA
Bacalar
Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Caye
Gladden Spit
Sapodilla
Caye
Mean
Guatemala/Honduras
MPA
Punta de
Manabique
Utila
Cayos
Cochinos
Median
Standard
Deviation
Standard
Error
Minimum
Maximum
26.05
15.57
26.05
15.55
0.31
4.51
0.22
2.60
25.83
11.07
26.27
20.09
24.88
24.53
6.14
2.75
17.14
32.33
Mean
The values calculated for the reefs of Xcalak, Bacalar Chico and Utila indicate an “alert”
status. Hol Chan and Gladden Spit were found to be in ”poor” condition, and further
10
management practices should be explored for these locations. Fortunately, no locations
were in “critical” condition at the time of this first report.
Due to the variation in the number of sites monitored at each location, there is no guarantee
that the values presented in this report are entirely representative of all of the locations, but
it does provide a baseline for later comparisons within the locations studied and across time.
Monitoring Sites
As previously mentioned, the representative unit in the monitoring program is the site, and
these sites have been selected based on their ecological importance to the MBRS. In the
case of coral reefs, all the sites are within MPAs.
Each site represents a section of the reef, or in some cases, a reef structure. These sites
are located in zones of both use and non-use. The mean cover for each site has been
graphed with its standard error. During future studies, this baseline information will be
compared, both temporally and spatially within each of the locations, in an attempt to
quantify any trends of change that occur on the reef.
Figure 4 shows the monitoring sites in Mexico, grouped by location, and each color
represents the habitat where it is located. 65% of the sites are in good condition with a value
of live coral cover equal to or greater than 20%.
The sites located near Cozumel have been classified as shallow fore-reef because they
developed on the insular platform, even though there is no reef crest. Banco Chinchorro and
Arrecife de Xcalak show well-defined habitat structure.
Coral Cover
México
60
Back-reef
55
Shallow Fore-reef
Deep Fore-reef
50
45
Cover (%)
40
35
30
25
20
15
10
5
0
F01
F02
F03
F04
Cozumel
F05
F06
B01
B02
F01
F02
F03
F04
D01
D02
B01
Banco Chinchorro
México
Sites
Figure 4. – Mean (+/- standard error) live coral cover at monitoring sites in Mexico.
11
F01
F02
F03
Xcalak
D01
D02
It is important to note that during 2005 Hurricanes Emily and Wilma hit the Yucatan
Peninsula (in August and November, respectively). Both directly impacted the MPAs off the
northern coast of Quintana Roo. Amongst the affected locations was the Cozumel Reef
National Park, a location monitored as part of the SMP.
The values reported in this report for Cozumel are from 2004. The monitoring results for
Cozumel from 2005, that include the monitoring conducted after the hurricanes, can be
found in the report “Report of the effects of hurricanes Emily and Wilma on the coral reefs of
the West coast of the Cozumel Reef National Park” (Alvarez-Filip and Nava-Martínez, 2005)
at the following website: http://pyucatan.conanp.gob.mx/wilma.htm.
Using the SMP data, the Cozumel Reef National Park included in its report “Report of the
Monitoring Program of the Cozumel Reef National Park 2004-2005” the results of the
monitoring during those seasons, as well as the results of the monitoring conducted after
hurricanes Emily and Wilma (Annex III). This report shows the differences in the observed
values of benthic cover before and after the hurricanes.
Monitoring in Belize was conducted mostly on back-reefs and shallow fore-reefs. 30% of the
sites in Belize have a live coral cover equal to or greater than 20% (good to optimal
conditions). (Figures 5a and 5b)
Coral Cover
Belize (1)
60
Back-reef
55
Shallow Fore-reef
Deep Fore-reef
50
45
Cover (%)
40
35
30
25
20
15
10
5
0
B01
B02
D01
D02
Bacalar Chico
D03
B01
B02
D01
D02
Hol Chan
B01
B02
D01
Caye Caulker
Belize
Sites
Figure 5a. - Mean (+/- standard error) live coral cover at monitoring sites in Belize.
12
D02
B01
D01
D02
Glover's Reef
Coral Cover
Belize (2)
60
Back-reef
55
Shallow Fore-reef
Deep Fore-reef
50
45
Cover (%)
40
35
30
25
20
15
10
5
0
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
Gladden Spit
B01
B02
D01
Sapodilla Caye
Sites
Figure 5b. - Mean (+/- standard error) live coral cover at monitoring sites in Belize.
In the case of Guatemala (Figure 6), there are only two monitoring sites, at Punta de
Manabique, and they are located in an area of high sedimentation and river discharge,
where the reef forms only in patches. The average cover is above 20%.
The location of these reef patches, near the Rio Dulce and Rio Motagua river mouths, is
important, as they may be the first reefs to be impacted by anthropogenic activities, such as
sedimentation, nutrient loading (agricultural fertilizers, sewage), harmful chemicals
(pesticides, industrial waste), and solid waste (trash, discarded matter). The patchy nature
of the reefs in Guatemala made 30m transects nearly impossible, so “U” shaped transects
were placed over a patch to properly survey the corals. Sediment-resistant species
(Montastraea cavernosa, Siderastrea sidereal, Agaricia spp.) were the most common in this
area.
13
Coral Cover
Guatemala/Honduras
60
Back-reef
55
Shallow Fore-reef
Deep Fore-reef
50
45
Cover (%)
40
35
30
25
20
15
10
5
0
B01
B02
P. Manab.
F01
D01
D02
F01
Utila
F02
D01
D01
D01
Cayos Cochinos
Guat.
Honduras
Sites
Figure 6. – Mean (+/- standard error) live coral cover at monitoring sites in Guatemala and Honduras
There are two monitoring locations in Honduras, Utila and Cayos Cochinos.
Turtle Harbor is located on Utila Island. The reef here has developed on an insular platform,
four to five meters deep, that drops off to form a vertical wall. Coral colonies tend to grow in
plate-like structures along this drop-off. A mean cover of 15.57% is observed at this location.
Only one site, located on the shallow fore-reef, has coral cover in an acceptable range
(Figure 6).
In Cayos Cochinos, four our of 5 sites are in good condition. The reef structures are very
similar to those at Utila. They are located on an insular platform, at an average depth of five
meters, culminating in a steep (but not vertical) slope. This location is influenced by several
rivers that flow into the sea nearby.
14
Coral Cover Map of the reef
Coral cover is divided into five categories based on ecological status. These categories
have been determined based on their relevance to management. Stony coral cover should
be analyzed along with cover of sponges, gorgonians and Millepora to provide a general
picture of reef health (Map 2).
Conditions:
¾ Critical, from 1.00% to 10.00%. – Sites in this category show signs of reef
deterioration. The sites in this category should be analyzed carefully, since they have
very low coral cover.
Action: Factors leading to deterioration of the reef need to be identified in order to
propose restoration actions, to develop a more efficient management plan
and to assess the feasibility of closing the site to all types of activities.
¾ Poor, from 10.01% to 15.00%. - This category represents sites that may be subject to
significant stresses or external pressures that could endanger the stability of the
system and lead to rapid deterioration.
Action: Factors causing this deterioration need to be determined to propose
restoration actions and to develop a more efficient management plan.
¾ Alert, from 15.01% to 20.00%. Reefs in this category, as well as local human uses,
need to be monitored to determine what management measures should be applied to
prevent a decline in live coral cover.
Action: Stress-causing factors need to be determined, and efficient management
practices need to be proposed, in an attempt to prevent deterioration.
¾ Good, from 20.01 to 30.00%. Coral cover is not a significant management issue at
these sites.
Action: Continue monitoring to detect possible changes and propose preventative
actions to avoid deterioration.
¾ Optimal, 30.01% or more. These sites exhibit optimal conditions.
Once again, because the reef is an assembly of diverse organisms where inter- and intraspecific relationships are important, live coral cover needs to be analyzed along with the
other live components of the benthic reef system to provide a more complete picture of a
site’s status.
The patterns observed on scleractinian coral cover along the region are the result of the first
monitoring only, and they are reported as a baseline for future comparisons with data
obtained during subsequent monitoring.
15
Map 2. - Scleractinian Coral Cover observed in the MBRS region
16
3.1.2
Algal cover
After stony corals, algae are the most prevalent component of the reef benthic community
and in some locations, cover more area than the corals themselves. Macroalgae (green,
red, brown) form part of the bottom trophic level of the reef food web. Algal cover varies
with depth, season, and natural nutrient fluctuations, but sudden, significant changes in
algal cover are often an indicator of anthropogenic influences, including nutrient pollution
(fertilizers, sewage) and decreases in numbers of herbivores (overfishing, climate change,
food web alteration) (Rogers, 2001). Increased algal cover reduces the available substrate
for coral recruitment, so it is an important parameter to measure when surveying reef status.
Filamentous algae, macroalgae (Dictyota, Lobophora, Halimeda), and blue-green algae are
combined for this measure.
The baseline algal cover is 35.38% for the region (median of 34.83%), with a standard
deviation of 15.13 and a standard error of 1.88%. The minimum recorded value is 11.90%
and the maximum is 77.26%. The regional levels indicate a condition of “alert” for algal
cover.
The mean macroalgal cover reported by Kramer (2003) for the entire region of the Wider
Caribbean, Gulf of Mexico, Bahamas and Brazil is 23 %. Therefore, an additional 12% of the
benthic community is composed of algae in the MBRS region when compared to the rest of
the tropical Western Atlantic, contributing to the “alert” status.
The north to south variation of algal cover in the MBRS region is presented in Figure 7. In
some cases, the standard error is not given because those sites were grouped into one long
transect as a result of incorrect data entry. Unfortunately in these circumstances, the degree
of uncertainty is lost.
Reef Habitats
Coral and algal cover are two of the main benthic components on the reef. The relationship
between them may give us an indication of the health of our reef systems. Table 3 shows
the algal cover for each of the MBRS habitats.
Table 3 – Mean algal cover by habitat in the MBRS.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
27.98
36.20
35.39
Median
26.00
40.19
40.26
17
Standard
Deviation
12.49
13.09
17.30
Standard
Error
2.79
3.09
3.61
Minimum
Maximum
12.17
11.90
1.67
55.10
56.79
61.55
Algal Cover
100
Back-reef
90
Shallow Fore-reef
Deep Fore-reef
80
Cover (%)
70
60
50
40
35.3
30
20
10
Caulker Reef
C.
México
Belize
Gladden Spit
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
F01
D01
D02
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 7. – Mean (+/- standard error) algal cover, by site, from North to South in the MBRS Region. The green line represents the regional mean.
18
Based on the classifications shown on Map 3, the back-reef represents the habitat that is in the best
condition. The high algal cover found on the fore-reef habitats puts them in the “alert” or “poor”
categories. (Figure 8)
Algal Cover
MBRS Habitats
50
Good Condition < 30%
40
Cover (%)
30
20
10
0
Back-reef
Shallow Fore-reef
Deep Fore-reef
Habitat
Figure 8. - Mean (+/- standard error) algal cover by habitat in the MBRS. The green line represents the
regional mean.
Algal cover by location
Table 4 shows the algal cover for each location. Similar to coral cover, a variation in the
number of sites that are currently monitored in each location prohibits assurance that the
values reported here are completely representative of an entire location, but baseline values
can be given (for later reference) and comparisons can be made at the site level. Any
differences between mean and median algal cover in Table 4 are caused by the influence
that extreme values (high or low) have on the mean but not the median.
Table 4. - Percentage of algal cover for the MBRS locations.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean
32.72
23.03
41.20
Median
29.14
18.20
45.58
19
Standard
Deviation
10.12
12.27
16.16
Standard
Error
4.13
4.34
6.60
Minimum
Maximum
22.37
11.90
12.58
47.85
44.31
56.79
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Mean
39.28
67.32
19.42
30.06
26.07
39.85
19.62
Median
38.28
66.15
17.84
27.17
25.25
43.72
18.31
Standard
Deviation
10.46
8.19
6.65
6.35
6.51
11.76
4.15
Standard
Error
4.68
4.10
3.33
3.66
2.91
3.55
2.39
Minimum
Maximum
26.75
59.73
13.17
25.67
19.53
16.88
16.28
55.10
77.26
28.83
37.33
36.56
55.00
24.26
Minimum
Maximum
23.36
42.68
32.87
28.38
54.38
48.74
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
Mean
25.87
48.11
42.95
Median
25.87
47.28
44.96
Standard
Deviation
3.55
5.89
6.54
Standard
Error
2.51
3.40
2.92
Banco Chinchorro, Caye Caulker, Glover’s Reef, South Water Caye, Sapodilla Cayes and
Punta de Manabique are all in good or optimal condition. The sites in a condition of “alert”
are Cozumel, Bacalar Chico and Gladden Spit. The rest of the sites show conditions from
“poor” to ”critical.”
Monitoring sites
Figures 9, 10a, 10b and 11 show algal cover at the monitoring sites for the four countries.
The green line indicates the maximum acceptable value of 30% cover. Each color
represents one of the reef habitats.
Monitoring season should be considered when comparing sites (especially during seasonal
coral recruitment), and it is also important to take into account the location of the sites or
MPAs, as it might not be appropriate to compare sites near coastal influences with those
that are offshore.
Figure 9 shows algal cover for sites in Mexico. 55% of the sites are in good condition (cover
equal to or less than 30%). Banco Chinchorro has the most sites in good condition, followed
by Cozumel and Xcalak.
20
Algal Cover
México
80
Back-reef
Shallow Fore-reef
70
Deep Fore-reef
Good Conditionn < 30%
60
Cover (%)
50
40
30
20
10
0
F01
F02
F03
F04
F05
F06
B01
B02
Cozumel
F01
F02
F03
F04
D01
D02
B01
Banco Chinchorro
F01
F02
F03
D01
D02
Xcalak
México
Sites
Figure 9. – Mean (+/- standard error) algal cover by site, in Mexico
In Belize, 40% of the sites show a good condition (Figures 10a and 10b). The rest of the
sites show conditions from “alert” to “critical” (Map 3). Hol Chan, Gladden Spit, and Bacalar
Chico are the locations with problem sites (greater than 30% cover), and Caye Caulker and
Sapodilla Cayes have sites with lower algal cover.
Algal Cover
Belize (1)
80
70
Back-reef
Shallow Fore-reef
60
Deep Fore-reef
Cover (%)
50
40
30
20
10
0
B01
B02
D01
D02
Bacalar Chico
D03
B01
B02
D01
D02
Hol Chan
B01
B02
D01
Caye Caulker
Belize
Sites
Figure 10a. – Mean (+/- standard error) algal cover by site in Belize (1)
21
D02
B01
D01
D02
Glover's Reef
Algal Cover
Belize (2)
80
Back-reef
Shallow Fore-reef
70
Deep Fore-reef
60
Cover (%)
50
40
30
20
10
0
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
Gladden Spit
B02
D01
Sapodilla Caye
Sites
Figure 10b. – Mean (+/- standard error) algal cover by site in Belize (2).
Both sites at Punta de Manabique in Guatemala have low algal cover. The same
sedimentation and high turbidity that is harmful to corals might be keeping algal growth
down by lowering light penetration (Figure 11).
All eight sites located in Honduras exhibit values above 30% algal cover, which places them
in the “alert,” “poor” or “critical” categories. When averaged by location, both Utila and
Cayos Cochinos show an “alert” status (Figure 11).
Algal Cover
Guatemala/Honduras
80
Back-reef
70
Shallow Fore-reef
Deep Fore-reef
60
Cover (%)
50
40
30
20
10
0
B01
B02
P. Manab.
F01
D01
D02
F01
Utila
F02
D01
D01
Cayos Cochinos
Guat.
Honduras
Sites
Figure 11. – Mean (+/- standard error) algal cover by site in Guatemala and Honduras.
22
D01
Map of algae cover in the reef
The algal cover is divided into five categories based on management implications (Map 3).
Algal cover needs to be considered along with coral, sponge, gorgonian and Millepora cover
to provide a complete picture of reef health.
Conditions:
¾ Optimal, from 1.00% to 20%. This range of algal cover is considered optimal.
Herbivore density should be surveyed for these sites.
¾ Good, from 20.01 to 30.00%. This range of algal cover is considered good.
Populations of herbivorous fishes should be surveyed and protected to keep algal
growth low.
Action: Possible stress agents need to be determined in order to propose preventive
management actions and avoid deterioration.
¾ Alert, from 30.01% to 40.00%. Algal cover, and possible sources of stress
(herbivorous fish density, pollution, nutrient loading), need additional monitoring.
Action: Possible stress agents need to be determined in order to propose preventive
management actions and avoid deterioration.
¾ Poor, from 40.01% to 50.00%. - This category includes sites that may be subjected
to increased levels of stress or external pressures that may threaten the system’s
stability and lead to rapid deterioration.
Action: Stress agents causing deterioration must be determined in order to propose
mitigating actions and a more efficient management plan.
¾ Critical, 50.00% or more – This category includes sites that show signs of reef
deterioration. The sites with algal cover in this range must be monitored more closely.
Action: Stress agents causing deterioration must be determined in order to propose
restoration actions. These sites will also require more efficient management,
and the feasibility of closing the site to all types of activities must be
considered.
This information must be analyzed along with other reef components, especially herbivorous
fish density and live coral cover. These results establish the baseline that will allow for future
comparisons with data obtained in subsequent monitoring, to determine temporal changes
in algal cover.
23
Map 3. - Algal cover observed in the MBRS region
24
Live coral cover and algal cover are the two most important components of the benthic reef
community. Other sessile organisms do play a role in reef ecology and are reported below,
but at this time, the remaining benthic components are not divided into management
categories (e.g. “alert,” “critical,” etc.) but are only compared by habitat, location, and site.
3.1.3 Gorgonian Cover
Soft corals, or gorgonians, are represented in the reef as a secondary group, as they are not
reef builders. However, they are found in most of the reef habitats and dominate some
areas. Their densities may be important for some sites.
Gorgonians do not have a permanent skeletal structure; the body shape is maintained
through hydrostatic pressure. In certain sites soft corals may be a good indicator of the
structure of the sea landscape, along with scleractinian corals. These organisms offer
protection to fishes and serve as food to some gastropods of the genus Cyphoma.
Within the MBRS, gorgonian cover oscillates between 0.49% and 22.41%, with an average
of 8.76% (median of 8.33%), a standard deviation of 5.67 and a standard error of 0.70%.
In Figure 12, the average cover for gorgonians can be observed for each of the monitoring
sites. The green line indicates the average cover for the entire region.
Gorgonian Cover
30
Cover (%)
20
10
8.7
Caulker Reef
C.
México
Belize
Gladden Spit
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
F01
D01
D02
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 12. – Mean(+/- standard error) gorgonian cover, by site, North to South, in the MBRS region. The
green line indicates the regional mean.
25
Reef Habitats
Table 5 shows the mean gorgonian cover for each of the reef habitats. The deep fore-reef
shows the highest values.
Table 5. - Percentage of gorgonian cover by habitat in the MBRS.
Habitat
Mean
Back-reef
Shallow fore-reef
Deep fore-reef
7.58
7.47
12.14
Standard
Deviation
5.09
6.59
5.43
Median
6.84
4.60
10.46
Standard
Error
1.14
1.55
1.13
Minimum
Maximum
0.52
0.63
4.85
18.57
19.72
25.42
Gorgonian Cover
MBRS Habitats
Cover (%)
12
8
4
0
Back-reef
Shallow Fore-reef
Deep Fore-reef
Habitat
Figure 13. - Mean (+/- standard error) gorgonian cover by reef habitat.
Table 6 shows the average gorgonian cover by location. Cozumel, Hol Chan, Caye Caulker,
Gladden Spit and Punta de Manabique are below the regional average.
Table 6. – Percentage of gorgonian cover by location in the MBRS.
Mexico
MPA
Cozumel
Banco
Chinchorro
Xcalak
3.69
3.25
Standard
Deviation
2.76
11.53
11.30
12.07
11.40
6.39
5.21
Mean
Median
26
Standard
Error
1.13
2.26
2.13
Minimum
Maximum
0.83
8.31
2.64
3.69
19.72
16.53
Belize
MPA
8.20
3.43
6.88
13.57
8.36
3.43
6.67
13.22
Standard
Deviation
5.16
2.67
3.18
3.93
8.60
6.81
9.53
8.42
6.50
7.27
2.05
5.18
4.48
Mean
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Caye
Gladden Spit
Sapodilla Caye
Median
Standard
Error
2.31
1.33
1.59
2.27
0.92
1.56
2.58
Minimum
Maximum
2.39
0.49
3.50
9.83
16.22
6.37
10.67
17.67
6.93
0.63
6.64
12.00
18.57
14.69
Guatemala/Honduras
MPA
Mean
Punta de Manabique
Utila
Cayos Cochinos
Median
0.68
13.97
14.91
0.68
15.61
14.29
Standard
Deviation
0.22
6.53
5.08
Standard
Error
0.16
3.77
2.27
Minimum
Maximum
0.52
6.78
8.40
0.83
19.53
22.41
As mentioned before, this is a group that may be important due to its density in some sites,
given that its presence/absence helps to define the reef landscape.
Map of Gorgonian cover in the reef
The average gorgonian cover, by site, is divided into three categories. The categories define
the soft coral status in the region (Map 4).
¾ From 0.49% to 6.00%.
¾ From 6.01% to 11.00%.
¾ 11.01% or higher.
These categories are based only upon gorgonian cover, and this information is important
when included in the analysis of sites that may have low scleractinian coral cover (Section
3.1.7).
These results reflect the status of the sites and locations at the moment of this baseline. The
information presented can be compared with the results of subsequent monitoring to
determine any change over time.
27
Map 4. - Gorgonian cover observed in the MBRS region
28
3.1.4 Sponge cover
Like gorgonians, sponges are an important reef component. Most are not reef builders, but
they are found on all reefs and dominate some areas. At some sites, sponges, along with
scleractinian corals and gorgonians, help to define reef structure.
Sponge cover for the MBRS oscillates between 0.00% and 17.64 %, with an average of
4.65% (median 2.84%), a standard deviation of 4.48 and a standard error of 0.56% (Figure
14). The green line in the figure indicates the regional average.
Sponge Cover
Back-reef
Shallow Fore-reef
Deep Fore-reef
Cover (%)
20
10
4.6
Caulker Reef
C.
México
Gladden Spit
Sapodilla P.
Utila
Caye Manab.
Belize
Guat.
F01
F02
D01
D01
D01
F01
D01
D02
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 14. – Mean (+/- standard error) sponge cover, by site, North to South, for the MBRS region. The green
line indicates the regional mean.
Reef Habitats
Table 7 gives the average sponge cover for each of the habitats. The shallow fore-reef has
the highest sponge cover (Figure 15).
Table 7. - Percentage of sponge cover by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
3.05
7.16
4.50
Median
2.17
6.33
3.00
29
Standard
Deviation
3.63
5.18
4.07
Standard
Error
0.81
1.22
0.85
Minimum
Maximum
0.00
0.57
0.63
15.51
17.64
17.49
Sponge Cover
MBRS Habitats
10
8
Cover (%)
6
4
2
0
Back-reef
Shallow Fore-reef
Deep Fore-reef
Habitat
Figure 15. – Mean (+/- standard error) sponge cover by habitat.
Table 8 gives the average sponge cover by location. Cozumel, Banco Chinchorro, Glover’s
Reef, Punta de Manabique and Utila are the areas with highest cover.
Table 8. – Percentage of sponge cover by location.
Mexico
MPA
10.82
10.20
Standard
Deviation
3.36
6.69
2.56
4.23
1.96
5.66
1.91
2.00
0.78
Standard
Error
0.96
0.83
0.55
2.51
Mean
Cozumel
Banco
Chinchorro
Xcalak
Median
Standard
Error
1.37
Minimum
Maximum
6.51
15.15
2.18
1.33
17.64
6.41
Minimum
Maximum
0.68
0.17
1.00
1.33
5.87
3.61
3.50
9.17
Belize
MPA
3.12
1.15
2.63
6.33
2.84
0.42
3.00
8.50
Standard
Deviation
2.14
1.65
1.11
4.34
4.47
1.74
1.80
5.05
0.63
2.17
2.09
2.16
0.65
0.94
0.65
0.38
2.17
0.00
1.05
6.74
6.25
2.18
Median
Standard
Deviation
Standard
Error
Minimum
Maximum
Mean
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Caye
Gladden Spit
Sapodilla Cayes
Median
Guatemala/Honduras
MPA
Mean
Punta de
12.22
12.22
4.65
3.29
Manabique
7.49
4.40
8.87
5.12
Utila
Cayos
Cochinos
5.01
4.51
3.31
1.48
This information is analyzed with the other benthic parameters in section 3.1.7.
30
8.93
0.57
15.51
17.49
1.68
10.20
Map of sponge cover
The average sponge cover, by site, is divided into three categories. The categories define
the sponge status in the region (Map 5).
¾ From 0% to 5.00%.
¾ From 5.01% to 10.00%.
These categories are based only on sponge cover, and these data are intended to be the
baseline for future comparisons. This information is important when included in the analysis
of sites with low scleractinian cover.
31
Map 5. - Sponge cover observed in the MBRS region
32
3.1.5 Encrusting Coralline Algae
Encrusting coralline algae are an important benthic component on the reef as they cement
together loose coral fragments and other rubble into hard, smooth substrate that is ideal for
coral recruitment. Color ranges from dark pink or purple to grey, and these algae cover
large areas of some reefs in the region.
Encrusting coralline algae cover in the MBRS region ranges from 0.00% to 17.76%. The
mean cover is 3.40% (median=2.13%) with a standard deviation of 4.41 and a standard
error of 0.55% (Figure 16).
Encrusting Coralline Algae Cover
20
Back-reef
Shallow Fore-reef
Deep Fore-reef
Cover (%)
15
10
5
3.4
Caulker Reef
C.
México
Gladden Spit
Sapodilla P.
Utila
Caye Manab.
Belize
Guat.
F01
F02
D01
D01
D01
F01
D01
D02
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 16. – Mean encrusting coralline algae cover, by site, North to South, for the MBRS region. The green
line represents the regional mean.
Reef Habitats
Table 9 gives the average encrusting coralline algae cover for each of the reef habitats.
Highest numbers are reported for the deep fore-reef.
Table 9. – Percent cover of encrusting coralline algae by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
2.39
2.68
5.05
Median
1.33
1.43
3.38
33
Standard
Deviation
2.86
4.09
5.75
Standard
Error
0.66
0.99
1.23
Minimum
Maximum
0.00
0.00
0.00
9.00
15.21
17.76
Table 10 gives the average cover of encrusting coralline algae by location. Cozumel, Banco
Chinchorro, South Water Caye, Sapodilla Cayes, Punta de Manabique, Utila and Cayos
Cochinos show values under the regional average.
Table 10. – Percent cover of encrusting coralline algae by location.
Mexico
MPA
Mean
0.54
0.58
2.63
Cozumel
Banco Chinchorro
Xcalak
Median
0.21
0.42
2.70
Standard
Deviation
0.92
0.59
1.25
Standard
Error
0.38
0.21
0.51
Standard
Deviation
2.10
6.76
2.71
8.41
1.22
4.90
0.60
Standard
Error
0.94
3.38
1.36
4.86
0.55
1.48
0.34
Standard
Deviation
0.65
2.55
1.16
Standard
Error
0.46
1.47
0.52
Minimum
Maximum
0.00
0.00
0.42
2.37
1.43
4.09
Minimum
Maximum
0.67
2.50
3.33
2.17
0.00
0.00
0.17
6.34
17.76
9.00
17.50
2.33
15.21
1.33
Minimum
Maximum
1.69
0.29
1.05
2.61
5.23
3.55
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Mean
3.58
10.55
6.88
11.83
0.89
3.85
0.83
Median
3.66
10.97
7.59
15.83
0.00
2.11
0.99
Guatemala/Honduras
MPA
Mean
Punta de Manabique
Utila
Cayos Cochinos
2.15
2.40
2.61
Median
2.15
1.68
3.36
Encrusting coralline algae cover varies greatly throughout the region.
deviation and standard error exceed the mean at some sites.
In fact, standard
Map of encrusting coralline algae
The cover averages, by site, were grouped into three categories for encrusting coralline
algae cover (Map 6).
¾ From 0% to 5.00%.
¾ From 5.01% to 10.00%.
These cover categories are based only on the cover for encrusting coralline algae. This
information is important when considered as part of the analysis of the entire benthic
community (section 3.1.7).
34
Map 6. - Cover of coralline algae observed in the MBRS region
35
3.1.6 Millepora
Millepora cover in the MBRS region ranges from 0.00% to 10.83%. The mean cover is
1.86% (median=1.19%) with a standard deviation of 2.05 and a standard error of 0.25%
(Figure 17).
Millepora Cover
12
Back-reef
Shallow Fore-reef
Deep Fore-reef
Cover (%)
8
4
1.8
Caye
Glover's
Caulker
Reef
México
Belize
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
Gladden Spit
F01
D01
D02
South W.
C.
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 17. – Mean Millepora cover, by site, North to South, for the MBRS region. The green line represents
the regional mean.
Reef Habitats
Table 11 reports the average Millepora cover for each of the reef habitats. Both the deep
fore-reef and the back-reef have higher cover than the shallow fore-reef (Figure 18).
Table 11. - Percent cover of Millepora by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
2.18
1.40
2.09
Median
0.95
0.63
1.34
36
Standard
Deviation
2.36
2.48
1.50
Standard
Error
0.53
0.58
0.31
Minimum
Maximum
0.00
0.00
0.31
7.69
10.83
4.73
Millepora Cover
MBRS Habitats
2.5
2.0
Cover (%)
1.5
1.0
0.5
0.0
Back-reef
Shallow Fore-reef
Deep Fore-reef
Habitat
Figure 18. – Mean Millepora cover by habitat in the MBRS.
Table 12 shows the average cover of Millepora by location.
Table 12. – Percent cover of Millepora by location.
Mexico
MPA
Cozumel
Banco
Chinchorro
Xcalak
0.38
0.30
Standard
Deviation
0.28
0.60
0.94
0.63
0.63
0.42
0.92
0.15
0.38
Standard
Error
0.72
0.32
0.24
0.80
1.17
0.95
0.69
Mean
Median
Standard
Error
0.11
Minimum
Maximum
0.15
0.90
0.00
0.00
1.11
2.48
Minimum
Maximum
0.34
0.17
3.17
1.19
4.01
1.50
4.33
3.67
1.50
0.00
0.84
7.69
10.83
3.15
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Caye
Gladden Spit
Sapodilla Caye
1.98
0.80
3.71
2.06
1.34
0.77
3.67
1.33
Standard
Deviation
1.60
0.65
0.48
1.39
4.30
2.94
2.16
4.73
2.24
2.49
2.63
3.14
1.19
Mean
Median
Mean
Median
Guatemala/Hondura
MPA
Punta de Manabique
Utila
Cayos Cochinos
0.00
1.17
2.02
0.00
1.26
1.68
Standard
Deviation
0.00
0.31
2.01
37
Standard
Error
0.00
0.18
0.90
Minimum
Maximum
0.00
0.82
0.00
0.00
1.43
4.64
Map of Millepora cover
The cover averages, by site, were grouped into three categories (Map 7).
¾ From 0% to 2.00%.
¾ From 2.01% to 5.00%.
¾ 5.01% or higher.
These cover categories are based only on Millepora cover. This information is important
when included in the complete analysis of the benthic community for each site (Section
3.1.7).
38
Map 7. - Millepora cover observed in the MBRS region
39
3.1.7 Live components of the reef
This section includes an analysis of the entire benthic reef community (hard corals, algae,
gorgonians, sponges, encrusting coralline algae and Millepora).
When grouping all of these components together, the reefs of the MBRS range from 39.61%
to 99.20% live cover. The mean cover is 77.52% (median=78.34%) with a standard
deviation of 13.87 and a standard error of 1.72%.
Reef Habitats
Back-reef
The mean live cover for the back-reefs of the region is 67.71% (median=65.51%) with a
standard deviation of 14.51 and a standard error of 3.24% (Figure 19). Cover on the backreef ranges from 39.61% to 94.33%.
Live Components
Back-reef
100
80
Cover (%)
67
60
40
20
0
B01
B02
Banco
Chinchorro
B01
Xcalak
B01
B02
B01
B02
Bacalar Chico
B01
B02
B01
B02
South W.C
B03
B04
B05
B06
Gladden Spit
México
B06
B01
B02
Sapodilla
Caye.
Belize
B01
B02
Punta
Manabique
Guatemala
Sites
Coral
Algae
Gorgonians
Sponges
Coralline Algae
Millepora
Figure 19. – Mean live benthic cover, by site, for the back-reef in the MBRS region. The green line indicates
the regional mean.
40
Shallow fore-reef
On the shallow fore-reefs of the region, the live total live cover ranges from 60.03% to
94.11% (Figure 20). The mean cover for this habitat is 76.86% (median=77.75%) with a
standard deviation of 9.10 and a standard error of 2.14%.
Live Components
Shallow Fore-reef
100
80
Cover (%)
76
60
40
20
0
F01
F02
F03
F04
F05
F06
F01
Cozumel
F02
F03
F04
B. Chinchorro
F01
F02
Xcalak
F03
F02
F01
F02
Gladden Spit
F01
Utila
C. Cochinos
México
Belize
F01
Honduras
Sites
Coral
Algae
Gorgonians
Sponges
Coralline Algae
Millepora
Figure 20. - Mean live benthic cover, by site, for the shallow fore-reef in the MBRS region. The green line
indicates the regional mean.
41
Deep fore-reef
The mean live component coverage for the deep fore-reefs of the region is 83.54%
(median=84.05%) with a standard deviation of 11.20 and a standard error of 2.34% (Figure
21). Cover in this habitat ranges from 58.03% to 99.20%.
Live Components
Deep Fore-reef
100
83
Cover (%)
80
60
40
20
0
D01
D02
D01
D02
D02
D01
D03
B. Chinchorro
D01
D02
D01
B. Chico
México
D02
D01
D02
D01
D02
D01
D02
D01
Glover Reef South W.C. Gladden S.Sapodilla
C.
Belize
D01
D02
Utila
D01
D01
D01
C. Cochinos
Honduras
Sites
Coral
Algae
Gorgonians
Sponges
Coralline Algae
Millepora
Figure 21. - Mean live benthic cover, by site, for the deep fore-reef in the MBRS region. The green line
indicates the regional mean.
Scleractinian corals and algae are the components with the highest coverage throughout the
MBRS region (Figures 19, 20,21). Two back-reef sites have total coverage less than 40%,
while other sites in all three habitats have coverage around 60% or higher.
3.1.8 Ratio of Main Live Components to Algae
This section compares the main live components (MLC=stony corals, gorgonians, sponges,
encrusting coralline algae, and Millepora) to algae in order to develop a baseline that can be
used by later studies to determine any trends in change to the benthic reef community
(Figure 22). The mean ratio of MLC to algae in the MBRS region is 1.19, meaning that
typical reefs in this region are not overrun with algae (Figure 23).
A value of one indicates a reef with equal cover of MLC and algae. Values above one
represent reefs that have higher MLC cover than algal cover, while values below one
indicate areas that have higher algal cover
42
Main Live Components Cover vs. Algal Cover
80
Main Live Components Cover Mean
Algal Cover Mean
Cover (%)
60
42
40
35
20
Caye Glover's
Caulker Reef
México
Belize
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
Gladden Spit
F01
D01
D02
South
W. C.
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 22. – Mean MLC and algal cover, by site, North to South, in the MBRS region. The green line indicates the average regional algal cover, and the
blue line represents the average regional MLC cover.
43
Main Live Components : Algae Ratio
5.0
Back-reef
Live Components : Algae Ratio
Shallow Fore-reef
Deep Fore-reef
4.0
3.0
2.0
1.19
1.0
Caye Glover's
Caulker
Reef
México
Belize
Sapodilla P.
Utila
Caye Manab.
Guat.
F01
F02
D01
D01
D01
Gladden Spit
F01
D01
D02
South W.
C.
B01
B02
Hol
Chan
B01
B02
D01
B01
B02
D01
D02
Bacalar
Chico
B01
B02
B03
B04
B05
B06
B06
F01
F02
D01
D02
B01
B02
D01
D02
D03
Xcalak
B01
B02
D01
D02
D02
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
D01
D02
B01
B02
F01
F02
F03
F04
D01
D02
Cozumel
B01
B02
D01
D02
F01
F02
F03
F04
F05
F06
0.0
Cayos
Cochinos
Honduras
Sites
Figure 23. – Mean ratio of MLC cover to algal cover, by site, North to South, in the MBRS Region. The green line represents the regional average.
44
Reef Habitats
Average MLC and algal cover, by habitat, is reported in Table 13. The deep fore-reef has
the highest value for MLC coverage, but algal cover is also high in this habitat. The highest
MLC:algae ration is found on the back-reefs of the region.
Table 13. – MLC:algae ratios by habitat.
Habitat
Mean (coverage)
Live
Algae
Components
39.85
40.80
48.37
Back-reef
Shallow fore-reef
Deep fore-reef
Ratio
MLC:Algae
27.98
36.20
35.39
1.42
1.13
1.37
A comparison of MLC and algal cover can be seen in Figure 24. The regional mean is 1.19.
Main Live Components : Algae Ratio
Meoamerican Barrier Reef Systems
60
50
Cover (%)
40
Ratio 1.42
Ratio 1.13
Ratio 1.37
30
20
10
0
Back-reef
Shallow Fore-reef
Habitat
Figure 24. – MLC:algae ratio, by habitat, for the MBRS region.
45
Deep Fore-reef
Proportion of the Main Live Components/Algae by Location
For the purpose of this analysis, all sites were grouped by location; the average cover for
the main live components, algal cover and the MLC:algae ratios are given for each of the
locations in Table 14.
Table 14. – Ratio of MLC to algae, by location in the MBRS region.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean (cover)
Ratio
Live Components
Algae
MLC:algae
42.80
46.01
36.28
32.72
23.03
41.20
1.31
2.00
0.88
Live Components
Algae
MLC:algae
35.55
27.90
64.67
54.52
62.50
26.47
43.27
39.28
67.32
19.42
30.06
26.07
39.85
19.62
0.91
0.41
3.33
1.81
2.40
0.66
2.21
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Mean (cover)
Ratio
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
Mean (cover)
Live Components
Algae
41.10
40.60
49.44
25.87
48.11
42.95
Ratio
MLC:algae
1.59
0.84
1.15
As mentioned above, when the MLC:algae ratio is lower than one, algal cover is higher than
MLC cover. Under these circumstances, the reef is probably under some kind of stress,
allowing algae to out compete the other components for space. Xcalak, Bacalar Chico, Hol
Chan, Gladden Spit and Utila have MLC:algae ratios that are less than one. Cayos
Cochinos has a ratio that is between one and the regional mean value of 1.19. The rest of
the locations are above the regional mean.
46
3.2 Condition of Coral Colonies in the Mesoamerican Barrier Reef Systems
This section details the condition of the reef-building stony corals in the MBRS region. A
baseline health status is vital to ensure that resource managers can identify any negative
trends in the state of the reef.
3.2.1 Species richness of scleractinian corals
The species richness (number of species identified) is the simplest parameter analyzed in
this chapter. The mean number of species observed for the MBRS region is 11 (median=11)
with a standard error of 0.56 species (Figure 25). Species richness in the region ranged
from 7 (Punta de Manabique) to 23 (Xcalak).
Identification of the species is completed in-situ along transects (i.e. no intensive search for
species is conducted), so values might reflect lower species richness than that which
actually occurs at the site, if rare species are not located on a transect. The methodology
applied by the SMP does not require a roving search for all species of stony coral, so this
parameter is limited as an indicator of reef health.
Map 8 displays the species richness observed for each site.
47
Species Richness
25
Back-reef
Shallow Fore-reef
Deep Fore-reef
No. Species
20
15
10
5
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sites
Figure 25. - Species richness, by site, North to South, in the MBRS region.
48
Sapodilla P.
C.
Manb.
Guat.
Utila
F01
D01
B01
B02
D01
D02
D03
Xcalak
F01
D02
D01
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
B02
B01
B02
F02
D01
D02
Cozumel
B01
BO
D01
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Map 8. - Numbers of scleractinian coral species observed in the MBRS region.
49
3.2.2 Diameter of coral colonies
Coral colony diameter might be a good indicator of reef stability because areas with less
disturbance typically have larger colonies than areas that have to continuously rebuild due
to high stress conditions. Maximum diameter was measured and recorded for each coral
along a transect.
For the purpose of this study, all colonies were analyzed together, regardless of species.
Later studies should include individual analyses of colony size, by species or by genus
(specifically Acropora, Montastraea, and Diploria).
The mean maximum diameter for the MBRS region is 33.52cm (median=29.03) with a
standard deviation of 13.91 and a standard error of 1.84cm. Region wide, mean maximum
diameters ranged from 16.88cm to 71.10cm (Figure 26).
Kramer (2003) reports a mean maximum diameter 71cm for the Wider Caribbean, Gulf of
Mexico, Bahamas, and Brazil; however, only colonies equal to or larger than 25 cm are used
in that report. For this study, all colonies (at least 40) on each transect are measured,
regardless of size. This explains the significant difference between the Kramer data and
these.
Reef Habitats
Table 15 reports the average maximum diameter for the coral colonies at each reef habitat.
The highest mean is found on the back-reef.
Table 15. - Average diameter (cm) of coral colonies by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
Median
39.44
30.12
29.59
37.30
28.71
25.19
50
Standard
Deviation
17.19
6.61
11.85
Standard
Error
3.66
1.77
2.59
Minimum
Maximum
16.88
22.62
17.59
71.10
42.03
62.81
Mean Maximum Diameter of Coral Colonies
100
Back-reef
Shallow Fore-reef
Deep Fore-reef
Diameter (cm)
80
60
40
33
20
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sapodilla P.
C.
Manb.
Guat.
F01
D01
B01
B02
D01
D02
D03
Xcalak
F01
D02
D01
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
B02
B01
B02
F02
D01
D02
Cozumel
B01
BO2
D01
F01
F02
F03
F04
F05
F06
0
Utila
Cayos
Cochinos
Honduras
Sites
Figure 26. – Mean (+/- standard error) maximum diameter of coral colonies, by site, North to South, in the MBRS region. The green line represents the
regional mean.
51
Mean Maximum Diameter of Coral Colonies
MBRS Habitats
50
Diameter (cm)
40
30
20
10
0
Back-reef
Shallow fore-reef
Deep fore-reef
Habitat
Figure 27. – Mean maximum diameter of coral colonies by habitat.
Average diameter of coral colonies by location
Table 16 shows the average maximum diameter of the coral colonies by location. The
results given here include all colonies, regardless of species or size. Some locations have
different numbers of sites, so these results may not be totally representative of a location
when compared to another.
Table 16. - Average diameter (cm) of coral colonies at MBRS locations.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean
32.00
33.26
30.50
Median
29.35
27.86
30.22
Standard
Deviation
7.24
12.97
6.66
Standard
Error
2.96
5.80
2.72
Standard
Deviation
20.44
12.14
13.66
7.24
4.67
11.82
6.17
Standard
Error
9.14
6.07
6.83
1.81
2.34
3.94
3.56
Minimum
Maximum
23.68
20.48
22.16
41.42
48.27
39.35
Minimum
Maximum
19.51
21.15
40.18
21.08
16.88
17.59
51.60
70.41
46.60
71.10
38.32
26.90
49.89
62.81
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Mean
35.93
32.13
57.37
30.90
20.66
27.98
58.69
Median
27.62
30.38
59.10
32.10
19.43
22.62
61.66
52
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
Mean
31.57
25.40
29.21
Median
31.57
25.19
29.21
Standard
Deviation
7.59
3.92
3.26
Standard
Error
5.37
2.26
3.26
Minimum
Maximum
26.20
21.59
26.90
36.93
29.43
31.52
Most locations have an average diameter larger than 20 cm.
It is important to mention that the diameter of the colonies depends on the species and the
habitat where they are located. Some species have small sizes in general, or different types
of growth depending on the zone where they develop.
Map of average diameter of coral colonies on the reef
The average maximum diameters, by site, were grouped into three categories (Map 9).
¾ From 1 to 20.00 cm.
¾ From 20.01 to 35.00 cm.
¾ 35.01 cm or larger.
A separate analysis that includes only the major reef-building species is necessary to
determine their average size. Patterns observed in these data are the result of the first
monitoring and are represented here, only as a baseline, which can be used for comparison
during future surveys.
53
Map 9. - Average diameter of scleractinian coral colonies observed in the MBRS region
54
3.2.3 Coral Colony Height
In addition to maximum diameter, maximum height helps to determine which reefs are under
physical stress (requiring regrowth) and which areas have healthy, large colonies, serving
as the backbone of the reef.
Maximum height is only appropriate for branching and boulder-forming species. Encrusting
and plate-forming species grow out rather than up and therefore never reach comparable
heights. However, as with diameter, all colonies, regardless of species or size, are included
in this analysis. It therefore becomes necessary to perform an analysis by location and
habitat so that resource managers can take into account species composition, in these
areas, when interpreting results.
In high use areas, height may serve as a good indicator of the impact of tourism on the reef.
These locations have a high density of visitors, who are often inexperienced snorkelers or
divers, and unintentional contact between these people and the corals can lead to
fragmentation (i.e. lower maximum heights).
Colony fragmentation may lead to less fit corals, as energy expenditure rises to regenerate
broken pieces. In cases of considerable damage, total death can occur. These colonies
might then be replaced by algae or rapid growth coral species that are not necessarily major
reef-builders.
The mean maximum height for the reefs in the MBRS region is 20.93cm (median=19.46cm)
with a standard deviation of 9.56 and a standard error of 1.27cm. Maximum mean heights
range from 7.0cm to 47.22cm (Figure 28).
Reef Habitats
Table 17 reports the average maximum heights for each reef habitat. The back-reef has the
highest values.
Table 17. - Average maximum height of coral colonies by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
25.86
19.74
16.55
Median
21.97
19.52
15.10
Standard
Deviation
11.36
4.66
7.64
Standard
Error
2.42
1.25
1.67
Minimum
Maximum
11.07
11.10
7.00
47.22
31.03
36.54
The values on the deep fore-reef are lower than those at the other habitats. This is due to
the fact that most species grow in a plate-like form in deeper waters and in areas with a
slope or wall, and as stated earlier, plate-forming colonies do not reach any significant
height.
55
Mean Maximum Height of Coral Colonies
60
Back-reef
Shallow Fore-reef
Deep Fore-reef
Height (cm)
40
20
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sapodilla P.
C.
Manb.
Guat.
F01
D01
B01
B02
D01
D02
D03
Xcalak
F01
D02
D01
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
B02
B01
B02
F02
D01
D02
Cozumel
B01
BO2
D01
F01
F02
F03
F04
F05
F06
0
Utila
Cayos
Cochinos
Honduras
Sites
Figure 28. – Mean (+/- standard error) maximum height of coral colonies, by site, from North to South, in the MBRS region. The green line represents the
regional mean.
56
3.2.4 Average height of coral colonies by location
Table 18 reports the average maximum heights of coral colonies for each location. These
results include all colonies, regardless of species or size. The data may not be
representative of each entire location due to the fact that different numbers of sites are
monitored in each location, but they give a snapshot of the conservation status in each area.
Table 18. - Average height of coral colonies, by location, in the MBRS.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean
21.03
24.71
18.21
Median
20.54
24.07
18.58
Standard
Deviation
2.59
9.82
2.44
Standard
Error
1.06
4.39
1.00
Minimum
Maximum
17.68
15.07
13.78
24.27
39.20
20.77
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Gladden Spit
Sapodilla Caye
Mean
Median
21.34
18.39
35.20
14.47
15.06
22.87
35.13
15.76
17.66
36.06
14.75
15.15
20.55
30.89
Mean
Median
Standard
Deviation
14.87
8.04
8.83
6.48
2.16
7.66
9.58
Standard
Error
6.65
4.02
4.41
1.62
1.08
2.55
5.53
Standard
Deviation
2.67
4.83
4.15
Standard
Error
1.89
2.79
2.93
Minimum
Maximum
10.87
11.09
23.60
7.98
12.33
16.34
28.40
47.22
27.15
45.06
20.42
17.61
39.53
46.10
Minimum
Maximum
11.07
7.00
11.10
14.84
15.43
16.96
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
12.95
9.85
14.03
12.95
7.14
14.03
Map of average height of coral colonies on the reef
The average heights of the colonies, by site, were grouped into three categories (Map 10).
¾ From 1 to 15.00 cm.
¾ From 15.01 to 30.00 cm.
¾ 30.01 cm or larger.
Patterns of coral colony height in these data are the result of the first monitoring and are
represented as a baseline that is intended to be used as a comparison in future studies.
Like maximum diameter in the previous section, maximum height should be analyzed for
important individual, reef-building species such as Acropora palmate, Montastraea
cavernosa, M. annularis, and Diploria spp.
57
Map 10. - Average height of scleractinian coral colonies observed in the MBRS region
58
3.2.5 Mortality of scleractinian coral colonies
Mortality is one of the primary indicators of reef health. This section considers colonies that
show any mortality, old or recent. The results are reported as a percentage of colonies that
show some mortality.
On average, 40.13% (median=37.5%) of coral colonies in the MBRS region show some
form of partial mortality with a standard deviation of 28.62 and a standard error of 3.79%.
The percentage of colonies exhibiting mortality ranges from 0% to 98% (Figure 29).
Reef Habitats
Table 19 reports the average rate of mortality for each reef habitat.
Table 19. - Average mortality of coral colonies by habitat.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
44.85
39.74
35.45
Median
41.73
39.91
28.57
Standard
Deviation
30.32
26.72
28.56
Standard
Error
6.46
7.14
6.23
Minimum
Maximum
0.69
0.25
0.00
98.00
80.56
97.30
The highest mortality rates are observed on the back-reef, and the lowest rates occur on the
shallow fore-reef.
59
Percentage of Colonies with Mortality
Mesoamerican Barrer Reef Systems
100
Back-reef
Shallow Fore-reef
Deep Fore-reef
Colonies (%)
80
60
40
20
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sites
Figure 29. – Mean mortality rates, by site, North to South, for the MBRS region. The red line indicates the regional mean.
60
Sapodilla P.
C.
Manb.
Guat.
F01
D01
B01
B02
D01
D02
D03
Xcalak
F01
D02
D01
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
B02
B01
B02
F02
D01
D02
Cozumel
B01
BO2
D01
F01
F02
F03
F04
F05
F06
0
Utila
Cayos
Cochinos
Honduras
Average mortality of coral colonies by location
Table 20 shows the average rate of mortality for coral colonies by location.
Table 20. – Average mortality rate by location in the MBRS.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean
(%)
60.13
52.13
41.33
Median
68.69
47.06
44.23
Standard
Deviation
20.50
11.07
12.64
Standard
Error
8.37
4.95
5.16
Minimum
Maximum
29.90
40.63
21.62
80.56
66.67
55.77
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover’s Reef
South Water
Gladden Spit
Sapodilla Caye
Mean
(%)
61.89
0.69
54.37
39.02
32.53
29.64
94.39
Median
74.47
0.70
58.00
34.75
32.65
27.03
97.30
Standard
Deviation
39.61
0.10
22.20
13.18
4.56
21.20
5.54
Standard
Error
17.71
0.05
11.10
3.29
2.28
7.07
3.20
Standard
Deviation
4.49
0.14
8.98
Standard
Error
3.18
0.08
6.35
Minimum
Maximum
0.50
0.58
28.00
28.57
26.83
3.45
88.00
98.00
0.81
73.47
58.00
38.00
63.16
97.87
Minimum
Maximum
6.98
0.00
9.52
13.33
0.25
22.22
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
Mean
(%)
10.16
0.09
15.87
Median
10.16
0.02
15.87
Cozumel, Banco Chinchorro, Xcalak, Bacalar Chico, Caye Caulker, and Sapodilla Cayes
have mortality rates higher than the regional average.
These results should be compared with respect to coral cover. Reefs with less cover tend to
have lower mortality than crowded reefs, so a lower rate mortality is expected at the
sites/locations that have low cover.
61
Map of coral mortality on the reef
The mean mortality rates, by site, were grouped into five categories.
¾ From 0% to 15.00%.
¾ From 15.01% to 35.00%.
¾ From 35.01% to 55.00%.
¾ From 55.01% to 80.00.
Patterns observed in this analysis are the result of the first monitoring and are reported as a
baseline, to be used for comparison during future studies.
Coral mortality is caused by several factors, both natural and anthropogenic, including
storms, predation, eutrophication, collisions, pollution, bleaching, and ship groundings,
among others. It is important to determine the causes of coral mortality in the region in
order to make recommendations for management.
62
Map 11. - Percentage of coral colonies with mortality observed in the MBRS region
63
3.2.6 Diseases of the Coral Colonies
On average, 0.37% (median=0.00%) of the coral colonies on the reefs of the MBRS region
are infected with a disease (standard deviation=1.49 and standard error=0.20%). The
prevalence of coral diseases ranges from 0.00% to 10.00% throughout the region (Figure
30). Most likely, these low numbers are not representative of the disease status along the
reef. It is quite possible that the surveyors do not have sufficient knowledge in coral
diseases, so more in-depth training is necessary.
the MBRS is shown on Figure 30.
Under normal, relaxed conditions, corals should be able to successfully fight off disease, so
instances of infection are probably secondary to some other natural or anthropogenic stress.
Percentage of Colonies with Disease
12
Back-reef
Shallow Fore-reef
10
Deep Fore-reef
Colonies (%)
8
6
4
2
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sapodilla P.
C.
Manb.
Guat.
F01
D01
B01
B02
D01
D02
D03
Xcalak
F01
D02
D01
B01
F01
F02
F03
D01
D02
Banco
Chinchorro
B01
B02
B01
B02
F02
D01
D02
Cozumel
B01
BO2
D01
F01
F02
F03
F04
F05
F06
0
Utila
Cayos
Cochinos
Honduras
Sites
Figure 30. - Mean disease rate in coral colonies, by site, from North to South, in the MBRS region.
64
3.2.7 Bleaching of Scleractinian Coral Colonies
As a possible indicator of climate change, coral bleaching is a phenomenon that concerns
both the scientific and management communities, worldwide. Bleaching occurs when coral
polyps expel their symbiotic zooxanthellae and occurs during times of stress, including
warming of tropical waters.
On average, 2.47% (median=0.13%) of the colonies in the MBRS region show some degree
of bleaching (standard deviation=6.54 and standard error=0.87%). Bleaching rates range
from 0.00% to 38.00%, region wide (Figure 31).
As stated above, bleaching events typically occur during heightened sea temperatures, so
monitoring for this parameter should be completed during hotter months. Bleaching events
can only be detected a few weeks, during which corals either recover or die. For this
reason, low bleaching levels might be a factor of the monitoring seasons (i.e. surveyors are
only reporting mortality).
Percentage of Colonies with Bleaching
40
Back-reef
Shallow Fore-reef
Deep Fore-reef
Colonies (%)
30
20
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
F01
F02
D01
D02
Bacalar
Chico
Hol
Chan
Caye
Caulker
Glover´s
Reef
South
W.C
Gladden Spit
México
Belize
Sapodilla P.
C.
Manb.
Guat.
F01
D01
B01
B02
D01
D02
Xcalak
F01
D02
D01
B01
B02
D01
D02
D03
Banco
Chinchorro
B01
B02
B01
F01
F02
F03
D01
D02
Cozumel
B01
BO2
D01
B01
B02
F02
D01
D02
0
F01
F02
F03
F04
F05
F06
10
Utila
Cayos
Cochinos
Honduras
Sites
Figure 31. - Mean bleaching rate of coral colonies, by site, from North to South, in the MBRS region.
65
3.3 REEF FISHES
When monitoring the coral reefs of the MBRS region, it is important to not only consider the
reef building corals and other benthic components, but also the complementing fish
communities. These species make up an important taxonomic group economically, socially,
and ecologically. Within the SMP, the reef fishes are probably the most heavily exploited,
directly utilized resource that is measured, and the main threats to these species are
overfishing by humans, destruction of their habitat (including mangrove forests and
seagrass beds), and pollution of coastal watersheds.
Several species are targeted for their commercial value, and the livelihoods of many men
and women depend on their sustainable harvest or use for tourism. In addition, the taking of
reef fishes has, historically, been an important part of several of the cultures that exist in this
region.
Reef fishes are those that depend directly on the reefs for food and protection. Some
species of reef fishes feed on macroalgae (herbivores), some feed on other fishes and
invertebrates (carnivores) and others feed on coral polyps (coralivores). In addition, reef
fishes that travel back and forth between the reef and other ecosystems (seagrass beds,
mangrove forests) to feed or spawn often provide the reef with an important source of
nutrients, through their waste. This additional inflow of nutrients from fish waste is vital to
productivity (Roger, 2001).
A total of 9,374 individuals were counted during 563 transects conducted for fish surveys
during this monitoring period. Annex II lists the species of adult fish considered for this
analysis. Fish density, family composition, size structure, recruit density, herbivore biomass,
and carnivore biomass is analyzed.
3.3.1 Total Fish Density in the MBRS region
On average, MBRS sites have a fish density of 34.68 ind./100m2 (median=29.00
ind./100m2) with a standard deviation of 21.81 and a standard error of 2.84 ind./100m2.
Values ranged from 5 to 110.56 ind./100m2 throughout the region (Figure 32).
These values are less than those reported by Kramer (2003) for the Caribbean, Gulf of
Mexico, Bahamas, and Brazil region (mean=48 ind./100m2).
66
Adult Fish Density
140
Back-reef
Shallow Fore-reef
120
Deep Fore-reef
Density (ind/100m2)
100
80
60
40
34.68
20
Bacalar
Chico
Hol Chan
México
South W.C
Belize
Gladden Spit
Sapodilla P.
Utila
C. Manabi.
Guate.
F01
F02
D01
F01
D01
D01
B01
B02
B01
B02
D01
Glover's
Reef
B01
B02
B03
B04
B05
B06
F01
F02
D01
D02
Caye
Caulker
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
D03
B01
F02
F03
D01
D02
Xcalak
B01
B02
D01
D02
Banco
Chinchorro
B01
B02
D01
D02
Cozumel
B01
F01
F02
F03
F04
D01
F01
F02
F03
F04
F05
F06
0
Cayos
Cochinos
Honduras
Sites
Figure 32. – Mean (+/- standard error) adult fish density, by site, North to South, for the MBRS region. The green line represents the regional mean.
67
Table 21 reports the reef fish density for each habitat. Highest values are seen on the
shallow fore-reef (Figure 33).
Adult Fish Density
MBRS Habitats
50
40
Ind/100m2
34.68
30
20
10
0
Arrecife Posterior
Arrecife Frontal Somero
Arrecife Frontal Profundo
Habitat
Figure 33. – Mean (+/- standard error) adult fish density, by habitat in the MBRS region. The green line
represents the regional mean.
Table 21. - Average adult fish density (ind./100 m2) by reef habitats.
Habitat
Back-reef
Shallow fore-reef
Deep fore-reef
Mean
29.07
43.07
33.56
Median
21.25
33.00
27.92
Standard
Deviation
19.53
21.50
18.46
Standard
Error
4.26
5.21
4.23
Minimum
Maximum
6.67
18.75
5.00
74.38
77.78
65.22
Total density of adult fish in each location
Cozumel (Mexico) and Hol Chan (Belize) had the highest fish densities for the region. The
lowest values were observed in Caye Caulker (Belize) and Gladden Spit (Belize).
68
Adult Fish Density
MBRS Locations
70
60
Ind/100m2
50
40
34.68
30
20
10
México
Belize
Guatemala
Cayos
Cochinos
Utila
Punta
Manabique
Sapodilla Caye
Gladen Spit
South Water
Caye
Glover's Reef
Caye Caulker
Hol Chan
Bacalar Chico
Xcalak
Banco
Chinchorro
Cozumel
0
Honduras
Sites
Figure 34. – Mean (+/- standard error) adult fish density, by location, in the MBRS region. The green line
represents the regional mean.
Table 22 reports density values for each of the surveyed locations.
Table 22. - Average density (ind./100m2) of adult fishes by location.
Mexico
MPA
Cozumel
Banco Chinchorro
Xcalak
Mean
58.75
38.48
31.93
Median
57.50
36.40
29.00
Standard
Deviation
34.10
13.22
12.24
Standard
Error
13.92
5.40
5.47
Standard
Deviation
13.81
8.47
4.45
20.58
14.29
8.78
9.71
Standard
Error
6.18
4.24
2.22
10.29
7.15
2.78
5.61
Standard
Deviation
9.27
27.97
30.00
Standard
Error
6.56
16.15
17.32
Minimum
Maximum
19.17
23.75
18.13
110.56
61.88
50.00
Minimum
Maximum
32.72
45.42
11.05
27.92
13.33
5.00
17.33
65.22
64.38
20.72
74.38
47.08
32.50
35.33
Minimum
Maximum
13.97
21.25
18.75
27.08
71.47
71.67
Belize
MPA
Bacalar Chico
Hol Chan
Caye Caulker
Glover's Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Mean
43.93
57.87
14.96
46.72
26.93
15.50
24.22
Median
38.82
60.84
14.04
42.29
23.65
15.21
20.00
Guatemala/Honduras
MPA
Punta de Manabique
Utila
Cayos Cochinos
Mean
20.53
39.24
37.04
Median
20.53
25.00
20.71
69
Map of adult fish density in the reef
The average adult fish densities, by site, were grouped into three categories (Map 12):
¾ From 1.00 to 25.00 ind./100 m2.
¾ From 25.01 to 45.00 ind./100 m2.
¾ 45.01 ind./100 m2 or more
Patterns observed for adult reef fish density along the MBRS region are the result of the first
monitoring and are reported here as a baseline, to be used for comparison during future
studies.
70
2
Map 12. - Adult fish density (ind./100m ) observed at MBRS sites.
71
3.3.2 Adult fish density by family
The most abundant families of fishes, counted during this study, are Acanthuridae,
Haemulidae, Lutjanidae and Scaridae (Figure 36). These results match those reported in
Kramer (2003) for the Wider Caribbean. He reports that Acanthuridae, Haemulidae, and
Lutjanidae are the three most common families found during their surveying.
Of the families that are counted (see Appendix II), surgeonfishes (Acanthuridae) and
parrotfishes (Scaridae) together make up approximately 50% of the total calculated
abundance. The grunts (Haemulidae) represent 18%, and snappers (Lutjanidae) represent
another 10% of the total counted fishes. Snappers are especially common on the backreefs of the region.
Numbers of both herbivorous (Acanthuridae, Scaridae) and piscivorous (Serranidae,
Sphyraenidae, Carangidae) species are highest on deep fore-reef sites in Bacalar Chico,
Banco Chinchorro and Cayos Cochinos. Lowest values are observed at Gladden Spit,
Xcalak, and South Water Caye.
Angelfishes (Pomacanthidae) and Butterflyfishes
(Chaetodontidae), which feed on coral polyps and sponges, were observed in greatest
density, in Cayos Cochinos, the Sapodilla Cayes, and Banco Chinchorro.
Triggerfishes (Balistidae), were most abundant in the Sapodilla Cayes, and Microspathodon
chrysurus (Pomacentridae) was the most common species at Banco Chinchorro and
Xcalak.
Average density of fish families by habitat
Back-reef densities (by family) of adult reef fishes are comparable to those reported by
Kramer (2003) for shallow (<5m) sites across the Wider Caribbean (Figure 36).
Both Haemulidae and Acanthuridae have the same percentage as that reported by Kramer
(2003). Scaridae has a value of 18%, versus 31% in Kramer (2003), and Lutjanidae has a
value of 13%, versus 9% in Kramer (2003) (Figure 35).
Adult Fish Density by Family
Back-reef
Scaridae
18%
Serranidae
1%
Acanthuridae
30%
Pomacentridae
2%
Pomacanthidae
3%
Balistidae
1%
Carangidae
3%
Lutjanidae
13%
Chaetodontidae
7%
Haemulidae
22%
Figure 35. – Average adult fish densities, by family, for back-reef sites in the MBRS.
72
100
Acanthuridae
Balistidae
Carangidae
Chaetodontidae
Haemulidae
Lutjanidae
Pomacanthidae
Pomacentridae
Scaridae
Serranidae
60
40
20
México
Belize
Gladden Spit
B01
B02
Sapodilla P.
C
Manb.
Guate.
F01
F02
D01
South W.C
B01
BO2
D01
Glover's
Reef
B01
B02
B03
B04
B05
B06
F01
F02
D01
D02
Caye
Caulker
F01
D01
D02
Bacalar Chico Hol Chan
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
D03
B01
F02
F03
D01
D02
Xcalak
B01
B02
D01
D02
Banco
Chinchorro
B01
B02
D01
D02
Cozumel
B01
F01
F02
F03
F04
D01
0
F01
F02
F03
F04
F05
F06
Inds/100m2
80
Utila
Cayos
Cochinos
Honduras
Sites
Figure 36 – Average adult fish density, by family, in the MBRS Region. Data are displayed, by site, from North to South.
73
Figures 37 and 38 display the percentage of fish densities, by family, for the fore-reef
habitats. Acanthuridae makes up the largest percentage of counted individuals for both
habitats, followed by Scaridae, Haemulidae, and Lutjanidae on the shallow-fore reef and
Haemulidae, Scaridae, and Lutjanidae on the deep fore-reef.
Adult Fish Denstiy by Family
Shallow Fore-reef
Serranidae
3%
Acanthuridae
25%
Scaridae
20%
Pomacentridae
4%
Balistidae
4%
F
Pomacanthidae
4%
Carangidae
2%
Chaetodontidae
6%
Lutjanidae
12%
Haemulidae
20%
Figure 37. – Average adult fish density, by family, for shallow fore-reef sites in the MBRS.
Deep Fore-reef
Serranidae
4%
Acanthuridae
28%
Scaridae
20%
Pomacentridae
4%
Balistidae
6%
Pomacanthidae
4%
Carangidae
3%
Chaetodontidae
4%
Lutjanidae
11%
Haemulidae
16%
Figure 38. – Average adult fish density, by family, for deep fore-reef sites in the MBRS.
74
Table 23 reports the average density for adult fish, by family, for each habitat.
Table 23. – Average adult fish density (Ind./100 m2) by family by habitat.
Habitat
Acant
Balist
Carang
Chaetod
8.06
8.15
8.67
0.32
1.16
2.01
0.81
0.66
1.05
1.93
1.90
1.48
Back-reef
Shallow fore-reef
Deep fore-reef
Family
Haemul Lutjan
6.00
6.76
4.98
Pomaca
Pomacent
Scarid
Serran
0.80
1.18
1.33
0.57
2.77
1.41
4.81
6.33
6.11
0.33
1.18
1.32
3.38
3.93
3.49
Most families had a region wide distribution, and all families were seen in all three habitats.
Families Serranidae (groupers), Carangidae (jacks), Balistidae (triggerfishes), and Scaridae
were all most abundant on the fore-reef.
Density of fish families by location
Figure 39 shows adult fish density, by family, at each of the locations in the MBRS region.
At almost all locations, Acanthuridae, Haemulidae, and Lutjanidae were the most common
families.
Serranid groupers were most common in Cayos Cochinos (Honduras), Hol Chan and
Bacalar Chico (Belize), and Banco Chinchorro (Mexico); these species were rare or absent
in Gladden Spit and South Water Caye (Belize) and Punta de Manabique (Guatemala).
Table 24 reports the densities of adult fish by family for each location.
MBRS Locations
70
60
Acanthuridae
Balistidae
Carangidae
Chaetodontidae
Haemulidae
Lutjanidae
Pomacanthidae
Pomacentridae
Scaridae
Serranidae
Inds/100m2
50
40
30
20
10
México
Belize
Guatemala
Sites
Figure 39. – Average adult fish density, by family, for each location in the MBRS region.
75
Cayos Cochinos
Utila
Punta Manabique
Sapodilla Caye
Gladden Spit
South Water C.
Glover's Reef
Caye Caulker
Hol Chan
Bacalar Chico
Xcalak
Banco Chinchorro
Cozumel
0
Honduras
Table 24. - Values of adult fish density (ind./100 m2) by family in the MBRS locations.
Mexico
Location
Cozumel
Banco
Chinchorro
Xcalak
Family
Haemul Lutjan
13.68
5.81
Acant
4.00
Balist
1.20
Carang
0.00
Chaetod
0.62
7.67
0.46
0.61
3.62
2.07
7.06
0.42
0.22
0.61
6.28
Pomaca
1.14
Pomacent
0.00
Scarid
3.82
Serran
0.88
3.40
1.10
4.28
9.19
1.96
2.93
0.87
1.38
11.30
0.41
Belize
Location
Bacalar
Chico
Hol Chan
Caye
Caulker
Glover's
Reef
South
Water Caye
Gladden
Spit
Sapodilla
Caye
Family
Haemul Lutjan
Acant
Balist
Carang
Chaetod
Pomaca
Pomacent
Scarid
14.39
14.53
1.68
2.45
1.47
3.96
1.02
2.03
10.40
9.84
2.96
0.24
0.91
0.80
20.21
1.67
0.00
8.59
0.47
6.79
3.33
Serran
3.56
5.99
0.85
0.63
1.46
0.00
5.43
13.07
1.75
1.88
3.63
0.58
0.88
0.77
2.14
0.68
3.33
7.71
5.05
0.21
0.00
3.28
0.78
0.26
1.51
5.68
4.11
0.42
0.83
4.53
0.26
0.29
0.29
1.42
1.13
2.67
0.46
0.04
2.25
0.00
4.44
1.11
2.00
3.22
0.89
2.67
0.67
5.11
0.78
Family
Haemul Lutjan
Guatemala/Honduras
Location
Punta de
Manabique
Utila
Cayos
Cochinos
Acant
Balist
Carang
Chaetod
Pomaca
Pomacent
Scarid
Serran
2.19
0.00
0.00
2.08
9.38
2.40
2.60
0.00
1.46
0.00
6.11
3.10
1.67
1.51
5.28
8.10
3.65
0.71
7.38
0.91
8.73
0.56
0.71
3.73
1.90
0.71
1.67
6.83
6.35
2.14
The information reported here establishes the baseline to be used as a comparison tool
during future studies.
3.3.3 Size structure of adult fishes
Overfishing often drives the average size of a species down because larger individuals are
more valuable and therefore taken out of the population (Trexler and Travis, 2000). For this
reason, size structure becomes an indicator of fishing pressure and has been examined
during this study. This work analyzes the size structure of the reef fish community as a
whole (regardless of species).
Most individuals counted during this study fall into three size categories, 6-10cm, 11-20cm,
and 21-30cm (Figure 41). Smaller numbers of smaller and larger individuals were
observed.
76
Reef Habitats
When comparing fish size, with respect to reef habitat, it becomes apparent that greater
numbers of large fishes are seen on the fore-reef than on the back reef; however, these
numbers are still quite low when compared to the other size categories (Figure 40).
Fish Size Structure
MBRS Habitats
3500
>40 cm
31-40 cm
21-30 cm
11-20 cm
6-10 cm
0-5 cm
3000
Frequency
2500
2000
1500
1000
500
0
Arrecife Posterior
Arrecife Frontal Somero
Habitat
Figure 40. – Adult fish size, by habitat, in the MBRS region.
77
Arrecife Frontal Profundo
Fish Size Structure
450
400
>40 cm
31-40 cm
21-30 cm
11-20 cm
6-10 cm
0-5 cm
350
Frequency
300
250
200
150
100
50
Gladden Spit
México
Belize
Sites
Figure 41. – Adult fish sizes, by site, from North to South, in the MBRS region.
78
F01
F02
D01
South
W.C.
F02
D01
D01
Glover's
Reef
B01
B02
Caye
Caulker
B01
BO2
D01
B01
B02
B03
B04
B05
B06
F01
F02
D01
D02
Hol
Chan
B01
B02
D01
D02
Bacalar
Chico
B01
B02
D01
D02
B01
B02
D01
D02
Xcalak
B01
B02
D01
D02
B01
B02
D01
D02
D03
D01
Banco
Chinchorro
B01
F02
F03
D01
D02
Cozumel
B01
F02
F03
F04
F01
F02
F03
F04
F05
F06
0
Sapodilla Punta Utila
Cayos
Caye Manab.
Cochinos
Guate.
Honduras
Table 25 shows the number of individuals counted in each size category, by habitat.
Table 25. – Size frequency (by habitat) for adult fishes in the MBRS region.
Sizes
Back-reef
0-5 cm
6-10 cm
11-20 cm
21-30 cm
31-40 cm
>40 cm
Habitat
Shallow fore-reef
207
868
1,152
265
28
31
Deep fore-reef
62
642
1,469
803
143
33
n
171
1,081
1,380
412
68
17
440
2,591
4,001
1,480
239
81
Fish sizes for the locations in the MBRS
At most locations, 11-20cm is the category with the most number of individuals counted
(Figure 42). 6-10cm and 21-30cm also have high frequencies.
Fish Size Structure
MBRS Locations
1400
>40 cm
1200
31-40 cm
1000
11-20 cm
21-30 cm
Frequency
6-10 cm
800
0-5 cm
600
400
200
México
Belize
Guatemala
Cayos.
Cochinos
Utila
Punta
Manabique
Sapodilla Caye
Gladden Spit
South Water
Caye
Glover's Reef
Caye. Caulker
Hol Chan
Bacalar Chico
Xcalk
Banco
Chinchorro
Cozumel
0
Honduras
Sites
Figure 42. – Adult fish sizes by location in the MBRS region
Larger size individuals (>20cm) are vitally important to the reef ecosystem, as they are the
most fecund and therefore most reproductively successful individuals of their species.
Therefore, high numbers of the larger size categories are an indicator of a healthy reef fish
community. Cozumel, Banco Chinchorro, Bacalar Chico, Hol Chan, Utila and Cayos
Cochinos are the locations with higher numbers of large individuals (Table 26).
79
Table 26. – Size frequency (by location) of adult fishes in the MBRS region.
Location
0-5
Cozumel
Banco Chinchorro
Xcalak
Bacalar Chico
Hol Chan
Caye Caulker
Glover's Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Punta de
Manabique
Utila
Cayos Cochinos
6-10
Size Categories (cm)
11-20
21-30
31-40
>40
n
0
38
3
50
41
5
114
38
58
81
9
363
148
356
400
62
364
207
118
73
367
307
461
491
475
157
373
222
124
57
586
123
95
93
167
31
34
45
61
7
125
10
7
22
15
1
5
3
3
0
40
2
0
17
13
2
7
2
0
0
1127
843
714
1029
1111
258
897
517
364
218
0
23
63
39
6
1
132
0
8
51
212
188
122
199
104
42
62
10
13
490
521
Monitoring in this area needs to continue, on a consistent basis, over an extended period of
time, in order to follow any trends in average fish size on the reef. In addition, analyses of
individual species should be conducted to learn the status of ecologically and commercially
important species.
80
3.3.4 Adult fish biomass
The average herbivore biomass for the MBRS region is 2,056 g/100m2 (median=1,549
g/100m2) with a standard deviation of 2,237 and a standard error of 289 g/100m2.
Throughout the region, values range from 0 to 10,465 g/100m2 (Figure 43).
The estimate of biomass of individual fish is calculated using an equation from Marks and
Klomp (in Lang 2003), W=aLb, where W is the weight (grams), L is the length (cm), and a
and b are constants estimated from a linear regression.
Primary carnivorous species (Serranid groupers, Lutjanid snappers and Sphyraena
barracuda) average 940 g/100m2 (median=536 g/100m2) with a standard deviation of 1,297
and a standard error of 167 g/100m2 (Figure 43). Values range from 0 to 7,155 g/100m2.
81
Adult Fish Biomass
10000
Herbivore Biomass
Carnivore Biomass
Biomass (g/100m2)
8000
6000
4000
2,056
2000
0
F01
F02
F03
F04
F05
F06
B01
F01
F02
F03
F04
D01
B01
F02
F03
D01
D02
B01
B02
D01
D02
D03
B01
B02
D01
D02
B01
B02
F01
D01
D02
B01
B02
D01
D02
B01
B02
D01
D02
B01
B02
B03
B04
B05
B06
F01
F02
D01
D02
B01
B02
D01
B01
B02
F01
D01
D02
F01
F02
D01
940
Cozumel
Banco
Chinchorro
Xcalak
Bacalar
Chico
Hol Chan
Caye
Caulker
México
South
Water C
Belize
Gover's
Reef
Gladden Spit
Sapodilla P. Utila Cayos
C Manab
Cochinos
Guate
Honduras
Sites
Figure 43. – Mean adult fish biomass, by site, North to South, for the MBRS region. The blue line represents the regional mean for herbivore
biomass, and the maroon line represents the regional mean for carnivore biomass.
82
Reef Habitat
On average, herbivore biomass is higher than carnivore biomass in all three reef habitats
(Figure 44). Overall, the highest numbers for both herbivore and carnivore biomass were
observed on the shallow fore-reef, and the lowest numbers for both were observed on the
back-reef.
Adult Fish Biomass
MBRS Habitats
3500
Herbivore Biomass
Carnivore Biomass
3000
2
Biomass (g/100m (
2500
2,056
2000
1500
1000
940
500
0
Back-reef
Shallow fore-reef
Deep fore-reef
Habitat
Figure 44. – Mean adult fish biomass, by habitat. The blue line represents the regional mean for herbivores
and the maroon line represents the regional mean for carnivores.
Biomass is calculated using the estimated lengths of individuals reported in the previous
section. Therefore, there might be some degree of variability based on observer skill and
experience. Table 27 reports the values for biomass in each reef habitat.
Table 27. – Adult Fish biomass values by habitat in the MBRS
Back-reef
Herbivorous Biomass
Carnivorous Biomass
Mean
Median
1066
595
822
307
Mean
Median
3230
1274
1907
600
Mean
Median
1830
920
1711
752
Standard
Deviation
759
710
Standard
Error
162
151
Standard
Deviation
3131
1824
Standard
Error
700
408
Standard
Deviation
1508
985
Standard
Error
337
220
Minimum.
Maximum.
32
0
2517
2568
Minimum.
Maximum.
0
0
10465
7155
Minimum.
Maximum.
54
0
5948
4404
Shallow fore-reef
Herbivorous Biomass
Carnivorous Biomass
Deep fore-reef
Herbivorous Biomass
Carnivorous Biomass
83
Biomass by location
Table 28 shows the biomass distribution by location (Figure 45).
Adult Fish Biomass
MBRS Locations
6000
5000
Herbivore Biomass
Biomasa Carnívoros
Biomass g/100m
2
4000
3000
2056
2000
940
1000
0
Cozumel
Banco
Chinchorro
Xcalak
Bacalar
Chico
Hol Chan
México
Caye
Caulker
South
Water
Caye
Glover's
Reef
Belize
Gladden
Spit
Sapodilla
Cayes
Punta
Manabique
Guatemala
Utila
Cayos
Cochinos
Honduras
Sites
Figure 45. – Mean adult fish biomass by location in the MBRS region. The blue line represents the regional
mean for herbivores, and the maroon line represents the regional mean for carnivores.
Table 28. – Mean adult fish biomass values by location, in the MBRS region.
Mexico
Location
Cozumel
Banco Chinchorro
Xcalak
Herbivorous
Biomass
Carnivorous
Biomass
5374
1557
2080
1767
1054
382
Herbivorous
Biomass
Carnivorous
Biomass
1963
1937
1023
1077
1075
745
247
1178
1571
492
436
907
342
73
Belize
Location
Bacalar Chico
Hol Chan
Caye Caulker
South Water Caye
Glover's Reef
Gladden Spit
Sapodilla Caye
Guatemala/Honduras
Location
Punta de Manabique
Utila
Cayos Cochinos
Herbivorous
Biomass
Carnivorous
Biomass
672
4558
5624
176
3849
667
84
Map of Herbivorous and Carnivorous Fish Biomass
The averages for biomass were grouped into three categories (Maps 13 and 14).
Map of herbivorous fishes
From 1.00 to 1250.00 g/100 m2
From 1250.01 to 4650.00 g/100 m2
4650.01 g/100 m2 and higher
Map of Carnivorous Fish Biomass
From 1.00 to 860.00 g/100 m2
From 860.01.01 to 2500.00 g/100 m2
2500.01 g/100 m2 and higher
85
Map 13. – Distribution of herbivorous fish biomass in the MBRS.
86
Map 14. - Distribution of Carnivorous fish biomass in the MBRS.
87
3.3.5 Density of recruits
Recruitment refers to the addition of juveniles from the water column into the established
adult population. The MBRS monitoring manual details the sizes that distinguish an
individual as a recruit and require it to be counted for this survey. Several ecologically
important, indicator species (listed below) have been included in the recruit monitoring in
order to determine number of individuals making it to the reef. These numbers can be
compared to numbers of individuals making it to adulthood.
Many habitat preferences start with recruitment, and there are several studies that have
tried to ascertain the degree to which the habitat influences the post-recruitment processes.
The response to the habitat may be the cause of spatial variation in recruitment (Tolimieri,
1998). Also, recruitment rates vary widely in space and time, as well as between species.
These variations may play an important role in the identification of areas that act as sources
of larval distribution (Almada-Villela, et al., 2003) and even influence the distribution,
composition and abundance of the adult population (Doherty & Fowler, 1994). Effects on
social organization (Aldenhoven, 1986), changes in the structure of the community and
connectivity patterns (Jones, 2001) are other important reasons to study recruitment. Thus,
observing changes in recruitment rates may indicate which populations have a greater
possibility of resisting fishing activities and which are more susceptible to alterations in the
reef fish community.
Figure 46 displays the average densities of fish recruits in the MBRS region. Densities vary
widely amongst sites and species. A more in-depth analysis by species would be a useful
future study.
88
Recruit Fish Density
Gramma loreto
Halichoeres pictus
Stegastes leucostictus
Scarus taeniopterus
Chaetodon capistratus
Halichoeres maculipina
Stegastes dorsopunicans
Scarus iserti
Chaetodon striatus
Holichoeres garnoti
Stegastes diencaeus
Stegastes variabilis
Sparisoma viride
Acanthurus coeruleus
Halichoeres bivittatus
Chromis cyanea
Stegastes planifrons
Sparisomoa aurofrenatum
Acanthurus bahianus
Bodianus rufus
Thalassoma bifasciatum
Stegastes partitus
Sparisoma atomarium
200
Ind/100m 2
150
100
Banco
Chinchorro
Xcalak
Bacalar Chico
Hol Chan
Caye Caulker
South Water
Caye
México
Belize
Gover's Reef
Gladden Spit
F01
B01
D01
B01
B02
D01
F02
B01
F01
D02
B05
D01
B04
B02
B01
D02
D01
B02
B01
D02
B02
D01
B01
D02
B02
D01
B01
D02
B02
D01
B01
D02
D01
B02
B01
F03
D02
D01
F04
B01
F03
F02
0
D01
50
Sapodilla
P. Cayos
Caye
ManabCochinos
GuateHonduras
Sites
Figure 46. – Mean recruit densities, by site, North to South, in the MBRS region. All species are included to display relative abundance in the
reef fish community.
89
Reef Habitats
Figure 47 shows the relative density of recruits in each of the reef habitats. The highest
overall recruitment, as well as recruit diversity, is found in the deep fore-reef. More than
80% of the predetermined species list are found on deep fore-reef sites. Species with
highest densities on these habitats, included Stegastes partitus, Chromis cyanea and
Thalassoma bifasciatum. Within Pomacentridae, species in genus Chromis are more
common on the fore-reef because they are planktivores, and these habitats have higher
abundances of their prey. Genus Stegastes (also in Pomacentridae) prefers the reef crest
the back-reef due to the availability of shelter and spawning sites that these species prefer.
On the back-reef, the species with highest densities are Thalassoma bifasciatum,
Halichoeres bivittatus, Stegastes partitus and Scarus iserti.
Most abundant species on the shallow fore-reef include Chromis cyanea, Halichoeres
garnoti and Gramma loreto.
MBRS Habitats
100
90
80
Acanthurus bahianus
Gramma loreto
Stegastes diencaeus
Sparisoma atomarium
Bodianus rufus
Halichoeres pictus
Chaetodon striatus
Scarus iserti
Sparisoma viride
Holichoeres garnoti
Chromis cyanea
Stegastes partitus
Scarus taeniopterus
2
Density (ind/100m (
70
60
50
40
30
20
10
0
Back-reef
Shallow fore-reef
Deep fore-reef
Habitat
Figure 47. – Mean recruit densities, by habitat, in the MBRS region.
Table 29 gives the average recruit density for the surveyed species in the MBRS region.
90
Table 29. - Recruit density (ind./100m2), by habitat.
Reef Habitats
Species
Acanthurus bahianus
Chaetodon striatus
Gramma loreto
Bodianus rufus
Holichoeres garnoti
Halichoeres pictus
Chromis cyanea
Stegastes diencaeus
Stegastes partitus
Scarus iserti
Scarus taeniopterus
Sparisoma atomarium
Sparisoma viride
Back-reef
Standard
Mean
Error
1.91
2.86
0.47
0.99
0.35
0.05
7.26
2.74
1.91
0.59
11.90
1.30
2.19
2.52
3.05
6.12
1.77
2.00
8.37
3.28
0.00
1.30
3.28
0.53
0.74
0.20
0.55
0.20
0.05
2.83
0.70
0.75
0.44
2.61
0.42
0.82
0.77
0.84
2.37
0.49
0.60
1.85
1.31
0.00
0.63
0.44
Shallow fore-reef
Standard
Average
Error
0.63
1.04
0.00
0.14
8.75
0.00
0.00
12.99
0.00
0.07
6.18
22.08
0.28
1.18
0.76
2.29
0.28
0.00
2.78
0.56
0.00
0.76
1.04
0.36
0.65
0.00
0.13
5.57
0.00
0.00
5.19
0.00
0.06
2.38
10.28
0.25
0.70
0.56
0.47
0.19
0.00
0.69
0.51
0.00
0.44
0.62
Deep fore-reef
Standard
Average
Error
0.81
1.00
0.34
0.61
3.11
0.61
2.01
6.54
0.69
0.32
11.99
12.55
0.56
0.71
0.59
12.52
1.30
1.52
7.55
2.82
0.02
2.23
1.15
0.27
0.46
0.16
0.22
1.34
0.31
0.89
1.97
0.35
0.19
2.27
3.25
0.17
0.30
0.36
4.36
0.51
0.66
1.70
1.29
0.02
0.91
0.32
Recruits by Location
Figure 48 displays the distribution of the fish recruit density in the different MBRS locations.
The highest densities of recruit fishes were observed at Bacalar Chico, Hol Chan and
Glover’s Reef in Belize and Banco Chinchorro in Mexico (Figure 48). Chromis cyanea is the
most common species observed in Banco Chinchorro; Halichoeres bivittatus is the most
common species in Hol Chan; Scarus iserti and Thalassoma bifasciatum are the most
identified species in Bacalar; and Stegastes partitus was most common in Glover’s Reef.
91
MBRS Locations
160
140
Acanthurus bahianus
Gramma loreto
Stegastes diencaeus
Sparisoma atomarium
Chaetodon striatus
Scarus iserti
Sparisoma viride
Bodianus rufus
Halichoeres pictus
Holichoeres garnoti
Chromis cyanea
Stegastes partitus
Scarus taeniopterus
Ind/100m
2
120
100
80
60
40
20
0
Banco
Chinchorro
Xcalak
Bacalar
Chico
Hol Chan
Caye
Caulker
Southwater
México
Glover's
Reef
Belize
Gladden Spit
Sapodilla
Cayes
Punta
Manabique
Cayos
Cochinos
Guatemala
Honduras
Sites
Figure 48. – Mean recruit densities, by location, in the MBRS region.
Table 30 shows the average recruit density, by species and location, in the MBRS region.
92
Table 30. – Mean recruit density (ind./100m2), by location, in the MBRS region.
Species
Acanthurus bahianus
Chaetodon striatus
Gramma loreto
Bodianus rufus
Holichoeres garnoti
Halichoeres pictus
Chromis cyanea
Stegastes diencaeus
Stegastes partitus
Scarus iserti
Scarus taeniopterus
Sparisoma atomarium
Sparisoma viride
Banco
Chinchorro
Xcalak
Bacalar
Chico
0.00
0.00
0.00
0.21
15.63
0.00
0.00
20.21
0.00
0.21
5.21
33.96
0.00
0.00
0.00
3.02
0.21
0.00
1.98
0.83
0.00
1.15
0.31
0.00
0.31
0.00
0.00
1.67
0.21
0.10
1.25
0.00
0.10
3.85
3.33
0.52
0.00
0.00
1.35
0.42
0.00
3.23
0.00
0.00
0.63
1.56
3.44
4.12
0.31
0.42
0.57
0.42
15.16
9.72
1.67
0.00
15.52
4.58
2.13
3.75
6.00
8.08
0.55
3.30
8.07
9.06
0.00
3.35
2.38
Locations of the Mesoamerican Barrier Reef Systems
Hol
Caye
South
Glover's Gladden Sapodilla
Chan
Caulker
Water C.
Reef
Spit
Caye
3.23
6.25
1.04
0.63
1.15
0.52
17.50
7.40
0.42
0.00
22.81
5.00
3.75
2.81
2.40
17.50
0.21
2.40
16.25
3.13
0.00
9.06
3.44
0.00
0.00
0.00
0.00
1.04
0.00
1.46
0.31
0.00
0.00
1.35
1.35
0.00
0.00
0.21
0.83
0.63
0.00
1.77
0.63
0.00
0.00
1.35
93
1.35
0.10
0.31
0.94
0.42
0.21
0.21
5.73
0.63
0.63
16.25
11.46
0.73
0.63
1.46
5.00
3.23
4.48
3.65
6.98
0.00
1.15
0.73
1.77
2.50
1.25
3.54
5.83
0.10
0.73
1.77
1.67
2.08
13.96
18.02
4.58
0.63
3.02
36.88
1.04
0.00
11.46
1.67
0.00
0.21
1.88
1.25
1.98
0.26
0.00
0.00
0.00
1.25
4.79
1.61
0.47
14.06
6.04
0.10
3.02
1.77
4.74
1.77
0.00
7.86
1.15
0.00
0.10
2.45
0.28
1.00
0.00
1.56
0.28
0.00
2.33
3.94
4.56
0.00
4.94
2.22
0.00
2.22
0.00
0.44
4.83
5.39
12.50
2.22
0.00
0.00
5.00
Punta de
Manabique
Cayos
Cochinos
0.00
0.00
1.25
0.00
0.00
0.00
0.42
0.00
6.04
0.00
63.13
0.00
0.42
0.21
0.42
0.42
0.00
1.67
2.08
0.63
0.21
0.00
0.42
0.63
0.63
0.00
1.04
2.71
2.92
0.00
0.21
0.42
0.00
0.42
1.67
1.04
0.00
0.00
1.46
0.00
1.88
4.79
2.50
2.50
1.25
1.25
Map 15. - Recruit fish density observed at the MBRS sites.
94
4 SEAGRASS
Seagrasses are flowering plants that live in tropical and sub-tropical coastal waters
worldwide. They are the primary food source for marine turtles and manatees and provide
habitat for fishes and many marine invertebrates, some of which are commercially important
(e.g. lobsters and conch). In addition, seagrasses absorb nutrients flowing from coastal
sources and stabilize the sediments, which helps keep the water clear.
Out of approximately 59 species of seagrasses living worldwide in temperate, sub-tropical
and tropical waters (Short et al., 2005), only seven live in the MBRS region.
Seagrasses are found on muddy bottoms of estuaries, shallow sandy areas close to the
coast, reef lagoons and around sand banks. In addition, seagrasses may also grow in
deeper sandy areas with clear waters.
Seagrasses can reproduce sexually as well as asexually. During sexual reproduction, plants
produce flowers, and pollen is transferred from the male flower to the ovaries in the female
flower. Most seagrasses are sexually dimorphic meaning each individual only produces
flowers of one sex, so there are male and female plants as well as flowers. The seeds
produced can remain inactive in large “seed banks” for several months. During asexual, or
vegetative, reproduction, new plants emerge without flowering or creation of seeds. The
grasses grow horizontally, through rhizomes that sprout new plants. This allows the
formation of large seagrass beds from only a few plants and serves as a recovery
mechanism when trauma reduces numbers of individual plants.
Seagrasses have a large range in the MBRS region. However, distribution and density may
vary with the seasons. Typically, seagrass beds are more densely populated during months
with clear, long days and high temperatures (April to June).
4.1. Types of Seagrass
The seven species of seagrasses observed in the MBRS region are commonly identified by
the shape and vascular patterns of their leaves and the way that the leaves connect to the
rhizomes.
The dominant species in the region is turtle grass, Thalassia testudinum, although large
areas of manatee grass, Syringodium filiforme, are also found. The other species in the
region are Halodule wrightii, Ruppia maritima and three species of Halophila, H. decipiens,
H. englemanni and H. baillonis.
95
Figure 49. Seagrass anatomy (Modified
from the Guide to the Seagrasses of the
USA, 2001).
4.2. Importance of Seagrass.
Seagrass beds are considered to be
amongst the most productive ecosystems
in the world (Odum, 1957; McRoy &
McMillan, 1977; Zieman & Wetzel, 1980;
Frankovich & Fourqurean, 1997). As
stated above, they stabilize coastal
sediments and capture and recycle
nutrients, in addition to providing
nourishment and shelter to many
organisms. Several species of fishes and
marine invertebrates use seagrass beds as spawning grounds. In addition they serve as
feeding sites for dozens of marine bird species and reduce wave energy (coastal
protection).
4.3. Threats to Seagrass.
Coastal development, agro-chemical pollution, and sewage are threatening seagrasses
worldwide. Increased sedimentation, from agriculture and construction, can suffocate
seagrasses, and the subsequent high turbidity levels can reduce light levels to dangerously
low levels.
In general, growing populations in coastal areas of the MBRS are placing seagrass beds in
danger. In areas with increasing populations, rivers and estuaries need to be carefully
managed to maintain segrass habitat and the economic and ecological services that
seagrasses subsequently provide.
Many seagrass beds are found near large coastal cities and ports where coastal
developments, dredging and marina/jetty construction threaten them. There are many
conservation tactics that are used to protect seagrasses during coastal development,
including fine mesh sediment traps. If applied properly, these tactics can successfully
minimize damage.
Clearly, seagrass is an important part of the MBRS Synoptic Monitoring, and the four
countries have received support in materials and equipment. To date, data has been
collected at 33 sites, in seven locations in the region, and these data are stored in the
Regional Environmental Information System (REIS).
4.4. Current Situation
Biomass, productivity, density, leaf area index, community composition and other related
ecological parameters were monitored during 2004 and 2005. Biomass values ranged from
96
3 to 1,596 g/m2 due to the fact that samples were taken in different environments. These
data are comparable to other monitoring efforts, including CARICOMP (Linton & Fisher,
2004).
Seagrass Biomass
2000
1800
1600
1400
1200
1000
800
600
400
200
Banco
Chinchorro
Bahia de Chetumal
Xcalak
Mˇxico
Port
Honduras
R’o
Sarst n
Belize
Punta
Manabique
Guatemala
04
03
02
01
02
01
02
01
03
02
01
04
03
02
01
13
12
11
10
09
08
07
06
05
04
03
02
01
05
04
03
02
01
0
Cayos
Cochinos
Honduras
Sites
Figure 50. Mean (+/- standard error) seagrass biomass, by site, from North to South, in the MBRS region.
Table 31. Seagrass biomass by location in the MBRS region.
Biomass (g/m2)
MPA
B. Chinchorro
Chetumal Bay
Xcalak
Port Honduras
Rio Sarstun
Punta Manabique
Cayos Cochinos
Mean
1,039.98
71.44
1,344.99
965.19
705.47
464.97
425.73
Median
Standard
Deviation
1,074.31
25.98
1,514.35
924.05
666.34
361.26
431.71
385.87
88.50
387.88
522.71
322.04
424.60
145.68
97
Standard
Error
86.28
14.17
100.15
213.39
113.86
141.53
51.51
Minimal
291.31
0.00
301.24
426.06
109.64
43.58
191.19
Maximum
1,781.65
273.22
1,717.19
2,000.44
1,300.33
1,150.13
618.27
Above Ground vs. Below Ground Biomass of
35.00
Thalassia
ABG (g) [Thalassia]
BGB (g) [Thalassia]
30.00
25.00
20.00
15.00
10.00
Banco
Chinchorro
Bahia de Chetumal
Xcalak
Mˇxico
Port
Honduras
Belize
R’o
Sarst n
Punta
Manabique
Guatemala
04
03
02
01
02
01
02
01
03
02
01
04
03
02
01
13
12
11
10
09
08
07
06
05
04
03
02
01
05
04
03
02
0.00
01
5.00
Cayos
Cochinos
Honduras
Sites
Figure 51. Above ground to below ground ratio of segrass biomass, by site, from North to South, in the MBRS
region.
Table 32 Above ground (photosynthetic) to below ground (subterraneous) ratio by location.
Below ground (g)
Above ground
Above ground:Below
MPA
[Thalassia]
(g) [Thalassia]
ground Ratio
14.64
3.62
0.25
B. Chinchorro
0.53
0.63
1.18
Chetumal Bay
18.03
3.27
0.18
Xcalak
11.63
5.98
0.51
Port Honduras
6.54
6.33
0.97
Rio Sarstun
4.57
3.17
0.69
Punta Manabique
5.43
7.65
1.41
Cayos Cochinos
At most sites, the below ground biomass (roots + rhizomes) is greater than the above
ground biomass (shoots + leaves). This suggest healthy seagrass beds, as more roots are
available for nutrient uptake and more rhizomes are available for storage of starch. These
ratios also imply that the monitoring sites are not suffering from eutrophication and that the
water is clear. Large root/rhizome networks give seagrass beds extra stability during
hurricanes or other storms and increase asexual reproduction, a competitive advantage over
rapid growing macroalgae typical of eutrophied sites.
98
Map 16. - Seagrass biomass observed at the MBRS sites
99
Seagrass Biomass
Coastal and Reef Sites
1800
1600
1400
1200
1000
800
600
400
Banco Chinchorro
Xcalak
Port Honduras
R’o
Sarst n
Belize
Guatemala
Mˇxico
Punta
Manabique
04
03
02
01
02
01
02
01
03
02
01
04
03
02
01
05
04
03
02
0
01
200
Cayos Cochinos
Honduras
Sites
Figure 52. Mean (+/- standard error) seagrass biomass at the marine and coastal sites in the MBRS region.
Seagrass Biomass
Chetumal Bay
300
250
200
150
100
13
12
11
10
09
08
07
06
05
04
03
02
0
01
50
Bahia de Chetumal
Mˇxico
Sites
Figure 53. Mean (+/- standard error) seagrass biomass in Chetumal Bay, with semi-estuarine conditions.
Data for the Chetumal Bay has been displayed separately (Figure 53) because of a
significant difference in environmental conditions that could lead to incorrect comparisons
between sites/locations.
100
The variation between above ground to below ground ratios in Corozal Bay versus the other
sites may be due to eutrophication in that area (Figure 55). Eutrophied areas, such as
Canal Nizuc (Pedro Ramírez García, com. per.) have inverted ratios. Large, wide leaves
obtain nutrients from the water column, and individuals do not invest in roots or rhizomes
(only 10-20% below ground matter). This inversion makes the seagrass beds, along with
benthic, epibenthic, and even subterraneous fauna, more susceptible to storm damage.
Above Ground vs. Below Ground Biomass for
Coastal and Reef Sites
35.00
Thalassia
ABG (g) [Thalassia]
BGB (g) [Thalassia]
30.00
25.00
20.00
15.00
10.00
Banco Chinchorro
Xcalak
Port Honduras
Mˇxico
R’o
Sarst n
Belize
Punta
Manabique
04
03
02
01
02
01
02
01
03
02
01
04
03
02
01
05
04
03
02
0.00
01
5.00
Cayos Cochinos
Guatemala
Honduras
Sites
Figure 54. Above ground to below ground ratios of seagrass biomass for marine and coastal sites in the MBRS
region.
In the Chetumal Bay, the bottom is largely sandstone, and the semi-estuarine conditions in
this location lead to lower biomass.
Above Ground vs. Below Ground Biomass for
Chetumal Bay
4.50
Thalassia
ABG (g) [Thalassia]
BGB (g) [Thalassia]
4.00
3.50
3.00
2.50
2.00
1.50
1.00
Bahia de Chetumal
Mˇxico
Sites
Figure 55. Above ground to below ground ratios of seagrass biomass in the Chetumal Bay.
101
13
12
11
10
09
08
07
06
05
04
03
02
0.00
01
0.50
5 MANGROVES
5.1 Mangrove Biology
Mangrove ecosystems constitute the dominant coastal vegetation in tropical and subtropical
regions. In the four countries of the MBRS, mangroves have enormous economic, cultural
and ecological value.
Mangroves forests include several salt-resistant species that can successfully grow along
the boundary between land and marine environments, on continental as well as island
coasts. Mangroves have aerial roots that are specially adapted for growing in oxygen poor,
water infused systems. In addition, mangrove roots and leaves have evolved mechanisms
of salt excretion that allow these species to live where no other species of trees can survive.
There are four species of mangroves living in the forests of the Caribbean. These include
the red mangrove (Rhizophora mangle), the white mangrove (Laguncularia racemosa), the
black mangrove (Avicennia germinans) and to a lesser degree, the buttonwood
(Conocarpus erectus).
5.2 Importance of Mangroves
The ecological importance of mangroves is well documented, but their economic value is
consistently underestimated. Legal protection for mangroves is weak and often moving in
the wrong direction. Mangrove forests throughout the MBRS region are deteriorating, as a
result of anthropogenic activities. (Talbot-Wilkinson, 2001).
Mangroves are essential to healthy coastal ecosystems. The nutrients in the leaves and
branches that constantly fall into the water, sustain an incredible amount of life, by
supporting a large detritus community and (after decomposition) serving as the primary
driving force for planktonic or epiphytic algal food chains.
Commercial fisheries, worldwide, are dependant on healthy mangroves. As many as two
thirds of all marine fish species rely on mangrove forests for some part of their life cycle. In
addition, birds and several terrestrial species use these areas for feeding, and even
freshwater fish species utilize the protection that the mangrove root systems provide. Most
importantly, mangrove forests are the breeding and nursery grounds for numerous reef
species of ecological and economic importance, and species such as shrimp could not
survive without this ecosystem.
Mangroves provide other ecological services, including protection of coastlines from erosion
and storm/hurricane surges. Also, mangroves filter out excess sediment and nutrients from
river systems, protecting seagrass beds and coral reefs from sedimentation and
eutrophication. In a sense, mangroves help to buffer these important ecosystems from
human activity in coastal watersheds, such as agriculture, development, and industry.
5.3 Threats to Mangroves
A lack of understanding, regarding mangrove ecology has led to the destruction of more
than 50% of forests worldwide (Talbot-Wilkinson, 2001). As stated above, mangroves
102
provide innumerable services, including protection of coastlines, filtering of river discharge,
and protection of juvenile fishes and invertebrates. Therefore, mangrove forest demolition
could have catastrophic results.
Several human activities, both economic and social, lead to destruction of mangrove forests.
These activities include:
•
•
•
•
•
•
Excessive drainage.
Changes in water flow (channeling/canalization).
Deforestation.
Erosion and sedimentation associated with poor practices in soil conservation.
Land reclamation and construction.
Irresponsible garbage disposal
5.4 Current Situation
The four countries of the MBRS region have received support through both training and supply of
materials and equipment. To date, data has been collected at 18 sites in 10 locations, and these
data are stored in the REIS database. Complete and consistent data sets, however, are only
available for seven locations: Bacalar Chico (Belize), Rio Sarstun and Punta Manabique
(Guatemala), Omoa-Baracoa and Nueva Armenia (Honduras) and Banco Chinchorro and Arrecife
de Xcalak (Mexico). Data should be more consistent as the project continues.
Table 33. Average mangrove density, by location.
Density (trees/hectare)
MPA
Banco
Chinchorro
Xcalak
Bacalar Chico
Rio Sarstun
Punta de
Manabique
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
Mean
Median
Standard
Deviation
Standard
Error
Minimum
Maximum
3100
8380
1400
700
3300
8400
1400
n/a
1268
1932
400
n/a
517
864
283
n/a
1500
5700
1000
n/a
5000
11700
1800
n/a
4500
940
4600
1000
698
524
403
234
3600
300
4600
1800
1140
800
578
259
600
2200
103
While the highest mangrove density is seen at Arrecife de Xcalak, and the lowest it
observed at Rio Sarstun (Figure 56), it is necessary to use all of the parameters together
when analyzing the state of the mangrove communities in the MBRS region.
Mangrove Density
Mesoamerican Barrier Reef Systems Project
12000
10000
8000
6000
4000
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Omoa
Baracoa
Nueva
Armenia
Honduras
Sites
Figure 56. Mean (+/- standard error) mangrove density, by site, North to South, in the MBRS region.
104
02
01
02
01
02
01
04
02
02
01
02
0
01
2000
Map 17. – Mangrove density observed at MBRS sites
105
Table 34. Average mangrove height, by location.
Height (m)
Standard
MPA
Mean
Median
Deviation
Banco Chinchorro
Xcalak
Bacalar Chico
Rio Sarstun
Punta de
Manabique
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
Standard
Error
Minimal
Maximum
5.91
5.92
6.27
9.86
6.00
5.50
6.82
9.00
1.62
2.08
1.79
2.36
0.12
0.10
0.34
0.89
2.00
2.00
1.10
7.00
10.00
12.00
9.00
14.00
7.21
6.77
7.00
5.00
2.57
5.20
0.22
0.76
2.00
1.40
15.00
16.00
11.69
6.29
9.56
1.31
0.91
29.60
Table 34 displays the average heights at each of the locations in the MBRS region. The
tallest trees are observed at Omoa-Baracoa and Nueva Armenia on coastal Honduras
(Figure 57).
Average Height of Mangroves
Mesoamerican Barrier Reef Systems Project
25
20
15
10
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Omoa Baracoa
02
01
02
01
02
01
04
02
02
01
02
0
01
5
Nueva Armenia
Honduras
Sites
Figure 57. – Mean (+/- standard error) mangrove height, by site, from North to South, in the MBRS region.
106
Table 35. Average diameter at breast height (dbh), by location in the MBRS region.
Diameter at Breast Height (cm)
MPA
Mean
Banco Chinchorro
Xcalak
Bacalar Chico
Rio Sarstun
Punta de Manabique
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
Median
Standard
Deviation
Standard
Error
Minimal
Maximum
7.73
5.02
7.81
16.45
9.27
12.86
6.78
4.55
8.59
13.77
8.91
4.14
3.95
1.99
3.00
10.13
3.62
14.64
0.29
0.10
0.57
3.83
0.31
2.14
2.55
2.45
1.59
0.75
2.39
1.59
23.49
17.63
12.73
30.56
19.58
58.89
18.48
14.96
13.54
1.79
0.32
54.11
Table 35 displays the diameters at breast height (dbh) from the locations in the MBRS
region. The largest trees are observed at Nueva Armenia and Rio Sarstun (Figure 58).
Diameter at Breast Height (DBH) of Mangroves
35
30
25
20
15
10
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Figure 58. Mean (+/- standard error) dbh, by site, North to South, in the MBRS region.
02
01
Omoa Baracoa
Sites
107
02
01
02
01
04
02
02
01
02
0
01
5
Nueva Armenia
Honduras
Table 36. Average mangrove basal areas by location in the MBRS region.
Basal Area (m2/ha)
Standard
Standard
MPA
Mean
Median
Deviation
Error
Banco
Chinchorro
Xcalak
Bacalar Chico
Rio Sarstun
Punta de
Manabique
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
Minimal
Maximum
18.35
19.17
7.71
20.52
17.53
20.51
7.71
n/a
3.64
4.22
2.03
n/a
1.49
1.89
1.43
n/a
14.65
12.68
5.68
n/a
25.10
25.01
9.73
n/a
35.01
28.05
36.00
32.72
1.45
21.29
0.84
9.52
32.96
2.57
36.08
61.09
46.99
50.09
21.31
9.53
14.06
79.25
Mangrove Basal Area
80
70
60
50
40
30
20
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Omoa Baracoa
Nueva
Armenia
Honduras
Sites
Figure 59. Mean (+/- standard error) basal area, by site, North to South, in the MBRS region.
108
02
01
02
01
02
01
04
02
02
01
02
0
01
10
Table 37. Average mangrove biomass using protocol found in Golley et al., which calculates
biomass using diameter and density.
Mean
Standard
Standard
MPA
Median
Minimal
Maximum
2
g/m
Deviation
Error
81.27
80.12
21.03
8.58
50.22
113.50
Banco Chinchorro
142.63
147.98
30.01
13.42
96.83
188.93
Xcalak
37.07
37.07
11.28
7.97
25.79
48.34
Bacalar Chico
39.04
n/a
n/a
n/a
n/a
n/a
Rio Sarstun
Punta de
Manabique
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
141.45
40.99
142.24
38.90
8.65
17.10
4.99
7.65
130.48
22.98
151.63
69.82
71.40
64.96
25.03
11.19
35.23
105.22
Mangrove Biomass Calculated using Golley
et al
(1962)
200
180
160
140
120
100
80
60
40
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Omoa Baracoa
02
01
02
01
02
01
04
02
02
01
02
0
01
20
Nueva
Armenia
Honduras
Sites
Figure 60. Mean (+/- standard error) mangrove biomass (using method in Golley et al.), by site, from North to
South, in the MBRS region
109
Table 38. Average mangrove biomass using protocol found in Cintron and Shaeffer-Novelli, which
calculates biomass using diameter and height.
Biomass (Cintron and Shaeffer-Novelli)
Mean
Standard
Standard
MPA
Median
Minimal
Maximum
g/m2
Deviation
Error
75.84
71.41
21.07
8.60
55.39
116.61
Banco Chinchorro
91.26
94.85
31.71
14.18
46.48
125.60
Xcalak
34.62
34.62
7.67
5.42
26.95
42.29
Bacalar Chico
97.98
n/a
n/a
n/a
n/a
n/a
Rio Sarstun
Punta de
133.25
116.44
27.04
15.61
111.91
171.40
Manabique
147.12
163.28
112.85
50.47
10.35
324.15
Omoa-Baracoa
Nueva
Armenia/Cayos
Cochinos
348.81
446.24
220.91
98.79
64.35
634.84
Mangrove Biomass Calculated using Cintron and Shaeffer
Novelli(1984)
600
500
400
300
200
Banco
Chinchorro
Xcalak
Mˇxico
Bacalar Chico
R’o Sarst n
Belize
Guatemala
Omoa Baracoa
02
01
02
01
02
01
04
02
02
01
02
0
01
100
Nueva
Armenia
Honduras
Sites
Figure 61. Mean (+/- standard error) mangrove biomass (using protocol in Cintron and Shaeffer-Novelli), by
site, North to South, in the MBRS region.
Mature, non-harvested mangrove forests have larger trees (height, dbh) than areas that are
regrowing because of deforestation, storm damage, or pollution. Figures 56, 57, and 58
give a more complete picture of mangrove forest condition for the region when studied
together. Areas with high density, are not always healthier (trees might be very small), and
forests with large trees might have unhealthy, low densities. It is necessary to look at all of
these parameters when analyzing mangrove status. In forests growing in non-carbonated,
alluvial soils, there is a close relationship between tree size and age, while the relationship
in those forests growing in carbonated soils is not as strong. On a regional scale, forests
seemingly range in maturation level from young (5.8m tall) to old (19.8m tall).
110
6 MARINE POLLUTION
A Synoptic Monitoring Program was implemented as part of the MBRS Project’s activities in
the region. To this end, a manual of methods was developed to guide the collection,
preservation and analysis of samples, and the calculation of results (Almada-Villela et al.,
2003). In the section on marine pollution, the manual calls for the analysis of hydrocarbons
and organochlorine pesticides in sediments and fishes. The white grunt (Haemulon plumieri)
(Figure 62) was selected as a bioindicator organism. The manual specifies the analysis of
the following parameters: cholinesterase activities in muscles and PAHs metabolites in bile.
The white grunt is also being used in the Florida Keys (Downs et al., in press). A Regional
Environmental Information System, a web-based database, was implemented to allow the
public, users, managers, etc. to have access to the information obtained through the
Synoptic Monitoring Program.
Figure 62. Bioindicator organism selected for the Synoptic Monitoring of the Mesoamerican Barrier Reef
System, the white grunt (Haemulon plumieri).
Despite the relatively small amount of published works on this subject in the MBRS region,
pollution has been identified, as one of the most significant threats to the health of the coral
reef and related ecosystems (Dulin et al., 1999; Arrivillaga y García, 2004). This report
shows the results of the first pollution monitoring in which sediments and fish were analyzed
throughout the entire MBRS region.
111
6.1 Materials and Methods
The first monitoring in the MBRS region was conducted in June 2005. Sediment and white
grunt (Haemulon plumieri) samples were collected from 17 MBRS sites.
The concentrations of the different fractions of petrohydrocarbons, such as aliphatic
hydrocarbons, unresolved complex mixture (UCM), policyclyc aromatic hydrocarbons
(PAHs) and total hydrocarbons (HCs); and organochlorine pesticides (including
polychlorinated biphenyls, or PCBs) were analyzed in the sediment samples and in the liver
of the grunts. In addition, cholinesterase activity was measured in the liver, muscles and
brain of the fishes, as well as the concentrations of PAHs metabolite in bile. All the analyses
were implemented according to the detailed procedures in the Manual of Methods for the
MBRS Synoptic Monitoring Program (Almada-Villela et al., 2003).
Since the current analytical technology allows the analysis of dozens of individual pollutants,
the results for the organochlorine pesticides, PCBs and hydrocarbons are presented in
groups of chemical families; however, the annexes include tables with the complete results.
The 18 types of PCBs that NOAA uses were analyzed, in addition to three that are used as
indicators: PCBs 8, 18, 28, 29, 44,52, 66, 87, 101, 110, 118, 128, 138, 153, 170, 180, 187,
195, 200, 206 and 209. The pesticides analyzed are: 1,2,4,5- Tetrachloro benzene, 1, 2, 3,
4- Tetrachloro benzene, Pentachlorobenzene, Hexachlorobenzene, Pentachloroanisol, α-,
β-, γ- and δ-Hexachlorocyclohexane, Heptachloro, Heptachloro epoxy, α- and γ-Chlordane,
cis-Nonachlor, trans-Nonachlor, Aldrin, Endrin, Dieldrin, Mirex, Endosulfan II, o,p’-DDT, p,p’DDT, o,p’-DDD, p,p’-DDD, o,p’-DDE and p,p’-DDE. The PAHs analyzed are: Naphthalene, 1
Methyl-Naphthalene, 2 Methyl-Naphthalene, 2, 6-Dimethyl-Naphthalene, 1, 5-DimethylNaphthalene, 2, 3-Dimethyl-Naphthalene, 1, 2, 4-Trimethyl-Naphthalene, 1, 3, 5-TrimethylNaphthalene, Acenaphtene, Acenaphtilene, Fluorene, Phenantrene, Anthracene, 1 MethylPhenantrene, 2 Methyl-Phenantrene, Fluoranthene, Pyrene, Benz(a)anthracene, Crysene,
Benzo[a]Pyrene, Benzo(e)Pyrene, and Perylene; and the metabolites of the PAHs are: OHPyrene, Benzo (a) Pyrene, OH-Naphthalene and Phenantrene. These metabolites may be
grouped as Pyrene, Naphthalene, Phenantrene, and Benzo(a)pyrene.
112
6.2 Results
Table 39 shows monitoring stations as well as the names of the sites and their coordinates
to facilitate their location. These sites are shown on Map 18.
Table 39. Sample collection sites for the first pollution monitoring in the MBRS.
Site
1a
1b
1c
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
8a
8b
8c
9a
9b
9c
10a
10b
10c
11a
11b
11c
12a
12b
12c
13a
13b
13c
14a
14b
14c
15a
15b
15c
16a
16b
16c
17a
17b
17c
Location
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
La Ceiba
La Ceiba
La Ceiba
Rio Chamelecon
Rio Chamelecon
Rio Chamelecon
Barra del río Ulúa
Canal Quilimaco
Canal Quilimaco
Canal Quilimaco
Omoa
Omoa
Omoa
Bahía de Sto. Tomas
Punta de Manabique
Punta de Manabique
Punta de Manabique
Rio Sarstun
Rio Sarstun
Rio Sarstun
Rio Dulce
Rio Dulce
Rio Dulce
Placencia Lagoon
Placencia Lagoon
Placencia Lagoon
Caye Caulker
Caye Caulker
Caye Caulker
Houlover Creek
Houlover Creek
Houlover Creek
Belize River
Belize River
Belize River
Chetumal Bay
Chetumal Bay
Chetumal Bay
Bacalar Chico
Bacalar Chico
Bacalar Chico
Xcalak
Xcalak
Xcalak
Country
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Honduras
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Guatemala
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Belize
Mexico
Mexico
Mexico
Belize
Belize
Belize
Mexico
Mexico
Mexico
Latitude
15 57 24.9
15 57 33.5
15 57 27.6
15 48 11.1
15 48 11.1
15 48 11.1
15 54 09.1
15 54 09.1
15 54 09.1
15 54 39.5
15 54 39.5
15 54 39.5
15 50 33.8
15 50 33.8
15 50 33.8
15 47 00.8
15 47 00.8
15 47 00.8
15 43 35.4
15 43 35.4
15 43 35.4
15 57 50.0
15 57 50.0
15 57 50.0
15 53 50.4
15 53 50.4
15 53 50.4
15 48 56.4
15 48 59.1
15 49 03.3
16 31 59.6
16 32 04.2
16 32 05.7
17 43 13.5
17 43 13.5
17 43 13.5
17 2926.0
17 29 23.4
17 29 18.8
17 32 04.0
17 32 04.0
17 32 01.8
18 16 15.2
18 16 12.8
18 16 12.8
18 10 01.7
18 10 01.0
18 10 01.1
18 13 55.5
18 13 55.5
18 13 55.5
113
Longitude
86 29 15.7
86 29 07.4
86 28 46.2
86 46 11.1
86 46 11.1
86 46 11.1
87 47 22.8
87 47 22.8
87 47 22.8
87 44 37.8
87 44 37.8
87 44 37.8
87 57 14.6
87 57 14.6
87 57 14.6
88 02 34.9
88 02 34.9
88 02 34.9
88 36 21.4
88 36 21.4
88 36 21.4
88 33 16.4
88 33 16.4
88 33 16.4
88 54 58.9
88 54 58.9
88 54 58.9
88 45 14.7
88 45 11.9
88 45 09.8
88 22 33.3
88 22 37.6
88 22 32.4
88 00 37.5
88 00 37.5
88 00 37.5
88 11 06.0
88 11 16.7
88 11 05.1
88 14 12.8
88 14 12.8
88 14 08.1
87 53 10.3
87 53 12.4
87 53 12.4
87 53 08.9
87 53 13.4
87 53 13.8
87 50 07.7
87 50 07.7
87 50 07.7
Ecosystem
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Pollution
Map 18. Stations where samples of sediments and fish were collected (June, 2005).
114
6.3 Fish.
Table 40 shows the concentrations of PAHs metabolites in the bile of the grunts collected for
this monitoring.
Table 40. PAHs metabolite concentrations in bile in the white grunt (Haemulon plumieri).
Pyrenes
(µg/mL)
Naphthalenes
(µg/mL)
Phenantrenes
(µg/mL)
Benzo(a)Pyrenes
(µg/mL)
Cayos Cochinos
0.090
43.579
63.308
0.288
Cayos Cochinos
0.172
12.962
60.215
0.211
Cayos Cochinos
0.155
22.691
134.061
0.208
Cayos Cochinos
0.093
20.688
38.603
0.236
Cayos Cochinos
0.113
41.004
60.864
0.303
Punta de Manabique
0.066
52.593
28.943
0.236
Punta de Manabique
0.192
120.695
36.315
1.231
Punta de Manabique
0.039
49.875
60.482
0.169
Punta de Manabique
0.138
49.016
78.505
0.336
Caye Caulker
0.130
36.283
51.967
0.279
Caye Caulker
0.115
43.579
84.118
0.305
Caye Caulker
0.049
37.571
35.205
0.105
Site
Caye Caulker
0.083
48.444
30.432
0.146
Xcalak
0.175
50.590
65.713
0.415
Xcalak
0.317
58.745
71.105
0.646
Figure 63 shows the median concentration of naphthalenes and phenantrenes, and Figure 64 those
for pyrenes and benzo(a)pyrenes (June, 2005).
140
Concentrations of Naphthalenes and Phenanthrenes in the Gall
Bladders of Haemulon plumieri
Naphthalenes
Phenanthrenes
120
100
80
60
40
20
0
Cayos Cochinos
Punta Manabique
Caye Caulker
Xcalak
Sites
Figure 63. Median concentrations of naphthalenes and phenantrenes in bile of the white grunt (Haemulon
plumieri) in different sites in the MBRS region (June, 2005).
115
The highest median concentrations of naphthalenes were found in Punta de Manabique,
and the lowest in Cayos Cochinos. The differences observed are significant in the case of
naphthalenes (ANOVA Kruskal-Wallis, H3,15=10.9; P=0.013) but not for phenantrenes
(H3,15=2.65; P=0.45). No significant differences were found between the median for pyrenes
(H3,15=4.82; P=0.19) or for benzo(a)pyrenes (H3,15=4.84; P=0.18). This means that the
concentrations do not differ between monitoring sites.
Concentrations of Pyrenes y Benzo(a)Pyrenes
in the Gall Bladders of
Haemulon plumieri
1.4
Pyrenes
Benzo(a)Pyrenes
1.2
1
0.8
0.6
0.4
0.2
0
Cayos Cochinos
Punta Manabique
Caye Caulker
Xcalak
Sites
Figure 64. Median concentration of pyrenes and benzo(a) pyrenes in the bile of the white grunt (Haemulon
plumieri) in different sites in the MBRS region (June, 2005).
The concentrations of naphthalenes and phenantrenes are much higher than those of the
pyrenes and benzo(a) pyrenes (see the vertical scale on Figures 63 and 64). This may be
due to a bioaccumulation and/or a metabolism differential of the PAHs for these fishes. It is
not possible to determine the causes conclusively based on the information available to date
for this species.
Table 41 shows the concentrations of hydrocarbons and organochlorine components
(pesticides and PCBs) in the liver of the white grunt. Due to the great quantity of individual
components that are analyzed through high-resolution gas chromatography, this Table
shows results summarized by chemical groups. In the annexes to this report we show the
complete tables, with all the individual components analyzed.
116
Table 41. Concentrations of hydrocarbons, and organochlorine pesticides (including PCBs) in the liver of the White Grunt (Haemulon
plumieri) collected in the MBRS region.
Aliphatic
(µg/g)
UCM
(µg/g)
PAHs
(µg/g)
HCs
(µg/g)
1234TC
B (ng/g)
HCHs
(ng/g)
Chlordane
(ng/g)
DDTs
(ng/g)
Pesticides
(ng/g)
PCBs
(ng/g)
Cayos Cochinos
ND
8.020
7.607
15.627
4.874
2.186
ND
3.773
10.833
41.663
Cayos Cochinos
11.767
27.621
35.989
75.376
18.483
23.029
2.235
1.536
45.284
142.033
Cayos Cochinos
1.414
15.163
51.858
68.435
60.003
22.793
1.831
19.463
104.091
163.199
Cayos Cochinos
9.687
78.866
60.670
149.223
5.437
23.142
21.117
13.147
62.852
145.838
Cayos Cochinos
ND
ND
27.846
27.846
ND
11.169
ND
0.693
11.862
53.440
Punta de Manabique
ND
ND
17.547
17.547
ND
7.411
ND
17.996
25.408
49.078
Punta de Manabique
ND
ND
11.053
11.053
23.786
28.522
ND
13.106
65.414
104.752
Punta de Manabique
ND
ND
6.171
6.171
ND
2.518
ND
24.244
26.762
40.828
Punta de Manabique
35.824
289.825
44.458
370.106
ND
5.297
ND
75.101
80.397
50.518
Punta de Manabique
ND
ND
12.640
12.640
ND
1.998
2.282
11.291
15.571
39.867
Caye Caulker
ND
ND
30.526
30.526
17.799
14.719
ND
12.928
45.446
97.294
Caye Caulker
13.881
ND
21.309
35.190
9.575
0.000
ND
20.221
29.795
13.056
Caye Caulker
58.081
96.987
119.864
274.931
24.813
28.379
2.003
90.544
145.739
106.317
Caye Caulker
31.423
48.475
27.408
107.306
17.935
4.311
ND
11.235
33.481
80.905
Caye Caulker
77.513
166.984
18.496
262.993
9.042
ND
ND
40.557
53.857
141.503
Xcalak
294.572
696.337
191.801
1182.710
109.511
ND
ND
ND
109.511
72.221
Xcalak
79.555
121.770
84.921
286.247
48.203
ND
8.940
29.645
86.788
173.378
Xcalak
195.371
339.129
238.798
773.298
68.772
ND
ND
ND
68.772
192.907
Xcalak
271.400
423.393
171.249
866.043
37.822
ND
ND
ND
37.822
146.728
Site
ND = Not detected
117
Figure 65 shows the median concentrations of hydrocarbons and Figure 66 the median
concentrations of organochlorine pesticides in the livers of white grunts in the MBRS.
Concentrations of Hydrocarbons in the Livers of
Haemulon plumieri
800
700
Aliphatics
UCM
PAHs
600
500
400
300
200
100
0
Cayos Cochinos
Punta Manabique
Caye Caulker
Xcalak
Sites
Figure 65. Median concentrations of the different hydrocarbon fractions analyzed in the livers of the white
grunts (Haemulon plumieri) collected at different locations in the MBRS region.
The greatest concentrations of hydrocarbon fractions were found in Xcalak, Mexico and the
smallest in Punta de Manabique, Guatemala. A non-parametric Kruskal-Wallis ANOVA was
conducted for aliphatic hydrocarbons (H3,19=12.13 P=0.0069), UCM (H3,19=9.04; P=0.02)
and PAHs (H3,19=10.61; P=0.01), which showed significant differences respectively.
Concentrations of Organochloride Pesticides in the Livers of
Haemulon plumieri
250
200
1234TCB
HCHs
Chlordanes
DDTs
PCBs
150
100
50
0
Cayos Cochinos
Punta Manabique
Caye Caulker
Xcalak
Sites
Figure 66. Median concentrations of organochlorine pesticides, including PCBs, in the livers of the white grunts
(Haemulon plumieri) in different sites of the Mesoamerican Barrier Reef System.
118
The concentrations of PCBs were the largest of all the organochlorine components. As for
pesticides, the pattern found is different in each site. Thus, in Cayos Cochinos the
hexachlorocyclohexanes (HCHs) prevail, while in Punta de Manabique and Caye Caulker
DDTs are the most abundant and tetrachlorobenzene is the predominant one in Xcalak. This
seems to indicate different patterns of pesticide use in the sites monitored.
Table 42 shows the results of cholinesterase activity in the different tissues of the white
grunt. Figure 67 shows the median activity for these enzymes, by monitoring site.
Table 42. Cholinesterase activity in different tissues of the white grunt (Haemulon plumieri).
Site
AChE Muscle
(nmol/min/mg prot)
AChE Brain
(nmol/min/mg prot)
AChE Liver
(nmol/min/mg prot)
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
Punta de Manabique
Punta de Manabique
Punta de Manabique
Punta de Manabique
Punta de Manabique
Caye Caulker
Caye Caulker
Caye Caulker
Caye Caulker
Caye Caulker
Xcalak
Xcalak
Xcalak
Xcalak
60.917
85.594
70.76
126.365
102.652
50.73
139.606
137.379
113.278
136.409
143.303
133.171
104.258
169.512
70.168
175.27
84.388
153.406
170.507
185.328
165.266
185.471
264.386
210.603
101.07
444.81
312.847
250.498
259.275
192.254
255.714
318.553
214.681
128.856
133.26
105.701
125.576
149.09
377.634
715.245
490.343
537.889
537.829
766.686
642.232
597.798
751.504
715.204
819.16
603.17
857.48
664.564
798.893
1009.585
835.44
460.723
1377.237
119
Cholinasterase Activity in Tissues of
Haemulon plumieri
1600
1400
AChE Muscle
AChE Brain
AChE Liver
1200
1000
800
600
400
200
0
Cayos Cochinos
Punta Manabique
Caye Caulker
Xcalak
Sites
Figure 67. Median activity of cholinesterase in liver, muscle and brain of the white grunt (Haemulon plumieri) in
different sites within the MBRS region.
The least cholinesterase activity in the muscle of fish was found in Cayos Cochinos, which
may indicate that there are more organophosphorous or carbamic pesticides in this site;
however, this result is not statistically significant (H3,19=5.45; P=0.14). In the brain, the least
activity was found in Xcalak, although this result is also not significant (H3,19=6.38; P=0.095).
The highest cholinesterase activity was found in the liver of the fish, with the smallest values
found at Cayos Cochinos. These differences were not statistically significant (H3,19=6.96;
P=0.073).
It is necessary to understand better the response of the grunts to the presence of
anticholinergic pollutants, and in particular, to organophosphorous and carbamic pesticides,
to be able to adequately interpret the results obtained. Bioassays are currently being done
in order to better determine this species’ biochemical and physiological response.
120
6.4 Sediments
Table 43 shows the results obtained for the different hydrocarbon fractions in sediments.
Table 43. Concentrations of hydrocarbon fractions in sediments collected at various monitoring sites
in the MBRS region.
Sample
1a
1b
1c
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
8a
8b
8c
9a
9b
9c
10a
10b
10c
11a
11b
11c
12a
12b
12c
13a
13b
13c
14a
14b
14c
15a
15b
15c
16a
16b
16c
17a
17b
17c
Site
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
La Ceiba
La Ceiba
La Ceiba
Rio Chamelecon
Rio Chamelecon
Rio Chamelecon
Canal de Quilimaco
Canal de Quilimaco
Canal de Quilimaco
Omoa
Omoa
Omoa
Punta de Manabique
Punta de Manabique
Punta de Manabique
Rio Sarstun
Rio Sarstun
Rio Sarstun
Rio Dulce
Rio Dulce
Rio Dulce
Placencia Lagoon
Placencia Lagoon
Placencia Lagoon
Caye Caulker
Caye Caulker
Caye Caulker
Houlover Creek
Houlover Creek
Houlover Creek
Belize River
Belize River
Belize River
Chetumal Bay
Chetumal Bay
Chetumal Bay
Bacalar Chico
Bacalar Chico
Bacalar Chico
Xkalak
Xkalak
Xkalak
Aliphatic
(µg/g)
UCM
(µg/g)
PAHsBPM
(µg/g)
PAHsAPM
(µg/g)
PAHs
(µg/g)
Total -HCs
(µg/g)
ND
0.06
0.106
ND
ND
ND
ND
ND
ND
ND
0.048
ND
ND
ND
0.058
ND
ND
ND
0.333
0.014
ND
0.013
0.082
0.038
0.377
0.404
0.274
0.296
ND
ND
0.235
0.598
1.424
0.451
0.074
ND
1.239
1.237
0.977
0.166
0.765
0.345
1.077
1.206
0.312
1.339
1.241
5.248
0.699
0.855
0.876
0.12
1.257
1.408
0.366
ND
0.478
0.348
0.739
0.196
0.301
0.054
0.578
3.179
5.32
5.779
0.784
ND
0.503
49.559
28.548
27.193
1.034
ND
0.609
4.743
4.261
4.708
5.699
0.72
3.711
2.081
3.911
3.762
0.384
ND
ND
22.391
8.601
14.128
19.727
5.821
4.632
7.478
5.764
3.308
4.924
14.302
13.174
1.729
1.952
2.312
0.25
0.53
0.51
ND
0.27
ND
ND
ND
ND
ND
ND
ND
0.02
0.46
0.02
0.11
0.27
ND
0.07
0.08
0.03
ND
ND
0.33
0.11
0.13
0.15
0.05
ND
ND
ND
ND
0.01
ND
ND
0.16
0.13
ND
0.01
0.01
ND
ND
ND
0.05
ND
ND
0.05
0.05
0.35
ND
ND
0.33
0.49
0.32
0.03
0.27
0.03
0.07
0.1
0.03
0.04
0.07
0.02
0.14
0.78
0.17
0.26
0.31
0.05
0.95
0.38
0.66
0.17
0.02
0.21
0.54
1.23
0.73
1.2
0.11
0.88
0.61
0.88
0.88
ND
0.04
0.41
0.72
0.3
0.34
0.91
0.64
0.78
1.21
1.55
1.21
0.25
0.71
1.27
0.57
0.03
0.04
0.57
1.02
0.83
0.03
0.54
0.03
0.07
0.1
0.03
0.05
0.08
0.02
0.17
1.25
0.18
0.37
0.58
0.05
1.02
0.45
0.68
0.17
0.02
0.53
0.65
1.36
0.88
1.26
0.11
0.88
0.61
0.88
0.88
ND
0.04
0.57
0.85
0.3
0.35
0.92
0.64
0.78
1.21
1.6
1.21
0.25
0.75
1.31
0.91
0.03
0.04
0.69
2.34
2.34
0.4
0.54
0.51
0.41
0.84
0.23
0.35
0.18
0.6
3.35
6.57
6.02
1.16
0.58
0.55
50.92
29.02
27.88
1.22
0.11
1.18
5.77
6.02
5.86
7.25
0.83
4.59
2.93
5.39
6.07
0.84
0.11
0.57
24.48
10.14
15.45
20.81
7.23
5.76
9.77
8.57
4.83
6.51
16.29
19.74
3.34
2.84
3.23
ND = Not detected
121
Figure 68 shows the median concentrations of total hydrocarbons and the fractions of the
PAHs, which are more toxic, for each monitoring site.
Concentrations of PAHs and Hidrocarburos
in Sediments
35
PAHs
HCs
30
25
20
15
10
5
lak
Xk
a
rC
hic
o
ma
l
ca
la
Ba
de
Ch
e tu
lov
er
Cr
ee
k
Be
Ha
u
B.
lice
r
R’o
el
.d
oo
n
eC
au
lke
Pt o
Ca
y
Pl a
ce
nc
ia
La
g
Du
lce
n
R’o
Ca
bo
ars
t
R’o
S
did
o
Es
co
n
Om
oa
R’o
im
ac
o
Ul
a
C.
de
Qu
il
Ce
iba
Ch
am
ale
c—
n
La
C.
Co
ch
in
os
0
Sites
Figure 68. Median concentrations of total hydrocarbons and PAHs in sediments.
The highest concentrations of hydrocarbons were obtained in Rio Escondido (Guatemala)
and, in the northern part of the study area, in the Belize River and the region around the
transboundary area of Chetumal Bay (New River, Corozal, Chetumal and Xcalak) in Belize
and Mexico. These differences between the median concentrations were found to be
statistically significant through a Kruskal-Wallis analysis of variance (H16,51=44.08;
P=0.0002). The concentrations of PAHs appear more homogeneous, with little variation
among the sites; however, a Kruskal-Wallis ANOVA indicates significant differences among
the sites (H16,51=30.4; P=0.016).
Figure 69 shows the median concentrations by country of the total hydrocarbons and PAHs.
The highest concentrations of total hydrocarbons were found in Guatemala and Belize,
which is statistically significant (H3,51=15.7; P=0.0013). The concentrations of PAHs did not
have significant differences amongst the countries in the MBRS (H3,51=6.7; P=0.08).
122
Concentrations of PAHs and Hidrocarburos
in Sediments (by country)
10
PAHs
HCs
8
6
4
2
0
Mexico
Belize
Guatemala
Honduras
Sitios
Figure 69. Median concentrations by country for total hydrocarbons and PAHs in sediments.
Figure 70 shows that, in general, the concentration of PAHs with high molecular weight
predominates over the PAHs with low molecular weight, which indicates that they are
derived from a pyrogenic source (through organic material combustion) and not from
petroleum. This result is highly significant (H1, 102=38.7; P=0.0000). Exceptions are Cayos
Cochinos, La Ceiba and Xcalak where PAHs with low molecular weight clearly predominate,
which indicates that they come from petroleum.
Concentrations of PAHs in Sediments
1.8
Low Molecular Weight
High Molecular Weight
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
Sites
123
Xk
ala
k
hic
o
rC
Ba
ca
la
Ca
ye
Ca
ulk
Pu
er
ert
od
el
R’o
Be
lice
Ha
ulo
ve
rC
ree
Ba
k
h’a
de
Ch
etu
ma
l
La
go
on
Du
lce
R’o
Pla
c
en
cia
tn
ars
R’o
S
Ca
bo
o
Es
co
nd
id
Om
oa
R’o
ac
o
im
uil
Ul
a
Ca
na
ld
eQ
—
n
La
Ce
iba
Ch
am
ale
c
Ca
yo
s
Co
ch
in
os
0
Figure 70. Policyclyc aromatic hydrocarbons (PAHs) in sediments, grouped by molecular weight.
Table 44 shows results of the concentrations of organochlorine pesticides, including PCBs,
in sediments.
Table 44. Concentrations of organochlorine pesticides, grouped by chemical family.
Sample
1a
1b
1c
2a
2b
2c
3a
3b
3c
4a
4b
4c
5a
5b
5c
6a
6b
6c
7a
7b
7c
8a
8b
8c
9a
9b
9c
10a
10b
10c
11a
11b
11c
12a
12b
12c
13a
13b
13c
14a
14b
14c
15A
15B
15c
16a
16b
16C
17a
17B
17C
Site
Cayos Cochinos
Cayos Cochinos
Cayos Cochinos
La Ceiba
La Ceiba
La Ceiba
Rio Chamelecon
Rio Chamelecon
Rio Chamelecon
Canal de Quilimaco
Canal de Quilimaco
Canal de Quilimaco
Omoa
Omoa
Omoa
Punta de Manabique
Punta de Manabique
Punta de Manabique
Rio Sarstun
Rio Sarstun
Rio Sarstun
Rio Dulce
Rio Dulce
Rio Dulce
Placencia Lagoon
Placencia Lagoon
Placencia Lagoon
Caye Caulker
Caye Caulker
Caye Caulker
Haulover Creek
Haulover Creek
Haulover Creek
Belize River
Belize River
Belize River
Chetumal Bay
Chetumal Bay
Chetumal Bay
Bacalar Chico
Bacalar Chico
Bacalar Chico
Xcalak
Xcalak
Xcalak
Chlorobenzene
(ng/g)
HCHs
(ng/g)
Drines
(ng/g)
DDTs
(ng/g)
Chlordane
(ng/g)
Total
Pesticide
(ng/g)
PCBs
(ng/g)
0.671
2.201
0.931
0.395
0.103
0.599
1.163
1.586
0.435
1.626
0.583
1.211
0.061
2.152
1.754
0.813
0.359
ND
3.613
2.118
1.635
2.948
0.771
1.554
3.182
3.202
3.584
3.553
2.968
2.699
0.363
2.418
2.167
5.215
1.748
0.404
0.608
0.113
0.158
3.125
3.311
0.659
11.838
13.148
ND
ND
4.924
18.653
0.021
1.108
1.802
0.021
0.119
ND
0.25
0.027
0.652
0.688
14.518
0.341
0.191
ND
0.546
0.206
0.219
ND
ND
0.132
ND
2.663
0.543
0.178
0.872
0.536
0.095
0.559
0.624
6.392
0.905
0.588
0.464
0.295
1.369
1.204
0.488
0.487
0.125
1.06
0.037
0.429
0.455
0.317
1.146
0.712
0.479
0.552
ND
1.675
1.8
2.675
0.402
4.753
2.403
2.029
1.019
0.049
1.363
0.258
0.113
0.172
0.384
ND
0.149
0.062
0.721
3.243
ND
ND
1.489
0.169
1.612
0.552
0.056
1.613
1.899
1.81
0.286
0.932
0.207
1.584
0.535
1.015
0.37
0.372
0.535
ND
0.741
1.438
0.258
0.055
ND
0.076
ND
ND
ND
0.421
0.244
ND
0.491
3.577
ND
ND
ND
0.128
ND
0.366
0.11
0.315
0.236
0.229
0.378
0.182
0.54
0.288
0.274
0.169
0.502
0.517
0.045
0.072
0.168
ND
3.534
0.639
0.516
0.171
0.347
0.529
0.696
0.538
0.459
0.387
0.994
0.582
0.669
0.661
0.019
0.151
0.366
6.204
0.168
2.8
1.042
4.205
1.905
2.541
11.209
0.413
ND
0.189
6.127
0.226
18.588
11.19
0.15
ND
0.141
0.014
ND
0.321
0.286
0.145
0.344
0.089
0.04
0.032
0.164
ND
0.04
ND
ND
0.376
ND
0.24
1.04
0.128
0.024
ND
0.4
0.169
0.383
0.307
0.147
0.201
0.206
0.012
0.09
0.12
0.199
ND
0.131
0.618
0.122
0.203
0.256
0.163
4.285
3.609
0.141
ND
0.144
1.118
0.186
1.384
1.023
3.372
4.349
2.458
0.818
1.808
2.336
2.785
17.046
1.699
2.549
1.234
2.138
1.338
6.132
2.318
0.858
2.069
0.714
8.16
7.318
4.156
6.114
3.422
3.807
5.284
5.623
11.283
6.953
4.725
5.49
1.924
5.125
5.255
5.886
3.36
2.334
8.474
1.305
3.907
5.152
8.209
4.278
19.577
29.969
1.778
ND
7.705
31.701
3.108
21.483
19.26
1.55
1.857
1.541
ND
1.265
0.133
ND
ND
ND
ND
ND
1.376
0.081
2.638
2.682
2.738
2.733
1.038
ND
0.598
0.536
ND
0.031
1.555
0.463
0.391
0.052
ND
0.274
0.064
0.321
0.891
ND
ND
ND
1.003
0.977
0.317
0.741
1.064
1.42
0.014
1.884
2.004
3.483
ND
2.535
0.667
0.786
0.051
0.677
ND = Not detected
124
Figure 71 shows median concentrations by site for organochlorine pesticides and PCBs
grouped by chemical family.
Concentrations of Organochloride Pesticides and PCBs in Sediments
25
PCBs
Chlordanes
DDTs
Drines
HCHs
Clorobenzenes
20
15
10
5
la
k
Xk
a
e
C
Pt
au
o.
lk
er
de
lR
’o
Be
lic
H
e
au
lo
ve
rC
re
B.
ek
de
C
he
tu
m
al
Ba
ca
la
rC
hi
co
La
go
on
C
ay
D
ul
ce
n
Sa
rs
t
R
’o
Pl
ac
.
R
’o
R
’o
C
ab
o
on
di
do
Es
c
O
m
oa
ac
o
U
la
ui
lim
Q
C
.d
e
C
ei
ba
C
ha
m
al
ec
—
n
La
C
.C
oc
h
in
os
0
Sites
Figure 71. Median concentrations by site for organochlorine pesticides and PCBs
4
3.5
3
Clorobenzenes
HCHs
Drines
DDTs
Chlordanes
PCBs
2.5
2
1.5
1
0.5
0
C. Cochinos
La Ceiba
Chamalec—n
Ul a
C. de Quilimaco
Omoa
R’o Escondido
Cabo
R’o Sarst n
Sites
Figure 72a. Organochlorine pesticides and PCBs grouped by chemical family, by monitoring site.
125
R’o Dulce
14
12
10
Chlorobenzenes
HCHs
Drines
DDTs
Chlordanes
PCBs
8
6
4
2
0
Placencia
Lagoon
Caye Caulker
Puerto del R’o
Belice
Haulover Creek
Bah’a de
Chetumal
Bacalar Chico
Xkalak
Sitios
Figure 72b. Organochlorine pesticides and PCBs grouped by chemical family, by monitoring site.
As in the case of PAHs, the highest concentrations of pesticides were found in the northern
part of the study area, in the Belize River, Corozal, Chetumal Bay and Xcalak. In particular,
the high concentration of DDTs is to be noted in sediments in Xcalak, as well as the high
concentrations of chlorobenzenes in Corozal and Chetumal.
In particular, the concentrations of total hexachlorocyclohexanes (HCHs), and total
chlordanes exceeded the probable effect levels (PEL) in some stations (PEL, Buchanan
1999). If the concentrations of a pollutant exceed the PEL, there is a high probability that the
sample is toxic to marine fauna. These levels were exceeded for HCHs in the stations
located at the mouth of Chetumal Bay, the mouth of Haulover Creek, in the Placencia
Lagoon and in almost all the monitoring stations in the Gulf of Honduras (Map 19). The PEL
was exceeded in the case of chlordanes at the mouth of Chetumal Bay (Map 20). The
results for sediments coincide with those of cholinesterase activity, since the highest levels
of inhibition were found precisely in Xcalak, at the mouth of the Bay.
126
Map 19. Monitoring stations where PEL (red dots) and TEL (yellow dots) levels of
hexachlorocyclohexanes in sediments were exceeded. Green dots indicate those stations where
there is the least probability of finding a toxic Effect
127
Map 20. Monitoring sites showing the levels of chlordanes in sediments with respect to PEL and
TEL. Green dots indicate those stations where there is a low probability of finding a toxic effect.
128
7 WATER QUALITY
7.1 Description
Poor water quality is an excellent early indicator of possible threats to the MBRS
ecosystems. Therefore, it is essential to include water quality as one of the primary
parameters monitored by the SMP.
The coastal waters of the MBRS provide many valuable resources to the people of the
region. However, constant use (e.g. coastal development, agriculture, aquaculture) and
growing populations are placing pressure on these areas and polluting the water quality.
Agricultural activities in coastal watersheds increase sedimentation, eutrophication, and
organochloride pollution in the river, estuarine, and marine ecosystems. Bananas, citrus,
African palm, and sugarcane are vital sources of income and major exports for the countries
of the MBRS region, so sustainable practices need to be developed and implemented in
order to ensure continued agriculture without risking other coastal resources.
Coastal development is another industry that is economically important but often
environmentally devastating. Sewage and waste discharge, dredging, and sand or
limestone mining have negative effects on the coastal water quality.
Direct marine activity (ports, shipyards, tourism, cruise ships) degrade water quality through
fuel spills, pollution of ballast water, bilge cleaning, and solid waste disposal. The cruise
ship industry is a significant source of water pollution. Daily waste created by a typical
cruise ship is as follows (http://www.surfrider.org/a-z/cruise.asp):
•
•
•
•
•
540 m3 of gray water (from washrooms, showers, and laundries).
113 m3 of black water (sewage).
13.5 m3 of oily water from bilge.
50 liters of hazardous materials, such as perchloroetilene from dry cleaners,
photographic development liquids, paint, solvents, etc.
7 tons of solid waste (garbage).
Ballast water is another issue with cruise ships. Up to 1,000m3 is taken into the ship’s hull
and used to balance the ship on the high seas. Often times, this water become polluted or
contaminated with diseases that damage systems when the water is discharged. Also,
foreign species can be transported from one port or one tourist destination to another via
this water (http://www.surfrider.org/a-z/cruise.asp).
Lastly, aquaculture poses a threat to coastal water quality through activities that lead to
eutrophication, new diseases, and possible invasive species (Arriola, 2003).
To date, water quality monitoring has not been completed on a regular basis. Currently, we
only have a small set of data which was collected by the Mexican Navy, with support from
the MBRS Project and some scattered data that were collected at seagrass and mangrove
monitoring sites.
129
In 2003, the MBRS project acquired nine multi-parametric sondes and distributed them
throughout the region. General characteristics and recipients are shown below (Table 45).
Table 45. Multi-parametric sondes used in the MBRS region.
DATE OF PURCHASE
28 March 2003
29 May 2003
22 July 2003
22 July 2003
4 September 2003
4 September 2003
4 September 2003
4 September 2003
31 May 2005
BRAND
YSI
YSI
Water Quality Monitoring Kit HORIBA
2012139
Water Quality Monitoring Kit HORIBA
2012139
YSI
YSI
YSI
YSI
YSI
RECIPIENT
Chetumal, Mexico
Cancun, Mexico
Guatemala City
Guatemala City
Cayos Cochinos, Honduras.
Puerto Cortés, Honduras.
Belize City, Belize.
Punta Gorda, Belize.
DiBio, Honduras.
Because of the cost associated with water quality monitoring, it was necessary to provide
the four countries with all the appropriate equipment to collect data. Unfortunately, this
equipment has not been utilized on a regular basis, and technical problems are frequent.
In addition to equipment issues, very few labs in the region are capable of analyzing water
samples to evaluate nutrient levels. An agreement has been established with El Colegio de
la Frontera Sur Unidad Chetumal in Chetumal, Mexico (specifically the Institutional
Chemistry Lab) (ECOSUR) where samples from Mexico and Belize can be processed. The
Laboratorio de la Unidad de Gestión Ambiental in Puerto Cortés, Honduras can process the
samples from Honduras, and possibly Guatemala.
The results obtained by the Secretaría de Marina in Mexico in 2005 are shown below.
During 2005, eight water quality monitoring campaigns were conducted in the locations
established by the MBRS Monitoring Network, in Chetumal Bay and along the Mayan Coast
(February, March, May, June, July, August, September and November). Nutrient levels
were higher in Chetumal Bay than along the Mayan Coast; highest levels were observed at
the Rio Hondo river mouth. Orthophosphates were similar across the monitored area, and
surveyors measured fecal coliform in the Rio Hondo river mouth from June to September.
The field methodology proposed by the SMP manual (2003) was followed. Surface water
samples were taken in each location (five replicas per location). The pH, temperature,
salinity and dissolved oxygen were measured in situ by means of a multi-parametric sonde
YSI-300.
Water samples were collected in one-liter plastic bottles and were stored on ice
(approximately 4 - 6° Celsius) for approximately 4 to 6 hours. Nutrient analyses were
conducted in the ECOSUR lab. Bacteriological analysis were conducted in the portable
laboratory located in the Chetumal Naval Sector.
Nutrient concentration was determined according to the methods established by Parson et
al., (1984) for saltwater, using a spectrophotometer (Milton Roy Spectronic 21). Fecal and
total coliform were estimated using the multiple fermentation tube method (NMX-AA-042).
130
7.2 Results
Temperature. Temperatures between 29 and 35 degrees Celsius were registered in the
monitored locations. The maximum values occurred near the wharf in Mahahual.
Station
Location
Salinity. The lowest salinity was observed at the Rio Hondo
1
Laguna Guerrero
river mouth (<6ppt) during August and September (the rainy
2
Punta Calentura
season). In Laguna Guerrero, the salinity varied between 15
3
Rio Hondo
and 20 ppt; in Punta Calentura, between 20 and 30 ppt.
4
Mahahual
5
Xcalak
Dissolved Oxygen. DO levels ranged from less than 3 mg/L
6
Canal de Zaragoza
to 6 mg/L.
Nitrites (NO2). In the Chetumal Bay, nitrite levels stayed around 0.004 mg/L during most of
the year. Highest levels were seen at the Rio Hondo river mouth. Along the Mayan Coast,
levels stayed right around 0.005 mg/L. During the month of March, levels were higher than
both in the Bay and along the Coast.
Nitrates (NO3). In Laguna Guerrero, Punta Calentura, Mahahual, Xcalak and Canal de
Zaragoza the concentration of nitrates varied around 0.1 mg/L, with the exception of
February 2005, when higher values were observed (0.30mg/L). For most of the year, the
values in the Rio Hondo river mouth varied between 0.3 and 0.55 mg/L. Only during
September 2005 were values under 0.1 mg/l observed.
Map 21. Monitoring stations for water quality.
131
Ammonium (NH4). The levels of ammonium in Chetumal Bay ranged between 0.1 and 0.15
mg/L. Levels were slightly higher in the Rio Hondo river mouth, reaching 0.18 mg/L. Along
the Mayan Coast ammonium levels stayed around 0.05 mg/L.
Orthophosphates (PO4). The levels of orthophosphates in Chetumal Bay varied between
0.01 and 0.03 mg/L, except during September when there was a spike in orthophosphate
levels (0.08 mg/L). In the marine locations (Mahahual and Canal de Zaragoza), the levels
fluctuated from 0.005 to 0.030 mg/L, reaching a maximum in August, after hurricanes Emily
and Stan brought extra rain.
132
Rio Hondo Nutrients Data
Rio Hondo Physical Data
35
30
25
20
15
10
5
0
15
10
5
0
Feb-05 Mar-05 Apr-05 May-05 Jun-05 Jul-05 Aug-05
Feb-05
pH
Mar-05
Apr-05
Salinity (ppt)
May-05
Jun-05
Temp. (0C)
Jul-05
Phosphates (uM)
Ammonia (uM)
Nitrites (uM)
Nitrates (uM)
DO (mg/L)
Xcalak Physical Data
Xcalak Nutrients Data
40
35
30
25
20
15
10
5
0
6
5
4
3
2
1
0
Mar-05
Jun-05
pH
Jul-05
Salinity (ppt)
Aug-05
Temp. (0C)
Sep-05
DO (mg/L)
Apr-05
Phosphates (uM)
Nitrites (uM)
May-05
Jun-05
Jul-05
Aug-05
Ammonia (uM)
Nitrates (uM)
Fecal Coliform. Fecal coliform was measured only in the Rio Hondo river mouth. There was
a huge spike in these data in June (average of 20.0 nmp/100ml), which coincides with the
start of the rainy season.
Rio Hondo Fecal Coliform
25
20
15
10
5
0
Feb-05 Mar-05 Apr-05 May-05 Jun-05 Jul-05
Fecal Coliform (nmp/100mL)
133
8 DISCUSSION AND CONCLUSIONS
The average value for a series of parameters recorded along the MBRS region is presented
here in this first baseline report of the status of the Mesoamerican Barrier Reef Systems.
These values represent the baseline, against which data obtained in future monitoring
exercises will be compared.
Six parameters are surveyed for benthic cover under this monitoring program. Of these, live
components accounted for 67% of the total area monitored. The benthic components with
the greatest coverage were hard corals and algae, together comprising an average of 58%.
The rest of the benthic cover is comprised of rock, sand and Thalassia.
The parameters of the principal live reef components were grouped to define a single
indicator, as follows:
Benthic cover: Various benthic components are grouped in this indicator. These
include live coral, algae, gorgonians, sponges, coralline algae and Millepora. In this
indicator, high algal cover is inversely related to reef health, whereas for all other
parameters a high cover represents a favorable condition.
All coral species are included in the coral cover parameter. Coral colonies exhibit different
growth patterns, depending on the species and the reef zone in which they occur. This
analysis shows that a typical reef in the MBRS region should have colonies measuring 33
cm (± a std. dev. of 13) in diameter. This average applies for all colonies of all
species. In general, mature undamaged reefs have larger colonies than reefs that
have been impacted by either natural events or anthropogenic activities.
Mean colony height for the MBRS region is approximately 21 cm (± a std. dev. of 9.5).
This parameter includes all colonies, regardless of growth type (e.g. branching,
boulder-forming, plate-like, encrusting). Encrusting and plate-like species rarely
exceed five centimeters in height, and therefore bring down the mean. This
parameter could be a good indicator of the impact of tourism on the reef because
branching corals, such as Acropora spp., are easily broken by inexperienced divers
and snorkellers. A change in their average height could therefore signal a negative
impact from tourist activities.
The percentage of colonies that show some type of mortality is also monitored. The
parameter addressing overall colony condition is defined as:
Condition of the colonies: colony diameter, colony height and presence of mortality
are grouped in this indicator,. Higher values for diameter and height indicate good
reef condition whereas the percentage of colonies with mortality is inversely related to
reef health.
To determine the relationship between the main live components (MLC) of the reef and the
algae, the following indicator is defined:
134
MLC : Algae Ratio: For this indicator, the values of live coral, gorgonians, sponges,
coralline algae and Millepora cover were added together and divided by algal cover.
The three indicators defined above include most of the parameters recorded under the SMP
in relation to the benthic composition of the reef.
Three parameters related to reef fish community structure were selected due to their
importance within the reef and associated ecosystems:
Fish density: this indicator represents the density of adult fish. The mean for the
MBRS region is 34 ind./100m2 with a standard deviation of 21. Herbivorous species
should be in an equilibrium with both carnivorous species and algal cover.
One of the main limiting factors on coral reef growth is hard substrate, necessary for coral
recruitment.
Herbivores clear away macroalgae, leaving spaces where coral can
successfully settle, so their density is an important indicator of reef status.
This indicator also gives clues to areas which might be affected by unsustainable fishing
levels, especially regarding species of commercial importance.
Carnivorous fish populations, including species of economic importance (groupers,
barracudas, snappers), are extremely low on most reefs monitored. High demand, and the
associated fishing pressure, probably explains this dearth of large predators.
Another useful element when determining reef health is recruit fish density. Presence of
large numbers of recruits implies a healthy adult fish population that is spawning on the reef
or nearby in seagrass beds and mangrove forests.
Surgeonfishes and parrotfishes are the most observed species at the MBRS monitoring
sites. Reefs with low recruitment rates require further study, in order to pinpoint possible
causes.
Fish recruits: this indicator includes the density of recruit fishes.
Finally, in order for healthy fish populations to exist on the reef, successful spawning must
occur. Larger individuals produce more offspring and are more reproductively fit, so reef
sites with a large population of bigger individuals are probably less susceptible to fishing
pressure. Therefore, another indicator of reef health is as follows:
Fish sizes: This indicator involves the size structure of the reef fish community, but it
should be analyzed carefully in an attempt to control for any surveyor biases (from a
lack of experience or proper training).
Anthropogenic pollution is an important part of the SMP. A pollution indicator has been
defined as:
HCH Pollution (hexachlorocyclohexanes): One way to evaluate whether or not
pollutant levels found in sediments are hazardous is to compare them to the Probable
135
Effects Level (PEL) published by the EPA (Buchman, 1999). The PEL is defined as
the concentration of a pollutant at which adverse effects are expected to occur.
Most pollution monitoring sites north of the Motagua River are above the PEL index for
concentrations of HCH.
The indicators defined here are similar to those proposed by the Healthy Reefs for Healthy
People Initiative. Some differences do occur, including the grouping of main live
components into one indicator to be compared with algal cover. Also, the grouping of larger
colonies (diameter and height) as favorable and the consideration of colonies with mortality
as a unfavorable are differences. All other indicators are similar, or the same as, those in
the Healthy Reefs for Healthy People Initiative.
Table 46 compares the MBRS locations with respect to the indicators described above.
Green represents an area in good condition, yellow indicates an area under possible stress,
and red color represents an area in critical condition.
These discussion are based on results obtained during the first monitoring session at each
site (from 2004 or 2005). This baseline is intended to be used for comparison during future
studies in the region, in order to identify any negative or positive trends in reef health.
Table 46. MBRS locations and ecological indicators used to obtain reef status.
MPA
Benthic
cover
Condition of
the colonies
MLC:Algae
Ratio
Fish
recruits
No data
available
Cozumel
B. Chinchorro
Xcalak
Bacalar Chico
Hol Chan
Caye Caulker
Glover's Reef
South Water
Gladden Spit
Sapodilla Caye
P. Manabique
Fish
sizes
Pollution
PEL- HCH
No data available
No data available
No data available
No data available
No data available
No data available
No data
available
Utila
C. Cochinos
Legend
Fish
density
No data available
Good condition
Shows stress
Critical condition
Annex I, shows the analysis of each of the indicators.
It is important to ascertain which indicators and which locations require the most attention
and are the most likely to be affected by successful conservation. Also, some stressful
136
conditions could be caused by a combination of interdependent factors, such as coral cover,
algal cover, and herbivore density.
Algal cover may increase during warmer parts of the year and decrease during cooler
months. For this reason, it is necessary to continue monitoring at least twice a year with the
purpose of determining any algal cycles that might occur.
Colony condition seems to be closely linked to coral cover and colony size. Sites with low
coverage and small colonies typically have more colonies with some level of mortality.
Each indicator represents a parameter or group of parameters that, when taken together,
provide us with a panorama of the state of the reef at the MBRS locations.
The following is a summary of each location:
Cozumel: The two hurricanes that ravaged Cozumel’s reefs during the 2005 season
considerably reduced live coral cover and many of the other groups making up the MLC
indicator. These stresses also have taken their toll on colony condition. An outreach
program needs to be designed that successfully educates tour operators and tourists on the
importance of maintaining current levels of live coral cover and bare rock (for successful
coral recruitment).
Banco Chinchorro: The condition of the colonies must be monitored closely, to determine
the cause of the high percentage of colonies with mortality. As for fish, fishing activity should
be analyzed in order to explain the absence of large individuals of some fish species.
Xcalak: Each site needs to be analyzed in detail because of stressed or critical conditions
for all indicators. A meeting of protected area managers and biologists to discuss
management practices and identify the sources of stress is suggested.
Bacalar Chico: While the fish community seems to be in relatively good health, a detailed
analysis of the benthic community is suggested because of current levels of stress.
Hol Chan: Causes of low coral cover and high algal cover need to be identified for this
location. Eutrophication is a possible stress factor.
Caye Caulker: Critical conditions in the fish community can probably be explained by the
heavy fishing pressure found in this location. However, a more detailed analysis of fishing
activity should be conducted and compared to the fish status. Also, monitoring in local
seagrass beds and mangrove forests needs to be initiated.
Glover’s Reef: A study of local activity might discover the causes of small coral colonies
and high mortality found in this location.
South Water Caye: Fishing activity needs to be studied more closely in this area. Also,
coral colony size is low.
137
Gladden Spit: The benthic community in this location is under stress (or worse). Agents
leading to this condition, along with possible remedies, should be identified. In addition,
fishing pressure seems to have led to low density and small sizes of adult fishes.
Sapodilla Cayes: Fishing activities must be analyzed in this transboundary area to
determine the agents causing the low density and small sizes of adult fishes.
Punta de Manabique: Fishing activities must be analyzed in this transboundary area to
determine the agents causing the low density and small sizes of adult fishes.
Utila: Tourist activities are a likely cause of the stressed or critical status of the benthic
community.
Cayos Cochinos: Causes of the stressed conditions in the benthic community need to be
identified.
Seagrass
Long-term monitoring programs on seagrasses are needed to measure the impact of
anthropogenic activities, climate change, and natural phenomena, such as tropical storms
and hurricanes. The SMP currently focuses on protected areas in the region, but expansion
outside these areas is needed.
The general public, NGOs, scientists and government officials must work together in order
to protect the valuable seagrass beds in the MBRS region. Information on the biology and
ecology of seagrasses, including detailed maps of their distribution and abundance, is still
scarce; therefore, scientific research and the current monitoring initiatives in the four MBRS
countries must be continued to fill the information gaps. Natural resource managers can use
this knowledge to evaluate any stresses on seagrasses, their potential for natural recovery,
and options to mitigate negative impacts.
There are new, modern parameters that are used to compare different seagrass
communities, such as: LAR (Leaf Area Ratio) and SLA (Specific Leaf Ratio). These two
ratios approximate RGR (Relative Growth Rate) over time.
Remote sensing is another technology that could make a significant contribution to the
monitoring program, since it would facilitate the measurement of loss of seagrass. Such
information is vital to management and decision-making.
The Relationship between Above Ground and Below Ground Biomass: Segrass
beds with high below ground biomass can generally have a better structural response
to natural and anthropogenic stresses (including storms and eutrophication). Large
root masses help to obtain nutrients, rhizomes allow for storage of starches.
138
Mangroves
Similar to the situation with seagrasses, long-term monitoring of mangroves concentrates on
protected areas and aims to measure the impact of anthropogenic and natural stresses
(including climate change) to the mangrove ecosystem. Monitoring in heavily impacted
areas, including ports and aquaculture facilities could give a more complete picture of
mangrove status.
The general public, NGOs, scientists and government officials must work together in order
to protect the valuable mangrove forests in the MBRS region. Information on the biology and
ecology of mangroves, including detailed maps of their distribution and abundance, is still
incomplete; therefore, scientific research and the current monitoring initiatives in the four
MBRS countries must be continued to fill the information gaps. Natural resource managers
can use this knowledge to evaluate any stresses on mangroves, their potential for natural
recovery, and options to mitigate negative impacts.
As with seagrasses, remote sensing offers an excellent opportunity to monitor losses (or
potential gains) in mangrove cover. This information is extremely useful for decision making
and resource management.
The main indicators used for mangroves are:
Density, Height and DBH: Mangrove forests with older, larger trees are generally
healthier and can withstand environmental stresses (including storms, pollution,
deforestation) more successfully than young, small forests.
Pollution
A way to evaluate if the concentrations of pollutants found in sediments are harmful is to
compare them to the Probable Effects Level (PEL) of the EPA (Buchman, 1999). The PEL is
defined as the concentration of a pollutant in sediments, above which adverse effects are
frequently found in fauna. On the other hand, the TEL (Threshold Effects Level) is the
concentration below which harmful effects are not frequently found in fauna. Concentration
values above the PEL were only found for hexachlorocyclohexanes (HCHs) and chlordanes.
In the case of the HCHs, the PEL was exceeded in 25% on the sediment samples analyzed,
and only in one sample in the case of the chlordanes.
The sites:
Placencia Lagoon
Corozal Bay
Xcalak
Belize
Belize
Mexico
Results for the above sites are particularly worrisome, since two out of three replicas
exceeded the PEL for the HCHs, which indicates a high probability that this pesticide is
affecting the fauna.
139
In the case of Rio Chamelecon, Rio Sarstun, Rio Dulce, Belize River and Chetumal Bay, at
least two of the three replicas analyzed had HCH concentrations between the TEL and the
PEL; therefore, there is some risk of finding harmful effects.
Table 47 compares the average concentrations of PAHs found in sediments in the SMP
study, grouped by country, with the concentrations published for several coastal ecosystems
in the Gulf of Mexico, as well as the values considered as “high” and “critical” by NOAA for
the northern Gulf of Mexico (Gold-Bouchot, 2004). The concentrations of PAHs in the MBRS
in this study are relatively low, compared to the concentrations found in the coastal
ecosystems of the Gulf of Mexico, and are under the concentrations considered as high or
critical by NOAA, contrary to the findings on pesticides, particularly Lindane (and HCH).
Table 48 compares the concentrations of PAHs metabolites in the bile of the white grunt
collected during this study, with the concentrations of these compounds obtained in catfish
(Ariopsis assimilis) in Chetumal Bay, while Table 49 compares the concentrations of
pollutants in the liver of these fishes.
Table 47. Average concentrations of total PAHs, as well as high and low molecular weight PAHs,
found in the MBRS countries compared to those found in the coastal lagoons and bays of the Gulf of
Mexico.
Lagoon/Bay
Chetumal
Sian Ka’an
Salada
Llano
Mandinga
Mancha
Pueblo Viejo
Tamiahua
Tampamachoco
Mecoacán
Carmen
Machona
Honduras
Guatemala
Belize
Mexico
Average MBRS
“High” USA
Critical
PAHs
(µg/g)
BPM*
(µg/g)
APM§
(µg/g)
2.34
1.16
6.65
5
5.68
6.73
3.81
3.42
4.48
0.95
1.31
1.85
0.33
0.67
0.61
0.84
0.55
2.4
35
0.27
0.55
0.21
0.31
0.8
0.39
1.12
0.88
1.21
N. R.
N. R.
N. R.
0.14
0.08
0.03
0.07
0.08
2.17
0.8
6.44
4.69
4.88
6.34
2.08
2.54
3.27
N. R.
N. R.
N. R.
0.2
0.59
0.58
0.77
0.47
Reference
Noreña-Barroso et al., 1998.
Gold-Bouchot et al., 1999.
Vázquez-Botello et al., 2001.
SMP-MBRS
SMP-MBRS
SMP-MBRS
SMP-MBRS
SMP-MBRS
O’Connor, 1990
Long and Morgan, 1990
*BPM = PAHs of low molecular weight; §APM = PAHs of high molecular weight; ¶N. R. = Not reported.
140
Table 48. Average concentrations of PAHs metabolites in the bile of the white grunt (Haemulon
plumieri) compared to the average obtained for the Mayan Catfish (Ariopsis assimilis) in Chetumal
Bay (Noreña-Barroso et al., 1998).
Naphthalenes
(µg/mL)
Phenantrene
(µg/mL)
Pyrenes
(µg/mL)
Benzo(a)pyrenes
(µg/mL)
Chetumal Bay
12.83
26.82
0.37
0.35
Cayos Cochinos
28.19
71.41
0.13
0.25
Punta de Manabique
68.05
51.06
0.11
0.49
Caye Caulker
41.47
50.43
0.09
0.21
Xcalak
54.67
68.41
0.25
0.53
Average MBRS
45.89
59.99
0.13
0.34
Site
Chetumal Bay is considered a polluted site, and when comparing the concentrations of
PAHs metabolites in bile we found that the concentrations of naphthalenes and
phenantrenes (low molecular weight PAHs characteristic of petroleum hydrocarbons) were
found in higher concentrations in the MBRS countries than in Chetumal Bay. The
concentrations of pyrenes are higher in Chetumal Bay, but those of benzo(a)pyrenes are
higher in Puerto Barrios and Xcalak than in Chetumal Bay. This is cause for concern, since
it has been reported that hepatic tumors have been found in the Mayan Catfish (Ariopsis
assimilis) of the Bay(Noreña-Barroso et al., 2004). Even taking into consideration that they
are different species, if the white grunt in the MBRS have higher concentrations of
metabolites, it is probable that they are also experiencing problems due to the presence of
these pollutants.
Table 49. Median concentrations of pollutants in the liver of the white grunt (Haemulon
plumieri) compared to the median obtained in the Florida Keys and for the Mayan Catfish
(Ariopsis assimilis) in Chetumal Bay.
Site
Alina's Reef§
Molasses§
White Banks§
Chetumal Bay*
Cayos
Cochinos
Punta de
Manabique
Caye Caulker
Xcalak
Average
MBRS
PAHs
(µg/g)
DDTs
(ng/g)
Chlordanes
(ng/g)
HCHs
(ng/g)
Pesticide
(ng/g)
PCBs
(ng/g)
N. R.
N. R.
N. R.
77.6
33.9
128.6
28.3
28.27
24.1
42.5
5.1
26.2
1.3
8.4
0.7
7.81
119
229.4
74.2
143.65
N. R.
N. R.
N. R.
83.84
35.99
3.77
1.83
22.79
45.28
142
12.64
18
N. D.
5.3
26.76
49.08
27.41
181.53
20.22
N. D.
N. D.
N. D.
4.31
N. D.
45.45
77.78
97.29
160.1
13.11
N. D.
4.31
45.45
97.29
30.53
§
*Noreña-Barroso et al., 2004. Downs et al., in press. N. R. = Not Reported. N. D. = Not Detected.
The concentrations of pollutants in the liver of the grunts in the Florida Keys are reported in
ng/g based on lipids, so they are not directly comparable with the results of this study.
141
Nevertheless they are included as they are the only results available in scientific literature. If
the contents of lipids range from 20 to 30%, then the concentrations found in the Florida
Keys must be divided by a factor between three and five, to make it comparable. Even
taking this into account, the concentrations of organochlorine pesticides in the Florida Keys
are similar or even smaller than those found in the MBRS monitoring sites, with the
exception of the results for chlordanes.
Table 49 shows that in some cases, the median concentrations of pollutants exceed those
of the catfish in Chetumal Bay. The PAHs in grunts in Xcalak are higher than in Chetumal
Bay. The same occurs with the HCHs in Cayos Cochinos and the PCBs in all the MBRS
sites, except for Puerto Barrios. Again, this is cause for concern, since it has been reported
that hepatic tumors have been found in the Mayan Catfish (Ariopsis assimilis) in the
Chetumal Bay (Noreña-Barroso et al., 2004). Even taking into account that they are different
species, if the white grunt in the MBRS have higher concentrations of pollutants, it is
probable that they are also experiencing problems due to the presence of these pollutants.
It has recently been reported that the corals in the Florida Keys show signs of stress due to
exposure to chemical pollutants (Downs et al., 2005b). The fact that persistent pollutants,
such as organochlorine pesticides and PAHs, were found in high concentrations in this
study compared to those found in the other sites which are considered impacted, makes us
suppose that the coral reefs in the MBRS are at risk due to the presence of these pollutants.
In order to determine the possible impact produced by pollutants, it is necessary to include
damage indicators, such as histopathological analyses of fish and corals and toxicity
analyses of sediments, as has been done in Chetumal Bay (Zapata-Perez et al., 2000).
Additionally, cellular diagnostic tools (Downs et al., 2005a and b) or the techniques included
in the RAMP protocol (Rapid Assessment of Marine Pollution; Galloway et al., 2002) could
be included. These additional analyses would give a more complete view of the situation
and facilitate the diagnosis of the possible direct causes of stress.
Twenty five percent (25%) of the sediment samples exceeded NOAA’s Probable Effects
Level (PEL) for Lindane (γ-HCH); therefore, harmful effects to the fauna due to the presence
of this pesticide may be expected.
The concentrations of PAHs metabolites and of some pollutants in the selected indicator
organism (Haemulon plumieri) exceeded the concentrations of the same pollutants found in
the Mayan Catfish (Ariopsis assimilis) in Chetumal Bay, a site considered to be impacted by
pollution, and they are similar to those obtained for the grunt in the Florida Keys.
With the information available at this moment, it is not possible to determine the sources of
the pollutants found, or their potential dispersion throughout the MBRS. It is also important
to consider the probable transport of the pollutants by wind (Alegría et al., 2000) and not
only by marine currents.
It is necessary to expand the monitoring network, to include, for example, sites north of
Chetumal Bay, and to add monitoring sites in Banco Chinchorro, Sian Ka'an, Cozumel and
Cancun. Since no samples were collected from these sites in this study, the Mexican part
of the MBRS was under-represented.
142
The highest level of nitrogenated nutrients was recorded in the interior of the Chetumal Bay.
The highest levels of nitrates, nitrites and ammonium, were recorded for the Rio Hondo.
From there, these nutrients are transported to Chetumal Bay.
The input of phosphates and coliforms appears to be related to surface runoff, resulting from
the rains caused by meteorological phenomena occurring during August and September.
9 RECOMMENDATIONS
Based on the results offered and the corresponding discussion, we offer recommendations
for management of the MBRS resources and for the improvement and strengthening of the
Synoptic Monitoring Program.
For Management:
1. For each locations previous information, wherever it exists, should be compared with
the information presented herein, to identify any current tendencies. A comparison
over time may reveal positive or negative trends. Also, there may be a case where a
particular location was always below or above the regional average and this historical
information would help to interpret current results.
2. Identify the specific anthropogenic activities that directly or indirectly affect the
ecosystems., These may include, for example, the sources of nutrients that cause
eutrophication and consequently an increase in the growth of macroalgae,
mismanagement of tourism sites, over-fishing in the reef zones, spillage of pollutants,
etc.
3. Evaluate whether the conditions found in a particular location are due to natural
disasters and/or climatic events.
4. Consider which management actions may be implemented to improve the conditions of
a site, based on that site’s particular characteristics, history, threats and the specific
human uses practiced there.
5. Focus conservation efforts and resources by prioritizing the sites that show stress, also
taking into account the feasibility and the potential for successful conservation.
6. Improve environmental education delivered to the general public, focusing specifically
on the importance of preserving the reefs, mangroves and seagrass, which are
breeding sites for many species and protect the coast from erosion, storms and
hurricanes. This information must be emphasized in educational activities targeting
hotel operators, tour operators and the tourists themselves.
7. Preserve sand dunes on beaches.
8. Use the information provided in this baseline study to educate all sectors of the public
about the current state of coral reefs and associated coastal ecosystems and inform
them of the threats found.
143
9. The results shown for pollution and water quality clearly establish the need to analyze
their terrestrial sources, as a first step towards managing these threats to the marine
and coastal ecosystems at their point of origin.
10. It is necessary to increase financing at a local, regional and national level to improve
conservation activities targeting these ecosystems. Specifically, it is necessary to
increase support personnel for monitoring in the marine protected areas and to
increase their salaries to reduce the high turnover rate of field staff.
11. Develop a regional campaign to educate recreational users, including tour operators,
tourists, etc. on the impact of human activities in the reef. This must include guidelines
for best practices in snorkeling and SCUBA diving.
For Monitoring:
1. Better mechanisms must be implemented to achieve a true sense of ownership of the
Synoptic Monitoring Program by all parties involved, especially protected area managers
and decision-makers, to ensure the continuation of this monitoring in the long-term.
2. It is necessary to update and improve the Manual of Methods for the MBRS Synoptic
Monitoring Program, using specific experiences acquired during fieldwork, and based on
available human resources and materials, as well as the most recent and functional
technologies.
3. It is necessary to establish a training calendar encompassing a variety of subjects
related to monitoring, so that the personnel in the four countries may update their
knowledge and new personnel may be trained. This will ensure that a cadre of qualified
monitors is always maintained, despite the high turnover of field staff.
4. At least one extra day for data entry must be included in the monitoring schedule for all
types of surveys to ensure the accurate and timely entry of data into the REIS.
5. The REIS is being enhanced to include a series of reports that will allow users to
produce basic statistical analyses on the data entered, thereby making the information
immediately useful to users and managers alike.
6. Actively promote seagrass, mangrove and water quality monitoring to increase the
quantity and quality of the data.
7. Make every effort to avoid the duplication of monitoring efforts in the region.
8. Make training and/or supervision a permanent part of the monitoring program.
9. Strengthen and improve the monitoring program and make every effort to ensure its
continuation recognizing that the usefulness of the information increases over time, and
that long-term monitoring offers the possibility of conducting temporal analyses.
144
10. A great variation in the estimation of fish size has been observed, which may suggest a
bias on the part the persons collecting the data.
The detailed analysis of the information obtained indicated that a higher level of training
is required for the estimation of sizes in the sub-aquatic environment where objects
appear a third larger than they are.
11. Although there is a fair amount of data on corals, there is little information on coral
bleaching and diseases. This suggests that this type of information is not being recorded.
This may be because the data collectors cannot identify these phenomena. In the case
of bleaching, it may be that the monitoring takes place after the event has passed, in
which case the phenomenon is only recorded as recent death without identifying the
cause as bleaching. More training on the identification of coral bleaching and diseases
is therefore recommended.
12. Bleaching events should be monitored, especially in response to reports by the support
agencies in the SMP network. Furthermore, we suggest that the national monitoring
coordinators subscribe to NOAA’s “Satellite Bleaching Alert E-mail List” to keep up to
date on the possibility of bleaching events and thus be able to follow up with a rapid
response monitoring.
13. In compliance with the Manual of Methods for the MBRS Synoptic Monitoring Program,
the necessary capacity/resources should be made available to conduct a rapid response
monitoring to evaluate damage when a catastrophic event (such as a hurricane, oil
spillage or ship grounding) occurs, soon after impact.
14. It is necessary to critically analyze mangrove and seagrass monitoring methods to
determine which are the most appropriate and feasible for improving the management of
these ecosystems.
15. A critical analysis of the structure of the water quality monitoring program is needed, to
determine the most appropriate and feasible options for successful implementation.
It is necessary to ensure long-term financing for pollution and water quality monitoring,
since the equipment, labor and purchase of chemical reagents needed for the analysis of
samples is very costly. A viable option to alleviate the high costs, at least in respect to
labor, would be to ensure the support of organizations that have the institutional capability to
continue the analysis of water, tissue and sediment samples in the future.
145
REFERENCES
Aldenhoven, J. M. 1986. Different reproductive strategies in a sex-changing coral reef fish
Centropyge bicolor (Pomacanthidae). Australian Journal of Marine and Freshwater Research
37:353–360.
Alegria, H. A., Bidleman, T. F. and Shaw, T. J., 2000. Organochlorine pesticides in ambient air of
Belize, Central America. Environmental Science and Technology 34(10): 1953-1958.
Almada-Villela PC, Sale PF, Gold-Bouchot G and Kjerfve B. 2003. Manual of Methods for the MBRS
Synoptic Monitoring Program. Selected Methods for Monitoring Physical and Biological Parameters
for Use in the Mesoamerican Region. Mesoamerican Barrier Reef Ecosystems Project (MBRS).
Belize, Belize. Pp. 149. Available at: http://www.mbrs.org.bz/espanol/docBD.htm#doc3
Arriola E., November 2002. National Consultancy report for modelling and physical Oceanography
Belize. Mesoamerican Barrier Reef System.
Arrivillaga A and García MA. 2004. Status of coral reefs of the Mesoamerican Barrier Reef Systems
Project region and reefs of El Salvador, Nicaragua and the Pacific coasts of Mesoamerica. In:
Wilkinson C (Editor). Status of coral reefs of the world: 2004. Chapter 18, Volume 2, Pp. 473-491.
Buchman, M. F. 1999. NOAA Screening Reference Tables, NOAA HAZMAT Report 99-1, Seattle,
WA, Coastal Protection and Restoration Division, National Oceanic and Atmospheric Administration,
12 Pp.
CARICOMP (2001). Caribbean Coastal and Marine Productivity (CARICOMP). A Comparative
Research and Monitoring Network of Marine Laboratories, Parks and Reserves. CARICOMP
Methods Manual Levels 1 and 2. CARICOMP Data Management Center and Florida Institute of
Oceanography. March 2001. 91 pp.
Cintron, G. and Shaeffer Novelli, AND. (1984). Methods for studying mangrove structures. In: S.C.
Snedaker and J.G. Snedaker (Eds). The Mangrove Ecosystem: Research Methods. UNESCO
Monographs on Oceanographic Methodology, 8. Pp. 91-113.
Doherty, P. and Fowler, T. (1994) An empirical test of recruitment limitation in a coral reef fish.
Science 263: 935–939.
Downs CA; Fauth, JE; Robinson, CE; Curry, R; Lanzendorf, B; Halas, JC; Halas, J and Woodley
CM. 2005b. Cellular Diagnostics and coral health: Declining coral health in the Florida Keys. Marine
Pollution Bulletin 51: 558-569.
Downs CA; Woodley, CM; Richmond RH; Lanning, LL and Owen, R. 2005a. Shifting the paradigm of
coral-reef 'health' assessment. Marine Pollution Bulletin 51: 486-494.
Downs, CA; Fauth, JE; Wetzel, D; Hallock, P; Halas, JC; Halas, J; Curry, R Woodley CM. In Press.
Environmental Forensics.
Dulin, P.; Bezauri, J.; Dotherow-McField, M.; Basterrechea, M.; Aspra de Lupiac, B.; and Espinoza,
J. 1999. Conservation and Sustainable use of the Meso-American Barrier Reef System. Threat and
Root Cause Analysis (draft). Available at: http://www.mbrs.org.bz/espanol/docBD.htm#doc3
Fourqurean, J.W., Boyer, J.N., Durako, M.J., Hefty L.N and Peterson, B.J. 2003 – Forecasting
Responses of Seagrass Distiributions to Changing Water Quality Using Monitoring Data. Ecological
Applications, 13(2), pp. 474-489.
146
Frankovich, T.A. AND J.W. Fourqurean. 1997. Seagrass Epiphyte Loads along a Nutrient Availability
Gradient. Florida Bay, USA. Marine Ecology Progress Series 159:37-50.
Galloway, TS; Sanger, RC; Smith, KL; Fillman, G; Readman, JW; Ford, TE and Depledge, MH.
2002. Rapid Assessment of marine pollution using multiple biomarkers and chemical
immunoassays. Environmental Science and Technology 36(10): 2219-2226.
Goenaqa, C. 1986. Los arrecifes costaneros en Puerto Rico: Estado Actual e implicaciones
Sociales. Science-Ciencia, Boletín Científico del Sur Vol 13 No 2.
Gold-Bouchot G, Zapata-Pérez O, Ceja-Moreno V and del Rio-García M. 1999. Concentrations of
Compuestos Organoclorados (pesticides and PCBs) e Hydrocarbures en Sedimentos de la Reserva
de Sian Ka’an, Quintana Roo. Reporte presentado a la Reserva de Sian Ka’an.
Gold-Bouchot, G. Hydrocarbures en el Sur del Gulf of Mexico. 2004.Pp. 657-682. En: Caso, M.,
Pisanty, I. and Ezcurra, E. (Comp.). Diagnóstico Ambiental del Gulf of Mexico, Vol. II. Secretaría de
Medio Ambiente and Recursos Naturales, Instituto Nacional de Ecología, Instituto de Ecología and
Harte Institute. Mexico, DF. 472 Pp.
Gold-Bouchot, G., M. Zavala-Coral, O. Zapata-Pérez and V. Ceja-Moreno. 1997. Hydrocarbon
Concentrations in Oysters (Crassostrea virginica) and Recent Sediments from Three Coastal
Lagoons in Tabasco, Mexico. Bulletin of Environmental Contamination and Toxicology 59(3): 430437.
Golley, F,; Odum, H.T. and Wilson, R.F. (1962). The structure and metabolism of a Puerto Rican
Red Mangrove Forest in May. Ecology 43: 9-19.
Humann, P. (1994). Reef Fish Identification – Florida, Caribbean, Bahamas. 2nd Edition. New World
Publications, Inc. USA. 396 pp.
P
P
Humann, P. (1998). Reef Coral Identification – Florida, Caribbean and Bahamas. 4th Edition. New
World Publications, Inc. USA. 239 pp.
P
P
ICRI, 2002 – Report of the Regional Workshop for the Tropical Americas, 14 -14 June 2002.
CONANP, Mexico
Kramer, P. A. 2003. Synthesis of Coral Reef Health Indicators for the Western Atlantic: Results of
the AGRRA Program (1997-2000). Pp. 1-59 in J.C. Lang (ed), Status of Coral Reefs in the western
Atlantic; Results of initial Surveys. Atlantic and Gulf Rapid Reef Assessment (AGRRA) Program.
Atoll Research Bulletin 496.
Lang, J. C. (ed), 2003. Status of Coral Reef in the Western Atlantic: Results of Initial Surveys,
Atlantic and Gulf Rapid Reef Assessment (AGRRA) Program. Atoll research Bulletin 496.
Lapointe B. E., 2004. Phosphorous-rich waters at Glover’s Reef, Belize? Marine Pollution Bulletin
n°48 p 193-195.
Linton, D. and Fisher, T. (Eds.) 2004 - CARICOMP Caribbean Coastal Marine Productivity Progam
1993-2003.
Long ER and Morgan LG. 1990. The Potential for Biological Effects of Sediment-Sorbed
Contaminants Tested in the National Status and Trends Program. NOAA Technical Memorandum
NOS OMA 52. NOAA Office of Oceanography and Marine Assessment, Ocean Assessment
Division, Seattle, Washington, USA.
147
Marks K.W and K.D. Klomp., 2003. Fish biomass conversion equations. Pp. 625-626 in J.C. Lang
(ed), Status of Coral Reefs in the western Atlantic; Results of initial Surveys. Atlantic and Gulf Rapid
Reef Assessment (AGRRA) Program. Atoll Research Bulletin 496.
MBRS Technical Document N°4. April 2003. Manual of Methods for the Synoptic Monitoring
Program. 141 pages.
McRoy, C.P. AND McMillan, C. 1977 – Production Ecology and Physiology of Seagrasses. In:
McRoy C.P.AND Helferrich, C. (eds.) Seagrass Ecosystems: A Scientific Perspective. M. Dekker.
New York. pp. 53-87.
Noreña-Barroso E., Simá-Alvarez R., Gold-Bouchot G. and Zapata-Perez O. 2004. Persistent
Organic Pollutants and Histological Lesions in Mayan Catfish Ariopsis assimilis from the Bay of
Chetumal, Mexico. Marine Pollution Bulletin 48: 263-269.
Noreña-Barroso, E.; O. Zapata-Pérez; V. Ceja-Moreno and G. Gold-Bouchot. 1998. Hydrocarbons
and Organochlorine Compounds in Sediments from Bay of Chetumal, Mexico. Bulletin of
Environmental Contamination and Toxicology 61(1): 80-87.
O’Connor TP. 1990. Coastal Environmental Quality in the United States, 1990. Chemical
Contamination in Sediment and Tissues. National Oceanic and Atmospheric Administration,
Rockville, Maryland, USA.
Odum H.T, 1957 – Primary Production of Eleven Florida Springs and a Marine Turtle Grass
Community. Limnol. Oceanogr. 2:85-97.
Parson, T.R., AND. Maita & C.M. Lalli. 1984. A Manual of Chemical and Biological Methods for
Seawater Analysis. Second Edition. Pergamon Press, Oxford, England. 173 pp.
Rogers, C.S.; Garrison, G.; Grober, R.; Hillis, Z.-M. and Franke, M.A. (2001). Coral Reef Monitoring
Manual for the Caribbean and Western Atlantic. St John, U.S. Virgin Islands. 107 pp.
Sale, P.F. (1997) Visual census of fishes: how well do we see what is there? Proceedings of the 8th
International Coral Reef Symposium 2: 1435-1440.
P
P
Sale, P.F. 1991. Habitat structure and recruitment in coral reef fishes. En Habitat Structure. The
physical arrangement of objects in space. Bell, S., McCoy, E. and H. Mushinsky (eds) Chapman and
Hall. New York, 464 pp.
Sale, P.F.; Kritzer, J.P. and Arias-Gonzalez, E. (2002). Recommendations for a Synoptic Monitoring
Program in the Mesoamerican Barrier Reef Region. Second Report on Coral Reef Ecology to
MBRS/MBRS PCU. 48 pp.
Short, F.T., MaKenzie, L.J., Coles, R.G., Vidler, K.P., Gaeckle, J.L. 2005 – Seagrass Net Manual for
Scientific Monitoring of Seagrass Habitat – Caribbean Edition. University of New Hampshire
Publication. 75pp.
Spalding, M.D., Raviolus, C. and Green E.P. 2001. World Atlas of Coral Reefs. UNEP-WCMC.
University of California Press. 424 pp.
Talbot, F. and Wilkinson, C.R., 2001 - Coral Reefs, Mangroves and Seagrasses: A Sourcebook for
Managers - Australian Institute of Marine Science.
Thattai D. V . and B. Kjerfve. December 2003. Modeling of tidal and wind-driven circulation in the
Meso American Barrier Lagoon, Western Caribbean.
148
Tolimieri, N., P.F. Sale, R.S.Nemeth and Gestring K.B. 1998. Replenishment of populations of
Caribbean reef fishes: are spatial patterns of recruitment consistent through time?. Journal of
Experimental marine Biology and Ecology. Vol. 230 (1) 55-71.
Trexler JC and Travis J., 2000. Can marine protected areas restore and conserve stock attributes of
fisheries?. Bulletin of Marine Science, 66(3): 853-873.
U.S. NOAA Coastal Services Center. 2001 - Guide to the Seagrasses of the Unites States of
America (Including U.S. Territories in the Caribbean).
Vazquez Botello A, Calva LG and Ponce Velez G. Polycyclic Aromatic Hydrocarbons in Sediments
from Coastal Lagoons of Veracruz State, Gulf of Mexico. 2001. Bulletin of Environmental
Contamination and Toxicology 67: 889-897.
Veron, J.E.N. 2000. Corals of the world. Stafford-Smith, M. (ed). Australian Institute of Marine
Science. Volumen I. 463 p.
Zapata-Pérez, O., R. Simá-Alvarez, E. Noreña-Barroso, J. Guemes, G. Gold-Bouchot, A. Ortega and
A. Albores-Medina. 2000. Toxicity of sediments from Bahia de Chetumal, Mexico, as assessed by
hepatic EROD induction and histology in Nile Tilapia Oreochromis niloticus. Marine Environmental
Research 50(1-5): 385-391.
149
ANNEXES
ANNEX I. Indicators of the Status of the Mesoamerican Barrier Reef System
This Annex contains tables showing a detailed breakdown of the various parameters which
comprise the reef status indicators presented in Chapter 8 of the main text, entitled
Discussions and Conclusions.
Table A.1 shows the analysis of the benthic cover indicator. The main benthic
components are coral cover and algal cover. Secondary components are sponges,
gorgonians, coralline algae and Millepora. Each of the benthic components is categorized,
where each category represents a range of values relating to reef status. For coral cover,
the categories range from 1 (lowest) to 5 (highest). For algal cover, the categories are
reversed with 1 assigned to the highest algal cover and 5 to the lowest.
The remainder of the benthic components are categorized from one to three since they are
considered secondary components of the reef landscape.
Table A.2 shows a detailed breakdown of the coral colony condition indicator which
combines diameter, height and percentage of colonies with mortality.
Diameter and height are categorized from one (lowest) to three (highest), and inversely, in
the case of mortality, from one (highest) to five (lowest).
Table A.3 gives the breakdown of the adult fish density indicator. In this analysis, the
MBRS regional mean is used as the reference value.
Table A.4 gives the breakdown of the fish recruitment indicator.
For the fish size indicator, the analysis done is very similar to the previous ones relating to
fish, so a detailed breakdown is not shown here.
150
Table A.1. – Breakdown of the benthic cover indicator.
Benthic cover
México
coral
Ran.(5)
AMP
Prom.
Cozumel
27.37
B. Chinchorro 26.61
Xcalak
18.85
4
4
3
algas
Prom.
32.72
23.03
41.20
Ran.(5)
3
4
2
Gorgonáceos Ran.(3)
Prom.
3.69
11.53
11.30
1
3
3
Esponjas
Prom.
10.82
6.69
2.56
Ran.(3) Acoralinas Ran.(3)
3
2
1
Prom.
0.54
0.58
2.63
1
1
1
Milleporas Ran.(3)
Prom.
0.38
0.60
0.94
1
1
1
Total
2.17
2.50
1.83
Belice
coral
Ran.(5)
AMP
Prom.
Bacalar Chico 18.67
Hol Chan
11.97
Caye Caulker 44.58
Glover's Reef 20.72
South Water 44.25
Gladden Spit 11.12
Sapodilla Caye 28.95
3
2
5
3
5
2
4
algas
Prom.
39.28
67.32
19.42
30.06
26.07
39.85
19.62
Ran.(5)
3
1
5
3
4
3
5
Prom.
8.20
3.43
6.88
13.57
8.60
6.81
9.53
2
1
2
3
2
2
2
Esponjas
Prom.
3.12
1.15
2.63
6.33
4.47
1.74
1.80
1
1
1
2
2
1
1
Prom.
3.58
10.55
6.88
11.83
0.89
3.85
0.83
1
3
2
3
1
1
1
Milleporas Ran.(3)
Prom.
1.98
0.80
3.71
2.06
4.30
2.94
2.16
1
1
2
2
2
2
2
Promedio
Total
1.83
1.50
2.83
2.67
2.67
1.83
2.50
Guatemala/Honduras
coral
AMP
Prom.
P. Manabique 26.05
Utila
15.57
C. Cochinos 24.88
Ran.(5)
4
2
3
algas
Prom.
25.87
48.11
42.95
Ran.(5)
4
2
2
Prom.
0.68
13.97
14.91
1
3
3
Esponjas
Prom.
12.22
7.49
5.01
151
3
2
2
Prom.
2.15
2.40
2.61
1
1
1
Milleporas Ran.(3)
Prom.
0.00
1.17
2.02
1
1
2
Promedio
2.33
1.83
2.17
Table A.2. – Breakdown of the coral colony condition indicator.
Coral Colony Condition
Mexico
Diameter
MPA
Category
( 1- 3 )
Mean
Mean
32.00
33.26
30.50
2
2
2
Diameter
Category
( 1- 3 )
Cozumel
B. Chinchorro
Xcalak
Category
( 1- 3 )
Height
Mortality
Category
( 1- 5 )
Mean
21.03
24.71
18.21
Mean
Total
2
2
2
60.13
52.13
41.33
2
3
3
Category
( 1- 3 )
Mortality
Category
( 1- 5 )
2.00
2.33
2.33
Belize
MPA
Mean
Mean
35.93
32.13
57.37
30.90
20.66
27.98
58.69
2
2
3
2
1
1
3
Diameter
Category
( 1- 3 )
Bacalar Chico
Hol Chan
Caye Caulker
Glover Reef
South Wather
Gladden Spit
Sapodilla Caye
Height
Mean
21.34
18.39
35.20
14.47
15.06
22.87
35.13
Mean
Total
2
2
3
1
2
2
3
61.89
0.69
54.37
39.02
32.53
29.64
94.39
2
5
3
3
4
4
1
Category
( 1- 3 )
Mortality
Category
( 1- 5 )
2.00
3.00
3.00
2.00
2.33
2.33
2.33
Guatemala/Honduras
MPA
P. Manabique
Utila
C. Cochinos
Mean
31.57
25.40
29.21
Height
Mean
2
1
1
Mean
12.95
9.85
14.03
152
1
1
1
10.16
0.09
15.87
Mean
Total
5
5
5
2.67
2.33
2.33
Table A.3. - Breakdown of the adult fish density indicator.
Adult fish density compared to the regional mean 35 ind/100m2
P
Mexico
Mean (35.30)
MPA
Cozumel
Banco Chinchorro
Xcalak
-10%
(31.77)
-20%
(28.78)
P
-30%
(25.18)
-40%
(21.59)
-50%
(17.99)
Mean
58.75
38.48
Mean
58.75
38.48
Mean
58.75
38.48
Mean
58.75
38.48
Mean
58.75
38.48
Mean
58.75
38.48
31.93
31.93
31.93
31.93
31.93
31.93
Belize
MPA
Mean
Mean
Mean
Mean
Mean
Mean
Bacalar Chico
Hol Chan
Caye Caulker
Glover's Reef
South Water Caye
Gladden Spit
46.74
57.87
14.96
46.72
26.93
15.50
46.74
57.87
14.96
46.72
26.93
15.50
46.74
57.87
14.96
46.72
26.93
15.50
46.74
57.87
14.96
46.72
26.93
15.50
46.74
57.87
14.96
46.72
26.93
15.50
46.74
57.87
14.96
46.72
26.93
15.50
Sapodilla Caye
24.22
24.22
24.22
24.22
24.22
24.22
Guatemala/Honduras
MPA
Mean
Mean
Mean
Mean
Mean
Mean
Punta de Manabique
Utila
20.53
39.24
20.53
39.24
20.53
39.24
20.53
39.24
20.53
39.24
20.53
39.24
Cayos Cochinos
37.04
37.04
37.04
37.04
37.04
49.14
Above the regional mean and up to 10% below
Up to 50% below the regional mean
Less than 50% of the regional mean
153
Table A.4. - Breakdown of the fish recruitment indicator.
Mean density of fish recruits per site
Mean
Location
Cozumel
Banco Chinchorro
Xcalak
Bacalar Chico
Hol Chan
Caye. Caulker
Glover's Reef
South Water Caye
Gladden Spit
Sapodilla Caye
Punta de Manabique
Utila
Cayos Cochinos
-10%
-20%
-30%
-40%
-50%
Density
Density
Density
Density
Density
Density
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
No data
available
82.92
18.54
102.59
126.88
10.94
66.25
114.58
54.69
53.72
77.29
No data
available
27.29
Above the regional mean and up to 10% below
Up to 50% below the regional mean
Less than 50% of the regional mean
154
ANNEX II. Fish species studied under the Synoptic Monitoring Program
A subset of adult fish species of have been selected for study under the MBRS Synoptic
Monitoring Program. These are listed in the following table.
Table A. 5. -Species surveyed in the MBRS Synoptic Monitoring Program.
ACANTHURIDAE
A. bahianus
A. chirurgus
A. coeruleus
CHAETODONTIDAE
C. capistratus
C. ocellatus
C. stiatus
C. sedentarius
C. aculeatus
LUTJANIDAE
L. campechanus
L. analis
L. cyanopterus
L. griseus
L. jocu
L. mahogani
L. synagris
O. chrysurus
L. apodus
HAEMULIDAE
H. flavolineatum
H. sciurus
H. chrysargyreum
H. plumieri
H. carbonarium
H. aurolineatum
H. melanurum
H. striatum
H. macrostomum
H. parra
A. virginicus
A. surinamensis
H. album
POMACANTHIDAE
H. ciliaris
H. bermudensis
P. paru
P. arcuatus
H. tricolor
BALISTIDAE/
MONACANTHIDAE
B. vetula
C. sufflamen
M. niger
A. scriptus
C. pullus
C. macrocerus
SCARIDAE
S. viride
S. aurofrenatum
S. chrysopterum
S. rubripinne
S. atomarium
S. taeniopterus
S. vetula
S. croicensis
S. guacamaia
S. coelestinus
S. coeruleus
155
SERRANIDAE
E. adscensionis
E. guttatus
E. morio
E. striatus
iE. tajara
C. cruentata
C. fulvus
M. bonaci
M. tigris
M. interstitialis
M. venenosa
LABRIDAE
B. rufus
L. maximus
CARANGIDAE
C. ruber
POMACENTRIDAE
M. chrysurus
SPHYRAENIDAE
S. barracuda
III Report on the Reef Monitoring Program. Cozumel Reefs National Park 2004-2005
156
Department of Monitoring and Academic
Linkage
Reef Monitoring Program Report
Cozumel Reefs National Park
2004-2005
Gabriela G. Nava Martínez, Lorenzo Álvarez Filip and Roberto Hernández Landa
Cozumel, Quintana Roo. March 22, 2006
Introduction.
Coral reefs are amongst the most important ecosystems in nature due to their great biological
diversity and productivity (Veron, 2000). In Mexico, the largest coral development is located in the
Atlantic Ocean (Carricart-Ganivet and Horta-Puga, 1993) along the Caribbean coast; it extends
almost continuously from Contoy Island to the southern border of the state of Quintana Roo, as a
complex reef system of approximately 400 Km long, which, in conjunction with the reefs in Belize,
Guatemala and Honduras form the second largest reef complex in the world, known as the
Mesoamerican Barrier Reef System (MBRS, Arias-Gonzalez, 1998).
Cozumel Island is located within this System, where one of the main reefs in the country develops.
As a result of its great biological diversity and importance is one of the main national and
international diving sites, leading Cozumel Island to rapid growth in tourism, especially in recent
years, by increasing infrastructure, visitors, and above all, the intensive use of its natural resources.
For this reason, in 1996, the reef area located in front of the western coast of the island was declared
a National Marine Park with the purpose of protecting the biodiversity of the communities in the reef
ecosystem.
Since then, some efforts have been made to implementing a monitoring program to evaluate the
effectiveness of the protection and changes in the communities. In 1997, Amigos de Sian Kaan
carried out a characterization of the reefs; in 2000, CINVESTAV (Arias-Gonzalez, 2000) conducted
monitoring on seven reefs; and the National Park (Lánz-Landázuri et al, 2002) carried out a
characterization of the reefs during 2002. In order to establish a program that could be carried out
long-term, during 2004 the monitoring program of the Cozumel Reefs National Park (CRNP) started,
following the guidelines of the MBRS Synoptic Monitoring (Almada-Villela et al., 2003) that is
developed jointly by the governments of Mexico, Guatemala, Belize and Honduras.
1
The objective of this long-term monitoring program is to produce information that allows the
evaluation on the changes of the reef communities through time. For this reason, the following
indicators were considered:
•
Percentage cover of the different components of the biotic substratum (hard coral, soft coral,
sponges, algae, other sessile organisms) and abiotic (sand, rock).
•
Structure of the coral community, considering coral species, density of the colonies,
mortality, maximum diameter, percentage of bleaching, diseases and other damage.
•
Structure of the fish community, considering families of commercial interest and
characteristic of the reef community, size distribution as well as the proportion of
herbivorous and carnivorous.
This report includes the results for 2004 and 2005, establishing the sites and main methods that will
be used in later years for the monitoring of reef communities within the National Park.
2
METHODS
Six reefs were selected within the polygon of the CRNP to be monitored, considering the areas of use
where they are located: restricted, intensive and low intensity use (Fig. 1). Within each zone, reefs
less than 15 m deep that had the largest number of visitors, especially divers, were selected; this was
determined based on the information obtained in previous years by the personnel of this National
Protected Area (1999-2003). Six perpendicular transects were placed along the coastline, following
the growth of the reef development.
The reefs selected were (Table 1): Paraiso, Chankanaab, Yucab, Paso del Cedral, Palancar, Dalila
and Colombia. The monitoring campaigns were carried out during March, April and October 2004.
The following year, the first monitoring period was during April-May, however, due to the impact of
the hurricanes that year, an evaluation was carried out 3 weeks after hurricane Emily (August 2005),
the second campaign was performed approximately 15 days after hurricane Wilma, during November
2005.
Table 1. Geographic coordinates (WGS84) of the monitoring sites.
Area of Use
Reef
Geographic coordinates
Intensive
Paraiso
20º 28’ 09.4” N
86º 58’ 58.9” W
Chankanaab
20º 26’ 25.8” N
87º 00’ 08.4” W
Yucab
20º 25’ 14.2” N
87º 01’ 02.9” W
Paso del Cedral
20º 22’ 26.0” N
87º 01’ 44.2” W
Dalila
20º 20’ 55.6” N
87ª 01’ 42.6” W
Colombia
20º 19’ 30.1” N
87º 01’ 37.9” W
Low Intensity
Restricted Use
3
Figure 1. Location of the monitoring sites.
4
The methods used in the monitoring program are based in the protocol established for the MBRS
Synoptic Monitoring Program (Almada-Villela et al, 2003), which considers the following methods:
Cover of the components of the substratum
The method of point intercept is used, it consists on swimming along the transect line (30 m)
registering every 25 cm the type of substratum just below that point. Due to the events that occurred
during 2005 (hurricanes Emily y Wilma), the results on the changes in cover were previously
analyzed by the Monitoring Department of the Park in the document: “Report on the effects of
hurricanes Emily and Wilma on the reefs of the West coast of the Cozumel Reefs National Park”
(Alvarez-Filip and Nava-Martínez, 2005), and therefore they are not included in this document.
Coral community
The number of live colonies in the first 10 m of each of the 6 transects was counted. Each one was
identified up to species. The forms carinata and undata were tallied as forms of the Agaricia
agaricites species, as well as the forms faveolata and franksi of the Montastrea annularis species. At
least 50 coral colonies were measured in each site, considering the maximum diameter. The
percentage of recent mortality, old mortality, bleaching (pale, partly bleached or bleached) and
percentage of diseases (black-band disease, white-band disease, white plague) was estimated. The
percentage for other ailments (tunicate overgrowth, ascidians, sponges, poliquets, algae, sediment on
the colony) was registered in May 2005. The differences between each campaign and years of
monitoring as well as within monitoring sites were evaluated.
Fish community
The method for adult fish consisted of performing a visual census, along linear transects 30m long by
2m wide, counting the individuals of each species found within the transect. The species registered
equaled those proposed in the monitoring manual based on the AGRRA protocol (Table 2). The
differences in abundance and density (ind/100m2) within the reefs, monitoring campaigns and
amongst the two years of monitoring (2004 and 2005) were evaluated.
5
Table 2. Adult fish species registered during monitoring.
Common
Name
Surgeonfish
Butterflyfish
Angelfish
Grunts
Snapper
Family
Acanthuridae
Acanthurus
Acanthurus
Acanthurus
Chaetodontidae
Chaetodon
Chaetodon
Chaetodon
Chaetodon
Chaetodon
Pomacantidae
Holacanthus
Holacanthus
Pomacanthus
Pomacanthus
Holacanthus
Centropyge
Centropyge
Haemulidae
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Haemulon
Anisostremus
Anisostremus
Haemulon
Lutjanidae
Lutjanus
Lutjanus
Lutjanus
Lutjanus
Lutjanus
Lutjanus
Lutjanus
Common
Name
Parrotfish
bahianus
chirurgus
coeruleus
capistratus
ocellatus
stiatus
sedentarius
aculeatus
ciliaris
bermudensis
paru
arcuatus
tricolor
argi
aurantonotus
flavolineatum
sciurus
chrysargyreum
plumieri
carbonarium
aurolineatum
melanurum
striatum
macrostomum
parra
virginicus
surinamensis
album
campechanus
analis
cyanopterus
griseus
jocu
mahogani
synagris
Grouper
Family
Scaridae
Sparisoma
Sparisoma
Sparisoma
Sparisoma
Sparisoma
Sparisoma
Sparisoma
Sccarus
Scarus
Scarus
Scarus
Scarus
Serranidae
Epinephelus
Epinephelus
Epinephelus
Epinephelus
Epinephelus
Epinephelus
Cepholopholis
Cepholopholis
Mycteroperca
Mycteroperca
Mycteroperca
Mycteroperca
Mycteroperca
Mycteroperca
adscensionis
guttatus
morio
striatus
itajara
mystacinus
cruentatus
fulvus
bonaci
phenax
tigris
interstitialis
venenosa
microlepis
Balistes
Canthidermis
Mellichtys
Aluterrus
Cantherhines
Cantherhines
vetula
sufflamen
niger
scriptus
pullus
macrocerus
Bodianuis
Caranx
Lachnolaimus
Microspathodon
rufus
ruber
maximus
chrysurus
viridae
aurofrenatum
chrysopterum
rubripinne
atomarium
radians
taeniopterus
vetula
croisencis
guacamaia
coelestinus
coeruleus
Triggerfish
Other
Common
Fish
6
RESULTS
Coralline community
A total of 916 colonies were measured during the two campaigns in 2004, and 1072 colonies in the
three evaluations performed in 2005, including a total of 26 species (Table 3). Of these, only seven
species provided more than 80% of the abundance in each of the monitoring surveys (Fig. 2).
Agaricia agaricites was the most abundant species in the two years, followed by Porites porites and
Agaricia tenuifolia. During the year 2005, these species were still dominant, although after the
impact of Emily, the two latter species showed damage from the hurricane, finding broken structures
in most colonies; however, after hurricane Wilma, their abundance was reduced to less than 5%.
Table 3. Hard coral species registered during the monitoring period 2004-2005
Genre/ Species
Agaricia
Agaricia
Agaricia
Agaricia
sp
agaricites
humilis
lamarcki
Agaricia
Colpophylia
Dendrogyra
Diploria
Diploria
Diploria
Eusmilia
Favia
Isophylastrea
Isophyllia
Leptoseris
Madracis
Meandrina
Montastrea
Montastrea
Mycetophyllia
Mycetophyllia
Porites
Porites
Siderastrea
Siderastrea
Stephanocoenia
tenuifolia
natans
cylindrus
labrinthiformis
sp
strigosa
fastigiata
fragum
rigida
sinuosa
cucullata
decactis
meandrites
annularis
cavernosa
lamarckiana
sp
astreoides
porites
radians
siderea
michelinii
Common name (Spanish)
Coral Lechuga
Coral Lechuga
Coral Lechuga (bajo relieve)
Coral de hojas de estrellas
blancas
Coral Lechuga (hojas delgadas)
Coral cerebro
Coral pilar
Coral cerebro
Coral cerebro
Coral cerebro (simétrico)
Coral de flor
Coral pelota de golf
Coral estrella rugoso
Coral Cactus sinuoso
Coral Lechuga
Coral estrella de diez rayos
Coral mazo
Coral de estrella
Gran Coral de estrella
Coral Cactus
Coral Cactus
Coral de dedo
Coral estrella
Common name (English)
Lettuce coral
Lettuce coral
Low relief lettuce coral
Whitestar sheet coral
Thin leaves lettuce coral
Boulder Brain coral
Pillar coral
Grooved brain coral
Brain coral
Symmetrical brain coral
Smooth flower coral
Golfball coral
Rouge Star coral
Sinuous Cactus coral
Sunray lettuce coral
Ten ray star coral
Maze coral
Boulder star coral
Great star coral
Ridged cactus coral
Cactus coral
Mustard Hill Coral
Finger coral
Lesser starlet coral
Massive starlet coral
Blushing star coral
7
The distribution of species amongst the sites was consistent during the two years. Yucab and Cedral
showed high density of the dominant species, Porites porites and Agaricia tenuifolia, although very
low on the massive coral colonies such as Montastrea annularis. In contrast, Chankanaab did not
register colonies of Agaricia tenuifolia and on Paraiso the abundance was almost naught on Porites
porites, while the colonies of Montastrea annularis showed the highest density in these sites after
Agaricia agaricites.
Subsequent to Wilma, there was a change in the species composition. The colonies of Agaricia
agaricites were still abundant in all the reefs, while the previously dominant Porites porites and
Agaricia tenuifolia were removed from the reef crest almost in their entirety. The species that
resisted the impact were mainly those that develop massive and sub-massive colonies firmly adhered
to the substratum, such as Siderastrea siderea, Montastrea cavernosa and Porites astreoides.
No differences were observed (F=0.12, p=0.7) in the density of the colonies between the two surveys
during 2004. However, there were significant differences (F=5.06, p=0.04) from September to May
2005, observing a slight reduction. No differences in the density were observed since this last
monitoring until Emily, given that the still broken colonies showed live tissue and remained in place,
but after Wilma, all these colonies were completely removed from the reef structures (Table 4).
8
September 2004
March 2004
Others
11%
Others
16%
Mann
6%
Aaga
26%
Aaga
29%
Mcav
6%
Mann
8%
Ssid
6%
Mcav
6%
Ssid
6%
Past
9%
Aten
9%
Ppor
19%
Past
10%
Ppor
24%
Emily 2005
May 2005
Others
17%
Aten
9%
Others
13%
Aaga
25%
Mann
5%
Aaga
35%
Mcav
10%
Mann
9%
Ssid
8%
Ppor
12%
Mcav
7%
Ssid
9%
Past
12%
Past
10%
Aten
9%
Aten
7%
Ppor
12%
Wilma 2005
Others
16%
Aaga
38%
Mann
6%
Mcav
8%
Ssid
15%
Past
11%
Ppor
Aten5%
1%
Figure 2. Composition of dominant species in each monitoring campaign.
9
Table 4. Density of the colonies (Ind/m2) in the monitored sites in each campaign.
Reef
Paraiso
Chancanaab
Yucab
Paso del Cedral
Dalila
Mar-04
1.1
1
1.6
1.2
1.4
Sep-04
1.00
1.20
1.31
1.23
1.61
May-05
0.9
1.02
1.05
1.17
0.85
Emily
0.92
0.92
0.92
1.05
1.17
Wilma
0.8
0.6
0.5
0.7
0.9
Size.
The mean size (based on the maximum diameter of the colony) did not significantly vary in the
two years. The larger colonies of dominant species were mostly observed on the reef sites of
Paso del Cedral, Dalila and Yucab.
10
The larger sizes of the massive colonies such as Montastrea annularis were registered in
Chankanaab, Paraiso and Colombia.
Colonies of Agaricia agaricites were distributed in the class of 10 to 20cm, while the other dominant
species were distributed between this and the class of 20 to 30 cm. Montastrea annularis, Montastrea
cavernosa, Siderastrea siderea and Porites astreoides had the majority of the colonies distributed
within the classes of 10 to 20 and 20 to 30 cm (Fig. 3).
Siderastrea siderea
Agaricia agaricites
Size distribution (cm)
>100
90-100
80 a 90
90-100
90-100
>100
80 a 90
>100
70 a 80
60 a 70
50 a 60
>100
90-100
80 a 90
70 a 80
60 a 70
50 a 60
0
40 a 50
5
30 a 40
10
20 a 30
30
25
20
15
10
5
0
15
10 a 20
Montastrea annularis
20
40 a 50
80 a 90
Agaricia tenuifolia
30 a 40
70 a 80
20 a 30
60 a 70
>100
90-100
80 a 90
70 a 80
60 a 70
50 a 60
40 a 50
30 a 40
20 a 30
0
50 a 60
10
40 a 50
20
30 a 40
30
20 a 30
50
40
30
20
10
0
40
10 a 20
Montastrea cavernosa
50
10 a 20
70 a 80
Porites porites
10 a 20
60 a 70
10 a 20
>100
90-100
80 a 90
70 a 80
60 a 70
50 a 60
40 a 50
30 a 40
20 a 30
10 a 20
0
50 a 60
100
40 a 50
200
30 a 40
300
20 a 30
80
70
60
50
40
30
20
10
0
400
Figure 3. Size distribution in the dominant species of corals.
11
2004
40
35
30
25
March
20
September
15
10
5
90 to 100
80 to 90
70 to 80
60 to 70
50 to 60
40 to 50
30 to 40
20 to 30
10 to 20
0 to 10
0
Old mortality percentage
2005
100
90
80
70
60
50
40
30
20
10
0
May
90 to 100
80 to 90
70 to 80
60 to 70
50 to 60
40 to 50
30 to 40
20 to 30
10 to 20
0 to 10
Emily
Wilma
Old mortality percentage
Figure 4. Number of colonies with old mortality
Mortality
Recent mortality (% of dead tissue) was relatively low during 2004, averaging 2.45% and showing
no differences between campaigns (H=1.25, p=0.26). In addition, there were no significant increases
observed from September 2004 to May 2005 (H=0.23, p=0.63). Only some differences between sites
were observed during these periods (H=15.47, p=0.008), Paraiso and Chankanaab were the sites with
the lowest percentage (1%) of recent death, while Yucab and Colombia registered the highest
12
percentages (12% y 6%). There was a significant increase after the hurricanes (H=9.86, p=0.007),
with mortality up to 24% after Wilma, but showing the same differences between sites (Fig. 4).
Old mortality (% of dead tissue) remained at 13% during 2004, showing no differences between
campaigns. Chankanaab had especially high values for this parameter, unlike the rest of the sites
(30%). An increase was observed from September to May, registering a mean of 22% (H=16.59,
p=0.002) up to 40% in Chankanaab. In most cases, old mortality significantly increased again for all
the reefs after hurricane Wilma, averaging almost 32%.
Bleaching, diseases and other ailments
Very few colonies with bleaching were detected during March; however, during the monitoring in
September a significant increase was registered (F=39.44, p=0.000) in all the reefs. During the
monitoring in May (almost June), another increase in the number of colonies with bleaching was
observed. A significant decrease was observed after Wilma, since the number of colonies in
existence was also reduced (Table 5).
Table 5. Percentage of bleached colonies by reef in each campaign.
March
Sept
May
Emily
Wilma
Paraiso
3.4
6.7
7.4
7.3
0.1
Chankanaab
1.3
5.6
8.2
7.3
0.1
Yucab
0.23
5.1
7.9
9.1
Cedral
0.3
5.4
10
11.1
0.08
Dalila
0.4
4.1
9.8
7.1
Colombia
0
4.8
7.7
5.7
0.24
The percentage of old colonies with diseases was low (< 2%) and the most frequent diseases were
white plague, black-band and yellow blotch.
Chankanaab reef showed a high percentage of colonies with algae and sponge overgrowth up to the
moment of the hurricanes. Yucab and Dalila also showed colonies with tunicate and ascidia
overgrowth. Colombia and Paraiso were the reefs that registered a higher number of colonies covered
by sediment.
13
Emily
Colombia
Dalila
Dalila
P.Cedral
P.Cedral
Sites
Colombia
Yucab
Yucab
Chancana'ab
Chancana'ab
Paraiso
Paraiso
0
10
20
30
40
0
50
10
20
30
40
Percentage of colonies
wilma
% colonies with sediment
Colombia
Dalila
Sites
Sites
May
% broken colonies
P.Cedral
% colonies with tunicates and
ascidians
Yucab
Chancana'ab
% de colonies with algae
Paraiso
% colonies with spongees
0
2
4
6
8
10
.
Figure 5. Percentage of colonies with overgrowth of sponges, tunicates and ascidians, broken
colonies and affected by sediment.
14
50
Fish community
During the first campaign in 2004, there were no differences between the means by reef (p<0.005;
Table 6). The families showed some differences in the composition and distribution within each reef
(Fig. 6). In Paraiso, grunts (Haemulidae) were dominant, since they represented 66% of the reef’s
abundance, with a density of 33.33inds/100m2, another abundant family in the reef was the
parrotfishes (Scaridae) with 4.83 inds/100m2 and surgeonfishes with 3.33 inds/100 m2.
In Chankanaab and Paso del Cedral, the dominant families were snappers (Lutjanidae) and grunts
(Haemulidae); these two families alone covered 72% and 60% respectively, of the abundance within
these reefs (Fig. 6). In Dalila, Yucab and Colombia, grunts, snappers and surgeonfishes also had the
highest abundance values but without showing significant differences with the rest of the families.
All the families in the census were found in almost all the reefs, with the exception of Chankanaab,
where no individuals of the family butterflyfish (Chaetodontidae) and angelfish (Pomacanthidae)
were found; density averaged 0.63 inds/100m2 in the rest of the reefs. The density for groupers
(Serranidae) was low in all the reefs, with a media of 0.44 inds/100m2, but it was significantly lower
in Colombia and Dalila (0.17 inds/100m2). In general, triggerfish (Balistidae) had an abundance of
1.19 inds/100m2 and parrotfish (Scaridae) of 3.82 inds/100m2.
Table 6. Density of individuals /100 m2 (mean +- standard deviation) by reef from March to October
2004
Reef
Paraiso
Chankanaab
Yucab
Paso del Cedral
Dalila
Colombia
March
83,06
39,17
44,44
72,78
35,56
38,06
SD
51,34
17,12
8,86
56,08
20,46
11,13
October
72,50
110,56
42,50
76,94
30,83
19,17
SD
41,13
81,13
31,88
48,71
9,17
10,26
15
Paraiso
Paso del cedral
OTHERS
OTHERS
OTHER COMMON FISH
OTHER COMMON FISH
BALISTIDOS
BALISTIDOS
SERRANIDAE
SERRANIDAE
SCARIDAE
SCARIDAE
LUTJANIDAE
LUTJANIDAE
HAEMULIDAE
HAEMULIDAE
POMACANTHIDAE
POMACANTHIDAE
CHAETODONTIDAE
CHAETODONTIDAE
ACANTHURIDAE
ACANTHURIDAE
0,00
0,00
10,00
20,00
30,00
40,00
10,00
20,00
30,00
40,00
50,00
50,00
Dalila
Chankanaab
OTHERS
OTHERS
OTHER COMMON FISH
OTHER COMMON FISH
BALISTIDOS
BALISTIDOS
SERRANIDAE
SERRANIDAE
SCARIDAE
SCARIDAE
LUTJANIDAE
LUTJANIDAE
HAEMULIDAE
HAEMULIDAE
POMACANTHIDAE
POMACANTHIDAE
CHAETODONTIDAE
CHAETODONTIDAE
ACANTHURIDAE
ACANTHURIDAE
0,00
10,00
20,00
30,00
40,00
0,00
50,00
10,00
20,00
30,00
40,00
50,00
30,00
40,00
50,00
Colombia
Yucab
OTHERS
OTHERS
OTHER COMMON FISH
OTHER COMMON FISH
BALISTIDOS
BALISTIDOS
SERRANIDAE
SERRANIDAE
SCARIDAE
SCARIDAE
LUTJANIDAE
LUTJANIDAE
HAEMULIDAE
HAEMULIDAE
POMACANTHIDAE
POMACANTHIDAE
CHAETODONTIDAE
CHAETODONTIDAE
ACANTHURIDAE
ACANTHURIDAE
0,00
10,00
20,00
30,00
40,00
50,00
0,00
10,00
20,00
Figure 6. Density of individuals by reef /100 m2 (median +- standard error) within the families in the
March 2004 census.
A difference in abundance on the Chankanaab reef was registered during the second campaign
(p=0.008), given that the grunts (Haemulidae) and snappers (Lutjanidae) almost tripled their
abundance (26.67 and 26.50 inds/100m2) and a significant reduction was registered (p=0.008) in the
Colombia reef of almost 50% abundance, in all probability due to the reduction of individuals of the
surgeon and grunt families (Acanthuridae and Haemulidae).
16
Table 7. Density of individuals /100 m2 (mean +- standard deviation) by reef during May, after the
hurricanes Emily and Wilma in 2005.
Paraiso
Chankanaab
Yucab
Paso del Cedral
Dalila
Colombia
May
69,79
102,08
31,04
58,33
36,04
32,71
SD
88,04
89,18
12,15
48,82
12,34
12,53
Emily
36,25
54,38
55,21
139,58
50,42
52,92
SD
23,58
33,08
36,85
84,64
20,35
29,66
Wilma
92,92
134,58
39,17
81,46
36,88
48,96
SD
53,29
71,49
13,42
48,29
9,49
21,84
In general, during 2004, the reefs on Paraiso (46.67 inds/m2), Paso del Cedral (44.92 inds/100m2)
and Chankanaab (44.92 inds/100m2) showed the highest density averages, while the Colombia reef
(17.17 inds/100m2) had the lowest values (Table 6). According to the tests between monitoring
campaigns (March-October), the parameters of abundance, density and richness did not show
significant differences in 5 of the 6 reefs monitored, changes were only significant in the Colombia
reef (T=3.05, p=0.012).
No significant differences in the community (Table 7) were observed from May to Emily during
2005 (Figure 7). The changes were more evident in the monitorings performed after Emily and
Wilma, mainly in the reefs of Paraiso (T=-3.24, p=0.005) and Chankanaab (T=2.42, p=0.03).
Table 8. Density (mean +- standard deviation) by monitored reef.
Reef
Paraiso
Chankanaab
Yucab
Paso del Cedral
Dalila
Colombia
2004
Mean
77,78
74,86
43,47
74,86
33,19
28,61
SD
7,46
50,48
1,37
2,95
3,34
13,36
2005
Mean
66,32
97,01
41,81
93,13
41,11
44,86
SD
28,49
40,34
12,30
41,86
8,07
10,71
The abundance of grunts in Paraiso after Emily had a significant reduction, to 5.88 inds/100m2 from
the 34 inds/100m2 reported during 2004, while Paso del Cedral significantly increased to 52.13
inds/100m2 (F=3.69, p=0.007). Parrotfishes (Scaridae) became dominant in the rest of the reefs, with
an average density of 6.11 inds/100m2.
17
Chankana
Parais
Others
Others
Other common fish
Other common fish
Balistidae
Balistidae
Serranidae
Serranidae
Scaridae
Scaridae
Lutjanidae
Lutjanidae
Haemulidae
Haemulidae
Pomacanthidae
Pomacanthidae
Chaetodontidae
Chaetodontidae
Acanthuridae
Acanthuridae
0,00
10,00
20,00
30,00
40,00
0,00
50,00
10,00
30,00
40,00
50,00
Ind/100m
Ind/100m
Paso del ced
Yuca
Others
Others
Other common fish
Other common fish
Balistidae
Balistidae
Serranidae
Serranidae
Scaridae
Scaridae
Lutjanidae
Lutjanidae
Haemulidae
Haemulidae
Pomacanthidae
Pomacanthidae
Chaetodontidae
Chaetodontidae
Acanthuridae
0,00
20,00
Acanthuridae
10,00
20,00
30,00
40,00
50,00
0,00
10,00
Ind/100
20,00
30,00
40,00
50,00
Ind/100m
Colomb
Dalil
Others
Others
Other common fish
Other common fish
Balistidae
Balistidae
Serranidae
Serranidae
Scaridae
Scaridae
Lutjanidae
Lutjanidae
Haemulidae
Haemulidae
Pomacanthidae
Pomacanthidae
Chaetodontidae
Chaetodontidae
Acanthuridae
Acanthuridae
0,00
10,00
20,00
30,00
Ind/100m
40,00
50,00
0,00
10,00
20,00
30,00
40,00
Ind/100m
18
50,00
Figure 7. Density of individuals /100 m2 (mean +- standard error) by reef of the families in the
November 2005 census (after Wilma).
Chankanaab registered a significant increase in density during May 2005 (F=2.99, p=0.02); also
showed a slight but not significant decrease in the evaluation after hurricane Emily, until November
2005 after hurricane Wilma (Fig. 8), where it significantly increased to 134 inds/100m2 (F=5.94,
p=0.0003). In Colombia, a significant increase in the abundance of the registered values was
observed, as opposed to the values registered during 2004 (F=11.58, p=0.0001). Paso del Cedral,
Dalila and Yucab did not show significant variations between monitoring.
Colombia
Dalila
Paso del Cedral
Yucab
Chankanaab
Paraiso
0,00
20,00
40,00
60,00
80,00 100,00 120,00 140,00 160,00
marz-04
octu-04
Colombia
Dalila
Paso del Cedral
Yucab
Chankanaab
Paraiso
0
50
100
mayo-05
emily
150
200
wilma
Figure 8. Density of individuals/100m2 (mean +- standard deviation) by reef and by monitoring
season, during 2004 (graph above) and 2005 (graph below).
19
During 2005 (Table 7), the reefs that averaged the highest abundance were Chankanaab (58.21
inds/100m2), Paso del Cedral (55.88 inds/100m2) and Paraiso (39.79 inds/100 m2), while the lowest
was registered in the Yucab reef (25.08 inds/100m2).
DISCUSSION
Coralline community
The reefs in Cozumel were dominated, until Wilma, by small and fragile species (Agaricia
agaricites, Porites porites, Agaricia tenuifolia). Most of these species are corals that reproduce all
year long and settle rapidly (99% of the larvae settle before two weeks), which made them abundant
in the system (Edinger & Risk 1995). Precisely after the impact of the hurricanes, the greatest impact
was to these species. The reefs that used to show a high density of this type of corals were, in
consequence, the most affected (i.e. Yucab). The species that were not removed were the main reef
builders, Montastrea annularis, Montastrea cavernosa and Siderastrea siderea, which provide the
highest percentage of calcium carbonate to the substratum. These species reproduce only once a year
during the full moon in the summer (Edinger & Risk 1995), hence, the change in the structure of the
community could produce changes in the diversity of the system, in such a way that the species that
provide more structure to the reef may reproduce and settle in “clean” substratum, without
competition from the rapid-growth and dispersion species, which may be favorable for reef
development.
The average size for Montastrea annularis was 39 cm, fairly smaller than the 70 cm reported for this
species in the Caribbean (Kramer, 2003). The colonies registered were relatively small, compared to
other reefs in the Caribbean; this may be due to the differences in reef development and depth in the
region.
The colonies in Chankanaab showed high competition with algae until before the hurricanes. This
algal growth had been previously reported, evidenced by the growth of cyanophyte algae due to an
increase of nutrients in the area, however, hurricane Wilma performed a cleaning of the substratum,
removing all these algae that affected coral development and leaving the reef algae-free. In the same
manner, the Dalila and Colombia reefs showed a higher number of colonies with sediment during
May, which was also reduced in November after Wilma.
During the summer 2005, the effects of bleaching were evident in the reefs in Cozumel. Although in
observations after the monitoring, a recovery in some of the colonies that were slowly going back to
20
their normal coloration pattern was observed. However, the competition with other organisms such as
algae and sponge registered high values in all the reefs, which could affect their complete recovery.
The average of recent and old mortality registered in 2004 and May 2005 was in close proximity to
the one reported for the reefs in the Caribbean (Kramer, 2003). The mortality data may indicate how
long the reefs remain in their recent state, before moving into the old state, finally turning into
substratum or fragments without actually recovering live tissue (Kramer et al., 2003). Sedimentation,
bioerosion, algae or the overgrowth of other organisms may influence this transformation, which
varies spatially and temporally in such a way that when an increase in the proportion of old death
after a season with a high recent mortality and other afflictions (for example: increased bleaching
during the assessments in September and May) may indicate the possibility that the colonies are
declining instead of recovering, registering an increase in old mortality six months later.
Fish community
The mean density registered for the two years of monitoring (2004, 33 inds/100m2 and 2005, 38
inds/100m2) was found to be below the one reported for the Gulf of Mexico and the Caribbean of 48
inds/100m2 (Kramer, 2003). However, the mean between years did not vary significantly; on the
contrary, a slight increase was observed after hurricane Wilma in November 2005 (Table 8).
A higher abundance and richness of commercially important species has been reported in many
marine protected areas (McClanahan and Arthur, 2001); in contrast, in unprotected areas where
fishing pressure exists, the abundance of piscivorous of great size has been reduced (families
Serranidae, Lutjanidae and Carangidae) as well as obligated coralivorous fishes (Chaetodontidae,
Russ and Alcalá, 1989).
In this instance, herbivorous (surgeonfishs and parrotfish) and carnivorous (grunts, snappers and
triggerfish) showed an increase in density between the years, although this was not significant.
Generally, the mean for herbivorous is less than the mean reported for this region (Kramer, 2003) de
31 inds/100m2, while that of carnivorous (20.36 inds/100m2) was almost triple the mean reported for
this Caribbean region (6 inds/100 m2, Kramer, 2003) after hurricane Wilma in 2005. The density
values found for these years in Cozumel were similar to those reported for reef sites considered to be
under impact level (Kramer 2003) in the south of the Caribbean and Brazil.
21
During previous monitoring surveys (Arias-Gonzalez, and Lanz-Landázuri et al, 2002), surgeonfishs
and parrotfish showed a higher density than the one reported in 2004. However, during 2005, after
the hurricanes, an increase in the abundance of these families was observed, since these fishes started
feeding on the algae that grew in the reef substratum just after the disturbance. The means for
carnivorous (Serranidae, Lutjanidae and Haemulidae) also averaged higher densities than the ones
reported during previous monitoring.
Some studies have shown temporary increases in the abundance and diversity of fishes as a result of
the protection of the area (Roberts, 1995, McClanahan and Kaunda-Arara, 1996). A significant
difference was observed from the year 2002 to 2005 in the fish community in Cozumel, probably due
to the effect of the hurricanes (Emily and Wilma), on the physical structure of the reef, since the
distribution of families in the reefs was similar, with grunts showing a variation in their density.
However, the composition, richness and abundance of the fish community have remained stable.
During the monitoring conducted in 2000 and 2002, the reefs reported as having the largest
abundance were Paso del Cedral, Chankannab, Yucab, Santa Rosa and San Francisco, while Paraiso
was reported as having the lowest densities, possibly due to the construction of the international pier
Puerta Maya that had recently been completed near this reef (Arias-Gonzalez, 2000). During 2004
and 2005, out of all the reefs monitored, Chankanaab and Paso del Cedral were the ones where the
largest abundance was reported; and during these years, Paraiso reef was the one that showed the
higher densities, which may indicate a slight recovery for this group of organisms. In contrast, during
2002, Yucab was the reef that showed the highest densities, while at the end of 2005, it was the one,
along with Dalila, that showed the lowest values.
The effects of the hurricanes on this reef were much greater regarding the loss of live element cover
(Alvarez-Filip y Nava-Martinez, 2005) and structural complexity in the substratum, which may be
responsible for the generalized decrease of carnivorous such as snappers and grunts, since the
decrease in structural heterogeneity in the substratum reduces the abundance of benthic invertebrates
that these fishes feed on, while the loss of live coral coverage may significantly reduce the density of
obligated coralivorous such as butterflyfish (Bell & Galzin,1984, and Williams 1986).
On the other hand, the response of the fish community to these disturbances also meant an increase in
the density of herbivorous (parrotfish and surgeons) that had been reduced during 2004, which may
be considered as part of the cycle for the recovery of the natural components since herbivorous help
maintain the equilibrium in the recovery of corals and algae on the reef substratum. The fish
22
community that existed before the hurricanes allowed an immediate response from the ecosystem and
is could be expected that the processes that occur from this point onwards are the necessary ones to
maintain the high diversity and good condition of the reefs in the National Park.
The protection of an area and the time of protection have proven to be the main factors in the
prediction of abundance and number of species (McClanahan and Arthur, 2001). With the decree of
the National Park in 1996, the restrictions to fishing and the monitoring and management actions
implemented have allowed the important communities in the dynamics of the reef ecosystem to
remain through time.
The information obtained in the course of the monitoring indicated stability in the community until
before the hurricanes, for this reason, the increase in carnivorous fish and the response of the
species to the disturbances registered during this period may be indicating a positive response to the
protection enforced in the National Park; however, due to the events that occurred at the end of 2005
and the drastic changes reported in the communities and reef structure per se, it is necessary to give
continuity to the monitoring work for at least ten years (McClanahan y Arthur, 2001) and evaluate
neighboring unprotected sites to significantly prove the effects of protection and management.
23
REFERENCES
Almada-Villela PC, Sale PF, Gold-Bouchot G and Kjerfve B. (2003). Manual of Methods for the MBRS
Synoptic Monitoring Program. Selected Methods for Monitoring Physical and Biological Parameters for
Use in the Mesoamerican Region. Mesoamerican Barrier Reef Ecosystems Project (MBRS). Belize,
Belize. (pp. 149)
Alvarez-Filip, L y Nava-Martinez, G. 2005. Reporte del impacto de los huracanes Emily y Wilma sobre
los arrecifes de la Costa Oeste del Parque Nacional Arrecifes de Cozumel. RNMP.
Arias-González, J.E. 2000. Programa de monitoreo de siete arrecifes del Parque Marino Nacional
arrecifes de Cozumel. Reporte parcial. CINVESTAV. Mérida, Yuc. (pp. 50)
Bell, J. D., Galzin, R. (1984). Influence of live coral cover on coral reef fish communities. Mar. Ecol.
Prog. Ser. 15:265-274
Edinger, E.N. y Risk, M.J. 1995. Preferential survivorship of brooding corals in a regional extinction.
Paleobiology. 21, 2:200-219
Kramer, P. A., Kenneth W.M. y T.L. Turnbull. (2003). Assessment of Andros Island reef system,
Bahamas (Part2: Fishes). en J.C. Lang (ed.), Status of Coral Reefs in the western Atlantic: Results of
initial surveys, Atlantic and Gulf Rapid Reef Assessment (AGRRA) program. Atoll Research Bulletin
No. 496. (pp. 630)
Lanz-Landázuri, A., González-Vera, M.A. y G. Tuxpan-Torrijos. (2002). Caracterización y monitoreo de
los arrecifes coralinos del Parque Nacional Arrecifes de Cozumel. Departamento de Investigación y
Monitoreo, RNMP. Cozumel, Q. Roo. (pp 40).
McClanahan, T.R. y R. Arthur. (2001). The effect of marine reserves and habitat on populations of east
African coral reef fishes. Ecological Applications. 11(2): 559-569
McClanahan T.R. y B. Kaunda-Arara. 1996. Fishery recovery in a coral-reef marine park and its effect on
the adjacent fishery. Conservation Biology 10:1187-119.
Roberts, C. M. (1995). Rapid build-up of fish biomass in a Caribbean marine reserve. Conservation
Biology 9:815-826.
Russ, G.R. y A.C. Alcala. (1989). Effects of intense fishing pressure on an assemblage of coral reef
fishes. Mar. Ecol. Prog. Ser. Vol 56:13-27
24

Baseline of the Status of the Mesoamerican Barrier Reef Systems

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