Red Sea Study Main Report Final

Transcription

Thetis SpA
The Interuniversity
Institute For Marine
Sciences In Eilat
Marine Science Station
Uni. of Jordan/Yarmouk Uni.
Aqaba
Red Sea - Dead Sea Water Conveyance Study Program
Additional Studies
Red Sea Study
Final Report
July 2013
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TABLE OF CONTENTS
Executive summary ..................................................................................................................... 4 1 Introduction ....................................................................................................................... 8 2 Description of the existing and predicted future environmental conditions of the
GOAE in the No Action case............................................................................................. 9 2.1 2.1.1 Introduction: basic characteristics of circulation and mixing ...................... 9 2.1.2 Water column structure ............................................................................ 13 2.1.3 Insights from field measurements ............................................................ 15 2.1.4 Horizontal mixing and eddying ................................................................. 22 2.1.5 Insights from the circulation modeling ..................................................... 32 2.1.6 Summary .................................................................................................. 40 2.2 Water quality ......................................................................................................... 41 2.3 Ecology ................................................................................................................. 56 2.4 2.5 3 Currents .................................................................................................................. 9 2.3.1 Marine ecosystems .................................................................................. 56 2.3.2 The coral reefs: status and trends ........................................................... 58 2.3.3 Are the local populations of corals limited by recruitment? ..................... 64 2.3.4 Coral reef larvae abundance and distribution .......................................... 66 2.3.5 Genetic connectivity ................................................................................. 87 Pollution loads entering the Gulf ........................................................................... 90 2.4.1 Distribution and characteristics of main pollution sources ....................... 90 2.4.2 Pollution and sediment loads estimates .................................................. 95 Trends of environmental conditions (no abstraction scenario) and their
effects on marine environment ........................................................................... 103 2.5.1 Physical conditions ................................................................................ 104 2.5.2 Water quality .......................................................................................... 108 2.5.3 Ecology .................................................................................................. 112 Description of present environmental conditions in the vicinity of the intakes.............. 113 3.1 Currents from the shallow ADCP moorings ........................................................ 113 3.2 Water quality ....................................................................................................... 118 RSS-REL-T005.0
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3.3 Sediments ........................................................................................................... 120 3.4 Benthic habitats .................................................................................................. 129 3.5 Fish Communities ............................................................................................... 131 Effects of RDC abstraction............................................................................................ 135 4.1 Scenarios considered for the evaluation ............................................................ 136 4.2 Effects on water circulation ................................................................................. 138 4.3 4.2.1 Effects in the Northern Gulf ................................................................... 138 4.2.2 Effects in the vicinity of the preferred intake location ............................ 145 4.2.3 Effects at Gulf-wide scale ...................................................................... 147 4.2.4 Impact of selective withdrawal ............................................................... 149 4.2.5 Particle tracking – backward trajectories ............................................... 152 4.2.6 Particle tracking – forward trajectories................................................... 160 Effects on water quality....................................................................................... 163 4.3.1 Effects of the abstraction on the water quality of the GOAE ................. 163 4.3.2 Estimation of TSS and nutrients abstracted from RDC ......................... 163 4.4 Effects on marine environment/coral reefs ......................................................... 167 4.5 Future scenarios ................................................................................................. 175 4.5.1 Cumulative impact of RDC and other future abstraction ....................... 175 4.5.2 Cumulative impact of RDC and climate change .................................... 178 5 Addressing best option for RDC intake ......................................................................... 179 6 Gulf scale assessment and risks .................................................................................. 185 7 Next steps recommended ............................................................................................. 187 8 References .................................................................................................................... 188 Annexes
Annex 1 Field and laboratory activities carried out during the study and their results
Annex 2 Modeling activities
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Executive summary
This report summarizes the results achieved in the framework of the Red Sea Study project. Within
this study we conducted various environmental monitoring activities concerning several aspects of
physical oceanography and marine ecology in the Gulf of Aqaba/Eilat (GOAE), as described in our
Inception Report (June 24th, 2010). In addition we also adapted and applied numerical models to
support the assessment of the effects of RDC project on the environment of the Gulf. Both the monitoring and modelling activities provided us with relevant information to help understand the state and
functioning of the Gulf and insight into some still poorly understood conditions and processes. Such
knowledge provided a fundamental contribution to our assessment and evaluation.
The physical data (literature, historical, and new data from our study) suggest a picture of the Gulf in
which low-frequency motions and turbulent motions exchange water particles across the Gulf over
times ranging from a few days to a couple of weeks. Superimposed on these motions are energetic
internal tides that have little effect on net transport, but can result in significant vertical displacements
of isothermal surfaces, possibly at depths comparable to the contemplated RDC intake depths.
Data from hydrographic cruises corroborate knowledge on the structure of the water column of the
Gulf. Three layers can be identified: the upper layer, which experience significant seasonal fluctuations, and extends to about 200 m. The penetration of winter convection during 2009-2010 was
about 200m. The intermediate layer (200-400m) is the layer of permanent pycnocline, where a stable
decrease of temperature and increase of salinity were observed during all four cruises. The deep water layer, which extends from approximately 500m to the bottom, is quite homogeneous. In certain
respects however, the year 2010 which was the base year for our analysis was unusual. The extent
of the winter vertical mixing was comparable to or even slightly weaker than in previous years. More
notably, however, during the spring and summer the water column above 300 m was less saline than
during the previous 8 years. This is most likely an indication of increased water exchange between
the Gulf and the northern Red Sea.
Sampling of coral reef larvae (defined here as larvae of coral reef benthic invertebrates and coral
reef fishes) was also conducted to understand the spatial (horizontal and vertical) and seasonal variability of this important component of the marine ecosystem, since very limited data are available for
the Gulf. Major findings revealed that fish larval abundance varied considerably across the months
analyzed, but consistently peaked at depths of between 25 and 75m. To a large extend the pattern
appears independent of distance from shore (bottom depth), with the two sides of the gulf closely
mirroring each other. Both fish and invertebrate larvae exhibit a remarkable decline in abundance below the photic layer (> 120 m depth).
We also conducted genetic analysis on two important Red Sea coral species (Pocillopora and Seriatopora) and on the coral-pest snail Drupella. Our results demonstrated the absence of genetic structuring in the Pocillopora damicornis populations residing in the northern Gulf (Israel and Jordan) and
high connectivity between the sites sampled for this study. Populations of North Gulf are genetically
closely related one to another. Analysis of the genotypes of Seriatopora hystrix revealed similar results and pointed out moderate to low genetic differentiation among populations. Similarly, population
analysis of Drupella cornus AFLP loci from Aqaba and Eilat revealed high similarities between the
Israeli and Jordanian populations.
Biological surveys and sampling for benthic habitats (at the eastern site) and fish assemblages (at
the northern and eastern sites) were also carried out (limited to shallow scuba diving depths). At the
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northern candidate site the benthic habitat is characterized by seagrass meadows and sandy bottoms.
Seagrass beds in this area play significant role in harbouring juveniles of various commercial fish
(e.g. Lethrinids, Siganids and Mullids), and contribute to the nursery functions of these habitats. In
addition to being primary producers, the seagrass habitat also functions as a biofilter for pollutants.
They are also important for reducing the water turbidity and mitigate the influence of increased sedimentation rates. The eastern candidate intake site is a coral reef area. The results of the surveys
here have shown that there are about 20%, 18% and 25% coral cover at the reef flat, 9m depth and
15m depth, respectively. A narrow area in front of the pump room of the old power station was destroyed by dumping of rocks in the past. These rocks cover an area of about 35m wide (parallel to
the shoreline) and might extend to about 60m depth (exact distance was not measured due to depth
limitations).
Based on the understanding above, our assessment can be summarized as follows.
The exchanges of water between the Gulf and the northern Red Sea through the Strait of Tiran are
several orders of magnitude larger than those that would be induced by the proposed abstraction
flows, such that the latter would likely be imperceptible except in the immediate vicinity of the sink.
The effect of the abstraction on the heat budget of the gulf is also expected to be negligible.
Furthermore, since the proposed maximum abstraction rate is less than 0.5% of the exchange of water through the strait, the impacts on the gulf-wide scale will be minimal. The only possible change is
an extremely weak increase in the stratification of the upper thermocline at a depth of 20-40 m for
maximum abstraction from the northern intake. In the other scenarios the effect is even smaller and
in March the effects of abstraction are not discernable due to the deep winter mixing. Any potential
impacts of the abstraction on the gulf wide scale will be overshadowed by the projected impacts of
climate change. At the northern Gulf (regional) scale the impacts are not expected to be significantly
different from the impacts at the gulf-wide scale. At the local scale, significant effects on the circulation are expected to be confined to the immediate vicinity (200-300 m) of the intake. Maximum induced current speeds will occur at the location of the intake, and for the maximum abstraction rate,
these speeds will typically be between 4-11 cm/s, depending upon the intake location and depth.
These are comparable to the magnitude of the background flow.
The basic density stratification of the Gulf will tend to act to limit withdrawal layer for a deep water off
take to regions below the surface mixed layer during most of the year. In these deep layers the
plankton and larvae concentration are relatively low.
Considering effects on water quality, the residence time of water is the major controlling factor on
water quality in the GOAE. Residence time in turn is affected by the strength of stratification of the
water column. Therefore, increased stratification would increase the residence time of deep water in
the GOAE leading to an accumulation of nutrients, which could be potentially harmful to the coral
reef by triggering massive benthic algae blooms during winters with deep and prolonged convective
mixing of the open sea water column. The modelling results of the different abstraction scenarios do
not provide any evidence for significant changes in water column density structure. Therefore it is
expected that water quality will not be adversely affected (deep reservoir nutrient accumulation) by
abstraction of GOAE water at the maximal abstraction rate of 2·109 m3/yr.
Considering the effects on marine environment, the assessment of pumping focused on five possible
effects: (1) modification of heat flux; (2) changes in water-current magnitude and circulation; (3)
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changes in nutrient fluxes; (4) local damage to benthic communities, and (5) entrainment of larvae
and consequent repercussions to connectivity. Our physical and chemical oceanographic study suggests that the effects on heat flux and on nutrient dynamics will be negligible. The construction of the
pumping station will undoubtedly cause substantial damage to the local community, over several
hundreds of square meters. While surveys of the local communities at depth greater than scuba limit
(>30 m) are yet to be done, damage by the pipes is expected to occur over the shallow slope even if
the pumping inlet itself will be deeper. Effects of the pipes are expected to be temporary because
they will probably be soon colonized by benthic organisms. However the re-established community
on the substrate is expected to be different from the original, natural one. The assessment of the abstraction’s regional effect on coral-reef larvae was based on extensive sampling across the northern
Gulf and on Lagrangian particle-tracking simulations. This assessment was aided by a populationgenetic study involving three species (2 corals and one snail), which indicated genetic homogeneity
across the two sides of the Gulf (Aqaba and Eilat).
The existing data (National Monitoring Program NMP database) indicate that the supply of larvae is
not a limiting factor for the adult population of corals in Eilat (as well as in several publications from
other coral reefs in the world). However, no information on the role of larval supply is available for
other (non-coral) invertebrates and fishes. Hence, taking a precautionary approach, for the stake of
our ecological synthesis, we assume that larval supply can be an important limiting factor for populations of non-coral animals in local reefs.
Based on above assessments our findings are for a "go" decision, as long as the intake configuration, location, and depth are selected properly.
To minimize the effect on the environment, we recommend that the pumping intake will be located at
the eastern candidate site, based on considerations concerning morphology (relatively steeper bottom slope of eastern intake area), water circulation (currents along the east shore tend to be stronger
and the disturbance caused by the abstraction would be less significant), water quality (exposure to
sediment resuspension, sediment load from the wadi in cases of flooding events), bottom habitats (at
the eastern candidate site a barren submerged area was found), fish communities (Northern intake
site is dominated by well developed sea grass meadows that can serve as nursery area for the successful recruitment, nursery and development of juvenile fishes, particularly for economically important species, this site can support fishery stock along the Jordanian coast), and larval spatial distribution (measurements indicate that larvae and plankton are more abundant at the northern site
than at the eastern site). Particularly, at the eastern intake it is recommended to expand the construction and operation of the intake into the southern zone of the site, having relatively lower coral
cover.
Our synthesis is based on extensive sampling of invertebrate and fish larvae, down to 180m depth
(with some samplings extended to 210m depth), extensive current measurements at several stations
across the gulf, and on modeling. This synthesis resulted in a recommendation to place the intake
below the photic layer, raised at least 25 m above the bottom. Based on the range of the photic layer
depth, chlorophyll-a concentrations and the objective of avoiding withdrawal of water from the 60-120
m layer (where coral reefs larvae are common), we recommend locating the intake at a depth of at
least 140 m (bottom depth of 165 m). In so doing we expect that only a negligible proportion of the
larvae reaching the region upstream of the intake will be removed. A somewhat higher proportion of
those larvae (but still less than 1%) will be removed during the winter, when the water column is vertically mixed, and the water is abstracted from a thicker layer. Such values are at least one order of
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magnitude smaller than the present inter-annual fluctuations of the populations of corals and invertebrates at the local reefs.
The possibility of further deepening of the intake (e.g. to 200 m) was evaluated based on our extended sampling (down to 210 m depth) in spring 2011. While, a deeper intake will result in a reduced rate of larval abstraction from sea due to the continued decline of larval density with depth below 120 m, the magnitude of that decline in those deep waters (120-210 m) renders very small the
marginal benefit of extending the intake to 200 m depth.
Since results from our study show that some coral reef larvae are also present down to a depth of
210 m (limit of our sampling), to further refine and corroborate the selection of the precise depth,
from an environmental point of view, we recommend that prior to decision on the final location of the
intake an additional survey will be carried out by local (Jordanian) experts in the vicinity of the proposed intake site, down to a depth at least 20m below the designated intake depth.
In addition, for precautionary reasons, we strongly recommend expanding the Jordanian and Israeli
monitoring programs to continue operating in future years with added activities specifically designed
to address possible RDC impacts.
One of the major goals of the proposed RDC is to provide, through desalination, much needed fresh
water to meet the increasing needs of the population in this very dry region. In this respect it is clear
that to anticipate future needs it is most sensible to strive for the maximum availability of fresh water.
For this reason in most of our analysis, especially concerning the impacts on water quality and the
ecosystem, we concentrated on the maximum abstraction rate of 2 billion m3/yr. In this sense our
recommendations are cautious and conservative and represent a worst case option. The impacts of
varying abstraction rates were assessed mainly in terms of the speed of the currents induced by the
abstraction. Not surprisingly, for any given intake configuration, location, and depth the impacts will
increase with increasing abstraction rates. Modeling results at lower abstraction rates carried out according to the ToR and the agreed scenarios allowed us to evaluate different combination of intake
configuration, location, and depth. These could certainly be refined in a future study, running modeling scenarios aimed at directly supporting next design phases.
As requested by ToR we also assessed cumulative effects with other abstraction. The only other major abstraction that is known is the Jordan Red Sea Project (JRSP) in which it has been proposed to
abstract water from the same location as the northern intake that we considered in this study. Based
on the available information and the recommendation of the SMU, it was assumed that the abstraction rate of the JRSP will be 0.4 billion m3/yr. It was also recommended that the total combined abstraction of the RDC and JRSP not exceed 2 billion m3/yr. Thus there are potentially two cumulative
scenarios that should be considered in which the JRSP abstracts 0.4 and the RDC abstracts 1.6 billion m3/yr, respectively. Not surprisingly, the results are very similar to the results for each individual
intake considered separately.
Cumulative effects with climate change: global warming is expected to cause the water column in the
GOAE to be more strongly stratified therefore resulting in a longer deep water residence and an increase of the deep water nutrient reservoir. As a result of deep convective mixing during exceptionally cold and prolonged winters nutrient rich water will be transported into the surface layer and massive macro algae blooms could be triggered causing coral mortality in coastal fringing reefs. According to the modelling results the incremental effect of water abstraction on the warming and the stability of the water column are expected to be negligible.
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Introduction
This report represents the Final Report due in the framework of the Red Sea Study. The aim of the
study is to identify and assess all relevant potential oceanographic and environmental impacts of sea
water abstraction from the Gulf of Aqaba/Eilat (GOAE), under different intake and abstraction rate
scenarios. Hydrodynamics, water quality aspects and marine habitats are all considered within the
study.
According to the requirements of the Term of Reference, this Final Report provides:
-
a summary description of existing environmental conditions (for the most important components)
and predicted future environmental conditions in the no action case, based on the integration of
available data and new results acquired within the framework of this study (Chapters 2 and 3);
-
a description of the effects of abstraction on the Gulf of Aqaba/Eilat on the most important environmental components (chapter 4);
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remarks addressing best option for Red Sea Dead Sea Conveyance Project intake (chapter 5).
As requested during the Technical Steering Committee held at Dead Sea in Jordan on June 28th29th, 2011, the reports also presents a brief synthesis of the Gulf scale assessment and risks (chapter 6) and some recommended next steps for the study (chapter 7).
Annex 1 reports in detail on the field and laboratory activities carried out during the study and their
results, while Annex 2 describes the modeling activities.
Data and considerations presented in the following previous reports prepared in the framework of
Red Sea Study have been considered in the preparation of the present report:
-
Inception report;
-
Best Available Data report;
-
Mid Term report;
-
Draft final report.
This report also addresses the comments on the Draft final report received from the Study Management Unit member Dr. Steven Wright on June 23th, 2011 and from the Independent Panel of Experts.
This final report is based on all the results provided within the study which are now fully available.
The data acquired within this study have been organized within a GIS database and they have been
delivered to the Word Bank together with the present report.
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2
Description of the existing and predicted future environmental conditions of the GOAE in the No Action
case
2.1
Currents
2.1.1
Introduction: basic characteristics of circulation and mixing
The Gulf of Aqaba is a semi-enclosed ocean basin connected via a narrow, relatively shallow, energetic tidal strait to the rest of the Red Sea. From past studies of the Gulf, several major features of
the current physical behavior of the Gulf can be discerned (all will be discussed in more detail later in
this chapter):
1. Like much of the world’s ocean, the Gulf exhibits a seasonal cycle of stratification formation in
spring, maintenance of a shallow thermocline in summer, and subsequent deepening of the
thermocline to produce deep mixed layers in winter (Figure 2-1). As will be discussed below,
much of the seasonal stratification variability is determined by exchanges with the rest of the Red
Sea (Biton and Gildor, 2011a,b). Nonetheless, inter-annual variability in wintertime temperatures
appears to set the depth of maximum mixing (Genin et al., 1995).
2. Because of being generally warm (T>21 deg C), and subject to dry winds much of the year, the
Gulf is the site of high evaporation rates, estimated as between 0.5 cm/day (Ben Sasson et al.,
2009; Biton et al., 2011a) to 1 cm/day (Assaf and Kessler, 1976). Given a surface area of the Gulf
of ca. 3.2 x 109 m2 and using the more recent estimates of evaporation, this implies a net inflow to
the Gulf of ca. 185 m3, which is approximately three times the proposed abstraction rates for the
RDC.
3. Because the densities of the Gulf and the rest of the Red Sea are different, there are strong
density-driven flows. These exchange flows through the Straits of Tiran are substantially larger
than are the net flows through the Straits, with Murray et al (1984) estimating flows of nearly 3 x
104 m3/s entering (near the surface) and leaving (at depth) the Gulf through the Straits. More
recent calculations by Biton and Gildor (2011a) suggest that the exchange varies annually
between a maximum of nearly 4 x 104 m3/s (April) to a minimum of 0.5 x 104 m3/s (Sept. to Nov.),
with an annual mean of 1.8 x 104 m3/s. From a dynamical perspective, it is more correct to
compare the rate of abstraction to the rate of exchange flow. This is because evaporation will also
affect the circulation by increasing the salinity which in turn affects the density structure and the
pressure gradient. The effect of abstraction is similar to exchange flow in the sense that it takes
the water out with the salt. Since the gulf is a semi-enclosed concentration basin, the combined
effects of exchange flow through the strait and evaporation produce a characteristic salinity profile
with a noticeable subsurface salinity minimum in summer (Figure 2-2).
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4.
The currents in the northern Gulf are largely driven by the prevailing down-Gulf winds (Berman
et al., 2000) and by semi-diurnal internal tides generated in the Straits of Tiran (Berman et al.,
2000; Monismith and Genin 1984) and are typically low (10 cm/s). Notably, surface (barotropic)
tides are negligible. These internal tides vary annually and are stronger in deep water than
nearshore.
5.
The combination of winds and buoyancy forcing as modified by the earth’s rotation produces a
series of horizontal gyres throughout the Gulf (Berman et al., 2000, Biton and Gildor, 2011a)
although in the narrower northern Gulf (north of 27.5 deg N), they tend to be less organized and
more variable than in the south (Gildor et al., 2009; Gildor et al., 2010a). As seen in
computations and HF radar data (surface velocities), these energetic features can be as strong
as 80 cm/s (Gildor et al., 2010a).
These basic features can be used to develop a conceptual model of how the RDC abstraction might
be expected to influence the ecosystem of the northern Gulf of Aqaba, by affecting (a) the physical
environment directly; (b) influencing larval connectivity; and (c) by direct entrainment of larval organisms as well as other plankton.
At a most direct level, it is clear that the existing flows in the Gulf are much stronger than would be
the currents induced by the RDC abstraction. For example, in the August 2010 500m mooring data,
typical internal tidal currents of 10 cm/s averaged over the upper 120 m and across the Gulf (7km)
give flows of approximately 7 x 104 m3/s. The amplitude of the principal axis (standard deviation of
the currents rotated to maximize variance in one direction – see Emery and Thompson 2005) of the
measured currents averages 6 cm/s in the upper 120 m, giving a flow of 4 x 104 m3/s, i.e. 103 to 104
times larger than the abstraction flows.
Similar behavior is clear for the larger-scale exchange flows that exchange water properties between
the Gulf and the rest of the Red Sea. We can make this more concrete. Suppose that the temperature difference between the northern Red Sea and the northern Gulf is 2 deg C, then the abstraction
flow implies an additional net heat flux into the Gulf of 50 m3/s x 4.2 x106 Joules/deg C m3 (the heat
capacity of water) x 2 deg C = 4 x 108 Watts, or, when distributed over the entire surface of the Gulf
(2 x 109 m2) ≈ 0.2 W/m2. This should be compared with the estimated average net heat flux through
the Straits of 55 W/m2 with a seasonal range of 0 to 150 W/m2 (Biton and Gildor 2011a). Thus, it is
clear that the abstraction flows will have no discernable effect on the thermal structure of the Gulf
since the change in heat flux through the Strait is very much smaller than the existing flux.
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Figure 2-1 Temperature profiles in the northern Red Sea (black) and northern Gulf of Eilat
(red) for February (left) and August (right). The effect of the abstraction on the heat budget
can be estimated from the temperature difference.
Figure 2-2 Salinity profiles in the northern Red Sea (black) and northern Gulf of Eilat (red) for
February (left) and August (right). The effect of the abstraction on the salt budget can be
estimated from the salinity difference.
The influence on larval connectivity and entrainment is more subtle in that the oscillatory tidal currents may not effect large exchanges because in one limit, they may primarily produce motion of the
same water parcels (and organisms) back and forth over the intake, so that what is important is the
net exchanges they produce.
As a very rough first approximation, the RDC abstractions can be viewed as having an effect equivalent to catch or predation on the aquatic organisms of the Gulf. Thus, what matters is the rate at
which organisms are extracted, a number that can be compared to other rates such as growth, mor-
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tality or existing catch pressure. A very conservative estimate of this equivalent "mortality" can be obtained assuming: (1) that all organisms in a given volume are equally likely to be entrained, i.e. that
the volume of interest is well mixed1, in the present case by the net effects of internal tides and
gyres; (2) the volume of interest (i.e., the potential source of water for abstraction) is equal to the upper 100 m of the entire Gulf; and (3) that there are no organisms of any kind south of the Straits of
Tiran. In this case the effect of the abstraction is equivalent to an additional source of mortality with a
rate 4x10-9s-1, or equivalently, a timescale of ≈ 126 years. This equivalent "mortality" is orders of
magnitude smaller than any rates of real mortality or growth (typically on the order of day-1), thus implying that the abstraction should not be expected to have any noticeable effect on populations of entrained organisms in comparison to the biological or ecological factors.
In reality, the exact mixing mechanisms operating in the Gulf are likely more complicated than this
simple estimate would suggest. From the both the existing data and the new data collected in this
project, the best conceptual model would appear to one in which there is rapid mixing in gyres that
can recirculate fluid particles or larvae across the Gulf in ca. 1 day. Hence, the consequences, to
connectivity, of the abstraction are best evaluated in light of the results of the modeling tasks, which
will be discussed in detail subsequent sections and chapters.
1
In the chemical engineering literature this is known as a Continuously Stirred Tank reactor (CSTR).
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Water column structure
Figure 2-3 and Figure 2-4 show average monthly temperature and salinity profiles measured at station A (black), ~10 km south of the north shore of the Gulf, and the climatological hydrographic profiles at the same location (gray) from the model of Biton and Gildor (2011a).
Figure 2-3 Comparison between the model and observations: Monthly average temperature
profiles measured at station A based on monthly measurements courtesy of the Israeli
National Monitoring Program for the years 2003-2009 (black), and the climatological
temperature profiles at the same location (gray) of the model of Biton and Gildor (2011a).
Shaded areas indicate the inter-annual variability over 7 years.
Figure 2-4 Comparison between the model and observations: Monthly average salinity
profiles measured at station A based on monthly measurements courtesy of the National
Monitoring Program for the years 2003-2009 (black), and the climatological salinity profiles at
the same location (gray) of the model of Biton and Gildor (2011a).
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Three layers characterizing the Gulf water column can be distinguished: (1) a deep and quasistagnant layer; (2) the intermediate water, and (3) the surface water. The deep layer is slightly colder
than 21 C and fills the Gulf below approximately 500 m. The intermediate water temperature slowly
increases from 21◦C to 21.9◦C, and the surface layer has a temperature above 21.9◦C. Unlike the
deep water layer, the two upper layers are highly active and undergo strong seasonal changes. The
year can be divided into two phases, the restratification phase (April-August) and the mixing phase
(September-March). During the restratification phase the surface layer is rebuilt, increases its temperature and volume, and pushes the 21.9◦C isotherm from the surface down to ~200 m. In August
the temperature in the stratified surface layer at the northernmost Gulf increases almost linearly from
21.9◦ C at its base to SST ~27◦C (Figure 2-3) and comparably close temperature profiles exist
throughout the rest of the Gulf. From September to December, the surface layer increases its volume
at a much slower rate and the strong stratification starts to erode due to atmospheric cooling, until
the surface layer is vertically mixed, and a relatively thin (stratified) layer separates the surface layer
from intermediate water everywhere along the main axis. From January to March the surface layer is
mixed with the intermediate layer almost completely and the sea surface temperature in midFebruary is below 21.9 deg C in most places in the Gulf (Biton and Gildor 2011a; Plähn et al., 2002;
Klinker et al., 1976). In severe winters, the water column can mix down to the bottom (~700) at the
northernmost end of the Gulf, where the deep water is formed via both open water convection and
shelf convection [Wolf-Vecht et al., 1992; Genin et al., 1995; Biton et al., 2008a].
The seasonal cycle of stratification is controlled by the exchange flow between the Gulf of Eilat and
the Red Sea, and by surface fluxes.
Figure 2-5 Seasonal cycle of the exchange flow between the Red Sea and the Gulf of Eilat
[After Biton and Gildor, 2011]. 1Sv = 106 m3/s.
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The observed warming of the surface layer during the restratification phase (April-August) is mainly
due to advection of heat through the Straits, with a smaller contribution from surface heating (Biton
and Gildor, 2011a). During this phase, the water entering the Gulf through the Straits gradually reconstructs the stratification in the surface layer with increasing temperatures, while pushing the Gulf
intermediate water level downwards. The water reaches the northernmost Gulf, and the time it takes
varies from ~12 days in April to ~40 days in July, due to the substantial reduction in the exchange
flux through the Straits. Eventually, the whole upper ~150 m in the entire Gulf is replaced with northern Red Sea surface water.
J
F
M
A
M
J
J
A
S
O
N
D
Figure 2-6 Average modeled temperature profile throughout the entire Gulf (down to 400 m in
depth). Colored shaded areas indicate the seasonal mixing (gray) and restratification (light
gray) phases in the evolution of the Gulf stratification. The isotherm 21.9◦C separates the Gulf
intermediate water and the surface water.
During the mixing phase a small amount of advected heat from the Straits and large heat loss to the
atmosphere leads to efficient erosion of the stratification at the surface (note the increasing mixed
layer depth during this time in Figure 2-6).
2.1.3
Insights from field measurements
In order to improve the data available for calibration of the circulation model used to evaluate the effects of abstraction on particle entrainment, as well as to improve gaps in our knowledge of flows in
the Gulf, a series of deployments of oceanographic instruments to measure currents, temperatures,
and salinities were carried out for 3 separate periods on the 200 and 500 m isobaths on the Israeli
side of the Gulf offshore of the Steinitz Marine Lab. On each of these moorings, one 600 KHz and
one 150 KHz Teledyne RDI Acoustic Doppler Current Profilers (ADCPs) were installed at 50 to 60 m
depths looking upwards and downwards respectively. Likewise, a single 600 KHZ ADCP was deployed for shorter periods of time at shallow-water sites around the northern end of the Gulf, notably
at the proposed intake sites. Other details of these deployments are given in Annex 1. Water quality
parameters such as nutrients and dissolved oxygen were not measured specifically for this study
since they were not needed to support the model calibration. Instead relevant data from this period
were taken from the ongoing measurements conducted within the framework of the Jordanian and
Israeli national monitoring programs. These data were incorporated in Section 2.2.
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2.1.3.1
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Deep ADCP moorings
Measurements by the ADCPs mounted on the deep moorings show that while the averaged currents
are only 1-2 cm/s, instantaneous currents in the upper 200 m can be as high as 20 cm/s and the
dominant period is the tidal M2 component. The amplitudes of the averaged currents are similar in all
deployments and over both 200 and 500 m water depth, as can be seen from the following figures.
Assuming an averaged velocity of 5 cm/s during each tidal cycle, a passive tracer will move a distance of ~2 km, which is well beyond the region affected directly by the abstraction.
Zero to positive northwards components were found for the averaged currents at all water depths at
all times, with the only exception of the January 2011 deployment, when an average southwards current was measured at depths below 200 m.
Another characteristic of the averaged currents is non-zero east-west components, eastward in the
upper layer during all deployments, and westward in the lower layer. These non-zero averaged currents suggest a link between the two sides of the gulf, over a time scale of few days assuming passive-tracer behavior.
Figure 2-7 August 2010 deployment: The east/west component of the flow (measured by both
the upward looking 600 kHz ADCP and the downward looking 150 kHz ADCP) at the 500 m
mooring location. The color scale corresponds to speeds in cm s-1: positive values represent
eastwards currents. White patches indicate missing data.
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Figure 2-8 August 2010 deployment: Similar to Figure 2-7, but for the north/south component
of the flow. Positive values represent northwards currents.
Figure 2-9 August 2010 deployment: Averaged velocity component at each depth bin at the
500 m Mooring location. The averages were computed over the entire deployment period (~34
days during August-September 2010).
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Figure 2-10 October 2010 deployment: The east/west component of the flow (measured by
both the upward looking 600 kHz ADCP and the downward looking 150 kHz ADCP) at the 200
m mooring location. The color scale corresponds to speeds in cm s-1: positive values
represent eastwards currents. White patches indicate missing data.
Figure 2-11 October 2010 deployment: Averaged velocity component at each depth bin at the
200 m Mooring location. The averages were computed over the entire deployment period of
October 2010).
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Figure 2-12 October 2010 deployment: Averaged velocity component at each depth bin at the
500 m Mooring location. The averages were computed over the entire deployment period of
October 2010).
Figure 2-13 January 2011 deployment: The east/west component of the flow (measured by
both the upward looking 600 kHz ADCP and the downward looking 150 kHz ADCP) at the 200
m mooring location. The color scale corresponds to speeds in cm s-1: positive values
represent eastwards currents. White patches indicate missing data.
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Figure 2-14 January 2011: Similar to Figure 2.13, but for the north/south component of the
flow. Positive values represent northwards currents.
Figure 2-15 January 2011 Averaged velocity component at each depth bin at the 500 m
Mooring location. The averages were computed over the entire deployment period of January
2011).
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2.1.3.2
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Implications for selective withdrawal
The temperature measurements made on the moorings can also be used to infer vertical isotherm
displacements associated with internal waves. Figure 2-16a shows the temperature measured at 120
m depth on the 200m mooring in August 2010. Using the temperature profile measured in the August
2010 (similar to that seen in Figure 2-3), these were converted to isotherm positions (Figure 2-16b)
by inverting the dependence of temperature as a function of depth.
The standard deviation of the displacement seen at this mooring was 14m, with maximum displacement of up to 40m up or down. These displacements will have the effect of spreading the selective
withdrawal effect discussed in section 0 over a wider range of depths than calculated above. For example in summer, the effective withdrawal layer might expand from 20m above and below the intake
to ca. 40m above and below. As will be discussed below, the effects of internal waves on particle
entrainment in the model will also appear in a broadening of the “capture” zone of the intake.
Figure 2-16 (a) Temperatures measured at ca. 120 m on the 200 m mooring; (b) isotherm
displacements at 120m depth.
Finally, the observed velocities can be used to examine the spatial scale at which the abstraction
flow might be discerned. Note that a point sink in a withdrawal layer of thickness δ (an idealization)
Q
will induce a flow at distance r of u= 2πrδ . For δ = 20 m, the induced velocity would be 0.2
cm/s at a distance of 100 m from the intake, i.e. at distances slightly larger than the withdrawal layer
thickness the induced velocities would be essentially negligible.
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2.1.4
Horizontal mixing and eddying
2.1.4.1
ADCP transects
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The spatial structure of flows in the Gulf, at least as seen by current meters has been best revealed
in observations made along the entire Gulf of Aqaba, during February-March 1999 using a 150 KHz
ADCP mounted on the RV Meteor (Manasrah et al., 2004). These unique observations reveal a sequence of flow changes with time and space (Figure 2-17). These changes do not match the basic
tidal motion, and represent in some parts a phase difference in the horizontal current components of
about 90°. These appear to be a chain of cyclonic and anti-cyclonic eddies positioned along the Gulf
axis and occupying at least the upper 300m of the water column (Manasrah et al 2004; Manasrah
2002). The diameter of the eddies ranged from 5 to 8 km with velocities ranging from 0 to 0.30 ms-1.
Some of this spatial variability is seen in Figure 2-18, a plot of spatial variability in the northern Gulf
taken from Manasrah (2002). This spring-time data show that the current in the upper 200 m in the
western and eastern parts of the northern Gulf of Aqaba was dominantly directed to the NE, while in
the center the current was mainly SE. Consequently, an anti-cyclonic circulation was observed in the
upper 150 m between the western and central parts. Between 200 m to 300 m the NE current still
dominated in the western part, while a transition from NE to SE can clearly be seen in the east. Obviously, the two opposite currents are parts of a larger anti-cyclonic circulation between eastern and
western parts.
Figure 2-17 Time-latitude distribution of the current vectors along the axis of the Gulf of
Aqaba at 105 m depth on repeated tracks during February 21st-March 6th 1999.
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Figure 2-18 Distribution of the horizontal current vectors in the Northern Gulf of Aqaba at
selected depth levels during March 5th 01:40-March 6th 16:00 1999.
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Conversely to what observed at the whole gulf scale, in the northernmost part (10 km) of the gulf HF
radar measurements of the surface currents reveal that coherent eddies are very rare, and appear
only few times a year between November and April (Gildor et al., 2010). Therefore, it is not clear how
much such eddies contribute to horizontal mixing in this region.
2.1.4.2
High Frequency Radar current data
Since August 2005, Two 42 MHz SeaSonde HF radar systems have been operational in the northern
gulf near the city of Eilat, and since July 2008 an additional station was installed on the Jordanian
side near the MSS. This network is used to measure the complex surface circulation structure of the
northern GOAE with very high spatial (300 m) and temporal resolution (30 min) (Gildor et al., 2009).
Each of these stations measures the radial velocity of the surface currents. To reconstruct the velocity at a certain patch of water, at least two radar sites should measure the radial velocity there from
two different angles (ideally with at least 15o difference). Strictly speaking, the radar measures the
currents at the top few tens of cm of the water column. However, comparison to measurements by
an Acoustic Doppler Current Profiler (ADCP) demonstrate that the shear in the top few meters is
usually small, and most of the time the surface currents represent the upper 10-20 m.
The surface flow field can be quite complex and incoherent, as reported before (Fig. 2 of Gildor et
al., 2009). Often it is more structured, with the main component aligned with Gulf axis, and smaller
east-west component (Figure 2-19). However, due to the strong tidal signal, the direction of the flow
changes twice a day.
Figure 2-19 Two snapshots from the surface currents measured by the HF radar network
during October 2010 and February 2011.
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Occasionally (about 30% of the time, Gildor et al., 2009), temporary barriers to mixing exist at certain
sub-regions and can “trap” water masses for 1-3 days. This may have important implications for the
dispersion of pollutants, nutrients, larvae, etc., and therefore for a wide range of predictions. The
mechanism behind the barriers is still unknown and further analysis is required to better understand
their evolution and their effect on the ecological system.
Rarely, only few times a year between November and March, a coherent eddy occupying most of the
region and lasting for a day or so was observed (Gildor et al., 2010 and Figure 2-20). Although the
shape and center of the eddies change in time, they are the dominant feature in the gulf when they
are present. The associated velocities are relatively high, and can reach 100 cm s-1 near the edge of
the eddies, compared to the averaged velocities of 15 cm s-1 observed over most of the year. In addition, such eddies appear usually under calm condition, when the wind is relatively weak. The
mechanism behind the formation of such coherent eddies is yet unclear.
Figure 2-20 An example of coherent eddy from November 2005.
Large velocities appear also during strong storms, such as during February 15, 2011. An example
can be seen in the following Figure 2-21.
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Figure 2-21 Surface currents during the southern storm of February 15, 2011.
The HF radar data can also be used to estimate the connectivity between the two sides of the gulf by
advecting virtual passive particles. In order to do that, we need to fill spatial gaps and filter outliers.
As the data collected during this year is still under processing, we demonstrate the idea using data
from 2006 that was used in Carlson et al., 2010. The spatial gaps at each HF radar measurement
time were filled using open-boundary modal analysis (OMA)2, described by Lekien et al. (2004) for
mapping total velocities and by Kaplan and Lekien (2007) for mapping radial velocities.
Figure 2-22 presents three examples for January 2006. Nearly 200 particles were released within the
blue rectangles and their final locations after 36 hours are shown. The left and middle panels show
that particles that were released on the Jordanian side on January 24 at 18:40 GMT and on January
10:40 GMT, were drifted toward the Israeli coast. On the other hand, particles that were released on
the Israeli coast, on January 25, 10:40 GMT, stayed closed to the coast.
Figure 2-23 presents similar examples for August 2006. Here it is the opposite. Particles released on
the Israeli side crossed to the other side while those released along the Jordanian coast stayed near
the coast.
The above examples suggest that surface connectivity exists between the two sides of the gulf, although subject to strong variability in time due to the variability of the current fields.
2 The OMA procedure objectively maps the HF radar measurements using three sets of basis functions that are truncated at a
specified spatial resolution. Dirichlet modes (with zero horizontal divergence) represent the flow’s vorticity structure. Neumann
modes (with zero relative vorticity) account for horizontal divergence. Boundary modes are used to represent the normal flow
through the analysis domain open boundaries. Radial velocities were objectively mapped using the procedure of Lekien et al.
(2004) as detailed in Lekien and Gildor (2009), with a spatial scale of approximately 350 m. This spatial resolution threshold
resulted in a set of 100 Dirichlet modes, 130 Neumann modes, and 40 boundary modes (Lekien and Gildor 2009).
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Figure 2-22 Trajectories of virtual particles calculated based on the surface currents
measured by the HF radar for few occasions during January 2006.
Figure 2-23 Trajectories of virtual particles calculated based on the surface currents
measured by the HF radar for few occasions during August 2006.
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2.1.4.3
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Estimates of mixing times
The ADCP data shown in section 2.1.3.1 can be used to estimate horizontal exchange times associated with the observed flows. To do this, we can consider the time integral of the alongshore (U) and
cross-shore (V) velocities in different regions of interest:
T
X z ,T = ∫ U z , t dt
0
T
Y z ,T = ∫ V z ,t dt
0
with z = depth and t = time. Although flows must vary across the Gulf, these integrals can be used to
make a first-order estimates of the time it takes for water particles at different depths to travel along
and across the Gulf. In carrying out this analysis, we considered two velocities: (1) the velocity averaged over the upper 100m and (2) the velocity at 120m, about the depth of the potential intake.
A sample velocity record for the surface velocity measured on the 200m isobaths in August 2010 is
shown in Figure 2-24. Here the velocity has been split into components that have been high-passed
(the internal tides) and low-passed (low frequency currents) with a cutoff frequency of 0.4 cpd. These
velocities translate into the displacements shown in Figure 2-25. Interestingly, the high-frequency
motions contribute little to net displacements. For this case, water particles take ca. 4 days to traverse the Gulf. At the same time, at 120m, the pattern is more complicated (Figure 2-26), requiring ca.
25 days for particles to travel across the Gulf. A table of maximum cross-Gulf displacements for each
ca. month-long deployment is given below.
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Figure 2-24 Surface velocities on the 200m isobaths in August 2010. The East-North velocities
have been projected onto 45 deg (along Gulf) and 135 deg (across Gulf) directions.
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Figure 2-25 Surface displacements on the 200m isobaths in August 2010.
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Figure 2-26 Displacements computed for 120m on the 200m isobaths.
Table 2-1 Computed displacements in the cross-gulf direction during 2010 deployments
(about 1 month of duration each).
Period
Surface/200 m
120m/200 m
Surface/500 m
120m/500 m
August 2010
30 km
10 km
21 km
9 km
October 2010
14 km
28 km
25 km
15 km
From Table 2-1, it can be seen that the time to transport particles across the northern Gulf (6.5 km
wide) varies from about 5 to 20 days. Note that over 20 days (the longest period computed), the abstraction volume would be 8.6 x 107 m3. In contrast the volume of the Gulf mixed in this time is 9.5
km x 6.5 km x 100m (taking the upper portion of the water column where larvae are found) = 6.2 x
109 m3, i.e., the abstraction would take 1.5% of the mixed volume.
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2.1.5
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Insights from the circulation modeling
Within the context of this project we have developed a hierarchy of numerical circulation models to
help assess the potential impacts of water abstraction from the gulf. The first set of simulations for
this purpose consists of the control runs in which the models are used to reconstruct the present circulation. Since the models produce information at all locations and times, the control runs provide
additional insight that the field measurements alone cannot. For example, Figure 2-27 shows the
mean simulated temperature at a depth of 9.5 m (depth of the proposed northern intake) averaged
over 60 M2 tidal cycles (~31 days) for the month of Aug 2010. In general the water in the gulf is
cooler than the water of the northern Red Sea with a clear south to north temperature gradient. Two
main features that clearly stand out are the inflow of the Red Sea water which forms a tongue that
flows along the eastern shore, and the band of cooler temperatures along the eastern and northern
shores which is indicative of the wind induced upwelling observed by Labiosa and Arrigo (2003) in
satellite images.
Figure 2-27 Simulated temperature at 9.5 m averaged over 60 tidal cycles for the month of
August 2010.
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In Figure 2-28 (Mar 2010) and Figure 2-29 (Aug 2010) we show the residual currents at 25 m averaged over 60 tidal cycles. As noted above, it is the mean currents, not the high frequency tidal fluctuations, that are of primary importance since they will control most of the transport of dissolved and
suspended particles in the gulf.
Figure 2-28 Simulated currents at 25 m averaged over 60 tidal cycles for the month of March
2010.
The intense inflow of Red Sea water is quite apparent. The appearance of a chain of alternating cyclonic and anticyclonic eddies aligned along the gulf is also quite apparent as reported in previous
modeling studies (e.g. Berman et al., 2000; 2003) as well as in the ADCP measurements reported by
Manasrah et al. (2004) and Manasrah (2002) and as shown above in Figure 2-17. In the meandering
jet that forms the boundaries of these eddies, the mean current speeds can often exceed 20 cm/s. It
is also interesting to note that no coherent eddy appears in the northernmost part of the gulf which is
consistent with the HF radar measurements of near surface currents reported above in Section
2.1.4.2. The previous modeling studies showed that these eddies, which are formed in response to
the wind and tidal forcing, are generated due the constraints imposed by the geometry and the
shape of shoreline. Their precise locations and intensity are modified by the stratification.
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A similar map of the simulated, residual currents at 25 m for the month of Aug 2010 is shown in Figure 2-29. Here too the chain of eddies is apparent as is the intense inflow of Red Sea water which
flows along the eastern shore. Similarly no obvious coherent eddy appears in the northernmost region. It is quite possible that the constricted width of the northernmost section precludes the formation of such persistent eddies.
Figure 2-29 As in Fig. 2.28 except for the month of August 2010.
The intermediate model was designed to provide a zoom of the circulation in the northernmost 10 km
of the gulf which is the area most likely to be affected by the proposed abstraction. This model, with
a horizontal resolution of 124 m, was nested in the full gulf model as described in Section 9.1.5. In
the following figures we show some examples of the residual currents averaged over 60 M2 tidal cycles, as with the full gulf model results presented above.
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Figure 2-30 Simulated currents from the intermediate model at 1.5 m below the surface,
averaged over 60 tidal cycles for the month of March 2010.
Figure 2-30 shows the currents at 1.5 m below the surface for the month of March 2010. The circulation is dominated by a general cyclonic flow which mainly follows the shore and the isobaths. The
strongest currents are found over the steep bottom slope on both the east and west sides although
they tend to be somewhat stronger on the west side of the gulf. Typical speeds of the alongshore
flow are around 10 cm/s. Weaker currents are found along the north shore and in the center of the
gulf. In the southeastern part of the domain one can see a hint of the influence of the northern flank
of a cyclonic eddy which is located to the south.
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Figure 2-31 As in Fig. 2.30 except at 25 m below the surface.
In Figure 2-31 we show the currents at 25 m. The pattern is almost identical to the near surface flow
presented in the previous figure which is a result of the deep winter mixing at this time of the year. In
fact the current pattern at 120 m (not shown) is also vey similar as the winter mixing at this time extended from the surface to a depth of ~ 300 m.
The near surface mean currents for August are shown in Figure 2-32. In contrast to the winter case,
here the response of the sea to the direct influence of the northerly winds is clearly reflected in the
southwestward currents that appear over nearly the entire domain. This is due to the stratification of
the water column which also leads to significant changes in the current patterns at various depths as
will be seen in subsequent figures.
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Figure 2-32 Simulated currents from the intermediate model at 1.5 m below the surface,
averaged over 60 tidal cycles for the month of August 2010.
The mean currents in August at a depth of 25 m are shown in Figure 2-33. The pattern here is quite
different than the surface currents (Figure 2-32) and is reminiscent of the general cyclonic pattern
that characterized the March circulation with and an indication of the influence of the northern flank
of a cyclonic eddy located outside the domain to the south. The flow along the eastern shore extends
over a broader zone as compared to winter while along the western shore it is still restricted to the
region over the slope.
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Figure 2-33 As in Figure 2-32 except at 25 m depth.
The last figure that we present in this sequence is Figure 2-34 which shows the currents at 120 m
below the surface. Here the pattern is quite different than the circulation in the upper layers. The
general bathymetry-following cyclonic flow along the shores appears only in the northern half of the
domain. The southern half of the domain, however, is dominated by a coherent anticyclonic eddy
with inflow from the south along the western shore and outflow along the eastern shore. While we
cannot quantitatively compare the results here to the HF radar measurements presented above in
Section 2.1.4.2 (Figure 2-19 - Figure 2-21) due to the different time periods and averaging (the HF
measurements presented were instantaneous snapshots), they do nevertheless share some common features. For example, the coherent eddies observed in the ADCP transects along the entire
gulf (Section 2.1.4.1, Figure 2-17) and simulated by the full gulf model rarely appear in the HF measurements.
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Figure 2-34 As in Fig. 2.32 except at 120 m depth.
In this respect it is important to note that the HF measurements only sample the upper few meters of
the water column while the ADCP transects in Figure 2-17 represent the circulation at a depth of 105
m. We also note that the domain covered by the intermediate model is roughly the same as the area
covered by the HF measurements. In the intermediate model results presented here, no coherent
eddies spanning the width of the gulf appear in the average currents in the upper layers (shallower
than 25 m). The only occurrence of a coherent eddy appears in August at a depth of 120 m which is
well below the layer sampled by the HF radar. The other common feature shared by the HF radar
measurements and the model is the ratio between the mean and maximum current speeds. In both
cases the ratio is a factor of 6 or more. The mean near surface currents simulated by the model are
typically 10-15 cm/s while the maximum simulated instantaneous (1 hr mean) current speeds can
reach 60-70 cm/s.
One feature of the observed circulation during 2010 that was not expected was the noticeable reduction of the salinity in the spring and summer in the layer extending from the surface to the depth of
the subsurface salinity minimum. The salinity measured during the CTD cruises in May and August
(Figure 2-35) was as much as 0.15-0.20 psu lower than observed in previous years as can be seen
by comparing the red (measure 2010) and black (mean for the years 2003-2009) lines in the figure.
The most likely cause of such a change is an increase in the amount of Red Sea water entering the
gulf through the Strait of Tiran. A detailed analysis and study of this phenomenon is beyond the
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scope of this study especially in view of the lack of any field data from stations to the south. It may be
an important change that could be transient or long term and which warrants future monitoring. It
clearly means that 2010 was an unusual year in terms of the circulation. The model (blue lines) was
able to partially reproduce the feature.
Figure 2-35 Temperature and salinity profiles measured during the August CTD cruise (red
lines), simulated by the intermediate model (blue lines), and the multiyear means of the
respective months for the years 2003-2009 at Station A.
2.1.6
Summary
Overall, the physical data suggest a picture of the Gulf in which low-frequency gyres mix water particles across the Gulf over time scales ranging from a few days to a couple of weeks. Superimposed
on these motions are energetic internal tides that appear to have little effect on net transport, but can
result in significant vertical displacements of isothermal surfaces. This is important since the basic
density stratification of the Gulf will tend to act to restrict the withdrawal layer for a deep water off
take to regions below the surface mixed layer during most of the year as will be shown below in Sections 4.2.4 and 4.2.5 (see for example, Figs. 4-18 and 4-29). In these deeper layers the plankton and
larvae concentrations are relatively low.
Most importantly, the existing flows in the Gulf are seen to exchange a volume of water that is several orders of magnitude larger than those that would be induced by the proposed abstraction flows
(see Section 4.2.1), such that the latter would likely be imperceptible except in the immediate vicinity
of the sink. The expected effect of the abstraction on the heat budget of the gulf is also expected to
be negligible. There is little doubt that our understanding of the general circulation of the gulf and our
ability to model the circulation at various scales have improved dramatically in recent years. This project has significantly contributed to these improvements and has also revealed new phenomena such
as low frequency, non-zero cross gulf currents that were measured for the first time or the noticeable
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reduction of the salinity of the upper 300 m occurred during the year of measurements in comparison
with previous years. From a basic scientific research perspective, we note that we still lack a mechanistic understanding of several circulation features such as mixing barriers (Gildor et al., 2009), the
rare coherent eddies (Gildor et al., 2010), and the spectrum of the internal waves field. The underlying physical understanding of these processes may not be crucial to the conclusions or recommendations of this report, but they do leave open several interesting scientific questions. To properly address these poorly understood characteristics of the circulation in the gulf would require additional
investigations which are well beyond the scope of the present study.
2.2
Water quality
The shores of the GOAE are lined with well developed fringing coral reefs, which have grown successfully despite the high latitude of the Gulf relative to where coral reefs are typically found. These
reefs are likely one of the most important components of the Gulf’s ecological system. They provide
recycled nutrients that support open water productivity (Erez, 1990; Silverman et al., 2007), provide a
food source and together with sea grass habitats, they function as nurseries for many pelagic species. Both coral reefs and sea grass meadows are very susceptible to changes in water quality especially in the GOAE considering that these habitats experience over an annual cycle naturally occurring large variations in environmental conditions such as temperature, light penetration, aragonite
saturation and nutrient levels (Silverman et al., 2007a).
The waters of the GOAE are generally considered to be oligotrophic and have been characterized as
mildly productive with an annual average primary production of 80 g C·m-2·yr-1 (Levanon-Spanier et
al., 1979). This state reflects the lack of regular supply of nutrients to the surface layer of the GOAE
(Lazar et al., 2008). Throughout the annual cycle the supply of nutrients to the surface layer of the
GOAE is very low except during the winter. The shallow sill (~250 m) at the Tiran Strait separating
between the GOAE and the northern Red Sea allow only warm nutrient poor surface water to enter
the Gulf (Reiss and Hottinger, 1984). Additionally, nutrient supply through terrestrial surface runoff is
limited to one or two flood events per year during the winter. More recent studies have shown that
the deposition of dust transported from nearby sources and subsequent biological fixation of nitrogen
acts as a significant nutrient source to the Gulf (Richter and Abu- Hilal, 2006), while others showed
no significant N-fixation at the northern part of GOAE (Hadas and Erez, 2004, IET Report). This is
not expected to be an issue with respect to the water quality at the intake.
Other than from scientific literature, data on water quality of the Gulf are available from the results of
various monitoring programs (Table 2-2). Location of monitoring stations is shown in Figure 2-36.
Dissolved inorganic nutrients
Stratification of the water column during the summer months (April-November) causes recycled nutrients to accumulate in the deep reservoir (>250 m) and prevents them from being transported into
the photic zone (Figure 2-37). As a result the surface layer concentrations of inorganic nutrients, particularly nitrogen and phosphate, in the GOAE are especially low during summer (<0.05 and <0.01
µmol/l, respectively) (Al-Qutob et al., 2002; Rasheed et al. 2003; Silverman et al., 2007b). However,
during winter, deep convective mixing (>250 m) in the GOAE results in nutrient enrichment (2-3 or-
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ders of magnitude) of the open and coastal surface water (Rasheed et al., 2002; Manasrah et al.
2005; Silverman et al., 2007b; Lazar et al., 2008). This enrichment supports phytoplankton and benthic macro-algae blooms. The latter have a detrimental affect on the coral reefs lining the coast of the
GOAE as a result of growing over and smothering the coral beneath them (Figure 2-38; Genin et al.,
1995; Silverman et al., 2007b). In addition, high nutrient levels have also been associated with decreased rates of net CaCO3 deposition by corals possibly resulting from an increase in CaCO3 dissolution as a result of increased boring organism activity (Lazar and Loya, 1991; Glynn, 1997; Silverman et al., 2007b) or by directly affecting the corals and reducing CaCO3 deposition rates in corals
(Kinsey and Davies, 1979; Marubini et al., 1996).
During summer stratification the upper ~100 m of the water column are almost completely depleted
of inorganic nutrients (e.g. Figure 2-37) and below this level a nutricline (Reiss and Hottinger, 1984;
Badran et al., 2001; Lazar et al., 2008) develops indicating the threshold between nutrient uptake by
primary production in the photic zone and the supply of recycled nutrients from deep water through
diapycnal mixing. Above the bottom at station A there is sometimes an additional nutricline indicating
the flux of recycled nutrients from the sediments (Figure 2-37). This pattern of repletion and depletion
during summer stratification below 100 m depth in the GOAE is typical of nitrate, phosphate and silicate. These parameters have been measured in the open and coastal water by both the Israeli and
Jordanian National monitoring programs for the last 10 years on a monthly basis. Prior to this period,
measurements were made for short periods of time within the framework of scientific projects (see
Table 2-2).
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Table 2-2 Available data bases on water quality for use in this study.
Data
type
Source/Location
Period of
measurement
Parameters measured
Water
Quality
Eilat coastal sampling stations (/From
RSMPP and INMP (1999-2002, 20032010)/Only surface water sampled
1999 – 2010
Sal, DO, pH, AT, NO2, NO3,
Si(OH)4, PO4, Chl_a, Secchi
depth, Temp
1975-2010
Si(OH)4, PO4, Chl_a, Temp,
PAR, fluorescence, Picoplankton, PP (14C)*
1999-2010
2003-2010
2003-2010
Sal, DO, pH, Temp, Sig T,
NO2, NO3, NH4, Si(OH)4,
PO4, Chl_a, Entereococcus,
HC
JNMP/Jordan Coastal Stations
2003-2010
Sal, DO, pH, Transparency,
Temp, Sig T, NO2, NO3,
NH4, Si (OH)4, PO4, Chl_a.
Entereococcus, HC
J-Industrial Complex Monitoring Program-South Boarder
2003-2010
Sal, DO, pH, Transparency,
Temp, Sig T, NO2, NO3,
NH4, PO4, SO4, F
Eilat Station A1/From DCP (19751977), REEFLUX (1989-1991), RSP
(1996-1998), RSMPP (1999-2002)
and INMP (2003-2010) data bases/vertical profile measurements
Eilat Stations FF and OS/From
RSMPP (1999-2002) and INMP
(2003-2010)/vertical profile measurements
INMP/Jordan station B1
JNMP/Jordan Reference Offshore
Station
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Figure 2-36 Northern GOAE shoreline with sampling stations that are sampled by the Israeli
(blue) and Jordanian (green) national monitoring programs at the surface (empty circles) and
vertical profiles (filled triangles) on a monthly basis from 1999-2010.
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Figure 2-37 Vertical profiles of nitrate (NO3-1) and density calculated as a function of salinity
and potential temperature (θ) in sigma units measured a station A on a monthly basis during
2005.
Figure 2-38 Benthic macro-algae bloom smothering acropora coral head in the northern
GOAE during winter of 2000. Under such conditions corals may suphoccate and die. In 1992
an ecceptionally deep mixing event occurred resulting in a benthic macro-algae bloom and
large scale mortality of coral in the Eilat reef (Genin et al., 1995). Picture was taken by D.
Zakai.
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Chlorophyll a
Chlorophyll a concentrations and primary productivity have been concurrently studied by LevanonSpanier et al. (1979). The authors presented an annual cycle of the two parameters during 19761977 based on monthly measurements between the surface and 200 m in the north-western section
of the Gulf. Phytoplankton succession has been studied by Kimor and Golandsky (1977) and more
recently by Lindell and Post (1995) including the pico-fraction. Studies that included chlorophyll a
concentrations along the eastern coast of the GOAE were mostly restricted to coastal waters along
the Jordanian coast or had temporal resolutions of 2-3 months (Leger and Artiges, 1978; Natour and
Nienhuis, 1980; Mahasneh, 1984; Wahbeh and Badran, 1990; Badran and Foster, 1998; Richter et
al., 2001; Rasheed et al., 2003; and Niemann et al., 2004). Badran et al. (1999) and Rasheed et al.
(2002) reported significantly higher nutrient and chlorophyll a concentrations in coastal coral reef waters as compared to water column waters just 3 Km offshore. This observation was supported by the
results of a study conducted by Labiosa et al. (2003) who showed that upwelling of nutrient rich water along the eastern coast of GOAE resulted in an apparent cross-shore gradient in chlorophyll a
concentrations. This was demonstrated Using SeaWIFS and MODIS imagery, however no direct
measurements of upwelling have been made to prove this theory conclusively. From long term records of chlorophyll a concentrations in the open water of the northern GOAE measured by the Israeli
National Monitoring Program at station A (Figure 2-39) it is evident that surface water concentrations
vary between a low value of 0.03 g/L during summer and 0.87 g/L during the onset of stratification
at the end of March and beginning of April. During the summer months the water column is stratified,
and a typical deep chlorophyll maximum (DCM) develops at 60 – 100 m depth near the limit of light
penetration and close to the nutricline that begins at ~100 m depth. Unlike surface concentrations,
which are very low during the stratified season (O 0.1 g/l), the concentration of Chlorophyll a at the
DCM is relatively constant at 0.36 ± 0.10 g/l. Nonetheless, the depth integrated concentration of
chlorophyll a is greater by a factor of 2 Dec-Feb than the summer months Jun-Oct (Stambler, 2006)
1.0
Chlorophyll a (g/l)
0.8
0.6
0.4
0.2
0.0
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Figure 2-39 Successive annual cycles of chlorophyll a measured in the 0-10 m surface layer
from 1999 to 2010 on a monthly basis at station A.
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Light penetration
The depth of light penetration limits how deep a reef will grow because of the association between
endosymbiotic algae also know as zooxanthellae and their coral hosts. Under poor light conditions
corals aren’t able to sustain their energetic demands, which are provided for by photosynthates of
their algal symbionts. In the GOAE the average depth of maximum light penetration calculated according to equation 1 following Kleypas et al. (1999) and using measurements made over a three
year period (1993-1996) in the GOAE of Iluz (1997) is 40 m (Silverman et al., 2007b). The minimum
and maximum depths are 10 m and 70 m, respectively. These extrema are caused by seasonal variability of light intensity at the sea surface and not variations in water quality. Regardless, the range of
values are very similar to those reported by Kleypas et al. (1999) for oceanic waters inhabited by
coral reefs.
Z noon
ln
 
PARmin

PARnoon 
K 490
1
Znoon – Depth of maximum light penetration, m
PARmin – minimum PAR necessary for reef growth, 250 E·m-2·sec-1 (Kleypas et al., 1999).
PARnoon – maximum daily PAR at sea surface, E·m-2·sec-1.
K490 – diffuse extinction coefficient of light (λ = 490 nm), m-1.
Light field measurements made at station A during 1996-2000 on a monthly basis indicated that the
euphotic zone depths (1% of light at surface) varied between 80 and 115 m (Stambler, 2006). Regular measurements of Secchi depth and PAR in the coastal and open waters of the northern GOAE
have also being made on a monthly basis by the national monitoring programs of Jordan and Israel
since 2000.
Carbonate chemistry
It has been shown that the degree of aragonite saturation (arag) also limits the latitudinal distribution
of coral reefs (Kleypas et al., 1999) by limiting the rate of CaCO3 deposition in corals (e.g. Langdon
and Atkinson, 2005; Schneider and Erez, 2006). Thus, a coral will calcify at an increasing rate as
arag increases and visa-versa. Since [Ca+2] is relatively constant in the oceans it could be said that
arag is actually a measure of the carbonate ion concentration ([CO3-2]) according to equation 2.
Where, Ksp-arag is the apparent solubility product for aragonite that is the mineral deposited by corals.
The coral reefs in the GOAE are considered to be relatively high latitude reefs, i.e. at the northern
latitudinal limit of coral reef distribution globally. However, since the Gulf is a terminal basin with high
evaporation rates, the water is relatively saline (average ~40.7 PSU) compared to other oceanic regions inhabited by coral reefs (~35 PSU) resulting in comparatively high total alkalinity (~2500
mol/kg). Therefore, the carbonate ion concentration is also relatively high. The average arag in
GOAE based on two years of measurements (2000-2002) on a monthly basis in the nature reserve
reef, Eilat was 4.0 (Silverman et al., 2007). The minimum and maximum arag values for this period
were 3.7 and 4.4, respectively. These values are somewhat higher than the corresponding values for
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the global distribution of coral reefs (min = 3.3, mean = 3.8, max = 4.1) defined by Kleypas et al.
(1999).
 arag
Ca  CO 

2
K sp  arag
2
3
2
Silverman et al. (2007) also showed that arag varied seasonally with temperature and productivity in
the adjacent open sea (Figure 2-40). More importantly this study showed that the rate of net calcification (Gnet) of an entire reef was well correlated with ambient arag demonstrating the importance of
this parameter in assessing the water quality in coral reef environments.
Figure 2-40 Daily average degree of aragonite saturation in the nature reserve reef in Eilat
plotted against daily average temperature. Filled data points indicate measurements made
during open sea water column stratification (nutrient depletion) and empty markers indicate
measurements made during open sea water column mixing depth >250 m (nutrient repletion).
Note the positive correlation between arag and temperature for nutrient deplete conditions.
Under nutrient replete conditions productivity offsets the expected reduction in arag with
temperature due to increased uptake of CO2.
Total alkalinity reflects the concentration of dissolved minerals in seawater and therefore should be
conservative with salinity, i.e. as salinity increases total alkalinity should increase linearly and visaversa (Brewer et al., 1997). In the GOAE total alkalinity is generally lower than the calculated value
as a function of salinity using the relations developed by Brewer et al. (1997) indicating that the entire Gulf is a net sink for Alkalinity, i.e. deposition of CaCO3 (Figure 2-41). This is in agreement with
the fact that there are many calcifying organisms in the GOAE primarily coral reefs, which reduce total alkalinity below conservation with salinity by precipitating their CaCO3 skeletons. Measurements
made at station A from 1989 to 2010 indicate that total alkalinity in the northern GOAE is increasing
over time, getting closer to its conservation with salinity value. This could be the result of a number of
processes: 1) reduction in calcification due to ocean acidification (e.g. Silverman et al., 2009). 2) In-
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crease in dissolution of CaCO3 in the deep water of the Gulf due to organic loading (see below). 3)
Increase in salinity – values are not normalized to constant salinity.
2.65
AT (mmol · kg-1)
2.60
2.55
2.50
2.45
2.40
2.35
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
Figure 2-41 Total alkalinity measured at station A at discrete depths ≤20 m (red squares) and
≥200 m (blue diamonds) from 1989 to 2010. The dashed line indicates the value of total
alkalinity calculated as a function of average salinity in the GOAE (40.7 PSU) using the
relation between total alkalinity and salinity developed by Brewer et al., 1997 (AT = 703.7 +
45.785 * 40.7 = 2567 mol/kg).
Microbiological parameters: Enterococcus
Enterococcus in the Jordanian water was mostly not detectable except in the northern stations,
which are near Tourist sites and the Port of Aqaba. Enterococcus was extraordinary higher near the
middle Port and sometimes in the enclosed lagoon. The higher values at different stations might be
caused by the livestock ship anchoring usually near Clinker Port or any uncontrolled discharge at different sites.
Table 2-3 Enterococcus (mpn3) in the surface offshore and coastal waters of the Jordanian
sector of the Gulf of Aqaba, Red Sea, during 2009. Data from Jordanian National Monitoring
Program.
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Northern Boarder
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
Enclosed LagoonNorth
<10
<10
<10
<10
<10
20
20
42
42
75
20
75
Middle Port
20
10
10
82
10
10
60
75
<10
80
48
20
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
South Region
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
3 Most Probable Number
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Fluoride and sulphate
Records of the monthly average fluoride and sulphate concentrations in the seawater of the Gulf Of
Aqaba are shown in Figure 2-42. Fluoride and sulphate are two conservative species, their concentrations are not affected by the biological productivity. The values of fluoride and sulphate concentrations were usually in the normal range. Concentrations of the two species showed in 2009 only minor
variations from one month to another.
3.2
Sulphate
Sulphate (g/l)
3.1
3.0
2.9
2.8
2.7
2.6
J
F
M
A
M
Fluoride (mg/l)
1.6
J
J
A
S
O
N
D
J
A
S
O
N
D
Fluoride
1.4
1.2
1.0
0.8
J
F
M
A
M
J
Figure 2-42 Concentrations of sulphate (g/l) and fluoride (mg/l), total in the surface water of
the Gulf of Aqaba – southern Jordanian area – during the period 2001-2010. Error bars
represent the standard deviation of the average concentrations over the 10 years.
Dissolved trace metals and organic pollutants
Dissolved trace metals and organic pollutants in seawater at representative sites near potential pollution point sources and the coral reef along the Israeli coast of the GOAE were measured in 20022004 (Herut and Ludwik, 2004). The concentrations of all metals were very low, in the ppt/sub-ppb
range, and all below Israeli standard for water quality. The results revealed low levels (below the analytical detection limits) of volatile organic compounds (<0.5 ug/L), PAHs (<0.1 ug/L), PCBs (<0.3
ug/L), and chlorinated pesticides (<0.03 ug/L, measured in 2002 only). However, significant, but low
concentrations of tributyltin (TBT) and its degradation products) were measured at the ports.
Organochlorine pesticide concentrations in water of the Gulf of Aqaba (Table 2-4) were found to be
very low ranged from below detection limit to 0.539 ug/kg (Al Masri et al. 2009).
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Spatial changes were found in the concentration of the total hydrocarbon (THC) in the Gulf of Aqaba
(Rasheeed et al. subm.). The concentrations of THC in water were generally low (less than 0.01
mg/l) except in the water of enclosed tourist lagoons that used for yachts and boats parking (average
0.02 mg/l).
Table 2-4 Organochlorine pesticides concentrations (µg/kg) in the water of the Gulf of Aqaba.
Organochlorine
Pesticide
HCB
Heptachlor
Aldrin
p,p’ - DDE
p,p’ - DDD
p,p’ - DDT
Β-HCH
Conc. ug/kg
<d.l
0.001
<d.l
<d.l
<d.l
0.539
0.201
2.2.1.1
Coral reefs effects on water quality
Coral reefs on the Jordanian and Israeli side of the GOAE have been shown to recycle particulate
organic matter imported from the open sea into biologically available dissolved inorganic nutrients
(Richter et al., 2001; Silverman et al., 2007). Rasheed et al (2003) have also shown rapid recycling
in carbonate sediments associated with the coral reef. Badran et al. (2001) & Rasheed et al. (2002)
reported significantly higher nutrient and chlorophyll a concentrations in coastal coral reef waters as
compared to water column waters just 3 Km offshore (order of magnitude during summer). Silverman
et al. (2007) showed that the reef is actually a source of dissolved nutrients for open sea productivity
during the summer, while during the winter it behaves as a sink (Figure 2-43).
Figure 2-43 Net production estimated from the diurnal cycle of NO3-1 (Pn-N) in the fringing reef
at the Coral Beach Nature Reserve on the western side of the Gulf plotted against the open
sea (1 km offshore) NO3-1 concentration for all studies conducted between 2000-2002. The
black line indicates the calculated linear trend and the dashed lines indicate the boundaries
of the 95% confidence interval. Positive values indicate that the reef is a source of dissolved
nutrient and negative a source. During winter mixing nitrate levels in the open sea are high.
During the stratified summer nitrate levels in the open sea decrease to <0.1 M.
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2.2.1.2
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Long term trends in water quality of the northern GOAE
During the 1970’s a significant productivity gradient with increasing oligotrophy towards the north
was observed from the Tiran Strait to the north end of the Gulf (Levanon-Spanier et al., 1979; Reiss
and Hottinger, 1984). During the 1990’s and 2000’s this gradient reversed as indicated by the 2-3
times higher primary production in the northern GOAE, the increasing trend with time of the deep water dissolved inorganic nutrient reservoir and corresponding decrease in the deep water dissolved
oxygen reservoir (Figure 2-44) (Lazar and Erez, 2004; Lazar et al., 2008). It was proposed that these
changes were caused by a significant nutrient input (250 tons N·yr-1 during the period of maximum
production) from fish farming in cages near the north shore of the Gulf on the Israeli side of the border (Op. Cit.). This hypothesis was supported by the results of a modeling study conducted by Silverman and Gildor (2008) who showed that the residence time of nutrients in the GOAE (a few decades) is significantly longer than the residence time of water (a few month to a couple of years) and
therefore nutrients released into the surface water in the northern GOAE could accumulate and be
retained in it for a relatively long time. Alternatively, much of the long term variability of the nutrient
inventories and dissolved oxygen concentrations in the deep water of the GOAE may be due to fluctuations in the hydrodynamics of the Gulf as suggested by Herut and Cohen (2004). Specifically, the
frequency of deep mixing events and the interaction between deep convective mixing and the horizontal circulation (Herut and Cohen, 2004; Atkinson et al, 2004, IET Report). In their modeling study,
Silverman and Gildor (2008) also showed that long term variations in the heat balance of the northern Red Sea associated with the long term variations in the Indian Ocean Monsoon can cause long
period fluctuations in the stratification strength of the water column in the GOAE. Therefore, over a
few years of relatively shallow winter vertical mixing nutrients can accumulate in the deep water reservoir and during a year with exceptionally deep mixing the excess nutrients will be flushed out of the
GOAE back to the Red Sea. Thus, during the 1990’s and 2000’s nutrients in the deeper water of
northern GOAE could have been increasing with time, as part of a natural “cycle” and does not necessarily indicate accumulation of nitrogen from the fish farms (Atkinson et al, 2004, IET Report). The
frequency of deep mixing events and the interaction between deep convective mixing and the horizontal circulation may be especially important in the context of the RSDSC and have implications on
the water quality variations in this area. In any event, the fish farms were removed from the northern
gulf nearly three years ago so their potential impact is no longer an issue at this stage.
Deep water nitrate levels increased from a typical value of 4 mol/l (early 1990’s) to 7 mol/l in 20032004, while dissolved oxygen decreased from 180 mol/l to 150 mol/l. After the deep mixing of the
water column during the winter of 2007 oxygen levels in the deep reservoir (Figure 2-45) increased
almost to the levels observed in the early 2000’s while nutrient levels decreased. Silverman and Gildor (2008) showed using a box model of the entire Gulf that an increase of nutrient levels in the deep
northern basin of the Gulf could occur as a result of nutrient loading into surface water at its northern
end and long term variations in convective mixing depth during the winter. Thus, while the residence
time of water in the Gulf is ca. 9 months in the surface layer and ca. 8 years for deep water (> 250
m), nutrients have a residence time on the order of 10’s of years. Hence, an increase in stratification
in the water column of the GOAE will likely result in a nutrient build up and decreased oxygen levels
in the deep reservoirs of the Gulf.
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Figure 2-44 Contour plots of Dissolved Oxygen, NO2, NO3-1, SiO2, PO4-3, and Chl_a measured
at discrete depths at station A (in the middle of the GOAE, 10 km south of its northern shore)
down to a depth of 750 m during the period 1999 – 2009 (including). The measurements were
made within the frameworks of the Red Sea Marine Peace Park Monitoring Program (1999 –
2002) and the Israeli National Monitoring Program (2003 – to present).
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Figure 2-45 Oxygen levels at different depths below the water surface at station A in the
GOAE from 2000 to the end of 2009 (INMP annual report, 2009). The trend in the dissolved
oxygen concentration is mainly controlled by deep mixing events (~600-700m) occurred in
2000, 2005, 2007, 2008 and horizontal circulation, and not related to fish cages operation in
the past (Atkinson et al, 2004, IET Report; Herut and Cohen, 2004).
The decrease in dissolved oxygen in the deep reservoir until 2005 (Figure 2-46) was accompanied
by a decrease in pH indicating the production of CO2 due to recycling of organic matter through aerobic processes (data not shown). This decrease in dissolved oxygen was also observed in the surface layer (Figure 2-46), which could only be explained by the decrease in the deep reservoir concentration since there was no significant warming. Consistent with the decrease in deep water pH
and surface dissolved oxygen, surface water pH also decreased significantly until 2005 (Figure
2-47). This decline (ca. 0.1 pH units) is somewhat larger than the expected decline due to ocean
acidification (Caldeira and Wicket, 2003) in this short period of time. This decline in pH was not offset
by the increasing trend in total alkalinity and caused a significant reduction in the carbonate ion concentration and arag. This likely caused a reduction in coral reef calcification in the GOAE as shown
by Silverman et al. (2007, 2009).
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235
Dissolved Oxygen (mol·L-1)
230
225
220
215
210
205
DO/t = -7 mmol · L-1 · 10 years-1
200
195
190
89
90
91
92
93
94
95
96
97
98
99
00
01
02
03
04
05
06
07
08
09
Year
Figure 2-46 Dissolved oxygen concentration at the surface in station A from 1989 to 2009
indicating the long term decreasing trend.
8.32
8.30
8.28
pH(25°C)
8.26
8.24
8.22
8.20
8.18
8.16
8.14
1996
1996
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Year
Figure 2-47 Long term record of pH measured at a constant temperature (25ºC) on samples of
surface water from station A from 1996 to 2009. Since the pH was measured at constant
temperature the decline reflects an increase in surface water CO2 concentration, which is
consistent with the decrease in surface dissolved oxygen concentrations.
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2.3
Ecology
2.3.1
Marine ecosystems
A qaba
The Gulf of Aqaba/Eilat (GOAE), which is part of the Syrian-African rift valley, is a long (180 km),
narrow (5-25 km), and deep (average 800 m, maximum 1800 m) northward extension of the Red
Sea. It is connected to the Red Sea through the Straits of Tiran where the sill depth is approximately
250 m. The Gulf is located in an arid region with annual rainfall of less than 30 mm and the surface
runoff is practically zero. The best estimate for the annual mean evaporation from the surface is 1.61.8 m (Ben-Sasson et al., 2009).
The Gulf is a concentration basin in which less saline water enters through the straits in the upper
layer and the more saline water, formed in the gulf due to excessive evaporation, flows out near the
sill depth (Murray et al., 1984). Estimates of the water exchange through the straits, based on the
observed thermohaline structure, vary between 30,000 – 70,000 m3/s. More recent calculations by
Biton and Gildor (2011a) based on model results suggest that the exchange varies annually between
a maximum of nearly 4 x 104 m3/s (April) to a minimum of 0.5 x 104 m3/s (Sept. to Nov.), with an annual mean of 1.8 x 104 m3/s. Hence, the volume of surface water loss through evaporation is about
two orders of magnitude smaller than the volume of water exchange through the Straits. In this respect, the situation is similar to other concentration basins such as the Mediterranean Sea. While the
evaporative loss is compensated by inflow through the Straits, it is this small imbalance that drives
the overall subtidal circulation. Salinity in the GOAE is among the highest in the world ocean and is
around 40.68 ± 0.2 psu. Variations around the mean are due mainly to the high surface salinity in
summer and the inflowing, less saline Red Sea water which appears as a subsurface salinity minimum in spring and summer.
Unlike open subtropical (and tropical) oceans, where the deep and intermediate water is cold, the
deep water in the Gulf remains at just below 21°C throughout the year (NMP reports 2003-2010).
The reason for this anomaly is the shallow sill at Bab-el-Mandeb, which effectively separates the
deep waters in the semi-enclosed Red Sea from those in of the Indian Ocean. For comparison, water
temperature at 1500m depth in the Gulf of Aden, which connects the Red Sea and Indian Ocean, is
<10ºC. The occurrence of warm water at depth substantially weakens the vertical stratification of the
water column in the GOAE. For example, below ~300 m, the vertical gradient in temperature in the
Gulf is ~0.09ºC / 100 m, compared with more than an order of magnitude steeper gradient in “normal” oceans at similar latitudes (e.g., 1.07ºC/100 m south of Bermuda, 1.67ºC/100 m at the Central
North Pacific). The weak stratification, together with low air temperature in winter, subjects the Gulf
to unique (among warm, sub-tropical water bodies) seasonal vertical mixing that can exceed 600 m
depth in cold winters (range of 250 to over 800 m) (Genin et al., 1995). Note that the occurrence of
deep mixing is limited to the Gulf of Aqaba, at the northern end higher-latitude part of the Red Sea.
Air temperature at lower latitudes, south of the Straits of Tiran, are too high to induce deep mixing,
even during the winter (Paldor and Anati, 1979; Reiss and Hottinger, 1984).
Due to deep mixing, the concentrations of nutrients in the upper water column exhibit an unusually
strong seasonality, changing from nutrient scarcity in summer to nutrient-replete conditions and phytoplankton bloom during winter-spring. Nearly each year a sharp nutricline exists, with relatively high
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nutrient concentrations in the deep water (e.g. reaching 6-7 μM NO3 at 500-700 m depth). The very
deep mixing (>700 m) after cold winters causes substantial nutrient entrainment that brings about
immense spring blooms of benthic algae. In some years those algae cover wide sections of the local
reefs, causing substantial coral death (Genin et al., 1995). As such events occur in the GOAE every
5-20 years, the mechanism can be categorized as an “intermediate” disturbance (sensu Connel
1978), a process known to be important in the maintenance of the high species diversity. Indeed the
diversity of reef corals in GOAE is among the highest in the world (Loya 1972; Connel 1978).
The year-round occurrence of warm waters is the key mechanism allowing coral reefs to flourish as
far north as the northernmost end of the GOAE. Fringing coral reefs are the overwhelmingly dominant type in the shallow waters. At greater depths, down to approximately 100 meters, coral carpets
covering marginal slopes are abundant. Growth of these deep reefs is facilitated by the clarity of the
water that allows light penetration to that depth. Below 100 m the reef becomes more patchy, sandy
stretches form greater proportion, and the corals are of different taxa and less abundant (Fricke and
Knauer 1986).
While its connection with the Indian Ocean places the biogeographic origin of Red Sea fauna and
flora within the Indo-Pacific domain, it's setting and geological history make for unique conditions that
have direct bearing on the development of reefs along the coasts of this elongated narrow sea. The
reefs are dominated by stony, hermatypic corals, consisting of a diverse mixture of branching, foliose
and massive species. Most abundant are corals belonging to the genera Acropora, Stylophora,
Montipora, Pocillopora, Porites, Platygyra, Pavona, Echinopora, and Favia (Loya and Slobodkin
1971). The hydrozoan Millepora is very abundant in the shallow, sub-tidal zone. Soft corals are also
abundant throughout the Red Sea, dominated by Sinularia, Sarcophyton, Lobophyton, and Xeniids,
with magnificent thickets of nephtheids (mostly Dendronephthya) found on elevated substrates and
vertical walls exposed to strong currents (Benayahu and Loya 1977(a) and (b)). Due to the clear water in the northern Red Sea, zooxanthellate corals reach at least 145 m in depth (Fricke et al. 1987).
The number of coral species found in the Red Sea is approximately 190, belonging to 70 genera
(Head, 1987). While the total number of species is generally higher in other tropical Indo Pacific reefs
(e.g., ~360 species in the Great Barrier Reef- Veron 1986), the local, within-habitat diversity in the
Red Sea is higher than in GBR (Loya 1972). However, almost any biological-ecological parameter
studied at that northern Gulf reefs represents the property of high level of variation on a small geographic scale (reviewd in Rinkevich 2005). These geographically small scale variations were reflected in studies revealing rates of coral recruitment, population genetics of corals, interactions of algae
and herbivorous organisms, natural catastrophe, substrate type, structure and topography, light intensity and sedimentation and more.
The fishes in the Red Sea coral reefs, like corals, share an Indo-Pacific origin. Especially abundant
and diverse are the guilds of site-attached and mobile zooplanktivorous species, schooling and individual herbivorous fish, including acanthurids, siganids, and scarids, and many benthic predators,
including serranids and balistids. Of the 462 reef-associated species (belonging to the ten richest
families) that inhabit the Arabian Sea, 69% have crossed successfully into the Red Sea; of these,
55% have crossed into the Gulf of Aqaba. Present-day differences in the species richness of reef associated species among the Arabian Sea, Red Sea and Gulf of Aqaba appear to be the product of
external, non-selective constraints on colonization (Kiflawi et al. 2006).
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The Red Sea coral reefs are among the most studied reefs in the world. Detailed accounts of their
structure and biological composition can be found in numerous publications. Useful references include Loya and Slobodkin (1971), Mergner (1971), Scheer (1971), Fishelson (1971), Benayahu and
Loya (1977a; 1977b), and Edwards and Head (1987).
2.3.2
The coral reefs: status and trends
During the last four decades, the coral reefs of Aqaba and Eilat have undergone major changes resulting from increasing impacts due to human activities, coupled with those from natural disturbances
(e.g., Genin et al., 1995; Meir et al., 2005, Rinkevich, 2005). Rapid developments in the cities of Eilat
and Aqaba intensified the pressure on the coral reefs of the Gulf, including fishing, diving and boating activities, sand deposition on the coast, phosphate loading, and more. Fortunately, stricter rules
are being applied on human activities near the coast and in the water in both cities to protect the
natural ecosystems. Another major development was a decision made by the Jordanian and Israeli
governments almost a decade ago to establish and support long-term marine monitoring programs in
Aqaba and in Eilat. Those monitoring programs provide comprehensive data and information on both
the water column and coral reef ecosystems in the region. That large set of data provides invaluable
information for our assessment of the physical, chemical and ecological effects of RDC. Especially,
the sections below on the present state of the coral reef and the role of larval recruitment in the
population dynamics of reef corals, are based on our processing of the Israel National Monitoring
Program (NMP) data base.
The NMP data base is open to the public for downloading of data and/or real-time measurements at
the following website: http://www.iui-eilat.ac.il/NMP/Default.aspx
Last year (2010) was the NMP’s seventh year of standard monitoring operations, carried out using
repetitive methods by mostly the same team. The abundance, diversity, sizes and health status of
reef corals are measured using the standard 10 m line transect method, where the cover of corals
(identified to genus or species), algae and other substrates are measured. The size of each coral
under the line is visually sorted as belonging to one of the following categories: small, medium, large,
and huge (1-5, 5-15,15-30, and >30 cm in diameter, respectively). A total of 121 such line transects
were carried in 2010 at 3 different sites at 2-3 depths per site (in the range of 5-20 m depth). Likewise, invertebrates are counted (during the night) along “belt transects”, 1 m in width, 50 m in length.
A total of 36 belt transect at 5 different sites (1-2 depths per site) were carried out in 2010. All the line
and belt transects are randomly positioned at each site.
The results are presented in the following figures (Figure 2-48a. through Figure 2-48i). See figure
legends for the main points shown.
Overall, during the seven years of monitoring by the NMP (2004-2010) the coral reefs of Eilat were
stable, exhibiting a slight growth in cover and health in 2007. Live coral cover has steadily increased
since 2007, and the normalized cover in 2010, while not as high as it was in 2007, has stabilized on
higher values than in 2004-6. Massive and encrusting forms of stony corals outnumber branching
species, although a single genus (Acropora spp.) is the dominant taxon in percent cover (Figure
2-48e and Figure 2-48f). Species composition and species diversity in the monitored sites are stable,
with no significant changes in the past seven years of monitoring. The density of sea-urchins (an important group of algae grazers) is recently decreasing, concurrently with a decrease in algal cover. At
most sites the abundance of sea urchins is the lowest encountered in the past seven years. The
years 2009-10 the growth potential of benthic algae, as indicated by settlement over plates protected
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from grazing, was unusually low, indicating relative scarcity of nutrients. The obvious reason is the
shallower-than-normal vertical mixing in the past two years (280-350 m, compared with 350-800 in
past years). Nutrient entrainment, hence algal growth, decreases after winters in which the mixing
does not reach great depths. It is possible that the observed decrease in the size of sea urchin populations was driven bottom-up by the scarcity of their algal food.
Year-to-year changes in the percent cover (normalized to rocky substrate) and total number of colonies per transect had coefficients of variation (CV) of 13.3% and 14.5%, respectively. Much higher
fluctuations (CV ranging 30% to 83%) was found for the common mobile invertebrates included in
the survey.
Figure 2-48a Average live coral cover (excluding soft corals) at each site (percent cover of
total area) in the years 2004-2010 at the different sites (Katza- oil terminal, NR- nature reserve,
IUI- Interuniversity Institute). Note the temporal stability in coral cover within sites and the
substantial variation among sites.
Figure 2-48b Average live coral cover on rocky substrate at each site (percent cover of total
rocky substrate) in the years 2004-2010 at the different sites (Katza- oil terminal, NR- nature
reserve, IUI- Interuniversity Institute). The normalization to percent cover on rocky substrate
allows a comparison between the extent of coral cover compared with full (100%) coverage.
The stability within site and the variation between site, observed in the non-normalized plots
(previous figure) is obvious also in the normalized values.
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Figure 2-48c Top - The average number of coral colonies per 10 m of line transect at each
site. Bottom – coral density normalized to hard substrate.
Figure 2-48d The coral live tissue index (=percent of skeleton covered with healthy, polypbearing tissue) of each living colony calculated for each site. Overall, the extent of damaged
tissue within colonies remains fairly stable with time since 2004, with substantial variation between sites.
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Figure 2-48e The twenty most abundant coral taxa in the reefs of Eilat (according to their cumulative measured length in the line transects of 2004) in the years 2004-2010, arranged according to their abundance in 2010.
Figure 2-48f Frequency distribution of the main taxa groups comprising reefs at permanent
photo-sites in 2010, according to the relative (percent) area which they occupy.
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Figure 2-48g The average density (per m2) of mobile invertebrates in the coral reefs of the Eilat Nature Reserve and off IUI in 2010.
Figure 2-48h The average density (per m2) of crinoids (Feather Stars, top) and Holothurians
(Sea Cucumbers, bottom) at the coral reefs of Eilat since 2004.
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Figure 2-48i The average density (individuals per m2) of Diadema setosum (top) other urchins
(middle) and all sea urchins (bottom) at the coral reefs of Eilat since 2004.
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Are the local populations of corals limited by recruitment?
Starting in 2005, in the coral-reef line transects carried out by NMP, each stony coral falling under
the transect tape was categorized as belonging to one of 4 size categories (small, medium, large,
and huge- see above for definitions). Thereby, the sizes of about 2500 individual corals were obtained each year. This 6 year long data base allows a general evaluation of the importance of “supply-side ecology” in determining the population size of reef corals in Eilat. That is, assessing the degree to which the populations and cover of corals are limited by the supply of larvae. With a detection
size threshold of ~ 1 cm, the group of “small” corals consists of colonies 1-5 cm in diameter. In the
following discussion, members of this group are termed “recruits”, representing colonies that recruited during the recent few years (most of the branching ones during the past year) and all, if survived
undisturbed, with grow with a few years (most of the branching ones within a year) into the next size
category (“medium” colonies). The growth rate of branching corals is in the range of centimeters per
year, while that of massive and encrusting corals is millimeters per year (based on the NMP photographic monitoring of individually marked colonies). Note that the following analysis can provide only
a general assessment, as it has some caveats and limitations, as described below.
The results indirectly suggest that neither the percent cover of all corals (Figure 2-49a- upper panel)
nor their abundance (number of colonies per area; Figure 2-49a- lower panel) are limited by recruitment. On the contrary, in both cases a negatively significant (P<0.0001) regression was found between the dependent variable (coral cover or the abundance of non-small corals per 100 m of line
transect) and the density of recruits (on hard substrate). That is, sites/years having more corals in
the category of small colonies had lower percent cover (of all corals) and lower densities of the sum
of medium + large + huge colonies.
A major caveat of the above assessment is that our analysis uses data on recruitment during the
past 6 years, whereas many of the larger corals included in the survey were older than 6 years,
some are perhaps over 100 years old. That is, there is a temporal decoupling between the size of the
population and the abundance of recruits (=small colonies). On the other hand, many of the surveyed branching corals grow in diameter by several centimeters per year, that is, move from the
“small” to the “medium” size (5-15 cm) category in 1 year. Therefore, under condition of recruitment
limitation, one expects a positive correlation between the number of recruits and mid-size colonies.
No such correlation was found, neither with concurrent abundance (R2=0.02, NS) nor with the abundance of medium corals after a time lag of 1 year (R2=0.05, NS).
Another assumption underlying our analysis is that the abundance of recruits measured at the different sites is representative, i.e., prevailed and is relative to other sites for many years. Indeed, a surprisingly stable difference between the sites prevailed for at least 6 years (Figure 2-49b). That is,
throughout that period, there have been sites that can clearly be identified as recruitment rich (for
example IUI) and there are sites that are repetitively recruit-poor (e.g. NR 5 and 10).
Based on the above findings we cautiously conclude that corals in the three main reefs of Eilat are
not limited by the recruitment of small colonies. Perhaps the main limiting factor for coral richness in
the Eilat reefs is the survival of small and medium colonies, where density-independent factors (e.g.,
southerly storms, algal cover, sediment accumulation) may be the main cause of mortality. That
populations of corals are not limited by recruitment is by no means unique to the reefs in Eilat, as
similar findings were found in coral reefs in both the Caribbean’s (Hughes and Tanner 2000) and the
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Great Barrier Reef (Hughes et al 2000). However, no information is available to allow a similar assessment of recruitment limitation in populations of invertebrates in Eilat and Aqaba, for which the
inter-annual variation in population size is substantial (Figure 2-48 g-i).
Coral cover (on hard substrate)
% cover - all corals
70
R2 = 0.3276
60
50
40
30
20
10
0
0
100
200
300
400
500
Recruits / 100 m of line transect
Abundance (# / 100 m)
Coral abundance
(medium + large + huge; on hard substrate)
600
R2 = 0.3377
500
400
300
200
100
0
0
100
200
300
400
500
Recruits / 100 m of line transect
Figure 2-49a Observed relationships between the abundance of small (<5 cm diameter) corals
(“recruits”) and the total percent cover of all corals (upper panel) or the density of all other
corals (mid, large and huge; lower panel) recorded in the NMP line transects in the years
2005-2010 at 3 different coral reefs sites in Eilat, 2-3 different depths per site (N=48). The
negative regression in both panels is statistically significant (P<0.0001).
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Recruits per 100 m (of line transect)
250
200
Katza-10
Katza-20
NR-5
150
NR-10
NR-20
IUI-5
IUI-10
IUI-15
100
50
0
2004
2005
2006
2007
2008
2009
2010
2011
Figure 2-49b The dynamics in the abundance of small corals (“recruits”) at the different sites
surveyed by NMP during the past six years 2005-2010. Note the long-term consistency in the
difference between recruitment-rich and recruitment-poor sites (e.g., IUI-5 vs. NR-10).
2.3.4
Coral reef larvae abundance and distribution
The objective of this chapter is to provide information on the distribution of fish and invertebrate larvae across the northern Gulf of Aqaba in different months and at different depths (in the range of 0180 m) as well as several deeper samplings reaching 210 m). . Whenever possible, larvae were
sorted to taxa of fish and benthic animals that reside as adults in the coral reef, hereafter collectively
termed “coral-reef larvae”.
The planktonic larvae of fish and invertebrates were sampled using a Multiple Opening-Closing Net
and Environmental Sensing System (MOCNESS), with a 1 m2 mouth opening and equipped with a
CTD, and a flow meter. Mesh sizes used were 600 µm for the fish larvae (towed at 1.7-2.3 knots)
and 100 µm for the invertebrate larvae (towed at 1.4-2 knots). MOCNESS nets of 600 µm mesh-size
are well within the range used for studies of fish larvae. Since plankton net tows (of all types) rarely
report trapping of coral larvae (“planulae”), we experimentally tested the suitability of the 100 µm
mesh net for their sampling. Several hundreds planulae were collected overnight from individual colonies of the coral Stylophora pistillata, using standard planulae traps (shaped like an upside-down
funnel with a collecting jar at the top, positioned overnight above the coral) . In the next morning, 100
planulae were separated under the microscope, transferred to a jar, taken to a boat, and inserted into a plankton net (100 µm mesh, single mouth) which was rapidly lowered to the water and towed
under the same conditions (speed and duration) as our MOCNESS tows. At the end of the tow the
planulae remaining in the net were collected and brought to the laboratory for microscopic screening.
This experiment was repeated 2 times, with the result of both replicates showing that the planulae
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survived the tow with no apparent morphological damage, with some of the larvae being alive and
active. Additional control tows with the MOCNESS were carried out to verify accuracy of discrete
sampling (lack of “contamination” by plankton from non-targeted depths) and overall performance.
Fish larvae were collected twice a month (starting in June), whereas invertebrate larvae were sampled once a month (starting in July). For details, see Annex 1 “Larval sampling”. Each sampling expedition took 2 consecutive days. Figure 2-50 shows the sampling sites and depths. For fish larvae
the upper 100 m were sampled at a resolution of 25 m, whereas the water-column between 100 and
180 m was sampled at 40 m resolution. For invertebrate larvae, the upper 180 m of the water column
was divided into three layers, each 60 m wide (except the shallowest station, where the bottom depth
was 50 m and the sampled layer was 0-25 m). Note that in order to minimize the risk of hitting the
bottom (which could damage both the reef and the MOCNESS), an elevation threshold of 25 m was
set. That is, the closest distance from the bottom in which larvae were sampled was 25 meters
above bottom (25 mab).
Following the project meeting in Venice in March 2011, and an approval of the following changes by
the World Bank, the MOCNESS sampling in March, April and May 2011 was extended to 210 m
depth, using 30 m resolution (210-180-150-120-90-60-0 layers) with concurrent reduction of the
sampling stations to the North Beach, the eastern coast and Mid Gulf (i.e. to compensate for the extra effort in sorting those added deep samples, no sampling was carried out along the coral reef of
Eilat).
Counts were corrected for the volume of water sampled per net, and absolute abundance estimates
are presented as larvae per 1 and 1000 m3, for invertebrate and fish larvae, respectively. Invertebrate larvae were sorted into 12 taxonomic groups (Table 2-5), defined based on the certainty in their
microscopic identification as larvae of benthic animals (“meroplankton”), rather than “holoplanktonic”
species. Therefore, at least one group of presumably abundant larvae, that of decapod larvae (e.g.,
crabs), for which such separation is complex, were excluded from our counts. A comparison of the
distribution and abundance between invertebrate larvae and holoplanktonic animals was made
based on concurrent counts in our samples of Chaetognaths (arrow warms) - a “classical” holoplanktonic taxon.
Fish larvae were pooled in a single taxonomic group. For the MSS and NR samples, the proportion
of fish larvae belonging to taxa with a benthic adult phase (i.e. coral-reef associated) was estimated
using depth-specific ‘conversion factors’. These factors (‘percent benthic’) were derived in an independent study, in which larvae collected along the NR site were identified to the family level (Figure
2-51) and separated from larvae of pelagic fishes. This analysis showed ranges of 60-80% and 2090% of larvae of benthic species in the near- and far-stations, respectively.
The microscopic sorting of planktonic larvae is a slow and laborious process. A total of 109958 individual invertebrate larvae and 22,292 fish larvae were sorted under the microscope in all the samples combined.
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Table 2-5 The 12 taxonomic groups used for sorting the invertebrate larvae.
Taxon
Common name
Bivalvia
Mussels, clams
Gastropoda
Snails
Polychaeta
Bristled warms
Tunicata
Sea squirts
Holothuroidea
Sea cucumbers
Asteroidea
Sea stars
Echinoidea
Sea urchins
Ophiuridae
Brittle stars
Crinoids
Feather stars
Planulae
Corals and other Cnidarians
Sipunculidae
Round worms
Brachiopoda
Shelled lophorites
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Figure 2-50 Map showing a schematic chart of the MOCNESS sampling stations of coral-reef
larvae. Triplicates of full circles along full lines indicate the path of consecutive samples at
different depths. For the invertebrate larvae, at stations where the bottom was deeper than
250m the sampled layers were 180 to 120, 120 to 60, and 60 to 0 m. At intermediate stations
(bottom depth of 150 m) only the two shallower layers (120-60 and 0-60) were sampled,
whereas at the shallowest stations (bottom depth of 50 m) only a single layer (0 to 25 m) was
sampled. Thereby, 25 m above bottom was the closest distance the MOCNESS reached to the
bottom. For fish larvae the upper 100 m were sampled at a resolution of 25 m, whereas the
water-column between 100 and 180m was sampled at 40 m resolution. An additional transect
was regularly carried out for fish larvae (only) at the Israeli side of the north beach (with
sampling locations being a mirror image of those along the Jordanian side). See text for
information on additional deep samples (down to 210 m deep) taken off MSS and North Beach
in March, April and May.
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Fish larvae
The abundance of fish larvae varied considerably across the six months analysed (Figure 2-52), but
consistently peaked at depths of between 25 and 75m (Figure 2-53). To a large extend the pattern
appears independent of distance from shore (bottom depth), with the two sides of the gulf close to
mirroring each other. Of the total abundance within the upper 140m, only a small fraction was found
in the 100 to 140m depth strata (Figure 2-54); especially in the summertime when the water column
is stratified. Focusing on the upper 75m, there does not appear to be a temporally consistent crossshore gradient in larval abundance (Figure 2-55). However, the waters closest to the shoreline do
seem to contain relatively higher abundances.
Across the north beach, abundances of fish larvae were similar along the Jordanian (eastern) and
Israeli (western) sections (Figure 2-56). Similarly, abundances of fish larvae along the north beach
follow a similar pattern as that along the MSS and NR sites; at least in the upper depth strata (075m), above bottom depth of 150m (Figure 2-57).
In summary, the majority of fish larvae in the vicinity of the proposed eastern intake site appear to be
concentrated in the upper 75m; certainly within the upper 100m and mostly between 25 and 75m.
The similarity in this pattern between the eastern and western shorelines suggests that it is relatively
free of sampling noise.
Figure 2-51 The proportion of the total fish larvae collected at each of the specified depth
strata, which belonged to taxa having a benthic adults phase. The results are based on
samples obtained close to (~500m) and far from (~2km) the western shoreline of the GOA, as
part of an independent study (Kimmerling & Kiflawi unpubl.). No samples below 75m were
taken close to the shoreline.
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3000
2500
Abundance
2000
1500
1000
500
0
June
July
Aug
Sep
Oct
Nov
Figure 2-52 Total abundance of fish larvae in the upper 75 meters, calculated by adding the
abundance per 1000m3 of the upper three depth strata. Averages and standard deviations are
calculated across the shallow (150m) and deep (250m) MSS and NR profiles, and the mid-gulf
profile (i.e. n=5 per month). Abundances are corrected for benthic taxa.
Relative abundance (150m)
0.0
.2
.4
.6
.8
1.0
0
-25
-50
-50
Depth
Depth
0
-25
-75
-100
0.0
-125
-150
-175
-175
0
.4
.6
.8
.8
1.0
1.0
0
-25
0.0
.2
.4
.6
.8
1.0
-25
-50
-75
0.0
.2
.4
.6
.8
1.0
Depth
-50
Depth
.6
-75
-150
.2
.4
-100
-125
0.0
.2
-75
-100
0
-125
-25
-125
-150
-50
-150
-75
-175
Depth
-175
June
July
August
September
October
November
-100
-100
-125
-150
-175
Figure 2-53 Depth profiles of the relative abundance of fish larvae for casts made over the
nominal bottom-depth specified (in parenthesis) by the x-axis label. Relative abundance is the
proportion of the maximum number of larvae found in the specified cast. The maximum
numbers themselves (larvae per 1000m3) are provided in the legend of each plot;
corresponding to the 6 months specified in the general legend. Abundances are corrected for
benthic taxa.
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Figure 2-54 Percent of fish larvae found between 100 and 140 m of the total in the upper 140
meters. Averages and standard deviation are based on the MSS and NR profiles obtained in
the station where the bottom depth was 250 m and at the mid gulf station where the bottom
depth was 400 m (i.e. N=3 profiles per month). Abundances are corrected for benthic taxa.
3000
150m
250m
450m
250m
150 m
No. of larvae
2500
2000
1500
1000
500
0
June
July
August
September October
November
Figure 2-55 Cross-gulf profile of the abundance of fish larvae within the upper 75 meters.
Values are the sum of the expected number of larvae within 1000m3, sampled at each of the
upper three depth strata. Coloured bars (white to green) run east to west over bottom depths
of 150m, 250m, 450m, 250m and 150m. Abundances are corrected for benthic taxa.
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1200
1400
1200
1000
800
800
600
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pth
De
De
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Oct
Sep
Aug
July
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50-7
0
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2 -5
ge
ran
ran
s
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1000
Larvae per 1000m
3
1600
Larvae per 1000m
3
1800
June
0-25
s
0-25
Nov
Oct
Sep
Aug
July
June
Figure 2-56 Abundance of fish larvae along the north beach, east and west of the border (right
and left panels, respectively). The depth stratum 0-25s was sampled over bottom depth of 50
m. The remaining strata were sampled over bottom depth of 150 m.
Log (abundance) - Longshore
4
3
2
June
July
August
September
October
November
1
0
0
1
2
3
4
Log(abundance) - North Beach
Figure 2-57 A comparison of log transformed abundances of fish larvae between samples
collected in the North Beach and along the eastern and western shorelines (blank and solid
symbols, respectively). Data pertains to the upper three depth strata, above bottom depth of
150 m (i.e. three points per month, per side). No correction for benthic taxa was applied to the
longshore abundances.
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Invertebrate larvae
Larvae of mollusks (gastropods and bivalves) were by far the most dominant group, comprising together 91% of the total larvae counted (Figure 2-58). At the other extreme, planulae (larvae of corals
and other cnidarians) were extremely rare, with an average of 0.3 m-3, comprising 0.16% of the total
larvae.
Figure 2-59 shows the distribution of the total number of larvae and the 3 most abundant taxa (echinoderms, bivalves, and gastropods) at the different stations and depths When averaged over the entire year, a remarkable similarity was found in the abundance of invertebrate larvae, across the entire sampled region Figure 2-60, with slightly higher abundances at intermediate distance from shore
in the north beach (NB-mid) and the eastern side (MSS-mid). Noteworthy is the similarity between
the near-reef waters and that in the deep, open waters in the middle of the gulf (MG), suggesting
strong cross-shore transport and mixing (see discussion below). The distribution of invertebrate larvae in north beach, on the other hand, exhibits a seasonal deviation from that pattern (Figure 2-61):
during the cooling months (November, December) abundances in the north beach are significantly
higher (paired t-test, P<0.006) than those along the east and west coast, whereas no such difference
(P=0.53) is observed for the summer months (July, August). This pattern is explained by the occurrence of downwelling (water sinking) during the cooling months (Monismith et al., 2006) and upward
swimming against the downwelling by depth-retaining zooplankton (Genin et al., 2005). This mechanism generates immense aggregations of zooplankton along oceanic fronts (e.g., Olson and Backus
1985; Olson et al. 1994; Shanks et al., 2000) including the north beach (A. Genin unpublished data).
Apparently no such accumulation of plankton is observed in the summer when the water warms up
and stratification strengthens, both of which inhibiting downwelling. The abundance of larvae of fish
in the north beach, on the other hand, was similar to that along the west and east coast in all seasons (Figure 2-57).
A key pattern, most relevant to the question of the depth of the RDC intake, is the depth distribution
of larvae (Figure 2-62a, b, c). Both fish (Figure 2-53 - Figure 2-55) and invertebrate larvae (Figure
2-59) exhibit a remarkable decline in abundance below the photic layer (> 120 m depth). During
summer, only 7% of the total invertebrate larvae were found below 120 m depth, while during winter
that average was 20%.
The details of this decline in the designated eastern intake area (MSS station) are seen best in the
two sampling sessions that extended to 210 m depth (in April and May, Figure 2-62d). As in previous
plots, the major jump in the decline of larval abundance with depth occurs at the bottom of photic
layer (around 100-120m). Below that depth and down to our sampling limit (201m) larvae continue to
decline with depth (Figure 2-62d). However, that decline is minuscule relative to the jump at 100120m.
The absence of such rarity of larvae below 120m during the winter can be explained in terms of vertical mixing. The depth of the mixed layer (measured monthly by NMP and a concurrent study; results not shown), indicate vertical mixing depths of 102, 169 and 244 m on November 23rd, December 19th, and February 14th, respectively. Vertical mixing homogenizes the vertical distribution of
small, weakly swimming plankters (Farstey et al., 2002), resulting in an extension of their vertical distribution to depths below the photic layer (which is 90±20 m depth in the northern Gulf of Aqaba).
This extension to depths below the normal boundary, may be a result of direct, passive mixing of the
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animals themselves (by the physical mixing) or due to their tracking of their phytoplanktonic food,
which, by itself, is passively mixed, or both.
As corals are a focal group in this study, noteworthy is our observation on the abundance of their larvae (planulae). Figure 2-63 shows the average abundance of planulae at different depths in August,
the only month (of those for which the sample sorting has so far been completed) in which the average abundance of planulae exceeded 0.5 m-3. Fewer planulae were observed in April and May (0.09
and 0.01 per m3, respectively) with zero planulae observed in the samples taken in December, February and March. The average density of planulae in July, August, and November was 0.13, 0.79,
and 0.07 per m3, respectively. While the size and shape of the planulae sorted by us indicated that
they were coral larvae, we cannot exclude the (unlikely) possibility that some could have been the
larvae of other cnidaria (e.g. hydrozoans, antipatharians). Possible explanations of the rarity of
planulae in our samples are discussed below.
Noteworthy is the cross-shore decline in larval abundance off the eastern coast (MSS station, Figure
2-55 and Figure 2-64). Note that no such a cross-shore decline is exhibited by invertebrate larvae
along the west coast. In most of the months, the larvae within the photic layer were higher at the
shallower station (150 m bottom depth) than in the more seaward station (250 m bottom depth). This
trend is likely related to the fact that the coastal zone is the site of both the release (=source) and
settlement (target site) of benthic larvaeA pair-wise correlation analysis (Figure 2-65) between the
main taxa, their total density, and “classic” holoplanktonic taxon (Chaetognaths) indicated that except
bivalves all other taxa were not correlated with the holoplanktonic plankton. When the relatively uncommon Brachiopod larvae are excluded, of the 10 possible pairs of taxa, 7 were significantly correlated one with another (Pearson r>0.5; Bonferroni Probabilities P<0.0001). No significant correlation
was found between Chaetognaths and the total invertebrate larvae. These findings suggest that the
abundance and distribution of larvae is inherently different from that of holoplankton. Such a difference may be the outcome of different biology (feeding, behavior) and/or difference in their source location (coastal vs. open water). However, these findings should be considered tentative, as a robust
analysis of differences and similarities between larvae and holoplankton requires a much more elaborate analysis, especially of more holoplanktonic zooplankters (most important - copepods).
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Figure 2-58 The abundance (absolute- upper panel, relative- lower panel) of different taxa of
invertebrate larvae in our samples. Absolute values (upper panel) are indicated as the
average (±sd) density in all the samples sorted so far (N=89). Note dominance of gastropods
and bivalves and the rarity of planulae.
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Figure 2-59 Depth profiles of invertebrate larvae at all sampling station in all months for
which the microscopic sorting has been completed, for the total larvae (upper panel),
Echinoderm larvae (a group consisting larvae of sea urchins, brittle stars, sea cucumbers,
sea stars and crinoids; 2nd panel from top), bivalves larvae (3rd panel from top), and
gastropod larvae (lower panel). Note the uniform scale of the horizontal axes in all plots
except some from the north beach.
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Total larvae in 60‐120 m
600
500
500
Number / m^3
400
300
200
100
400
300
200
100
0
500
300
G
M
ea
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SS
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id
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M
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id
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Total larvae in 180‐210 m (April‐May 2011)
NB
‐m
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ne
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‐
500
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600
r
Number / m^3
Total larvae in 120‐180 m
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NB
‐
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‐
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NB
‐
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ar
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NB
‐
Number / m^3
Total larvae in upper 60 m
600
Figure 2-60 Average (±se) of total invertebrate larvae over all sampling dates at the different sites across the northern Gulf of Aqaba in the layers
indicated at the top of each panel. For obvious reasons, abundances in deep layers were sampled (and plotted) only in stations where the bottom
depth exceeds the samples layer (hence, the number of stations plotted in each panel declines with depth). Note the remarkable similarity between stations and the sharp decline of larvae with depth.
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Total invertebrate larvae
3
(number / m )
1200
y=x
North beach
1000
800
600
400
200
0
0
200
400
600
800
1000
1200
Reef stations (MSS, NR)
Figure 2-61 A comparison between the abundance of invertebrate larvae at the north beach
vs. their concurrent abundance along the west (NR) and east (MSS) coasts. A key feature
observed in this plot is that during the cooling months (November, December; full blue
circles) abundances in the north beach are significantly higher (paired t-test, P<0.006) than
those along the east and west coast (that is, most of the points are above the Y=X line). No
such difference (P=0.53) is observed for the summer months (July, August; empty red
triangles).
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Abundance (# / m3)
Winter (water column partly mixed)
700
Total
600
Gastropods
Bivalves
500
Echinoderms
400
300
200
100
0
0-60
60-120
120-180
Depth layer (m)
Summer (stratified water column)
700
Abundance (# / m3)
600
500
Total
400
Gastropods
300
Bivalves
Echinoderms
200
100
0
0-60
60-120
120-180
Depth layer (m)
Figure 2-62a Average (±sd) density of invertebrate larvae (colour coded for total, gastropods,
bivalves and echinoderms) at the three depth layers during the winter months (November,
December, February; upper panel) and summer (July, August; lower panel). Note the decline
with depth which is especially steep during the summer (see next figure).
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Winter (mixing water column)
20%
43%
0-60
60-120
120-180
37%
Summer (startified water)
7%
47%
46%
0-60
60-120
120-180
Figure 2-62b The relative abundance (%) of total invertebrate larvae during the winter (upper
panel) and summer (lower panel), based on abundances presented in Figure 1.3.4.11. Note
that during the summer only 7% of the total larvae are found below 120 m depth, with a higher
value (20%) observed in the winter.
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Figure 2-62c Depth profiles of total invertebrate larvae in April and May (when the MOCNESS
sampling was extended to 210 m depth with 30 m resolution). Note the relative rarity of larvae
below 120 m depth (except in the North Beach in April).
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Figure 2-62d Depth profiles of total invertebrate larvae in April and May (when the MOCNESS
sampling was extended to 210 m depth with 30 m resolution) along the east coast (Station
MSS far – bottom depth of 250, and Mid Gulf). Note the sharp decline (jump) in larval abundance occurring at the bottom of the photic layer (100-120 m) and very gradual decline farther
down (140-210 m).
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Figure 2-63 The abundance of planulae at the three depth ranges sampled during the month
of August 2010. Note the very low abundance of planulae (Y axis) and their sharp decline
below the photic depth. August was the only month (of those in which the samples have so
far been sorted) in which the average abundance of planulae exceeded 0.5 m-3. Fewer
planulae were observed in April and May and no planulae were observed in the samples taken
in February and March. While the size and shape of the planulae sorted by us indicated that
they were coral larvae, we cannot exclude the unlikely possibility that some could have been
the larvae of other cnidaria (e.g. hydrozoans, antipatharians).
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Figure 2-64 The decline in larval abundance off MSS in two layers 0-60 m depth (top panel)
and 60-120 m (lower panel) in different months in the shallower station (bottom depth 150 m –
blue bars) and the deep station (bottom depth of 250 m- red bars). Note that most of the
times the density of larvae was higher in the shallower station.
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Figure 2-65 Matrix of pair-wise Pearson correlation between the main taxa of invertebrate
groups, their total density, and a “classic” holoplanktonic taxon (Chaetognaths). Pairs
indicated with a red asterisk indicate a significant correlation (Pearson r>0.5; Bonferroni
Probabilities P<0.0001).
2.3.5
Genetic connectivity
Considering the limited extension of coral reefs in the most Northern tip of the Gulf, the foremost expected impact of RDSC project is on larval supply and recruitment of coral reef species by affecting
the connectivity among the Israeli and Jordanian reefs. The lifecycles of most coral reef species consist of a benthic, adult stage and a pelagic, larval stage. It is during the latter that dispersal is
achieved. Moreover, it is the ‘recruitment’ of larvae back to the reef, which is largely responsible for
defining the demographic dynamics of adult populations and structuring their communities. Thus,
changes in dispersal routes would quickly cascade to the reef state.
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Our preliminary observations suggest the existing of biological connectivity in the shallow-water marine assemblages. Circumstantial evidence for such possible connectivity may be seen by reappearance of several species, which had disappeared from Eilat’s nature reserve area, on artificial objects
in the northern tip of the gulf. Another support for connectivity is provided by Maier et al. (2005), suggesting that the coral nature reserve in Eilat is connected to southern reefs in the Sinai Peninsula. A
population genetic study on the soft coral Heteroxenia fuscescens, a common shallow-reef brooding
species in the Red Sea (Fucks et al., 2006), further revealed, by means of amplified fragment length
polymorphism markers, no genetic structuring characteristic to a specific location, indicating extensive gene flow among specimens inhabiting the northern Gulf. A study on fish otoliths has also suggested that the northern tip of the Gulf forms a conduit for larvae that settle along the Eilat reefs after
having passed along the Jordanian side (Ben-Tzvi et al., 2008).
It seems prudent, therefore, to consider the implications of any anthropogenic activity along the
Gulf’s tip that stands to affect the hydrology of these passageways. However, it is difficult to create
from ocean current trajectories (usually mean trajectories) and larval duration a generalized framework to characterize larval dispersal because of the variability (between years, within a single year)
of environmental situations and larval behaviors, becoming to be known at least as important as
oceanography processes in determining population genetics of marine organisms. Various recent
studies (in the Caribbean, Indonesia, etc.) have further indicated that larval dispersal can be more
complicated than physical parameters. Many fish larvae, for example, actually recruit back to their
natal reefs despite their ability to disperse. Recently, molecular genetics tools have contributed significantly to understanding larval dispersal and connectivity because dispersal patterns can be inferred by comparing patterns of genetic similarity between populations. As we have yet no clear evidence for the real existence of east-west, north-south types of connectivity trajectories (or their combinations) in the Gulf of Eilat/Aqaba, this study suggests that molecular biology tools, when performed adequately, may serve as the best tool for elucidating the net products of gene transfer directionalities between the northern Gulf populations, providing documentation for the prevailing type of
biological connectivity in this area.
In view the above, this part of the study is focusing on the major question of biological connectivity in
the northern Gulf. By using two types of molecular markers (polymorphic alleles on microsatellite loci
and AFLP), this study suggests elucidating profiles of population genetics of selected reef organisms
along both, Israeli and Jordanian coasts. Since developing any new set of microsatellite loci should
take at least two years of work, which is unfeasible, we have used here sets of microsatellite loci that
have already been developed for two important Red Sea coral species (Pocillopora and Seriatopora). We further used AFLP markers for an important reef organism residing along the Jordanian
and the Israeli coasts (the coral-pest snail Drupella). By employing above molecular markers, we
sampled DNA from organisms belonging to different populations of each selected species and elucidated their population genetics properties. These microsatellites and AFLP markers are also used to
fill in the gaps in knowledge on population genetics profiles of the selected reef species in the northern Gulf of Eilat/Aqaba, providing the necessary background information for future monitoring and
conservation measures.
The results of microsatellite analysis conducted on Pocillopora damicornis, demonstrated an absence of genetic structuring in the populations residing in the northern Gulf (Israel and Jordan) and
high connectivity between the sites sampled for this study (Figure 2-66; see Annex 1 for location of
sampling sites). Further analyses using clustering methodologies, each possessing a characteristic
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set of allele polymorphisms on the basis of the genotyping data from microsatellite alleles have revealed that the 227 sampled individuals are divided to 11 clusters, each containing individuals from
different collecting sites, showing, again, the genetic mixture of the corals’ genotypes in all northern
Gulf localities. Although the results of FST or clustering are informative for estimation of the genetic
subdivision of coral populations between Israeli and Jordanian sites along the northern Gulf, these
analyses cannot identify the direction of recruitment of coral larvae, nor are they informative about
the recruitment level. Therefore, we performed an assignment test, which enables inference of the
migration patterns of each colony. Population assignment test in which a sample is assigned to the
population with the highest log likelihood was performed. The results showed that in total, 67% of the
collected individuals in each location, possibly originated from a different location. Only Kisosky
beach and Aqaba south showed high percentage of self-assignment (53% and 54% respectively).
Individuals from Jordan were assigned with Israeli populations and vice versa. Pairwise population
genetic distance and identity further revealed high genetic identities between sites, and very small
genetic distance. These results demonstrated an absence of genetic structuring in the Pocillopora
damicornis populations residing in the northern Gulf (Israel and Jordan) and high connectivity between the sites sampled for this study. These microsatellite-based population tests unambiguously
identified only a single valid cluster in the northern Gulf populations.
Figure 2-66 Neighbor - joining tree of all Pocillopora populations in the northern Gulf.
Analysis of genotypes of Seriatopora hystrix revealed similar results and pointed out moderate to low
genetic differentiation among populations. In the same way, analysis of molecular variance showed
no significant difference between Israeli and Jordanian sites, as most of the variance (98%) was accounted to the “within population factor”. Finally “distance tree” analysis indicated that all populations
sampled in the study belong to a single large Seriatopora hystrix population residing in the northern
Gulf.
The results of COI4 analysis conducted on Drupella cornus showed clearly, as in the two studied
coral species that all North Gulf populations are closely related one to each other. Similarly, population analysis of Drupella cornus AFLP loci from Aqaba and Eilat revealed high similarities between
the Israeli and Jordanian populations.
4 Cytochrome Oxidase I gene
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In addition to what presented above, the absence of endemism of species within the northern GoA,
even of sub-species, is also indicative of high connectivity between the two sides of the northern
Gulf, perhaps even between different reefs along its entire length.
2.4
Pollution loads entering the Gulf
The coastal area of the upper Gulf of Aqaba is subject to strong anthropic pressures.
The spectacular marine ecosystem and coral reef generate a massive and ever increasing demand
of tourism, resulting in the non-stop construction of new touristic complexes and marinas.
Moreover, as the only kingdom’s seaport, the Aqaba zone offers unique development opportunities
for Jordan’s economy, resulting in the settling of ever growing industrial activities and in the continuous upgrade and expansion of port facilities and infrastructures, boosted by the launch, in 2001, of
the Aqaba Special Economic Zone as a duty-free, low tax multi-sectorial development zone.
Several sources of contamination exist in the upper Gulf of Aqaba, acting as pollutant drivers. They
generate the present pollution loads entering the sea (pressures), estimated according to the different mechanisms and paths (direct discharge; groundwater migration; atmospheric deposition etc.).
2.4.1
Distribution and characteristics of main pollution sources
Following a careful review of the relevant information available, the following main pollution sources
have been identified for the upper Gulf of Aqaba:
1. The cities of Eilat and Aqaba, including the resident population and the touristic complexes located on the northern coast of GOA;
2. The peripheral touristic complexes (resorts) located far from the main cities;
3. The marinas and leisure craft traffic;
4. The industrial zones;
5. Port activities and ship traffic;
6. Agriculture;
7. Fish farming.
Around the two main cities of Eilat and Aqaba located along the northern tip of the Gulf, residential
and touristic areas coexist in the highly populated coastal area.
The anthropic pollution generated in the area includes the domestic loads discharged with
wastewaters both from private houses and touristic complexes and the diffuse urban pollution
washed away by stormwater. Moreover, some large touristic structures contribute by discharging to
the gulf significant amounts of water withdrawn from the subsoil, after use for cooling in their air conditioning systems.
Both Aqaba and Eilat are served by municipal sewage systems connected to central wastewater
treatment plants.
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The current Eilat wastewater treatment plant, based on treatment in sand ponds and on a seasonal
reservoir, was originally designed to guarantee “zero flow to the sea”: no leaks or planned percolation are allowed, and the treated effluents are recycled for direct irrigation some 40 km to the north of
Eilat. Nevertheless, due to the recent tremendous growth in population, the quantity of sewage water
currently surpasses the treatment and recycling facilities so that system overload has led to periodic
breakdowns, resulting in untreated sewage spill to the Gulf (e.g. the event of September 2007, with
an outburst of a main pipe in the sewage system, discharging about 500 cubic meters of raw sewage
water into the Gulf).
As for Aqaba, the previous municipal wastewater treatment plant, also based on natural treatment in
sand ponds, recently (2005) reached its full treatment capacity due to population growth. It was
therefore upgraded with financial support from the U.S. Agency for International Development in order to ensure no discharge to the sea thanks to water re-use. It is not clear, though, if the rehabilitation of the existing natural plant included preventing further leakage of treated sewage into the
groundwater, which was reported for the past (Bein et al., 2004).
While the whole of the domestic and touristic users located in the Eilat area are reported to be connected to the Israeli WWTP, the peripheral areas in Aqaba which are not connected to the central
wastewater network are reported to be served by septic tanks, which are sealed and pumped out to
tankers (ASEZA, 2008). Of course it is still possible that some (a minor part) of the domestic users,
both in the Eilat and Aqaba, are neither connected to the WWTPs nor using sealed septic tanks,
simply discharging their wastewater effluents to the groundwater. Anyway the lack of Kjeldahl nitrogen found in central Eilat groundwater seems to indicate that direct leakage of untreated sewage is
negligible at least in that urban area (Bein et al., 2004).
As for the urban runoff, especially during the heavy rainfall events resulting in periodic floods to the
cities of Eilat and Aqaba, the street dust is washed away with its load of contaminants accumulated
in time during the dry weather period due to the different anthropogenic activities (mainly traffic and
industry) carried out in the area. The rainwater from the urban areas is simply discharged to the main
stormwater drainage channels, reaching the sea with no previous treatment to reduce urban contamination. Metal concentrations in street dust samples in Aqaba, are generally reported to be below the
mean world-wide values, but nevertheless still significant (Al-Khashman, 2007).
In contrast to the touristic complexes located in the vicinities of Aqaba and Eilat city, which are
served by the municipal sewage system, those located more to the south have local wastewater
treatment plants.
According to the “zero flow to the sea” policy, the wastewaters are locally re-used after treatment,
mostly for garden irrigation. However, they may act, although not proven, as a limited contamination
source (Bein et al., 2004).
At present the main touristic areas out of the city area are located in Tala Bay (Jordan) and Hof Almog (Israel). The Jordan coast, between the city of Aqaba and the Israel border, is also involved in
the massive construction of luxury touristic resorts over previously inhabited areas (Saraya Aqaba
resort, presently under completion and Ayla Oasis resort to be completed by 2017 in the area surrounding Saraya Aqaba).
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Finally, The Marsa Zayed project needs to be recalled too, dealing with the transformation of the
present area of the Aqaba main port into a $10 billion marina community that is the largest real estate project in Jordan's history.
The total design accommodation capacity of such new development projects largely exceeds the
present treatment capacity of Aqaba municipal WWTP.
There are three marinas located at the northern tip of the Gulf of Aqaba/Eilat: the Eilat Marina, situated behind the beach in the Eilat hotel zone; the Aqaba Royal Yacht Club, lying on the waterfront of
Aqaba and, more to the south along the Jordanian coast, the Tala Bay marina.
Moreover, more than 300 additional yacht berths are expected to be created by year 2017 along the
Aqaba city waterfront with the implementation of the above mentioned Marsa Zayed project.
As wastewater collection and treatment facilities for boats and crews are reported to exist for the local marinas (at least in Eilat) and specific prohibition exists, minimum to null wastewater discharge to
the gulf water is expected from leisure craft boats. Conversely, emission of contaminants to the air
from the boats/yachts engines will be considered, as it can be reasonably assumed that, also due to
the proximity of the exhaust pipes to the sea surface, most of the pollutants released to the air during
navigation end up in the gulf waters.
Very few relevant industrial activities exist on the Israeli side of the gulf, apart from the Mekorot
desalination plant, withdrawing brackish water from the subsoil, and the nearby operating salt company, both located in the area between the city of Eilat and the Israeli-Jordan border.
The main industrial settlement in the area is located on the Jordanian coast, in the vicinities of the
Saudi Arabia border, and is served by port facilities.
Most of the existing industries at the site (the so called “South Zone”) are involved in the fertilizer
business (Jordan Phosphate Mines Company), while the main remaining non-fertilizer related industries and facilities include the Red Sea Timber Factory, the Aqaba thermal Power Station, fueled by
natural gas and by fuel oil, and East Gas Co., importing the natural gas from Egypt.
Although a dedicated wastewater treatment plant exists in the area, some leakage and leaching to
the sea of liquid industrial waste from the industrial zone is deemed likely (ASEZA, 2008).
The industrial activities are planned to be expanded in the next future, involving:

The expansion of the existing South zone: Aqaba Development Company intends to expand the
already industrial district over 12 km2 of vacant readily developable land, to create a bigger Industrial Estate (the ‘Southern Industrial Zone’). The area is adjacent to the site where the new
Aqaba seaport will be built over the coming five to seven years. Moreover, a railway extension
is about to be constructed to serve the new port and industrial area. Beside the integrated agrochemical/fertilizer cluster, the Southern Industrial Zone is intended to dedicate the remaining areas for heavy chemical industries, supporting industries and future industrial expansion (Jordan
Investment Board:
http://www.jordaninvestment.com/BusinessandInvestment/WheretoInvest/AqabaSpecialEconom
icZoneASEZ/tabid/268/language/en-US/Default.aspx).
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
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The creation of a new industrial area: the Aqaba International Industrial Estate, covering 275hectares, is presently under construction on a site 700 meters east of the Aqaba International
Airport, offering investment opportunities for different type of activities (Aqaba Special Economic
Zone Authority: http://www.aqabazone.com/index.php?q=node/527). The local infrastructures
include, among the others, a storewater drainage system, flood protection drainage channels
and full sanitary sewer network, connected to Aqaba municipal WWTP.
Port structures exist both along the Israeli and the Jordanian coast. Port activities and ship traffic
can contribute to the pollution of the upper gulf waters in many ways: through accidental release of
contaminants, including oil spill, during loading and unloading operations, discharge of ballast and
bilge waters, release (leaching) of toxic substances from the antifouling hull coatings, corrosion of
the sacrificial anodes and finally fallout to the sea of the contaminants from ship engine emissions.
The port facilities in the Eilat area (Israeli coast), operated by Eilat Port Company Ltd, include the
North Jetty (a naval base and a ship repair facility) the South Jetty (a modern facility with cranes for
handling general cargo and containers and a long quay for ship accommodation) and the Eilat Oil
Terminal.
An additional cargo quay just north of the port of Eilat is 200 m long and can accommodate vessels
up to 6 m draft. The port facilities include a specialized mechanical loading facility to handle bulk
cargoes such as potash, salt and phosphates and serves as Israel’s southern gateway to the Far
East, South Africa and Australia. Due to its peripheral location, though, to the lack of a railway connection and to the local competition of coastal tourism the ship traffic in the port is quite low.
The Eilat Oil Terminal, consisting of two jetties, forms the sea link of the Eilat-Ashkelon pipeline and
is intended both for crude oil unload/load operations and for distillates load operations. The oil terminal has a storage capacity of 160’000 cubic meters of crude oil, with an additional storage facility for
gas oil and fuel oil.
Along the Jordanian coast, three main ports exist: the Main Port, located close to Aqaba city; the
Container Port, located some 5 km to the south, and the Industrial Port, located in the vicinities of the
Saudi Arabian border, some 19 km to the south,
The industrial port consist of:
 an Oil Terminal, used for handling exports and imports of oil and oil products;
 a Timber Jetty, used in the past for the unloading of timber and livestock, but is not used extensively at the moment, as most of Jordan's timber imports come through the Main Port;
 the main industrial terminal, consisting of a jetty constructed to serve the adjacent industrial complex mainly used for handling bulk fertilizer and ammonia, and chemical products.
At present an expansion of the Industrial Port is planned on an area of approximately 60 ha facing
the Dirreh Bay, located between the existing port facilities and the Saudi Arabian border. The project
includes the construction of a General Cargo and Ro-Ro Terminal, a Grain Terminal and a Ferry
Terminal, aiming at replacing the existing Main Port of Aqaba, to be converted into a public waterfront area (Aqaba Development Corporation:
http://www.adc.jo/pages.php?menu_id=37&local_type=0 ).
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Stringent regulations exist to prevent pollution from ports and maritime activity in the study area, as
the MARPOL convention recognizes the Red Sea and in particular the Gulf of Aqaba as a “special
area” where the discharge into the sea of oil and oily mixtures from any oil tanker or ship of 400 DWT
or more is prohibited, and any such ship is to retain on board all oil drainage, sludge, dirty ballast and
tank washing waters, with discharges allowed only into accepted reception facilities. All the same the
“noxious liquid substances” listed in MARPOL category X (products deemed to present a major hazard) are not to be discharged into the sea under any circumstances, including ballast water, tank
washings or other residues or mixtures containing such substances. If tanks containing such substances need to be washed, the residues need to be discharged to a reception facility.
No ballast water reception facilities presently exist at the Port of Eilat, though, where only 2 small
road tankers for removal of oily bilge water are located (Unishipping Israel:
http://www.unishipping.co.il/eilat.html), while no operating waste reception facility at all exist for oil
wastes, sewage, bilge or ballast water at the Jordan ports (ASEZA, 2008). As only clean ballast water from the segregated ballast tanks (SBT) is allowed to be discharged into the sea in the terminal
area, ships entering the Port of Eilat are required to “change their ballast waters prior to arrival” (Eilat
Ashkelone Pipeline co. Operations Division, 2004).
As for oil spill prevention during loading/unloading operations at port, strict safety measures and regulations exist at the Eilat Oil Terminal, while a marine pollution prevention station equipped with a
marine pollution combat vessel was set up between the reef reserve and the Eilat Oil Terminal, with
the capability of dealing with spills as large as a few hundred tons from large vessels.
An oil spill combat unit also exists at the Main Aqaba Port, so that according to ASEZA the main existing risk (due to its distance) in the area is related to the (unlike) possibility of leakage from the
300’000 DWT floating oil storage vessel – ‘Jerash’ at the Industrial Port (ASEZA, 2008).
About phosphate dust deposition during ship load activities, which were long considered to represent
one of the major sources of nutrients to the upper Gulf, engineering improvements have been adopted since the late 90’s in the port of Eilat to limit the airborne dust (Atkinson et al, 2001). More recently the Aqaba Port Authority improved the operations in the Main Port in order to reduce the phosphate dust emissions, which in the recent past (2000-2001) had been evidenced to generate phosphate concentration in the local seabed sediments 2 orders of magnitude higher than elsewhere
along the Jordanian coast (Badran and Al Zibdah, 2005). Following such improvements the previous
typical dust pollution levels of 200 mg/m3 measured in the vicinities of the loading facilities are reported to have been reduced to levels less than 5 mg/m3 (Hub4: http://www.hub4.com/news/1904/phosphate-loading-a-case-study ).
Concerning agriculture, releasing nutrients in the subsoil with irrigation, which eventually reach the
Gulf waters via groundwater flow, a number of kibbutzs exist along the southern Arava valley, withdrawing irrigation water from the regional alluvial aquifer. The treated effluents of Eilat municipal
WWTP are also used for crop irrigation some 40 km north of Eilat.
Finally, fish farms are no longer a major source of pollution (Atkinson et al., 2001; Israel Environmental Bullettin, January 2005) since the two commercial fish farms (floating fish cages) which used
to be located close to the Jordanian-Israeli border at the northern tip of GOAE, were completely removed from the sea in 2008, after an eight years long public debate about their impact and role in
the deterioration of the local coral reef ecosystem. Alternative land based solutions are now being
developed. At present the main fish farming facility in the area is the inland based ARDAG maricul-
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ture facility in Eilat, producing 100-120 tons per year in a semi-closed system and discharging treated waters to the upper gulf through the Kinnet canal.
2.4.2
Pollution and sediment loads estimates
The pollution loads generated by the many sources identified in the above paragraph reach the sea
following different paths, as reported in Table 2-6. Some loads are directly discharged with
wastewater or rainwater, some leak into the subsoil and migrate to the sea with the groundwaters,
some fall over the sea surface after being released into the air and some are directly released to the
sea from ship and boat keels.
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Table 2-6 Inventory of pollution sources, contaminant release mechanisms and discharge paths for the upper Gulf area.
Source
Location
Eilat urban area
Northern coast
Aqaba urban area
Northern coast
Urban areas of Eilat and Aqaba
Northern coast
Urban traffic in Eilat and Aqaba
Northern coast
Hotel cooling systems
Northern coast
Touristic resorts
Hof Almog; Tala bay
Marinas and leisure boat traffic
Eilat Marina; Royal Yacht
Club; Tala bay Marina
Leisure boat traffic
Northern tip of GoA
Eilat industries
Eilat
Abstraction of nutrient-enriched groundwater
Groundwater contamination through irrigation with reclaimed wastewater
Release of contaminants from (antifouling)
boat keel paint
Engine exhaust gas emission while in motion
Discharge of treated wastewater and brine
Industrial manifacturing
Jordanian coast
Gas emission into the atmosphere
Export of fertilizers
Port of Eilat; Main Port of Aqaba; Southern Port area
Ship traffic
Northern Gulf of Aqaba
Resuspension of ore dust into the air during Deposition over the sea water in the
ship loading activities
close vicinities of the loading facilities
Diesel engine exhaust gas emission while in
Fallout over the sea water
motion
Direct release into the water at port (and
Corrosion of sacrificial anodes
while in motion)
Release of contaminants from (antifouling)
Direct release into the water at port (and
ship hull coating
while in motion)
Port of Eilat; Main Port of Aqaba; Southern
Emissions
Port area
Groundwater discharge through the reGroundwater nutrient enrichment through
gional alluvial aquifer and the upper unirrigation
confined shallow aquifer
Direct discharge through the kinnet caWastewater discharge from the facility
nal
Ship traffic
Ship traffic
Ship traffic
Ship traffic
Agriculture
Northern coast
Fish farming (ARDAG mariculture
facility)
Northern coast
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Mechanism
Spill of raw sewage from Eilat municipal
system
Leakage of raw and treated sewage from
Aqaba municipal system
Groundwater contamination through irrigation with reclaimed wastewater
Deposition of contaminants to the ground in
the urban areas
Path
Direct discharge to the sea
Groundwater discharge through the upper unconfined shallow aquifer
Groundwater discharge through the upper unconfined shallow aquifer
Contaminants
N, P, BOD5
N, P
N, P
Urban runoff
P, N, BOD5, trace
metals, PAHs
Direct discharge to he sea
N, P
Groundwater discharge and saline submarine groundwater discharge
Direct release into the water at berthing
place
N, P
Cu
Quick fallout over the sea water
Trace metals; PAHs
Kinnet canal
N, P
Trace metals, SOx,
NOx, particles
Fallout over the sea water
P
Trace metals, PAHs,
SOx, NOx, particles
Zn
Cu, Zn, organotins
Sox, NOx
N, P
N, P, BOD5
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The quantification of the pollution loads discharged into the upper Gulf waters from each pollution
source and according to the best available data and information from ongoing and past environmental monitoring programs, is reported in Table 2-8. The table does not include the atmospheric deposition monitored in recent years (Chen et al., 2007, 2008, Table 2-7), as the related loads are estimated in terms of fluxes, which are loads per square meter.
Table 2-7 Nutrient and trace metals dry deposition fluxes to the upper Gulf of Aqaba Chen et
al., 2007; Chen et al., 2008.
Element
Deposition flux [mg m-2 yr-1]
N*
194
P*
2.26
Al
342
Fe
216
Co
0.1
Mn
5.28
Cr
0.96
Cu
0.38
Ni
0.31
Zn
1.68
Pb
0.8
Cd
0.012
* Seawater soluble inorganic fraction only. The soluble inorganic nitrogen and soluble phosphate account for approximately
86% and 69% of total soluble nitrogen and total soluble phosphorus, respectively.
One of the most evident results from Table 2-8 is that the main sources for nutrient contamination
in upper Gulf waters are by large the Kinnet Canal, the discharge of cooling groundwater from Le
Meridien hotel and the groundwater flow at the northern tip of the Gulf. The ship ore loading operation at the ports of Eilat and Aqaba also represent one of the most relevant source of dispersion of
phosphate to the sea.
Direct discharge of wastewater (including salt brine) through the Kinnet Canal concerns the Ardag
fish farming facility, the NBT algae farming facility, the ISC Salt Terminal, the Mekorot desalination
plant and IOLR test facility and is subject to authorization and monitoring by the Israeli Ministry for
the Environment. According to the numbers provided by such Ministry, the average annual discharges of organic and nutrient loads were estimated for the period 2007-2009.
As for the future trends, the ARDAG fish farming test facility is expected to conclude the experimentations and to be stopped after year 2010. After that the nutrient loads from the Kinnet canal are expected to reduce to about half the present ones.
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Another relevant source of nitrogen and phosphorus is the direct discharge to the sea of groundwater extracted for cooling purposes (air conditioning) by touristic structures, carried out by the “Le Meridien” hotel in Eilat, as the local groundwater is contaminated with nutrients.
The load estimates reported in Table 2-8 are calculated according to the discharge rate supplied by
the Israeli Ministry of the Environment for the years 2007-2009 (12.585 Mm3/yr )and to the nutrient
concentrations in groundwater for the Eilat area (11.3 mg/l N-NO3, 0.017 mg/l P-PO4).
Nutrient loads (mainly nitrogen) are also significantly discharged by groundwater through the regional alluvial aquifer and the upper unconfined shallow aquifer along the north coast.
The average nitrogen fluxes, both for the alluvial and for the shallow aquifer into the Gulf of Eilat
were estimated in year 2004 by the Geological Survey of Israel based on the available relevant hydrogeological data and nitrogen concentration measured in groundwater in years 2002 and 2003.
Such calculations, giving an overall nitrogen load of about 6’790 kg/year, have been kindly revised
and updated upon request by the Geological Survey of Israel according to more recent data from
groundwater monitoring, yielding new preliminary estimates for the upper unconfined aquifer. Taking
account for the previous estimate of alluvial aquifer contribution, the total annual underwater nitrogen
discharge can be estimated in about 13’450 kg N/yr.
Assuming an average phosphate concentration in groundwater of 0.4 - 0.7 micromole per liter
(source: Geological Survey of Israel), a total phosphorus discharge of 18 – 32 kilograms of phosphorus per year is obtained, almost negligible compared with the other sources.
Indeed, the most relevant loads of phosphorus are discharged to the sea during ship loading operations at Eilat and Aqaba ports, as calculated in year 2001 by the International Expert Team charged
with the identification of the reasons for coral reef deterioration (Atkinson et al., 2001).
In that occasion the estimates were performed for the port of Eilat, based on direct sampling of dust
and on the results of a plume distribution computer model, indicated that on average 3.7 grams of
phosphorus were lost to the sea per ton of loaded ore. Although some further small improvement
(e.g. installation of a new loading chute) was adopted at the Port of Eilat shortly after the above
measurements and estimates were performed, it seemed reasonable to extend the above ratio of
phosphorus lost to the sea to loaded ore to the present (year 2010) situation.
Taking account for the significant improvements recently introduced in the loading facilities at the
Port of Aqaba to the aim of reducing phosphate loss to the sea, the same ratio of 3.7 grams of phosphorus per ton of loaded ore was adopted in our calculations for that port.
The resulting phosphorus loads are 1’961 kg/year for Eilat and 28’860 kg/year for Aqaba.
The direct discharge of spilled raw sewage from Eilat municipal system and from urban runoff with
stormwater are other sources, though less relevant than the others described above, of nitrogen,
phosphorus and BOD5. The urban runoff is also a source of contaminants as copper, zinc, lead and
PAHs.
The nitrogen loads discharged to the sea due to the occasional failures of the Eilat municipal sewage
system were calculated in year 2001 by the International Expert Team charged with the identification
of the reasons for coral reef deterioration, based on the spilled volumes recorded in the period 19952001.
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Although continuous work is being performed on the Eilat municipal sewage system to prevent further accidental spillage, the frequency of occurrence of failure events reported by the press for the
recent past (3 events in year 2007) reveals that the present situation is still critical, also due to the
increasing demographic trend in the area, and that the spillage problem is not likely to be definitively
solved unless a thorough restructuring and upgrade of the sewage system is performed.
As long as no such intervention is performed, it is deemed reasonable to regard the pollution loads
calculated in year 2001 as still representative of the present and future situation.
In absence of any direct measurement of pollutant concentration in runoff water in the study area,
the loads (nutrients and micropollutants) discharged from the urban areas of Eilat and Aqaba with
the stormwater were estimated according to:
 the results of the USA Nationwide Urban Runoff Program published by USEPA, providing an average estimation of the pollutant concentration in rainfall (USEPA, 1983);
 the overall yearly water runoff in the study area (runoff coefficient estimated by USEPA);
 the direct measurements for PAH performed in the same geographic area as the upper Gulf of
Aqaba.
Micropollutant loads, especially copper and Zinc, to the Gulf waters are discharged firstly through
the port activities along the Jordanian coast and secondly in the marinas from boat keels.
The direct release of copper (as antifouling agent) and zinc (hull coating and ship sacrificial anodes
for the protection against corrosion) from ship hulls at port and during navigation were estimated
considering:
 the Cu, Zn average release (μg cm-2 day -1) in static conditions (in port), and when the ship is in
motion, provided by the United States Environmental Protection Agency (USEPA, 2003);
 the current density requirement (A/m2) and zinc capacity (amp.hrs kg -1) for the zinc release from
ship sacrificial anodes (Botha, 2000);
 the time of ship stay at port during unloading/loading operations and the navigation time through
the gulf;
 the information supplied by ASEZA and by the private company running the port of Eilat, concerning the average annual number of cruises per ship type and to the available information concerning the respective port facilities.
Based on these information, the annual loads of copper from hull coating is estimated to be about
3695 kg/year; the annual load of zinc from hull coating and from ship sacrificial anodes is estimated
to be respectively about 1465 kg/year and 12912 kg/year.
It must be stressed that, being based on the maximum ship size which can be accommodated by the
berths, the total loads are likely to represent an overestimate or the actual ones. We are confident,
though, that at least the order of magnitude (about 4 tons/yr of copper and 14 tons/yr of zinc as a total) has been correctly identified.
The keels of leisure boat in the marinas release copper and zinc from keel antifouling coatings just
like the large vessels.
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The total loads released in the upper GoA can be computed based on the number of boats/yachts
per class of dimension hosted by the marinas in the area (Eilat Marina; Royal Yacht Club Aqaba; Tala bay Marina), assuming that the total number of hours of motion is small compared to the number
of hours the boats stay in the marina and using the same release rates (USEPA, 2003) used above
for the ship calculations.
As the keel wetted area depends on the boat size, and the private companies running the marinas
are kind of reluctant to supply such feature, a rough estimate of the dimensional split of the boats
hosted by the Eilat Marina (by far the largest in the area) has been worked out from the satellite imagery available on Google Earth and extended to the other two marinas.
Based on the above, the copper and zinc loads amounted respectively to 685kg/yr and 274 kg/yr.
Finally, micropollutant enter the Gulf also through deposition over the sea from engine exhaust gas
emission of leisure boats.
It is assumed here that, given the close proximity of yachts’ and boats’ exhaust pipes to the sea surface, the trace metals and PAHs discharged with engine exhaust gas entirely fall over the sea surface shortly after the emission. The pollution emissions were estimated according to the methodology proposed by the Environmental European Agency (EEA, 2009), supplying specific emission factors (pollutant mass/ consumed fuel mass).
As the average engine type and power (HP) can be attributed (on a statistical basis) according to the
boat size, the total loads discharged to the gulf waters were estimated based on the total number of
boats/yachts hosted by the local marinas, per class of dimension, and on their average number of
navigation hours in one year.
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Table 2-8 Summary of the estimated pollution loads annually reaching the upper Gulf of Aqaba [kg/yr]. Atmospheric fluxes not included.
Cu
Zn
Pb
8.8
41.3
37.2
3695
14377
Direct release of contaminants from boat keels in the marinas
685
274
Deposition of contaminants from engine exhaust gas emission of leisure boats
2.2
1.3
Direct discharge of spilled raw sewage from Eilat municipal system
Direct discharge through the Kinnet canal
Discharge of urban contaminants with stormwater
Groundwater discharge
Direct discharge of groundwater used for air cooling purposes
N
P
BOD5
880
110
6600
9210
1667
7185
564
86
2453
13450
25
142210
214
Cd
Cr
Ni PAHs
40.4
Discharge from the peripheral touristic resorts
Dispersion of phosphate to the sea during ship loading operations at
port
Direct release of contaminants from ship hulls at port
TOTAL
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166314 32923 16238 4391 14693.6
0.01 0.07 0.09
37.2
3.9
0.01 0.07 0.09 44.3
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Finally, sediment loads reaching the upper Gulf of Aqaba with stormwater have to be considered as
the coastal area of the upper Gulf of Aqaba is dotted with a number of alluvial fans composed of predominantly clastic materials deposited by infrequent but occasionally very powerful floods originating
in the mountain catchments.
Although no studies have estimated the sediment load as a result from the flush floods along the
Jordanian coast, long term (more than 40 years) monitoring of such phenomena have been undertaken in the small (0.6 km2) experimental drainage basin of Nahal Yahel, close to Eilat, which is a
tributary of Nahal Roded (Schick and Lekach, 1993).
Moreover, sediment loads monitoring has been undertaken in a number of basins in the semiarid,
arid and hyperarid Negev and Dead Sea regions, providing estimates for the mean annual sediment
yield (Schwartz and Greenbaum. Extremely high sediment yield from a small arid catchment - Giv’at
Hayil, northern Negev, Israel. Isr. J. Earth Sci. In press).
Taking account for these studies, a possible estimate of the annual sediment load to the sea has
been proposed and reported in Table 2-9. The table reports the total sediment load from each river
catchment, the sediment fraction reaching the sea, ranging between 18 and 32% of total sediment
load, and its fine fraction, creating long-lasting water turbidity at sea.
Due to the many assumptions and extrapolations forming the base for the calculation, this estimate
is necessarily affected by a significant degree of uncertainty.
The different hydrological and geomorphological characteristics of the basins in fact have not been
properly taken account for. This may be a significant source of inaccuracy in particular for Wadi Yutum, with its very large drainage basin extending to areas relatively far from the upper Gulf of Aqaba
and involving both spatial variability of sediment load control parameters and very long routing of distant generated sediments, with an increasing probability of entrapment before reaching the sea.
We believe, nevertheless, that the above calculation may be regarded at least as a reliable estimate
of the order of magnitude of the sediment loads reaching the upper gulf waters.
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Table 2-9 Estimation of suspended sediment load and silt&clay component for the
catchments draining in the Gulf.
Catchment
Nahal Roded
Basin area [km2]
Mean annual Mean annual
sediment yeld sediment load
[ton km-2 yr-1] [ton x 103 yr-1]
Suspended
sediment load
[ton x 103 yr-1]
Silt and clay
fraction of the
suspended sediment load [ton
x 103 yr-1]
42
68
2.9
0.9
0.5
Nahal Shahmon
8
91
0.7
0.2
0.1
Nahal Garof
3
108
0.3
0.1
0.1
30*
72
2.2
0.7
0.4
1500
36
54.1
17.3
9.7
Wadi T
10
88
0.9
0.3
0.2
Wadi Shallallah
10
88
0.9
0.3
0.2
Wadi Jeisheik
9
89
0.8
0.3
0.1
Wadi Mabruk
65
63
4.1
1.3
0.7
Wadi 9
28
73
2.0
0.7
0.4
Wadi 2
62
63
3.9
1.3
0.7
TOTAL
23.3
13.1
Nahal Shlomo
Wadi Yutum
* the extension of Nahal Shlomo Basin was roughly estimated. This is considered acceptable because the relative contribution
to the overall load estimation is not so high.
2.5
Trends of environmental conditions (no abstraction scenario)
and their effects on marine environment
Environmental conditions in the gulf have clearly changed over the past 20 years as shown in the
previous sections. The causes of these changes have been natural and anthropogenic, local and
global. It is likely that the environmental conditions in the gulf will continue to change in response to
both global changes and local development and the resulting anthropogenic forcing, although it is
difficult to precisely quantify the projected changes. Local development will include construction of
new tourist facilities, artificial lagoons, residential buildings, industrial development, and port expansion. Each of these will be accompanied by increases in population, additional pollution loads, and
other stresses on the ecosystem of the Gulf. Examples of major developments include the Ayla and
Saraya projects along the northern shore, the proposed move and expansion of the port of Aqaba,
the long-term plans for the “Southern Gate” of Eilat (moving the port to an artificial canal at the
northern end), and the construction of additional power and water desalination facilities.
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Physical conditions
A warming trend has already been observed in the northern GOAE. In the past 23 years (since 1988,
when routine measurements were started in Eilat) the sea surface temperature has risen at a rate of
0.41ºC/10 yr as shown in the upper panel of Figure 2-67. In fact the annual average of SST in 2010
was the warmest on record (since 1988). A similar warming trend has been observed in the deep
water but the rate of 0.21ºC/10 yr is only half that of the surface layer. Over a shorter period (since
the start of the “Peace Park” program) similar trends have also been observed as shown in the upper
panel of Figure 2-68. These trends are very similar to the warming observed in the central Red Sea
from the ERSST record over the last 30 years (Cantin et al., 2010).
28
dT/dt = +0.41ºC/10 yrs
T (ºC)
26
24
22
20
1988
21.4
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
T (ºC)
21.2
21.0
dT/dt = +0.21 ºC/10 yrs
20.8
20.6
20.4
1988
1990
1992
1994
1996
1998
2000
2002
2004
2006
2008
2010
2012
Year
Figure 2-67 Warming trends in the temperature of the surface layer (20-40 m), upper panel,
and in the deep water (below 400 m), lower panel, observed at station A in the northern GOAE
over the last 23 years.
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Figure 2-68 Time plots of temperature (upper panel) and salinity (lower panel) profiles at
Station A, located in the deep waters near the Gulf’s centre line approximately 10 km
southwest of its end (bottom depth 700 m). Data are from NMP report 2010. Black dots
represent the sampling depths.
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In the past salinity has exhibited a clear seasonal cycle as can be seen in the lower panel of Figure
2-68. However a rather surprising and abrupt change appears to have started in the second half of
2009 with a very clear decrease in the salinity of the upper 300 m of the water column. This has already been discussed above in Section 2.1 in the context of potential changes in the water exchange
through the Strait of Tiran. While it is too soon to tell if this represents a trend or a short-lived event, it
clearly has implications for water quality and the ecosystem.
As far as natural or global forcing is concerned, climate change may become a significant factor (yet
largely unknown). The region is a desert with no freshwater input other than the small amount of annual rainfall (<20 mm per year). Most climate projections for this region show this continuing. Topographically the gulf is an extension of the Arava Valley and surrounded by mountain ranges on both
sides. This effectively channels the winds so that they blow mainly from the north-northeast more
than 90% of the time. For this reason it is unlikely that the wind regime will change significantly in
any of the future climate change scenarios. Thus, it is expected that the change will be felt primarily
in terms of warming.
Based on the report prepared by Dr. Nick Brooks for the feasibility study consultant, the best estimate is that due to global climate change, the region of the gulf may be expected to warm by ~5 degrees by the end of the 21st century. While the rate of warming may change there is no definitive information available on this point. Therefore for the purpose of this assessment we assume that the
trend is linear and that the air temperature may increase by ~ 1 degree over the next 20 years. This
is rather similar to the observed recent trend.
A major concern is that the anticipated warming may strengthen the stratification of the gulf and subsequently reduce vertical mixing. In order to assess this possibility we ran the gulf wide model for the
projected climate change of the year 2030. Historical meteorological measurements conducted at the
IUI pier indicate that the warming trend of sea surface temperature reflects about 50-60% of the
change in air temperature. Thus we constructed surface forcing fields for this situation by assuming
that SST will warm by ~0.6 degrees over the next 20 years. The impact of the projected climate
change is best illustrated by the profiles of the Brunt-Vaisala frequency which is a measure of the
stratification (higher values indicate stronger stratification). Figure 2-69 shows the profiles for March
at a point located in the southern part of the gulf (left panel) and in the north near Station A (right
panel). The blue lines represent the model results for present conditions. The higher values above
300 m in the left panel clearly indicate that the southern part of the gulf remains stratified even in late
winter. The very noticeable maximum at a depth of 20-30 m is due to the combined effects of higher
surface temperature and the inflow of less saline Red Sea water in the upper layers which retains its
identity since it has not yet fully mixed with the local water in the gulf. In contrast to this, in the northern part of the gulf (right panel) the values of the Brunt-Vaisala frequency above 340 m are relatively
low and show very little variation with depth. This is indicative of the winter mixing which, in 2010,
reached a maximum depth of ~ 300 m. By this point the signal of the less saline Red Sea water has
disappeared. For the projected climate change scenario (red lines) the Brunt-Vaisala frequency increases at all depth. The implication of this is that the water column can be expected to be more stable in the future and the deep winter vertical mixing will be somewhat weakened.
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Figure 2-69 Brunt-Vaisala frequency in the southern (left panel) and northern (right panel) gulf
in March. The blue line is for present conditions (2010) and the red line is the projection for
the year 2030.
Figure 2-70 As in Figure 2-69 except in August.
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Figure 2-70 shows the Brunt-Vaisala frequency in August for the southern (left panel) and northern
(right panel) parts of the gulf. These profiles are fairly typical for a stratified ocean in summer. The
difference between the subsurface maximum (~ 40 m) and the deep water value is larger in the
south indicting again that stratification is stronger here than in the north. For the climate change scenario (red lines) the most noticeable change will be a strengthening of the subsurface maximum and
the associated suppression of vertical mixing.
2.5.2
Water quality
As reported in the above sections, trends were observed in the past years in the Gulf for some water
quality parameters. Between 1999 and 2005, which coincided with the period of highest production in
the fish cages (early 2000’s), there was a build-up of deep water nutrients and decline in oxygen levels both in the deep water and the surface water of the northern GOAE. This could have been a result of nutrient loading from the fish cages (Lazar and Erez, 2004; Lazar et al., 2008) or alternatively
caused by changes in the frequency of deep mixing and or changes in advection through the Tiran
Strait into the Gulf (Herut and Cohen, 2004). The decrease in dissolved oxygen in the deep reservoir
until 2005 was accompanied by a decrease in pH, thus indicating the production of CO2 due to recycling of organic matter through aerobic processes. This decrease in dissolved oxygen also became
apparent in the surface layer, which could only be explained by the decrease in the deep reservoir
concentration since there was no significant warming. Consistent with the decrease in deep water pH
and surface dissolved oxygen, surface water pH also decreased significantly until 2005. The reduction in pH was shown to cause a reduction in the ability of coral reefs in the GOAE to calcify and
maintain their CaCO3 frameworks as shown by Silverman et al. (2007, 2008).
No evidences are presently available to foresee if such trends will continue in the future. In fact, from
the beginning of the NMP in 2002 and until now substantial fluctuations were observed in the concentrations of oxygen, nitrate, phosphate, silicate, and chlorophyll a and pH, but with no apparent
trends (Figure 2-71), The annual dynamics of most of these parameters depend on the extent of vertical mixing in the winter, and mixing depth is a function of air temperature, water temperature, and
stratification (as well as wind, humidity and solar radiation). Therefore, a continued warming may
change the dynamics of these parameters. For example, shallower mixing due to warming, should
weaken entrainment of nutrients, which, in turn, will reduce their concentration in the upper water
column (the photic layer), with a concurrent increase of their concentration in the deep waters. Under
that scenario, the upper part of the water column is expected to become more oligotrophic (lower
concentrations of chlorophyll a). Furthermore, if the present decline in salinity (Figure 2-71) presents
a trend (rather than a short-term event), and if it is a result of enhanced influx of Red Sea surface
water (and an equivalent efflux of GOAE water to the Red Sea at greater depths above the sill at Tiran), it may decrease the influx of dissolved inorganic nutrients to GOAE; however the influx of nutrients within organic matter (plankton and POC) should increase. Which flux will be greater? The answer is yet unknown.
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Figure 2-71 Dynamics of (from top panel down) oxygen, pH, nitrite and nitrate, phosphate,
silicate, and chlorophyll a at Station A, located in the deep waters near the Gulf’s centre line
approximately 10 km southwest of its end (bottom depth 700 m). Data from NMP report 2010.
Black dots represent the sampling depths.
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2.5.3
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Ecology
Considering the state of the coral-reefs, long-term studies indicate that the present situation is worse
than it was 40-50 years ago, but the results of the NMP show that the coral-reefs in the northern Gulf
of Aqaba have been in nearly stable conditions in the past 6-7 years. Coral cover, richness, and
health in the reefs of Eilat have been quite stable. On the other hand, strong fluctuations are observed in the abundance of benthic invertebrates. Also, as stated in section 2.5. above, some major
developments are planned for the region, including major constructions, lagoons, hotels, and others.
On the other hand, both Jordan and Israel have recently implemented major, effective measures to
impose strict environmental rules and protection. Such measures included, for example, the removal
of fish cages from the sea, the build up of major pumping system for dust collection from phosphate
loading ports, and restriction of industrial developments near the coast. If such efforts are successful
and no major anthropogenic environmental disturbances occur, we foresee no major natural changes in the local coral reefs for the no abstraction scenario. The situation may, of course, be different if
uncontrolled anthropogenic disturbances do occur. In addition, two global trends may further worsen
the state of the local reefs: (i) a continued sea-water warming may reach above some threshold for
severe coral bleaching and/or (ii) acidification of sea water reaches below some pH threshold that
can inhibit calcification by corals and other calcifying organisms in the reef. However at this stage,
without apparent or explicable trends, no projections into the future are possible.
A noteworthy point regarding effect of climate change on marine environment is the absence (so far)
of coral bleaching events in the GOAE, not even in 1998, when coral bleaching occurred throughout
the Pacific and Indian Oceans. Therefore, under conditions of a warming world, where coral bleaching may become a major destructive cause in coral reefs, the GOAE may serve as an important refuge for corals, perhaps of global importance. However, warming does appear to have a delirious effect on coral growth as demonstrated by Cantin et al. (2010). According to their findings, the growth
of heliopora coral decreased by almost 30% relative to the 1970s. Cantin et al. (2010) concluded that
this reduction was caused by the warming and not ocean acidification. While this conclusion is based
on only three measurements of carbonate chemistry over the last 40 years in the central Red Sea, it
can be supported by the observations of total alkalinity increase over the last 22 years in the northern GOAE at station A (Figure 2-52). Assuming that surface water is at equilibrium with atmospheric
CO2 the increase total alkalinity offsets the effect of increasing dissolved inorganic carbon and essentially maintains the concentration of CO3-2 at a constant level. Nonetheless, both laboratory and
field observation clearly show that coral growth is strongly dependent on carbonate ion concentration. Therefore, the increase in total alkalinity could be the result of reduced coral growth following
ocean acidification and not necessarily warming.
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3
Description of present environmental conditions in
the vicinity of the intakes
3.1
Currents from the shallow ADCP moorings
The current profiles in the vicinity of the eastern and northern intake sites were measured during
summer (Aug-Sep 2010), winter (Jan-Feb 2011) and spring (April) by Workhorse 600 kHz ADCPs
installed on the sea bottom on a depth of about 34m.
The current measurements reveal that the current speed near the eastern intake site was slightly
stronger than that near the northern intake site, with very different patterns at both sites. These data
are described in greater detail in Chapter 8.3 and are only summarized here.
The average current speed and direction at the northern intake during summer, winter and spring
were 3.6 ± 0.23 cm/s; 5° ± 59.7°, 5.2 ± 0.38 cm/s; 312° ± 29.5° and 4.8 ± 0.49 cm/s; 11° ± 58.8°, respectively.
At the eastern site, the average current speed and direction during summer, winter and spring were
4.4 ± 0.90 cm/s; 48° ± 19.9°, 5.6 ± 0.34 cm/s; 188° ± 59.1° and 5.0 ± 0.86 cm/s; 187° ± 19.1°, respectively.
The common feature of the current patterns near both sites was the presence of a current reversal,
with flow parallel to the shoreline that had an irregular periodic signal with an average of 2-4 days. In
addition a difference in current direction in upper and lower water columns was observed during
summer, winter and spring. At the northern intake site, a counter-clockwise rotation in current direction profile was detected (75° at 7m – 240° at 31m in summer; 350° at 15m – 230° at 31m in winter;
170° at 5m – 230° at 31m in spring), whereas a rapid change in current direction with depth was observed at the eastern intake site (southward in 7-11m to northward in 15-27m in summer; southward
in 7-19m to westward in 21-31m in winter; southward in 11-23m to westward in 25-31m in spring).
The vertical profiles of the mean currents at the two sites are shown in Figure 3-1.
The maximum current speeds in summer were 30 cm/s at 3 m and 15 cm/s near the bottom at the
eastern site; 30 cm/s at 3 m and 20 cm/s near the bottom at the northern site. In winter, the maximum current speeds at the eastern site were 40 cm/s at 5 m and 30 cm/s near the bottom; 30 cm/s
at 3 m and 20 cm/s near the bottom at the northern site. In spring, the maximum current speeds at
the eastern site were 30 cm/s at 11 m and 20 cm/s near the bottom; 35 cm/s at 5 m and 25 cm/s
near the bottom at the northern site. Thus the near bottom currents in the eastern near shore zone
were stronger in winter than in summer and spring. A comparison of the full time series at both locations is shown in Figure 3-5.
Spectral analysis of time series data of the average current speed over the overall entire coastal water columns during summer, winter and spring at the Eastern and Northern Intake sites revealed that
tidal current signals were significantly detected at the Eastern Intake compared to the absence of
these signals at the Northern Intake site except for a semidiurnal signal (12.19 h) that was detected
in summer. The common tidal current signals during summer and winter at the Eastern Intake site
were the semidiurnal (12.19 h: principle lunar M2) and lunar or/and solar quarter-diurnal harmonics
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(6.10 h: M4; S4; MS4), where only a semidiurnal signal were detected during spring. Besides, other
tidal signals of 4.06 h, 3.16 h and 2.51 h were detected only in winter at the Eastern Intake site,
which is attributed to the (2MS6; 2SM6), (M8) and (M10) tidal constituents, respectively. Results of
the spectral analysis are shown in Figure 3-3.
The general current pattern in both sites suggests the connectivity of water masses in coastal areas
due to the current reversal that was detected during summer, winter and spring seasons. The analysis of current records in front of the MSS and IUI support the major findings of coastal current pattern
at the Intake sites regarding the existing of the current reversal and water masses connectivity - particularly during winter- along the coastal waters (see Section 8.3).
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5
5
Northern Intake-SUMMER
Eastern Intake-SUMMER
10
Cross shore current
Long shore current
Depth [m]
Depth [m]
10
15
15
20
20
25
25
30
-8
30
-6
-4
-2
0
2
4
-8
-6
-4
-2
0
-1
2
4
2
4
2
4
-1
Current speed [cms ]
5
Eastern Intake-W INTER
Northern Intake-W INTER
10
10
15
15
Depth [m]
Depth [m]
Cross shore current
Long shore current
20
25
25
30
-8
20
30
-6
-4
-2
0
2
4
-8
-6
-4
-2
-1
0
-1
5
10
Northern Intake-SPRING
Eastern Intake-SPRING
10
15
15
Depth [m]
Depth [m]
Cross shore current
Long shore current
20
20
25
25
30
-8
-6
-4
-2
0
-1
2
4
30
31
-8
-6
-4
-2
0
-1
Figure 3-1 Profiles of the average cross and long shore current [cm s-1] components in
summer (upper panels), winter (middle panels) and spring (lower panels ) at the northern (left
panels) and eastern (right panels) intakes. Cross shore currents are positive when directed
shorewards. Longshore currents are positive when directed clockwise at the northern intake,
counter clockwise at the eastern intake.
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Figure 3-2 Cross and long shore current [cm s-1] components of the raw data (10 minutes interval) at the northern (upper six panels) and eastern
(lower six panels) intake sites in summer (left panels), winter (middle panels) and spring (right panels). Cross shore currents are positive when
directed shorewards. Longshore currents are positive when directed clockwise at the northern intake, counter clockwise at the eastern intake.
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2
3
10
10
12.19h
Northern Intake-SUMMER
12.19h
-1
2 -2
0
10
-1
10
Power [cm s cpd ]
-1
2 -2
Power [cm s cpd ]
Eastern Intake-SUMMER
6.10h
2
10
1
10
1
10
0
10
-1
10
-2
-2
10
10
-2
10
-1
0
10
10
1
-2
10
10
-1
10
Northern Intake-WINTER
6.10h
10
-1
2 -2
1
10
0
10
-1
Power [cm s cpd ]
-1
2 -2
Power [cm s cpd ]
Eastern Intake-WINTER
12.19h
2
2
10
4.06h
1
3.16h
10
2.51h
0
10
-1
10
10
-2
-2
10
10
-2
10
-1
0
10
10
-2
1
10
10
-1
0
10
1
10
10
Frequency [cpd]
Frequency [cpd]
3
3
10
10
Northern Intake-SPRING
Eastern Intake-SPRING
12.19h
2
2
10
-1
1
2 -2
10
0
10
Power [cm s cpd ]
10
-1
10
3
3
2 -2
1
10
Frequency [cpd]
10
Power [cm s cpd ]
0
10
Frequency [cpd]
1
10
0
10
-1
-1
10
10
-2
-2
10
10
-2
10
-1
0
10
10
Frequency [cpd]
-2
1
10
10
-1
0
10
10
1
10
Frequency [cpd]
Figure 3-3 Spectra of time series of the average current speed in over entire coastal water
column in summer and winter at the northern and eastern intake sites.
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3.2
A qaba
Water quality
Water quality at the intake sites can be described by means of the water quality parameters recorded
during 2010 in the framework of the Jordanian National Monitoring Program. The data are available
for surface water (0-1 m). These data indicate that water quality of the two sites is very similar and
similar to the open water values. Annual distributions of temperature, pH, particulate matter, oxygen,
nutrients, and chlorophyll a at the northern intake and eastern intakes sites are presented in Figure
3-4 and Figure 3-5. The results exhibit notable seasonal changes in all parameters with higher concentrations generally in winter for most parameters (accompanied by lower recorded temperature)
except the pH, and particulate matter (Figure 3-4 and Figure 3-5). Particulate matter and pH showed
no major time variations. Their values fluctuated mostly within the standard error of the measurements. The higher concentrations of nutrients during winter are attributed to deep water vertical mixing and perhaps cross shore mixing due to density current formation (Lazar et al., 2008). Increased
nutrient levels in the photic zone enhance primary productivity resulting in higher phytoplankton
abundance and increased chlorophyll a concentrations (Op. Cit.). During the summer, thermal stratification of the water column results in a depletion of the inorganic nutrients in the surface layer leading to reduced phytoplankton biomass and chlorophyll a levels.
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7
(Temperature)
27
North
26
East
(Particulate Matter)
North
East
6
25
PM (mg/l)
Temp (oC)
28
A qaba
24
23
5
4
22
21
3
20
J
F
M
A
M
J
8.32
J
A
S
O
N
J
D
East
A
M
J
J
A
S
O
(Diisolve Oxygen)
pH
8.28
8.26
8.24
N
D
North
East
7.2
DO (mg/l)
8.30
M
7.5
(pH)
North
F
6.9
6.6
6.3
8.22
6.0
J
F
M
A
M
J
J
A
S
O
N
D
J
F
M
A
M
J
J
A
S
O
N
D
Figure 3-4 Monthly average of temperature, particulate matter, pH (measured in situ) and
dissolved oxygen values at the proposed north and east intake sites.
0.4
1.2
(Ammonium)
North
0.3
0.3
0.2
0.1
East
0.8
0.6
0.4
0.0
J
F
M
A
M
0.5
J
J
A
S
O
N
J
D
F
M
0.10
(Nitrite)
A
M
J
J
A
S
(Phosphate)
North
0.4
0.3
0.2
O
N
D
North
0.08
East
PO4-3 (uM)
NO2- (uM)
North
0.2
0.2
East
0.06
0.04
0.02
0.1
0.00
0.0
J
F
M
1.5
A
M
J
J
(Silicate)
A
S
O
N
J
D
F
M
0.4
North
A
M
J
J
A
(Chlorophyll a)
Chl a (ug/l)
1.2
O
N
D
N
D
East
0.3
1.3
S
North
East
1.4
SiO2 (uM)
(Nitrate)
1.0
East
NO3- (uM)
NH4+ (uM)
0.4
0.2
0.1
1.1
0.0
1.0
J
F
M
A
M
J
J
A
S
O
N
D
J
F
M
A
M
J
J
A
S
O
Figure 3-5 Monthly average of ammonium (NH4+), nitrate (NO3-), nitrite (NO2-), phosphate (PO4), silicate (SiO2) and chlorophyll a concentrations at the proposed north and east intake sites.
3
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3.3
A qaba
Sediments
Field activities were carried out to investigate sedimentation rates and sediment characteristics at the
two candidate sites.
Sedimentation rates were estimated using locally designed and manufactured simple sediment trap,
which were moored to the sea bed at 5 and 15 m depth in the two candidate intake sites. Details on
methods used are reported in Annex 1.
Surface sediment samples were collected from the two candidate intake sites by SCUBA diving.
From each site, sediments cores (15 cm long) and grab samples were collected at three depths (5,
15, and 30 m). Each core was then sectioned into three sections representing the layers 0-5 cm, 510 cm, and 10-15 cm. The cores were analyzed for sediment physical properties (grain size analysis
and mud content) and sediment chemical properties (calcium carbonate, organic carbon, ignition
loss, redox potential, total phosphorus, total organic nitrogen, and heavy metals: Cr, Pb, Cu, Cd, Zn).
Results of sedimentation rates from the Northern intake site (averaged 2.6±0.6 mg.cm-2.d-1) were 4
times higher than those from the Eastern intake site (averaged 0.60±0.03 mg.cm-2.d-1). The values
from deeper waters (e.g., 15 m) from both intake sites showed slightly higher rates when compared
to shallow waters (e.g., 5 m) from the same site (Figure 3-6).
Sedimentation rate (mg.cm-2.d-1)
4
5m
15 m
3
2
1
0
East intake
North Intake
Site
Figure 3-6 Sedimentation rate (mg.cm-2d-1) at the Eastern and Northern intake sites along the
Jordanian coast of the Gulf of Aqaba during the period May-June 2010. Bars represent the
standard deviation from the mean values.
The sedimentation rates from both sites are within the ranges reported along the Jordanian coast
(range between 0.5 – 2.5 and average of 0.88 mg.cm-2d-1). The higher values recorded at the northern intake site are expected and could be attributed to many factors including the construction and
the infrastructure work that take place in the northern tip of the Gulf, as well as to the dredging and
dumping activities for the establishment of the huge investment projects such as Al-Saraya, Ayla
Oasis and other hotels. Tourist activities, including the continuous and intensive glass boats, skiing
boats and swimming activities are other important factors, as they contribute to stirring the waters
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and to resuspending the fine sediment particles which are major components of sediments in the area of the traps.
Bottom surface sediments from different depths (5, 15, and 30 m) from the Eastern intake site
showed almost similar textural composition. The most dominant fractions were the fine sand (125180, 63-125 µm) which comprises about 53% of all sizes. The mud fraction comprises about 21% of
sediment from this site (Figure 3-7). At the Northern intake site, the most dominant fractions were the
medium sand (250-500, 180-250, and 125-180 µm) which comprises about 68% of all sizes. Mud
fraction at these stations is low and comprises less than 5%. The differences between depths were
minor (Figure 3-7).
East Intake Site
50
5m
15m
30m
Mass %
40
30
20
10
0
≥1000
500-1000
250-500
180-250
125-180
63-125
< 63
125-180
63-125
< 63
Grain size (µm)
North Intake Site
50
5m
15m
30m
Mass %
40
30
20
10
0
≥1000
500-1000
250-500
180-250
Grain size (µm )
Figure 3-7 Grain size distribution of sediment from the Eastern and Northern intake sites
along the Jordanian coast of the Gulf of Aqaba. Bars represent the standard deviation from
the mean values.
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The process of deposition is of great importance in determining the physical characteristics of the
sediments. The variations in textural properties and mud contents between the two sites could be
ascribed to the variety of sediment sources, topography and their response during currents and
waves, and the seasonal variability and activity of benthic infauna. The currents acting on the preexisting sediments cause a large scale sorting into areas of gravel, sand and mud. The distribution is
determined by topography and current strengths; that is, in areas of high current velocity there are
areas of gravel left as lag deposits.
The sediments at the Northern intake site are homogeneous with low mud content (<5%), and rich in
grains derived from land and nearby wadi (Wadi Araba). This is due to dynamic water conditions (active waves and relatively strong currents) in this terrigenous sand bottoms which leads to cleaning of
sediments from very fine materials due to absence of coral reef and rock structures.
Simple and direct information about the sediment oxygenation state, which is one of the most important variables in determining the biological productivity and the trophic structure, could be obtained from the color, odor and redox potential values of the bottom sediments. Sediments from both
intake sites (northern and eastern) exhibited negative redox potential values from all depths (Figure
3-8). The negative sign refers to poorer oxygenation states of the sediments.
Site
East Intake
North Intake
Redox Potential (mV)
0
-100
-200
5m
15 m
-300
30 m
Figure 3-8 Redox potential (mV) of bottom surface sediment from Eastern and Northern intake
sites along the Jordanian coast of the Gulf of Aqaba.
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Mean values for ignition loss in sediments from both sites ranged between 15-34 g kg-1 (Figure 3-9).
The eastern intake site exhibited relatively higher values than the northern site. No significant differences can be observed between depths, and in different sections of the core (Figure 3-9). Ignition
loss is indeed a simple and economic technique for estimation of total organic matter in sediment.
However, ignition loss values here need to be interpreted with care.
The higher ignition loss values recorded at the Eastern intake site could be due nature of source of
sediment in this site which is carbonate. Coral reef calcium carbonate sediment tends to lose weight
upon ignition due to carbonate partial decomposition and conversion to calcium oxide or even being
lost as carbon dioxide.
Ignition Loss
50
0-2 cm
2-6 cm
6-10 cm
-1
IL (g kg )
40
30
20
10
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
Figure 3-9 Ignition loss values (g kg-1) in bottom surface sediments from different water
depths (5, 15, and 30 m) and from different core sections (0-2, 2-6, and 6-10 cm) from the
Eastern and Northern intake sites along the Jordanian coast of the Gulf of Aqaba. Bars
represent the standard deviation from the mean values.
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High calcium carbonate concentrations in the surface bottom sediment at the eastern intake site
(more than 20%) were recorded (Figure 3-10). The northern intake site had considerably lower calcium carbonate concentration ranging between 5-11%, reflecting the nature of the bottom habitat. The
eastern intake site is a coral reef site; while the northern site is a deposition environment and noncoralline sea grass bottom habitat. No significant differences could be noticed between depths and
sections of the core (Figure 3-10).
Total phosphorus values ranged between 0.06 to 1.6 g kg-1 (Figure 3-10). The Eastern intake site
showed significantly higher total phosphorus values (average 0.74 g kg-1) compared to the Northern
intake site (average 0.1 g kg-1). For comparison the summary statistics of the chemical characteristics of sediment along the Jordanian coast of the GoA (Al-Rousan et al., 2006) reports average concentrations of 0.51 g kg-1, 0.22 g kg-1and 0.33 g kg-1 for the Hotels area, the Marine Science Station
and the Southern Industrial complex area respectively.
Calcium Carbonate
50
0-2 cm
2-6 cm
6-10 cm
CaCO 3 (%)
40
30
20
10
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
Total phosphorus
4,0
0-2 cm
2-6 cm
6-10 cm
3,5
2,5
-1
TP (g kg )
3,0
2,0
1,5
1,0
0,5
0,0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
S ite (depth)
Figure 3-10 Calcium carbonate (wt %) and total phosphorus (g kg-1) concentration in bottom
surface sediments from different water depths (5, 15, and 30 m) and from different core
sections (0-2, 2-6, and 6-10 cm) from the Eastern and Northern intake sites along the
Jordanian coast of the Gulf of Aqaba. Bars represent the standard deviation from the mean
values.
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With respect to organic carbon (Figure 3-11), all values exhibited concentrations ranging between
1.15 to 3.15 g kg-1. North intake site exhibited higher organic carbon concentration at 30m depth
than the other stations (3.15 g kg-1). Organic nitrogen concentrations (Figure 3-11) which refers here
to Kjeldahl digestion ranged from 0.02 to 2.5 g kg-1. The Eastern intake site exhibited the higher value averaging 1.5 g kg-1, compared to 0.21 g kg-1 the Northern intake site. For comparison the summary statistics of the chemical characteristics of sediment along the Jordanian coast of the GoA (AlRousan et al., 2006) reports average concentrations of 0.04 g kg-1, 0.23 g kg-1and 0.07 g kg-1 for the
Hotels area, the Marine Science Station and the Southern Industrial complex area respectively.
Organic Carbon
4
0-2 cm
2-6 cm
6-10 cm
-1
OC (g kg )
3
2
1
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
Total Nitogen
4,5
0-2 cm
2-6 cm
6-10 cm
4,0
3,5
-1
TN (g kg )
3,0
2,5
2,0
1,5
1,0
0,5
0,0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
S ite (depth)
Figure 3-11 Organic carbon (g kg-1) and organic nitrogen (g kg-1) contents in bottom surface
sediments from different water depths (5, 15, and 30 m) and from different core sections (0-2,
2-6, and 6-10 cm) from the Eastern and Northern intake sites along the Jordanian coast of the
Gulf of Aqaba. Bars represent the standard deviation from the mean values.
Generally, bottom surface sediments at the two intake sites were quite different in some chemical
properties. Sediment from the Northern intake site is terrigenous where it is admixture of both carbonate and terrigenous sediments in the Eastern intake site. The admixture sediment in this site is
characterized by high CaCO3, total phosphorus and organic nitrogen concentration as compared to
terrigenous silicate sediments. Terrigenous (non-coralline) sediments in Northern intake site are
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composed largely of land derived materials (from surrounding rocks and alluviums) poor in CaCO3
transported from shore and near shore area by winds, floods and waves.
The results of the heavy metal concentrations (cadmium, chromium, copper, lead and zinc) in bottom
surface sediments from both intake sites are shown in Figure 3-12. Concentrations of cadmium and
copper were generally low. Concentrations of lead, chromium and zinc relative to the other metals
were generally high.
Values of Cu in bottom sediment are similar from both intake sites and ranging from 2 to 13 mg.kg-1.
Cd and Zn showed higher values at the Eastern intake site with average of 2.6 and 67 mg.kg-1 compared to 0.07 to 48 mg.kg-1 for the Northern site. However, Cr was higher at the Northern intake site
(154 mg.kg-1) compared to the Eastern intake site (91 mg.kg-1).
-1
Cu conc. (mg kg )
25
0-2 cm
2-6 cm
6-10 cm
-1
Cu conc. (mg kg )
20
15
10
5
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
-1
Pb conc. (mg kg )
70
0-2 cm
2-6 cm
6-10 cm
50
-1
Pb conc. (mg kg )
60
40
30
20
10
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
S ite (depth)
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-1
Cr conc. (mg kg )
250
0-2 cm
2-6 cm
6-10 cm
-1
Cr conc. (mg kg )
200
150
100
50
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
Cd conc. (mg kg-1)
14
0-2 cm
2-6 cm
6-10 cm
10
-1
Cd conc. (mg kg )
12
8
6
4
2
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
-1
Zn conc. (mg kg )
200
0-2 cm
2-6 cm
6-10 cm
175
-1
Zn conc. (mg kg )
150
125
100
75
50
25
0
East Intake
(5m)
East Intake
(15m)
East Intake
(30m)
North Intake
(5m)
North Intake
(15m)
North Intake
(30m)
S ite (depth)
Figure 3-12 Heavy metal concentrations (mg.kg-1) in bottom surface sediments from different
water depths (5, 15, and 30 m) and from different core sections (0-2, 2-6, and 6-10 cm) from
the Eastern and Northern intake sites along the Jordanian coast of the Gulf of Aqaba. Bars
represent the standard deviation from the mean values.
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The following Table 3-1 compares the average concentrations measured at the two proposed intake
sites with the ones resulting from the Jordanian National Monitoring Programme for year 2009.
Chromium was not included in the monitoring.
Table 3-1 Average concentrations of heavy metals measured at the two proposed intake sites
during this study and average concentrations measured at representative sites along the
Jordanian coast in the frame of the National Monitoring Programme.
Cd [mg kg-1]
Pb [mg kg-1]
Zn [mg kg-1]
Cu [mg kg-1]
67
3.7
Northern intake
0.07
Eastern intake
2.6
7.0
48
5.2
Hotels area
N.D.
2.2
N.D.
6.7
Phosphate loading berth
5.6
24.0
6.5
10.3
N.D.
14.2
3.7
8.0
Apart from zinc (but much higher values - one order of magnitude - are reported for zinc in previous
studies for the same areas monitored by the NMP) the heavy metal concentrations found in the sediments at the two proposed intake sites are not significantly different from the ones found elsewhere
along the Jordanian coast.
The heavy minerals distribution patterns in sediments of the Gulf of Aqaba are correlated with the
mineralogy of the source rock including sandstone, metamorphic and granitic rocks.
Chromium concentrations in the sediments from the Gulf of Aqaba are reported to be generally high.
Average values around 50-70 mg/kg were reported from other sites (data from Jordanian monitoring
program; data from Abu-Hilal, 1993). The values depend on the nature and source of marine sediments; the igneous and metamorphic igneous rocks surrounding the gulf could contribute to higher
values.
Anyhow it should be noted that the recorded values for cadmium and chromium are within the most
commonly used international sediment quality guidelines5.
5 See table below
Contaminant
Ontario ministry
NOAA
FEDP
Canadian
Netherlands
Metals
Low-Severe
ERL-ERM
TEL-PEL
Interim-PEL
Target value-
(mg/kg dry wt.)
Max permissible
Cd
0.6-10
1.2-9.6
0.68-4.21
0.7-4.2
0.8-12
Cr
26-110
81-370
52.3-160
52.3-160
--
NOAA: National Oceanographic and Atmospheric Administration
FDEP: Florida Department of Environmental Protection
ERL: effects range low
TEL: Threshold Effect Level
ERM: effect range medium
PEL: Probable Effect Concentrations
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3.4
A qaba
Benthic habitats
The Jordanian coast of the Gulf of Aqaba was subjected to an intense survey to assess the health of
coral reefs in Jordan (Al-Horani et al., 2006). The benthic cover components were studied at three
depths including the reef flat, the 8m and the 15m depths in eight sites along the Jordanian coast. It
was found that hard corals distribution increase gradually from north to south and that the 15m deep
transects had the highest coverage of hard corals. On the other hand, soft corals showed the highest
coverage at sites where industrial activities are found. Coral death was low along the Jordanian
coast. The “hotels area”, the “phosphate loading berth” and the “Tala Bay” sites had more than 40%
seagrass coverage and were classified as seagrass habitats. It is generally concluded that the coral
reefs in Jordan are in good condition, although pressure resulting from the fast development in the
touristic, industrial and construction activities along the coast is adding to the pressure on the benthic
habitats and may represent the major threats to this ecosystem in future.
f Aq
aba
29.55
Gulf
o
Hotels Area (HA)
Public Cafés (PC)
Phosphate Port (PP)
Latitude (N)
29.5
Clinker Port (CP)
Red Sea
Ferry Port
Marine Science Station (MSS)
29.45
Public Beach (PB)
Visitors Center
As Sodasiat (ASD)
Tala Bay (TB)
29.4
Royal Diving Center
Oil Terminal
GULF OF AQABA
29.35
0
1
2
34.8
3
4
5 km
34.85
34.9
Thermal Power Station
Industrial Complex (IC)
34.95
35
35.05
Longitude (E)
Figure 3-13 Gulf of Aqaba map showing the sites studied in the benthos monitoring. Triangles
are the sites surveyed. Results are documented in (Al-Horani et al., 2006) and in the BAD
report of this project.
Concerning the northern candidate intake site for RDC project, the site is located at the northernmost
part of the Gulf (i.e. the Hotels Area). The benthic habitat is characterized by seagrass meadows and
sandy bottoms. In addition to being primary producers bottom habitat, the seagrass habitat also work
as biofilters for the pollutants and are important for reducing the water turbidity and decrease the influence of increased sedimentation rates. They are also important nursery ground for many fish spe-
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cies that live in such habitat. The sandy bottoms of less importance relative to the seagrass habitat,
though it has many kinds of dwelling organisms that function in nutrient cycling and many works as
biofilters and bioindicators. There are no coral reefs in the area, although some individual colonies
can be found scattered in the area. Therefore no additional specific surveys have been carried out in
this area.
The eastern candidate intake site is located in front of the old Thermal Power Station. Here additional survey has been carried out in the framework of Red Sea Study. Methods applied for the surveys
are described in Annex 1.
The results of the surveys have shown that there are about 20%, 18% and 25% coral cover at the
reef flat, 9m depth and 15m depth, respectively. This means that the area is in fact a coral reef area,
although the narrow area in front of the pumps room was destroyed by dumping rocks in the past.
The rocks dumped (Figure 3-14) cover an area of about 35m wide (parallel to the shoreline) and
might extend to about 60m depth (exact distance was not measured due to depth limitations). The
rocks are also covering the area to about 100m south to the pumps room.
Since rocks in the area were dumped some decades ago there should be some reasons for the fact
that the area was not recolonized by the corals. A probable explanation is that the rocks' surfaces
are exposed to grazers, feeding on all newly settled corals, except for hidden areas in some crevices; this explanation is supported by the evidence of low coral coverage in the entire area. Another
possible reason could be the disturbance induced to coral settlement and growth by wave action.
The detailed results of the transects have shown that the area located north to the pumps' room
(Figure 3-14) has a very well developed coral reefs with a cover percentages of about 30% for the
hard coral component. Contrary to this, the area located south of the pumps room, which was destroyed in the past by dumping rocks and rubbles in it, has much less coral cover percentages with
3%, 6% and 12% hard coral cover at the reef flat, 9m and 15m deep transects, respectively. This is
of course due to the dumped rocks in the area.
Detailed results of the surveys are included in Annex 1.
Figure 3-14 Photo of the eastern intake location (the old thermal power station site) showing
the pumps room (left) and underwater photo in front of the pumps room (right).
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3.5
A qaba
Fish Communities
Fish communities were surveyed at the northern and eastern candidate intake sites. Methods applied in the surveys and detailed results are reported in Annex 1.
Northern intake site
Dominant taxa and fish community parameters at the northern intake site have been found as follows:
Lethrinus borbonicus is the most abundant species on the surveyed area, followed by Lethrinus variegatus, Trachurus indicus, Siganus rivulatus, Decapterus macrosoma, Scolopsis ghanam, Parupeneus forsskali and P. macronema. The coral reef fish assemblages along the Jordanian coast
showed completely different picture. The most abundant fish species along the Jordanian reef were
Pseudanthias squamipinnis, Pomacentrus tichorous, Chromis dimidiata, Dascyllus marginatus (Khalaf and Kochzius, 2002).
In terms of relative abundance of families, the coral reef fishes along the Jordanian is dominated by
Pomacentridae, followed by Anthininae (subfamily of Serranidae) and Labridae (Khalaf and Kochzius, 2002), while visual censuses of fish assemblages at the northern intake site revealed the dominance of Lethrinidae, followed by Carangidae, Mullidae, Siganidae and Nemipteridae.
The seagrass beds play a significant role in harboring juveniles of various commercial fish (e.g. Lethrinids, Siganids and Mullids). Availability of food, shelter and protection from predators within the
seagrass lattice contribute to the nursery functions of these habitats. Hence, understand well the
contribution of grass beds to coastal fisheries in terms of fish distribution, species composition and
spawning seasons.
Some major characteristics of fishes characterizing, inhabiting or utilizing the seagrass habitat at the
northern most tip of Gulf of Aqaba are reported:
1. Lethrinus borbonicus (subnose emperor): It is the most abundant species in the studied area. It
forms 38.56% of the total population. Fish juveniles live in schools in shallow seagrass beds.
They use seagrass beds for shelter as well as for feeding. It feeds on crustaceans, mollusks and
echinoderms. Size estimation of these juveniles was between 20 to 35 mm in the area. Adults
are more solitary and lives at depth of about 15m or even more.
2. Lethrinus variegates (variegated emperor): It is the second abundant fish species. It forms
16.97% of the total population. Similar to L. borbonicus, this fish utilizes the seagrass beds.
3. Upeneus pori: this is a common species and can only seen at the northern part of the Jordanian
coast. It inhabits shallow coastal waters off sandy flats and the seagrass beds. This species lives
at depth range of 1 to 20m. It feeds on benthic invertebrates.
4. Parupeneus forsskali (Red Sea goatfish) and P. macronema (longbarbel goatfish): these fish are
distributed along through the Jordanian coast. Juveniles of both species live in mixed schools in
seagrass beds and forms 3.67% and 3.28% of the total population, respectively within the studied area. Both fish use seagrass habitat for shelter and on the associated invertebrates for feeding. Adult fish may stay living in seagrass or may migrate to the sandy bottoms around the reefs.
It feeds on a wide variety of small animals particularly crustaceans and worms.
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5. Scolopsis ghanam (Arabian threadfin bream): this is a common species of inshore water usually
found over sand flats. It forms about 4.15% of the total population in the studied area. Most of
the recorded individuals of this species in the area are juveniles and with size range of 20 to 40
mm. The fish was seen hiding among the leaves of the seagrass beds and utilizes it for shelter
as well as for feeding on the epiphytic invertebrates.
6. Siganus rivulatus (Rivulated rabbitfish) and Siganus luridus (Square tail rabbitfish): the two species live in schools and inhabit shallow water around sandy and seagrass meadows. They form
5.2 and 0.28% of the total population of the studied area. Most of the recorded individuals are juveniles observed to live among seagrass beds and use it for shelter and for feeding on the benthic algae.
7. Teixeirichthys jordani (Jordan`s damselfish): this species lives in aggregations over seagrass areas and sandy beaches. Juveniles are often found among the spines of the sea urchins in the
studied area. This is the first report about its assemblages and their habitat along the Jordanian
coast during a long term monitoring program carried out by the first author.
8. Sparus aurata (Gilt-head seabream): this is an exotic species found to inhabits the northern part
of the Jordanian coast (Ayla). The individuals observed in the studied area are adults and were
seen in site 3 at 9 meter deep. Individuals observed in the studied area are believed to be escaped from aquaculture plants at the Israeli side of Gulf of Aqaba.
9. Heniochus diphreutes (Pennantfish): this species is found in large aggregations in the water column above sandy flats or seagrass beds. In the studied area, juveniles were seen to live among
the spines of the sea urchins or having shelters of solid substrates such as rocks, tires, etc..
10. Dascyllus trimaculatus (the Domino): this is a coral reef species found in the surveyed area. In
their primary habitat, coral reef, the juveniles used to live in association with sea anemones.
However, in the present studied area, it was seen hiding among the spines of the sea urchins
with size range between 10 to 20 mm.
Eastern Intake Site
In this study 129 fish species belonging to 31 fish family have been counted from the eastern intake
site. In the Jordanian waters of the Gulf of Aqaba 507 species of fish have been recorded to date,
with around 51.1% of the fish species inhabit coral and boulders, 11.7% inhabits sandy bottoms and
8.3% live in sea grass meadows (Khalaf, 2004). Khalaf and Kochzius (2002) counted 198 fish species, whereas near Eilat, Rilov and Benayahu (2000) counted 142 species while in Dahab, 162 species were identified (Zajons, unpublished data). When comparing Literature data, differences between sites have to be taken with caution, because the observed species richness in a certain area
is influenced by sampling intensity, and timeframe of the investigation.
Pseudanthias sqamipinnis is the most abundant species on Jordanian coral reef and constitute
(RA=25.07) of the total fish population followed by, Paracheilinus octotaeniais (RA=16.59%) and Neopomacentrus miryae (RA=11.1%), Chromis pelloura (RA=9.54%). The 4 above mentioned species
usually live in small aggregations few meters above the sea bottoms, and feeds on zooplankton
(Khalaf and Disi, 1997). The most common species were Pomacentrus trichourus, followed by Chaetodon paucifasciatus, Dascyllus marginatus, Thalassoma rueppellii, Chromis dimidiata, Pseudanthias
squamipinnis, Parupeneus forsskali, P. Macronema, Amphiprion bicinctus and Anampses twistii.
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In terms of relative abundance, the ichthyofauna of the studied sites is dominated by the families
Pomacentridae (RA=37.52%), followed by subfamily Anthiniini (RA=28.56) and Labridae
(RA=21.48%), these three families’ form (RA=97.80%) of the total fish population.
The Chromis pelloura, which is an endemic species to the Gulf of Aqaba was only noticed at norther
transects at 15 m deep transects at the sandy bottom. Generally, fishes were most abundant at the
15 m transects followed by 8 m depth. The lowest number of individuals was found at the reef flat,
may be because it is very difficult for some of the species to resist the unfavorable conditions exist
within this area such as tides, wave action, food availability. The higher abundance in 15 m depth
can be explained by the high primary productivity at this depth (Al-Najjar, 2000).
Finally, the analysis of the dominant taxa and fish community parameters revealed the following: (1)
Labridae and Pomacentridae dominated the ichthyofauna in terms of species richness at all studied
sites, (2) Pomacentridae was the dominant family in terms of relative abundance, (4) abundance of
fishes was higher at 15 m depth than at 8 m depth and reef flat.
Concluding remarks
The fish community structure at the two candidate sites is different: the northern intake site is dominated by species inhabiting seagrass bed while the eastern intake site (Thermal Power Station) is
dominated by coral reef fish species.
The analysis of the dominant taxa and fish parameters at the northern intake site revealed the following:
1) Labridae dominated the ichthyofauna in terms of species richness;
2) Economical important species such as Lethrinidae dominated the ichthyofauna in terms of relative abundance followed by Carangidae, Mullidae, and Siganidae;
3) The fish Teixeirichthys jordani (Jordan`s damselfish) is only present at this site;
4) The seagrass beds play significant role in harboring juveniles of various commercial fish (e.g.
Lethrinids, Siganids and Mullids), and contribute to the nursery functions of these habitats;
5) This site is of importance to fishermen community.
The analysis of the dominant taxa and fish community parameters at the eastern intake site (Thermal
Power Station) revealed the following:
1) Labridae dominated the ichthyofauna in terms of species richness;
2) Pomacentridae dominated the ichthyofauna in terms of relative abundance;
3) There are no endangered or threatened species at this site;
4) The number of species and number of families is almost similar to other coral reef sites along the
Jordanian coast;
5) The fish Chromis pelloura which is an endemic species to the Gulf of Aqaba is highly abundant
at the northern transect at 15m deep is of interest, but it is also reported in other sites such as
Tala Bay and Phosphate Loading berth;
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6) In general the northern transects host more number of individuals than middle and southern
transects at all depths;
7) The sanddivers fish, Trichonotus niki and the peacock wrasse Xyrichtys sp. were observed outside the transect at the destructive area at more than 20 m depth;
8) The site is marked by a destroyed area (approximately 35-40 m) within the study site of Thermal
Power Station starting from 2 m depth to more than 30m depth;
9) If this site is selected as intake point, this section might be suitable for deployment of the intake
fittings material;
10) The area is considered as one of the sites for tourists.
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4
A qaba
Effects of RDC abstraction
Object of our study was to evaluate the effects on the environment of the Gulf of Aqaba/Eilat of abstraction of seawater ranging from 0.4 to 2 billion m3/year.
The World Bank, through its Feasibility Study consultant, indicated two candidate intake sites to be
considered for our study: the northern intake candidate site, located in Jordan in the immediate vicinity of the Israel/Jordan border and the eastern intake candidate site located in Jordan, close to socalled “old thermal power station”.
The approximate location for the two candidate intake sites are as follows (see Figure 4-1):
RDC EASTERN INTAKE APPROXIMATE LOCATION = 29°29’22’’N - 34°59’06’’E
RDC NORTHERN INTAKE APPROXIMATE LOCATION = 29°32’28’’N – 34°58’40’’E
Northern Intake
Eastern Intake
Figure 4-1 Intake candidate sites approximate location (background: multibeam shaded
colour bathymetry of the northern Gulf of Eilat/Aqaba bathimetry map from Sade et al., 2008).
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4.1
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Scenarios considered for the evaluation
The scenarios to be considered for the evaluation of the RDC projects as presented, and approved,
in the Best Available Data Report (and repeated in the Mid term Report) include 13 combinations of
intake location, configuration, depth, and abstraction rates. For all scenarios considered, it was decided and agreed with the World Bank to include the Ayla and Saraya development projects along
the north shore in Aqaba since both are already under construction. In both cases the plan is to circulate water through the respective lagoons to prevent potential problems of eutrophication. Thus
neither of these projects will lead to a net abstraction of water from the northern gulf. Therefore they
are both treated and a coupled sink-source pair. The inflow and outflow rates were taken as the maximum values as released by the developers. The values used were 8.5 and 3.5 m3/yr for Ayla and
Saraya, respectively. For comparison and assessment of the impacts it was also necessary to run a
control simulation in which there was no RDC abstraction (see Section 2.1.5). Based on internal discussions and analyses of our team we added a fourteenth scenario with an eastern intake located at
200 m depth.
In addition to the RDC scenarios three cumulative abstraction scenarios including a proposed nuclear power plant and/or the Jordan Red Sea Project (JRSP) were to be considered.
Since the submission of the revised Best Available Data Report and the Midterm Report, several revisions have been made to the specifications of the cumulative scenarios. At the Donor Countries'
meeting held on 22 March 2011 in Milan, it was announced that the proposed nuclear power plant
has been eliminated. Since we assume that the JRSP and the RDC northern intake are co-located,
this means that the original Scenario 14 as listed in the previous reports is identical to Scenario 10
above and the original Scenario 15 is identical to Scenario 13 above. This leaves only one scenario
in cumulative category, i.e., the original Scenario 16 which listed the RDC abstraction rate as 2 billion
m3/yr. Since then it has been agreed with the SMU and World Bank that the abstraction of the RDC
eastern intake in this scenario should be reduced to 1.6 billion m3/yr to give a cumulative JRSP+RDC
abstraction rate of 2 billion m3/yr.
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Table 4-1 Modelling scenarios to be considered for the evaluation of the RDC project effects.
intake configuration
Abstraction
rate (per year)
Intake location
CONTROL
-
-
-
-
SCENARIO 1
RDC EASTERN
open channel
-
-
0.4 billion m3
SCENARIO 2
RDC EASTERN
open channel
-
-
1 billion m3
SCENARIO 3
RDC EASTERN
open channel
-
-
1.5 billion m3
SCENARIO 4
RDC EASTERN
open channel
-
-
2 billion m3
SCENARIO 5
RDC EASTERN
Intake depth
Height
above the
sea bed
SCENARIO
-
Submerged
- 25 m (to provide indications
on preferred
depth)
not less
than 19 m
2 billion m3
not less
than 19 m
2 billion m3
SCENARIO 6
RDC EASTERN
Submerged
- 120 m (to provide indications
on preferred
depth)
SCENARIO 7
RDC EASTERN
Submerged
best depth selected by the
above analysis*
not less
than 19 m
0.4 billion m3
SCENARIO 8
RDC EASTERN
submerged
above analysis*
not less
than 19 m
1 billion m3
SCENARIO 9
RDC EASTERN
submerged
above analysis*
not less
than 19 m
1.5 billion m3
SCENARIO
10
RDC
NORTHERN
submerged
-8m
9.5 m
0.4 billion m3
SCENARIO
11
RDC
NORTHERN
submerged
-8m
9.5 m
1 billion m3
SCENARIO
12
RDC
NORTHERN
submerged
-8m
9.5 m
1.5 billion m3
SCENARIO
13
RDC
NORTHERN
submerged
-8m
9.5 m
2 billion m3
SCENARIO
14
RDC EASTERN
submerged
- 200 m
Not less
than 19 m
2 billion m3
*The results of the analysis of the hydrodynamic model simulations lead to the best depth selection of 120 m from the agreed
scenario. However based on the latest results and the ecological analysis, which were not available at the time that the scenarios were fixed, indications are that the preferred depth of the intake should be deeper than 120 m (see par.4.4).
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Table 4-2 Cumulative modelling scenarios to be considered for the evaluation of the RDC
project effects.
SCENARIO
RDC intake
position
RDC abstraction rate
Jordan Red Sea
Project
abstraction rate
Nuclear power plant Aqaba
Area abstraction rate
1.6 billion
m3/yr
0.4 billion m3/yr
-
EASTERN
SCENARIO 15
INTAKE
-120 m
4.2
Effects on water circulation
4.2.1
Effects in the Northern Gulf
In terms of the circulation, the main topic to be addressed is what are the horizontal extent and magnitude of the local disturbance to the circulation pattern that is induced by the abstraction of water
through the RDC. In order to answer this we present the following maps of the differences between
the residual currents (averaged over 60 M2 tidal cycles; slightly more than 31 days) in the respective
abstraction scenario and the currents in the control simulation (Section 2.1.5). All results presented
here are based on the simulations with the intermediate model. However, in order to emphasize the
effects of the abstraction, the maps are zoomed on the vicinity of the intake. The maps are presented
for the three submerged intake scenarios using the maximum abstraction rate of 2 billion m3/yr (scenarios 5, 6 and 13 in Table 4-1). The results for lower abstraction rates and for the surface intake are
summarized in Table 4-3.
We begin with Figure 4-2 which shows the horizontal extent of the effects of the abstraction on the
mean currents in Scenario 5 (25 m eastern intake) at a water depth of 25 m below the surface for the
month of March 2010. Figure 4-3 shows the corresponding vertical cross section of the induced current speed. Not surprisingly, the strongest impact occurs at the grid point of the intake where the
maximum disturbance to the currents is 9.7 cm/s. The horizontal extent of the disturbance is limited
to a radius of at most 2-3 grid points (~250 m). From the vertical cross section (Figure 4-3) it is clear
that convergence of water towards the intake due to the abstraction is confined to a layer centred at
the depth of the intake and extending ~10 m above and ~10 m below the intake. A secondary maximum in the induced current speed appears near the surface indicating that some water is probably
also entrained from uppermost part of the water column.
The corresponding map and cross section for August are shown in Figure 4-4 and Figure 4-5, respectively. Here the maximum induced current speed also appears at the grid point of the intake but
it is stronger than in March with a value of 11.6 cm/s. Horizontally it covers a slightly larger area than
in summer but is still restricted to within of ~300 m of the intake. In the vertical cross section the main
convergence zone is still confined to ~10 m above and ~10 m below the intake depth but now a secondary maximum appears near the bottom indicating that the water is also likely to be entrained from
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the lowest part of the water column. This near bottom disturbance may also have some implications
for sediment resuspension.
Figure 4-2 Horizontal map of currents induced by abstraction for Scenario 5, March 2010.
Figure 4-3 Vertical cross section of currents induced by abstraction for Scenario 5, March
2010.
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Figure 4-4 As in Figure 4-2 except for August 2010.
Figure 4-5 As in Figure 4-3 except fort August 2010.
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In Figure 4-6 and Figure 4-7 we show the horizontal and vertical extent of the disturbance for Scenario 6 (120 m eastern intake) for Mar 2010. As in Scenario 5, the horizontal extent of the impact at
the depth of the intake is limited to within a radius ~250-300 m from the intake, although here it is
elongated to the west probably due to the steep bottom slope to the east. The main vertical impact
extends 20-30 m above and 20 m below the intake but its magnitude is less than half of that in Scenario 5 with a maximum of only 4.5 cm/s. The corresponding map and cross section for August are
shown in Figure 4-8 and Figure 4-9, respectively.
As in the previous cases we again find that the horizontal extent of the induced currents is limited to
a radius of ~250 m from the intake. A comparison of the March (Figure 4-6) and August (Figure 4-8)
cases shows that in summer the disturbance is more symmetric than in winter although we do not
believe that this is a significant difference. The vertical extent of the disturbance is somewhat more
limited than in winter but the maximum here is 4.8 cm/s which is slightly stronger than in March. We
also note that there is no secondary entrainment from near the surface or near the bottom as was
found for the 25 m intake. This is most likely due to the deeper location and the subsequent spreading of the convergence zone over a thicker layer around the depth of the intake.
Figure 4-6 Horizontal map of currents induced by abstraction for Scenario 6, March 2010.
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Figure 4-7 Vertical cross section of currents induced by abstraction for Scenario 6, March
2010.
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In Figure 4-10 we show the horizontal map of the disturbance to the current field induced by the scenario 13 (8 m northern intake) for Aug 2010. As with the east intakes, here too the impact is limited to
2-3 grid points from the intake (~250-375 m), although here the zone affected tends to be more
elongated in the alongshore direction than in the eastern intakes. The vertical extent of the disturbance is restricted to a thinner layer than for the eastern intakes due to the shallower depth of the
northern intake and the gentler bottom slope in this region. The maximum induced current here is 7.8
cm/s. In the nearshore zone this implies that the impacts of the abstraction may be felt over the entire vertical extent of the water column.
The March figures are very similar to those from August and therefore they are not shown here.
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Figure 4-10 Horizontal map of currents induced by abstraction for Scenario 13, August 2010.
Figure 4-11 Vertical cross section of currents induced by abstraction for Scenario 13, August
2010.
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The potential effects of the abstraction rate of water through the RDC are summarized in Table 4-3
where we show the maximum induced current for the different intake options. Not surprisingly there
is a direct relationship between the abstraction and the impact – as the abstraction rate increases
(i.e., reading down the rows in the table) so do the effects of the abstraction. We also note that the
impact is usually stronger in summer since in the winter the effect is spread over a deeper layer due
to winter mixing of the water column and weakening of the stratification. By using this parameter as
the primary measure of the potential impact of the abstraction we can also rank the priority of the
various intake options in the order from least desirable (highest impact) to most desirable (least impact): (1) 25 m east, (2) northern, (3) surface east, (4) 120 m east. This order of priority is the same
for any of the abstraction rates considered. Thus from the circulation perspective, the recommended
option from the scenarios considered is the 120 m submerged east intake.
Table 4-3 Maximum induced current speed due to abstraction (abstraction rate in billions
m3/yr and current speeds in cm/s).
Abstraction
rate
Surface
east
25 m
east
120 m
east
North
Mar
Aug
Mar
Aug
Mar
Aug
Mar
Aug
0.4
1.4
1.6
-
-
1.5
1.1
2.6
3.3
1.0
3.1
3.8
-
-
2.3
2.6
4.9
5.2
1.5
4.9
5.6
-
-
3.3
3.7
6.4
6.5
2.0
5.8
6.8
9.7
11.6
4.5
4.8
7.7
7.8
For the 200 m intake with the maximum abstraction rate (Scenario 14), the results were similar to the
120 m intake with maximum induced current speeds of 3.5 and 5.2 cm/s in March and August, respectively. Thus based on considerations of minimizing the effects on the circulation, the deeper
(120 or 200 m) are to be preferred.
4.2.2
Effects in the vicinity of the preferred intake location
The results of the intermediate model simulations show that the direct impact of the water abstraction
on the currents is mainly localized horizontally to within ~300 m of the intake. Vertically, the disturbance typically extends 20 m above and 20 m below the intake, although during the maximum mixing
in March it can be as much as 40-50 m (see for example Figure 4-7). In order to refine the assessment of the potential impacts of the abstraction a high resolution model (~25 m horizontal resolution),
as described in Annex 2, was also adapted to the northern and eastern intake areas. Due to the extremely high computational demand of such a model it was not feasible to run it for the complete annual cycle. Instead, it was run for selected 10 day periods with initial and lateral boundary conditions
extracted from the intermediate model. The first three days of the simulation are considered as the
spin up or adjustment period. Thus results are shown which represent the averages for the last sev-
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en days of the selected simulation. Here we present one particular example for the simulations initialized from 12 August 2010 for the 120 m eastern intake.
As with the previous figures in the section, Figure 4-12 shows the current differences between the
abstraction simulation (Scenario 6) and the control run at 120 m depth in the vicinity of the intake in
August. Except for the shorter time duration of the average, this is essentially a further zoom of Figure 4-8. As before, the maximum induced current speed appears at the grid point of the intake. The
maximum speed is 4.5 cm/s and the disturbed zone is slightly elongated to the north. The vectors
indicate that the induced flow consists mainly of a weak anticyclonic circulation around the intake.
There is also a hint of a weak seaward flow in the region to the west of the intake.
Figure 4-12 Mean current differences for 15-22 August at 120 m as simulated by the
intermediate model.
The corresponding results from the high resolution model are shown in Figure 4-13. The ratio of the
high resolution to intermediate grids is ~ 5:1 and so the high resolution model is able to show the
smaller scale details. Nevertheless the general picture is quite similar to the results provided by the
intermediate model. Here too the maximum induced current speed appears at the grid point of the
intake with a value of 5.3 cm/s. As in the intermediate model results, the vectors here confirm that
the induced flow is mainly an anticyclonic circulation around the intake and a weaker seaward flow in
the region to the west of the intake. We also note that the region affected by the induced currents is
less symmetric and its horizontal extent is slightly smaller (<~ 200 m) than simulated by the intermediate model. Considering the differences between the resolutions of the two models, the comparison
is quite good and indicates that for the purposes of the ecological and water quality assessment the
intermediate model is adequate.
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Figure 4-13 As in Figure 4-12 but from the high resolution model.
4.2.3
Effects at Gulf-wide scale
On the gulf-wide scale, the main concern is that the abstraction of water from the northern tip of the
gulf will lead to an increase in the inflow of warmer and less saline Red Sea water through the Strait
of Tiran and may thereby change the stratification of the gulf. As noted in Chapter 2, however, the
proposed maximum abstraction rate is less than 0.5% of the exchange of water through the strait
and therefore it is anticipated that the impact will be minimal, especially in comparison to the projected effects of climate change.
In Figure 4-14 – Figure 4-16 we show the potential impact of the abstraction at the maximum proposed flow rate on the stratification in terms of the profiles of the Brunt-Vaisala frequency6 (see discussion in Section 2.5 regarding the potential impact of climate change). The only noticeable
change, although barely perceptible appears in the northern gulf profiles (located near Station A) of
the abstraction scenarios. The impact appears as a very weak variation in the stratification in the upper thermocline at a depth of 20-40 m (at the maximum in the profiles).
In March the effects of abstraction are not discernable due to the deep winter mixing. In any case the
potential impact of the abstraction on the gulf wide scale will be overshadowed by the projected impacts of climate change (compare to Figure 2-69 and Figure 2-70).
6 The Brunt-Vaisala frequency is a measure of the stratification: higher values indicate stronger stratification.
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Figure 4-14 Modelled vertical profiles of Brunt-Vaissala frequencies in the southern (left
panel) and northern (right panel) regions of the GOAE in August. The blue line is for no
abstraction and the red line is for the maximum abstraction rate at 25 m depth m from the
eastern intake (scenario 5).
abstraction and the red line is for the maximum abstraction rate at 120 m depth m from the
eastern intake (scenario 6).
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abstraction and the red line is for the maximum abstraction rate from the northern intake
(scenario 13).
4.2.4
Impact of selective withdrawal
In density-stratified fluids, it is well known that the withdrawal of fluid tends to be confined to a layer
centered at the level of the withdrawal (Monismith and Maxworthy 1989). The process is known as
selective withdrawal and has been used to manipulate reservoir water quality (Imberger and Patterson 1990). In the present case, it is worth considering whether or not the vertical extent of the flow
induced by the possible RDC intakes might be of limited extent and so might avoid entraining any
larvae from other depths.
To analyze this possibility, we can model the intake as a point sink (i.e. we neglect the details of the
intake design) a case for which it is found experimentally that the thickness of the withdrawal layer
(2δ) is determined by the relation
δ≈1.3(Q/N)1/3
(4.1)
with Q the flowrate and N=(-(dρ⁄dz)/ρ g)1/2 is the Brunt-Vaisala frequency (Spigel and Farrant 1984).
However equation 4.1 has only been derived for linear stratifications, i.e. fluids with constant N. To
apply these results to the vertically variable stratification found in the Gulf of Aqaba, we applied 4.1 in
modified form by noting that for layer of thickness δe there is an average value of the Brunt-Vaisala
frequency
N=(Δρ(δe )/ρ g/δe )1/2 = (g'(δe )/δe )1/2
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So that the withdrawal layer thickness equation could be written implicitly as
δe≈1.4 (Q2/(g' (δe ) )) 0.2
(4.2)
It is reassuring that equation 4.2 is quite close to what is given as the two layer result in Wood
(2001), i.e, the same functional form but with the constant equal to 1.45.
Equation 4.2 is solved by iteration using monthly density profiles measured at Station A by the Israeli
NMP. For the surface and 25m intakes, we assumed that they operated at the surface and doubled
the flow rate in equation 4.2 to account for the lack of a withdrawal layer above the intake. The results of these calculations are shown in Figure 4-17 (shallow intake) and Figure 4-18 (deep intake)
and summarized in Figure 4-19.
The calculated withdrawal layer thicknesses suggest that for much of the year, the deepest intake
will draw waters from depths of 70 m or more, whereas the upper intakes will generally be expected
to draw above those depths. It also appears that selective withdrawal will be somewhat less likely in
winter (e.g. January) when the surface mixed layer is quite deep.
Figure 4-17 Density profiles and withdrawal layer extent: Surface and 25m intakes. The solid
line is the assumed location of the intake (10m) and the dashed line shows the bottom of the
computed withdrawal layer.
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Figure 4-18 Density profiles and withdrawal layer extent: 120 m intakes. The solid line is the
location of the intake (120m) and the dashed lines shows the top and bottom of the computed
withdrawal layer.
Figure 4-19 Monthly variation in calculated withdrawal layer boundaries. The top of the
surface/25m intake layer is the free surface itself (depth=0).
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4.2.5
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Particle tracking – backward trajectories
In order to assess the source of water that reaches the intake we ran a series of backward (in time)
trajectories for particles released from the intake. This approach is commonly used in air pollution
assessments when assessing the source of air arriving at a receptor. In the case of the RDC the intake is the receptor. At each of the subsurface intakes considered, particles were released once every hour for an entire month. Each particle was tracked backward in time for 72 hr using the three dimensional currents simulated by the intermediate model. Results are presented here for the maximum abstraction rate of 2 billion m3/yr. All values shown in the following figures (Figure 4-20 - Figure
4-31) represent the percent of the total trajectory points that fall within a particular grid box of the intermediate model. Thus these figure effectively represent the distribution of the origin of water reaching the intake.
In Figure 4-20 and Figure 4-21 we show the horizontal distributions for the 25 m eastern intake for
the months of March and August, respectively. Note that the horizontal distributions represent vertically integrated values. In both seasons the cloud of points is aligned mainly in the alongshore direction due to the dominance of the alongshore component of the currents. As the distance from the intake increases, the amount of water originating at a given location decreases. In March (Figure 4-20)
nearly all of the water originates within a distance 2500 m from the intake, with a preference to water
coming from the north. In August the area supplying water to the intake is smaller than in winter with
nearly all of it originating from within a distance of less than 2000 m. Also the points are distributed
more symmetrically along the shore although there is some indication of a slight preference for water
originating in the south.
Figure 4-20 Horizontal distribution of the number of trajectory points falling in each grid box
(expressed as percent of the total) for the 25 m eastern intake in March.
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Figure 4-21 As in Figure 4-20 except for August.
Figure 4-22 and Figure 4-23 show the horizontal distribution for March and April, respectively, for the
120 m eastern intake. In general the results are similar to those for the 25 m intake in the sense that
the water reaching the intake comes mainly from the alongshore direction with a clear preference for
north in winter and nearly all of the water coming from within a distance of 2500-3000 m. In summer
the area is once again smaller than in winter, but here there is also a clear preference for water to
come from the north, unlike the shallower intake where it was more symmetric. We also note that
compared to the shallow intake, there is somewhat more of a tendency to draw water from the offshore region, most likely due to the blocking effect of the steep bottom slope.
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(expressed as percent of the total) for the 120 m eastern intake in March.
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Figure 4-24 and Figure 4-25 show the results for March and August, respectively for the northern intake. Here too the tendency is for the water to come mainly from the alongshore direction. There is a
clear seasonal preference for water to come from the area of Eilat in winter (Figure 4-24) and from
the area of Aqaba in summer (Figure 4-25). The horizontal area supplying water to the intake is also
smaller in summer than in winter as was seen for the eastern intakes.
(expressed as percent of the total) for the northern intake in March.
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In Figure 4-26 – Figure 4-31 we show the vertical distribution of the trajectory points for the three intake options (25 m east, 120 m east, northern) and for winter and summer. The values shown are
radially integrated in the horizontal distance intervals of one grid box and therefore the two dimensional distribution as a function of depth and distance from the intake. The most important result from
these figures is the central role of the stratification in controlling the layer from which the water reaching the respective intakes originates. In March (Figure 4-26, Figure 4-28, and Figure 4-30) the water
can come from a layer with a much larger vertical extent due to the deep winter mixing of the water
column. In contrast to this in summer (Figure 4-27, Figure 4-29, and Figure 4-31) the vertical extent
of the layer supplying water to the intake is limited by the strong stratification. For the two shallow intakes (25 m east and northern) the water is supplied mainly by the layer extending from the surface
to a depth of 40 m while for the deep intake (120 m east) the water reaching the intake originates in
a 60 m thick subsurface layer extending from ~80 – 140 m. These results are consistent with the
conclusion of the theoretical analysis of selective withdrawal presented in the previous section.
Figure 4-26 Vertical distribution of the number of trajectory points falling in each horizontal
distance interval from the intake (expressed as percent of the total) for the 25 m eastern
intake in March.
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Figure 4-27 As in Figure 4-26 except for August.
Figure 4-28 Vertical distribution of the number of trajectory points falling in horizontal
distance interval from the intake (expressed as percent of the total) for the 120 m eastern
intake in March.
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Figure 4-29 As in Figure 4-28 but for August.
Figure 4-30 Vertical distribution of the number of trajectory points falling in horizontal
distance interval from the intake (expressed as percent of the total) for the northern intake in
March.
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Figure 4-31 As in Figure 4-30 but for August.
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4.2.6
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Particle tracking – forward trajectories
The particle tracking module can also be used to assess the pathways that the larvae might follow
assuming that their primary method of movement is advection by the currents. Thus neutrally buoyant particles were released at various locations and tracked for 96 hours using a Lagrangian particle
tracking routine based on the three dimensional currents computed by the intermediate resolution
hydrodynamic model. The particles were released along seven cross sections as indicated in the
map in Figure 4-32. Each section extended outward from the coast for a distance of 1 km (eight grid
points). The particles were released at each horizontal grid point (~124 km) at 5 m depth intervals
from a depth of 5 m to 50 m (for deeper releases see at the end of section 4.4). In order to sample
various circulation regimes, a time series was created by selecting different days from the months of
March (maximum vertical mixing) and August (maximum stratification). Initial times were selected
from the beginning, the second third, and the last third of each month. For each simulation, particles
were release once every three hours over a period of 39 hours. Thus 9 tidal cycles were sampled for
each case. Depending upon the bottom depths along the cross sections, approximately 3000 particles were released along each section for each month.
Figure 4-32 Map showing locations of the cross sections along which the particles were
released (blue lines) and the intakes (red X's).
A particle was considered to have been entrained into the intake if it reached the grid point of the intake and it was located within a 15 m thick layer surrounding the intake. According to the design provided by Coyne and Belliers, the vertical extent of the proposed intake is 5 m. Thus the 15 m thick
layer that we specified assumes that if a particle enters to within +/- 1 intake thickness it is entrained.
This is also consistent with the vertical extent of the maximum current disturbance around the intake
as shown in Section 4.2.1. Results using an entrainment layer thickness of 20 m were not significant-
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ly different. The results are summarized in the Table 4-4 and Table 4-5, expressed as percent of particles from each section that are drawn into the intake. For each entry the values is the average percent removed for all three time periods in the month with the range for the individual days shown in
parentheses. Results are shown for the maximum abstraction rate of 2 billion m3/yr.
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Table 4-4 Particle tracking results for March.
Scenario/
Cross section
# of particles
1
2808
2
2769
3
2262
4
1911
5
2808
6
2847
7
3003
25 m East
% removed
(range)
0
(0)
0
(0)
0
(0)
0
(0)
0.32
(0-0.96)
1.1
(0.21-1.7)
0.53
(0-1.5)
120 m East
% removed
(range)
0
(0)
0
(0)
0
(0)
0
(0)
0.28
(0-0.64)
0.67
(0-1.3)
0.23
(0-0.70)
North
% removed
(range)
0
(0)
0
(0)
4.2
(0-12.5)
4.2
(0.16-8.9)
0.50
(0-1.4)
0.18
(0-0.43)
0.23
(0-0.50)
120 m East
% removed
(range)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
0
(0)
North
% removed
(range)
0
(0)
0.11
(0-0.33)
1.5
(0-3.1)
9.1
(7.2-10.4)
0.28
(0-0.75)
0.11
(0-0.21)
0.03
(0-10)
Table 4-5 Particle tracking results for August.
Scenario/
Cross section
# of particles
1
2808
2
2769
3
2262
4
1911
5
2808
6
2847
7
3003
25 m East
% removed
(range)
0
(0)
0
(0)
0.044
(0-0.13)
0
(0)
5.3
(1.7-9.6)
2.2
(1.8-2.4)
0.17
(0-0.4)
From the results it is clear that the largest loss of particles will occur in the immediate vicinity of the
respective intake. The cross sections surrounding each intake were located ~ 500 m on either side of
the intake and it is on the particles released from these sections that we see the largest impact. The
loss of particles is typically a few percent but it can be as high as ~10-12% depending upon the circulation pattern. In general for the shallow intakes (25 m east and north) the loss in summer is larger
than the loss in winter. In summer the water column is stratified so that most of the abstracted water
is taken from the upper thermocline. In winter the water column is well mixed and therefore the water
is abstracted from a larger volume consisting of the deep mixed layer. These results are consistent
with the back trajectory simulations (Section 4.3) which indicate the region from which the water is
primarily abstracted.
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As noted at the beginning of this chapter, in response analysis to the results of the larval sampling
that became available more recently and the resulting internal discussion of the team, we decided to
run an additional scenario with an intake located at 200 m. We also run an additional set of particle
tracking experiments based on these current fields. The results are presented below as part of Section 4.4.
4.3
Effects on water quality
4.3.1
Effects of the abstraction on the water quality of the GOAE
In ours assessment of the effect of abstraction on water quality at GOAE scale we were asked to
consider the effects of abstraction at the site on the eastern shore of the GOAE at 25 m and 120 m
depth. As discussed in detail in section 2.2 the water quality in the GOAE is mostly affected by the
residence time of water in it, which in turn is affected by how strongly stratified the water column is.
Therefore, increased stratification would increase the residence time of deep water in the GOAE
leading to an accumulation of nutrients, which could be potentially harmful to the coral reef by triggering massive benthic algae blooms during winters with deep and prolonged convective mixing of
the open sea water column. The modelling results of the different abstraction scenarios do not provide any evidence for significant changes in water column density structure (see section 4.2.3).
4.3.2
Estimation of TSS and nutrients abstracted from RDC
The amount of suspended solids and nutrients abstracted through the RDC is a relevant information
to understand the effects of abstraction on Red Sea ecosystems; from another point of view this information is useful to understand the quality of the brine water discharged into the Dead Sea.
In this section we consider the water quality near the eastern intake at the proposed intake depths of
25 and 120 m. The available nutrient and TSS data at the intake sites are very sparse (only surface
measurements) and considering the relatively large depth range from which water is extracted at the
planned intake depths according to the backward trajectory passive tracer modelling results (see
section 4.2.5) and since the horizontal distance of water from the intake being drawn is relatively
large (~6 km), it was decided to use station A data, which are also relatively similar to the data from
near the coast. For this analysis we calculated the monthly average nutrient levels at station A based
on measurements made every month during the period 2007-2010 by the NMP (Figure 4-33 and Figure 4-34) and TSS data measured at station A on a monthly basis during 2002-2007 (Figure 4-35).
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NO-1
(mol/l)
3
Z (m)
0
2
4
NO-1
(mol/l)
3
6
0
4
NO-1
(mol/l)
3
6
0
2
4
NO-1
(mol/l)
3
6
0
2
4
NO-1
(mol/l)
3
6
0
2
4
NO-1
(mol/l)
3
6
0
0
0
0
0
0
0
100
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6
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0
600
4
Jun
700
0
2
600
Apr
700
0
600
Mar
700
0
600
Feb
700
Z (m)
2
A qaba
Dec
700
Figure 4-33 Multi annual monthly average values of nitrate levels measured at station A once
a month during the period 2007-2010. The continuous line indicates the average and the
shaded area represents the standard deviation of monthly measurements around the
average. The dashed lines represent the theoretical range of depths from which water is
extracted at the 25 m intake (red, from surface) and the 120 m intake (blue). These ranges
were calculated by taking into consideration the stability of the water column (Brunt-Vaissala
frequency, see section 2.5.1).
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PO-3
(mol/l)
4
0 0.5
Z (m)
0
PO-3
(mol/l)
4
PO-3
(mol/l)
4
PO-3
(mol/l)
4
1 1.5 0 0.5 1 1.5 2
0
0 0.5
0
1 1.5 0
0
0.5 1
PO-3
(mol/l)
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0
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PO-3
(mol/l)
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1.5 0
0
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0
0
Z (m)
A qaba
600
Feb
700
0.5 1
1.5 0
0
600
Mar
700
0.5 1
1.5 0
0
600
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700
0.5 1
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0.5 1
1.5
600
Nov
700
Jun
700
100
600
1.5
600
May
700
0.5 1
0.5 1
Dec
700
Figure 4-34 Multi annual monthly average values of phosphate levels measured at station A
once a month during the period 2007-2010. The continuous line indicates the average and the
average. The dashed lines represent the theoretical range of depths from which water is
extracted at the 25 m intake (red, from surface) and the 120 m intake (blue). These ranges
were calculated by taking into consideration the stability of the water column (Brunt-Vaissala
frequency, see section 2.5.1).
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Z (m)
0
TSS (mg/L)
5
10
0
0
TSS (mg/L)
5
10
0
TSS (mg/L)
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TSS (mg/L)
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0
Z (m)
TSS (mg/L)
5
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A qaba
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0
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10
Apr
May
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Jul
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Aug
200
Sep
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Oct
200
Nov
200
TSS (mg/L)
5
10
5
10
Dec
200
Figure 4-35 Multi annual monthly average values of TSS levels measured at station A once a
month during the period 2002-2007. The continuous line indicates the average and the
average.
In order to calculate the loads of nutrients and TSS into the RDC we used the modeling results of
passive tracer backward trajectories which were released at the 25 and 120 m depth intakes, as
shown in Section 4.2.5. In addition to the March and August results, backward trajectories were also
computed for May and November. These values were integrated for each depth level of the model to
create a horizontal mean profile and used to calculate the weighted average concentration of nutrients and TSS of water arriving at the intake. These weighted averages were then averaged and considered to represent the annual average concentration of these parameters at the intake. The annual
average weighted concentration of nutrients and TSS was then multiplied by the annual abstraction
rate (2·109 m3/yr) to obtain the loads into the RDC.
Thus, for the 25 m intake depth the expected annual loads of nitrate, phosphate and TSS into RDC
are 12.9 T/yr, 8.2 T/yr and 10.7 kT/yr, respectively, while for the 120 m intake depth the expected
annual loads of nitrate, phosphate and TSS into RDC are 19.0 T/yr, 10.4 T/yr and 10.5 kT/yr, respectively. The latter estimates contain large uncertainty due to the large variations in the nutrient levels
throughout the water column annually and interannually.
Relative to the influx of nutrients through the Tiran Straits into the GOAE, the nutrient load into the
RSDSC is less than 1%. Based on our current understanding of how nutrients affect the coral reefs
in the GOAE this abstraction of nutrients is actually beneficial.
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4.4
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Effects on marine environment/coral reefs
The following section addresses the main concerns that have been identified as possible effects of
the abstraction on the marine environment. For the sake of being cautious and conservative, the following discussion considers the scenario of maximum pumping rate (2 billion cubic meters per year).
a. Sea water warming
Since the northern end of the Gulf of Aqaba is close to the proposed pumping locations, the only
source of water to replenish the abstracted quantity is from the south. Since the water in the south
(lower latitude) is warmer, we were concerned that the RDC pumping would cause warming. If it occurs, such warming may have a major effect on the ecology of the Gulf’s open water and coral reef
ecosystems through its effect on vertical mixing and stratification. As shown in the introductory section, the unusually deep mixing during winter is the key factor determining plankton and algal dynamics in the northern Gulf and, indirectly, the corals themselves (see Genin et al., 1995). However,
based on the modelling results presented in Section 4.2.3 (see Figure 4-14 - Figure 4-16) the estimated effect of the abstraction on sea temperature and stratification is expected to be negligible,
mostly due to the relatively large exchange of water between the Gulf and the Red Sea, which is two
orders of magnitude or more larger than the proposed abstraction rate. The present and projected
trends of sea water warming under the no abstraction case with projected climate change (Section
2.5) will overshadow any effects that might be expected due to the RDC pumping even at the maximum rate.
b. Change of circulation
As the general circulation is a key factor that determines the transport of key water-born commodities, such as nutrients, plankton, and larvae, abstraction-driven changes in the circulation may have
far reaching effects on the ecology of the northern Gulf’s ecosystems. Based on the results presented from the intermediate model (Section 4.2.1) noticeable changes in the circulation are expected to
be confined to the immediate vicinity (~300 m) of the intake. Therefore, circulation-driven ecological
effects are hereafter classified under “local effects”, discussed in section (d) below. The larger scale
effects of abstraction and change in circulation on coral-reef larvae are discussed in section (e) below.
c. Changes in nutrient fluxes
If pumping induces a perpetual upwelling, and the magnitude of that vertical current is substantial, it
can augment eutrophication; conversely, if it induces downwelling it may reduce nutrient entrainment. Neither process is desirable, although the effects of eutrophication on the coral reef are of
greater risk. However, the backward trajectory simulations presented in Section 4.2.5 indicate that
the water entering the pumps during the stratified season will originate in a layer of no more than 2030 m above and below the intake depth (Figure 4-27, Figure 4-29, and Figure 4-31). In the winter the
water enters from a thicker layer but at that time of the year the nutrient profiles are fairly uniform due
to the vertical mixing. Hence no significant change in the vertical flux of nutrients is expected.
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d. Local damage
We expect substantial damage to the local benthic community around the pumping facilities, especially during construction. The coral reef and/or sea grass meadows located along the path of the
pipes and under the pumping hub will be sacrificed. For the eastern intake option, after construction,
corals reef may be re-established on the hard artificial substrate (pipes, blocks, etc.), however, the
re-established community on that substrate is expected to be different from the original, natural one
(Perkol-Finkel and Benayahu, 2004, 2007; Perkol-Finkel et al., 2006). For example, in Eilat, soft corals tend to dominate raised substrates such as metal frames and pilings (Perkol-Finkel and Benayahu, 2004, 2007). For the option of North Beach intake, the sea grass meadow damaged by pipes is
likely to be re-established around the pipes (but not on them) within several years.
As mentioned above, local changes in the flow may also induce perpetual changes in the benthic
community structure. Enhanced flow in the 200-300 m around the pumps can augment the growth of
corals and possibly other coral-reef organisms (Denison and Barns 1988; Atkinson and Bilger 1992;
Atkinson et al., 1994; Lesser et al. 1994; Nakamura et al., 2003; Mass et al., 2010).
e. The effect of abstraction on coral-reef larvae
The removal of coral-reef larvae by pumping was considered a key factor to be investigated, as it
can potentially disrupt the dispersal of coral reef species and break possible connectivity between
coral reefs on the east and west coasts. As most benthic animals disperse via planktonic larval
stage, the entrainment of larvae by the intakes may reduce the supply of larvae, possibly hindering
the long-term maintenance of a stable reef community. That is, if larvae are transported along a
route that crosses the abstraction site and the abstraction becomes a barrier to larval transport then,
to the extent that the maintenance of a healthy reef community on one side of the Gulf depends on
larval supply from the other side (hereafter “sink” and “source” sites, respectively), it (the abstraction)
may put at risk the long-term maintenance of a rich community at the “sink” site. In some benthic
communities, connectivity among neighbouring communities is a key “life-support” process, intensively studied under the heading of “supply-side ecology” (Underwood and Fairweather 1989;
Hughes et al., 2000; and references therein).
It is because of the ecological importance of connectivity to coastal marine populations that substantial efforts were devoted in our study of the potential effects of abstraction on the coral reef larvae.
The following section presents our synthesis and recommendations.
(e.1.) Minimizing the abstraction of larvae from the sea. Two types of planktonic larvae are found in
the ocean: Lecithotrophic, which have a large amount of storage material and therefore do not need
to feed during their planktonic stage, and planktotrophic, which have little storage and need to feed
and grow prior to settlement. Members of the former type usually spend short time (hours to days) in
the water column, whereas planktotrophic larvae usually spend weeks to months in the water prior to
settlement. The larvae of corals (planulae) are lecitotrophic, whereas most of the other invertebrate
larvae sorted in our work are planktotrophic. Hence, for the vast majority of planktotrophic larvae, the
photic depth (90 ±20 m in the Gulf), below which planktonic food is scarce (except during mixing –
see below), is a lower boundary of distribution. Indeed the sub-photic layer we have sampled (180120 m) had significantly less larvae than the photic layer, especially when the upper water column
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was stratified (see Figures at chapter 2.3.4). Our deep, high-resolution sampling in spring 2011,
(Figure 2-62d) shows the steep decline (jump) in larval abundance at the bottom of the photic layer
(100-120 m depth) and the very gradual decline farther down. The percent of larvae in the 120-150
m depth layer is 2 - 6.4 % of the total, marginally declining at greater depths (0.3 - 3.7% at the 180210 m depth layer). These percentages were higher during the months of deep mixing (NovemberFebruary), with averages of 4.5% and 20%, for the fish and invertebrate larvae, respectively. As unicellular phytoplankton and microplankton (=the food of the larvae) are passively mixed throughout
the mixed layer (Farstey et al. 2002), small larvae with weak swimming capability are expected to be
passively mixed by the physical mixing. Alternatively, larvae (of all sizes) may extend their distribution throughout the mixed layer because their food is homogeneous throughout that layer.
Similarly to zooplankton, larvae cannot be considered entirely “passive particles” with regard to their
depth orientation within the water column. Nevertheless, since knowledge on their swimming behaviour is meagre, the underlying assumption of our discussion is that invertebrate larvae, like zooplankton, are passively drifting with horizontal currents.
Given the distribution of larvae along the water column it is clear that placing the intake below the
photic layer should minimize the abstraction of larvae, especially during the months when the water
column is stratified (April to October). The absence of knowledge on their behaviour also renders impossible any conclusion with regard to whether or not larvae that are removed by a deep-water intake would have otherwise been lost from the pool of potential recruits to coral reefs due to their
depth (or recruit in the deep reef). Regardless, since most larvae, of shallow and deep reefs alike,
are expected to feed on phytoplankton (i.e. in the photic layers), deep, sub-photic intake will minimize the abstraction of larvae (Figure 2-62a, b,c).
In order to minimize the risk of damage to the benthic communities and to our (very expensive) sampling gear, we avoided towing the MOCNESS closer than 25 m from the bottom. Hence, we have no
information on the distribution and abundance of larvae in that near-bottom layer. Nevertheless, as
ultimately planktonic larvae seek to settle on the bottom, the larvae which reach that near-bottom
layer ecologically represent the most important portion of the larval pool. Many of those larvae are
ready to metamorphose and settle after enduring the challenging period of planktonic stage (where
survival is thought to be exceedingly low – e.g., Jackson and Strathmann, 1981), so that removing
them from the benthic layer can aggravate the local damage incurred by abstraction. Pumping near
the bottom should therefore be avoided.
During periods of water cooling, induced downwelling and/or downward vertical mixing lead to the
accumulation of plankton (Genin et al., 2005) and larvae (Figure 2-61) in the waters off the north
beach. Since the amount of larvae removed by pumping (at a given rate) is a linear function of their
concentration, pumping at the eastern coast is preferred as the removal of invertebrate larvae will be
lower compared with corresponding pumping at the north beach.
A noteworthy point is the rarity of planulae in our MOCNESS samples (on average 1 planula per 4.5
m3 of water), which may be due to the possibility that short time after being released, the larvae descend to the layer near the bottom (<25 m above bottom), a layer in which we had not towed the
MOCNESS. Taking a cautionary approach, we recommend an avoidance of pumping in the 25 m
layer above bottom. This conclusion strengthens the aforementioned recommendation to avoid nearbottom pumping based on the fact that larvae in that layer are ready to settle.
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Overall, to minimize the abstraction of larvae from the sea we recommend that pumping will be done
at the eastern coast, at a minimal depth of 140 m (the deepest extent of the photic layer plus the
thickness of the layer disturbed by the abstraction), using an intake which is elevated at least 25 m
above bottom. While larval abundance in front of the MSS reef declines gradually with distance from
shore (Figure 2-64), the absolute magnitude of that decline below the photic layer is minuscule.
(e.2) Abstraction disruption of genetic homogeneity among the west and east populations. As described above (section 2.3.5), eastern and western samples of two coral species and one gastropod
species were genetically homogenous. Results of Bayesian clustering of all individuals and particularly assignment tests (see Annex 1 for details) revealed that while cross-gulf larval trajectories are
likely, the majority of biological connectivity occurs along the gulf’s coastal zones (north-south and
east-west directions). However the lack of genetic structure is consistent with both our current measurements and the results of the model simulations. Cross-gulf larval movements can also add to the
genetic homogeneity of the gulf’. For example, direct measurements of current in the deep waters
between Aqaba and Eilat (lower panel of Figure 2-24) show a prevalence of cross-gulf currents, fluctuating between Aqaba- and Eilat-ward flows with speeds of 1-2 cm/s. Under the influence of such
currents it would take 3 to 7 days for a drifting larva to be transported from one side of the Gulf to the
other. In previous studies, much stronger cross-gulf currents were measured using a ship-mounted
ADCP (Figure 2-17 and Figure 2-18). In such cases larvae would cross the Gulf in several hours.
Currents in the surface layer measured with a HF radar (Figure 2-19), as well as the associate particle trajectories (Figure 2-22 and Figure 2-23) also depict substantial cross-gulf exchanges. These
direct measurements nicely match the pattern obtained from particle tracking simulations for particles
released over an entire month from both sides of the gulf as shown in Figure 4-36. It is important to
note that in both the direct measurements (Figure 2-17, Figure 2-19, Figure 2-22, and Figure 2-23)
and the simulations (Figure 4-36) exchange of particles between the two coasts occurs throughout
the length of the Gulf’s northern section. We also note that Figure 4-36 (especially the upper panel)
shows some indication of a preference for alongshore trajectories, but ultimately these trajectories
also lead to particle exchanges between the western and eastern coastal zones.
Hence, the abstraction of larvae at a single pumping point is unlikely to create a barrier to larval exchange (=connectivity) among populations at the two sides of the Gulf.
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Figure 4-36 Simulated trajectories (96 hr long) of particles released once every 6 hrs along the
eastern (top panel) and western (bottom panel) coasts at the 0-60 m depth layer in August
2010. The black segments show the position of the particle source transects.
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(e.3.) Regional effects of larval abstraction.
A key question that can be addressed by particle (i.e. larva) tracking simulations is “what percent of
the larvae released along the reef some distance upstream of the pumps will end up being abstracted by the pumps”? Results for particles released in the upper 50 m of the water column were already
presented in Section 4.2.6. To further refine the estimates for deeper intakes, here we ran some additional particle tracking simulations using the same methodology as before except now we released
particles at deeper layers and for the two deep intake scenarios (120 m and 200 m intakes). We also
separately tracked the particles from the individual release depths. For the 120 m intake simulation
particles were every 10 m from 60-170 m while for the 200 m intake scenarios they were released
every 10 m from 170-230 m. We also limited the releases to four cross sections along the eastern
shore at distances of 0.5 and 3 km north and south of the intake as shown in Figure 4-37. Table 4-6
and Table 4-7 list the results for March and August from the 120 m and the 200 m eastern intake respectively.
Figure 4-37 Map showing the location of transects A, B, C and D (blue lines) along which
simulated particles (=larvae) were released. Red X's indicates the location of the shallow and
deep eastern intakes.
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Table 4-6 Percent of particles abstracted by a 120 m deep intake at the east coast from each
release depth at each of sections (A,B,C, and D) shown in Fig. 4.32, in the months of August
(stratified water column) and March (mixed water column). Note the generally higher
abstraction when the water column is mixed, an outcome of both the tidal currents and
vertical mixing (particles released in the photic layer are mixed down to the depth of intake).
Overall the percent abstracted is very low, even for particles released only 500 m away from
the intake (transects B and C).
Transect
A
Releasing
depth
60
70
80
90
100
110
120
130
140
150
160
170
August
0
0
0
0
0
0
0
0
0
0
0
0
0
0.37
0
0.37
0
0
0
0.51
0.51
0
0
0.85
C
60
70
80
90
100
110
120
130
140
150
160
170
0
0
0
0
0
0
0
0
0
0
0
0
0.73
0
0
0.51
0.51
1.02
0.51
0.51
0.51
0
0.85
0
D
B
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Transect
Releasing
depth
60
70
80
90
100
110
120
130
140
150
160
170
August
March
0
0
0
0
1.54
0
0
0.51
0
0
0
0
1.1
1.83
4.62
5.64
5.13
4.1
2.56
2.57
0.51
0
0
0
60
70
80
90
100
110
120
130
140
150
160
170
0
0
0
0
0
0
0
0
0
0
0
0
0.32
0
0.32
0.32
0.32
0
0
0
0
0
0
0
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Table 4-7 Percent of particles abstracted by a 200 m deep intake at the east coast from each
release depth at each of sections (A,B,C, and D) shown in Figure 4-37, in the months of
August (stratified water column) and March (mixed water column). Note the generally higher
abstraction when the water column is mixed, an outcome of both the tidal currents and
vertical mixing (particles released in the photic layer are mixed down to the depth of intake).
Overall the percent abstracted is very low, even for particles released only 500 m away from
the intake (transects B and C).
Transect
A
Releasing
depth
170
180
190
200
210
220
230
August
0.37
0
0
0
0
0
0
0.73
0
0.73
0.37
0
0
0
C
170
180
190
200
210
220
230
1.47
1.1
0.73
0
0
0
0.37
1.83
2.57
2.2
2.57
6.23
6.59
6.59
D
B
March
Transect
Releasing
depth
170
180
190
200
210
220
230
August
March
0
0
0
0
0
0
0
1.1
0.73
0.73
0
0
0
0
170
180
190
200
210
220
230
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Consider the regional effect of the abstraction, with an intake depth of 120 m. Under the worst case
scenario (maximum entrainment when the water column is mixed) a mere 0.18% of the larvae released within the 60-120 layer (where larvae concentration is highest) 3 km south of the intake will
be removed. Of those released within the 121-170 m layer none will be removed. Given the depth
distribution of larvae during mixing the total abstraction will be 0.06% of the total number of larvae
reaching the site.
Even lower proportions will be abstracted if we consider the larvae released 3 km north of the intake
and during the months of water column stratification (April-October).
For the 200 m intake the results are similar with the worst case being the abstraction in March from
the section located 3 km north of the intake. Hence on a regional scale (kilometres) the effect on larval supply is expected to be negligible.
On a local scale (larvae released 500 m away from the intake), the worst case scenario (i.e. mixed
water column) for an intake depth of 120 m amounts to the removal of 2.3% of the larvae released
500 m south of the intake, and for an intake at 200 m depth amounts to the removal of 4% of the larvae released 500 m north of the intake. While these are also small values, they must be added to
other local effects (see above sub-section d).
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The maximum proportion abstracted in the case of a shallow intake (25 m) is approximately twice
that of the deep (120 m) scenario, especially during the season when the water column is stratified
rendering the shallow intake option less desirable.
In our synthesis, we assume that larvae are passively drifting with the current. While this may be true
for the vast majority of small, weakly swimming invertebrate larvae, some fish larvae can swim and
orient in order to maximize their chances of reaching a suitable settling site (e.g., Paris and Cowen,
2004). Since the behaviour of larval fish is poorly known, no simulation can be of help in predicting
the effects of abstraction of larvae that actively determine their location regardless of the ambient
currents. Also, with time, the larvae grow and become better swimmer. Concurrently they also approach their settling place on the bottom. Therefore, for the sake of taking the more cautious approach, based on our extensive sampling program and physical modelling, we recommend that the
pumping will be done at 25 m above bottom at the depth where larvae are relatively rare. The combination of abstraction of larvae-poor waters together with the fact that only a few percent of the larvae found around the pump will end up in the intake, assures that the effects of such a deep pumping will likely be negligible on a regional scale.
Importantly, our synthesis of the expected effects of larval abstraction suffers from: (1) Short duration
of larval sampling– one year; (2) Limited temporal (among-year) and depth resolution; (3) No larval
sampling in the 25 m above bottom; (4) Simulation which are based on the assumption of horizontally passively drifting larvae. Therefore, our recommendations for pump location are based on a cautionary, conservative approach.
4.5
Future scenarios
4.5.1
Cumulative impact of RDC and other future abstraction
The final scenario that was considered was the cumulative impact of the RDC and other planned abstractions from the gulf. The only other major abstraction that is known is the Jordan Red Sea Project (JRSP) in which it has been proposed to abstract water from the same location as the northern
intake that we considered in this study. Based on the available information and the recommendation
of the SMU, it was assumed that the abstraction rate of the JRSP will be 0.4 billion m3/yr. It was also
recommended that the total combined abstraction of the RDC and JRSP not exceed 2 billion m3/yr.
Thus there are potentially two cumulative scenarios that should be considered in which the JRSP
abstracts 0.4 and the RDC abstracts 1.6 billion m3/yr, respectively. The case in which the two intakes
are co-located at the northern site is equivalent to our Scenario 13 in which a total of 2 billion m3/yr
are abstracted. The second case is with the JRPS abstracting 0.4 billion m3/yr (from the northern intake) and the RDC abstracting 1.6 billion m3/yr from the deep (120 m) eastern intake. The results are
shown in Figure 4-38 - Figure 4-41 which for the induced currents at each of the two intakes (Figure
4-38, March, Figure 4-39, August, for the 120 m east RDC, and Figure 4-40, March, and Figure 4-41,
August, for the JRSP). Not surprisingly, the results are very similar to the results for each individual
intake considered separately (very close to Scenario 9 for the 120 m east RDC, and Scenario 10 for
the JRSP). This is due to the fact that the impact of abstraction on the currents is a localized effect
limited to within a few hundred meters. No specific or noticeable cumulative effects appear in this
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scenario. Here the maximum induced current differences are 4.2 and 2.6 cm/s for the RDC and
JRSP, respectively, in March and 3.9 and 3.2 cm/s in August. These are almost identical to the respective values for the separate scenarios as listed in Table 4-3. The main difference is that here the
RDC abstraction is 7% stronger than in Scenario 9 (1.6 as compared to 1.5 billion m3/yr).
Figure 4-38 Horizontal map of currents induced by abstraction at the 120 m eastern intake for
Scenario 15, March 2010.
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Figure 4-40 Horizontal map of currents induced by abstraction at the northern intake (JRSP)
for Scenario 15, March 2010.
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Cumulative impact of RDC and climate change
As concluded in section 4.5.1 global warming will cause the water column in the GOAE to be more
strongly stratified likely resulting in a longer deep water residence and increase of the deep water nutrient reservoir. As a result of deep convective mixing during exceptionally cold and prolonged winters nutrient rich water will be transported into the surface layer and massive macro algae blooms
could be triggered causing coral mortality in coastal fringing reefs. According to the modelling results
there appears to be very little to no additional effect of water abstraction to the effect of warming on
the stability of the water column.
An additional water quality concern is the acidification of seawater due to increasing levels of atmospheric CO2. Partial pressure of atmospheric CO2 is expected to increase from a current level of 392
ppm to nearly 750 ppm by end of the 21st century according to the A2 “business as usual” scenario
for CO2 emissions (IPCC, 2007). This increase is projected to cause a decrease in oceanic pH on
the order of 0.2 pH units. According to Kleypas et al. (1999) the effect of ocean acidification in Red
Sea waters (including the GOAE) is expected to be the most pronounced because of its relatively
high salinity/alkalinity. However, as seen in section 2.3, an increasing trend in total alkalinity as well
as warming could partially buffer the increase in seawater dissolved inorganic carbon concentration
resulting from the increase of atmospheric CO2, thus reducing the effect of acidification on coral
growth and other biological processes and organisms affected by it.
According to Silverman et al. (2007) community calcification rates are well correlated with degree of
aragonite saturation and temperature. Thus, given a current annual average total alkalinity of 2520
mol/kg, temperature of 23.9ºC and salinity of 40.7 at atmospheric equilibrium with respect to CO2,
the aragonite saturation is 4.2. In 20 years the partial pressure of atmospheric CO2 will be 472 ppm.
Given the current warming and total alkalinity trends in 20 years both are expected to increase to
24.7ºC and 2570 mol/kg, respectively. The resulting degree of aragonite saturation will be 4.0, a reduction of only 0.2 (-5%). Using the empirical equation for community calcification developed by Silverman et al. (2007) yields a reduction in calcification rate of coral reefs of -3.5% relative to the current rate. If the alkalinity trend does not continue as suggested by the standardized measurements
that have been made since 2005 then the decrease in aragonite saturation will be greater (arag = 0.34) and the resulting decrease in calcification will be -10.8%. If the warming and alkalinity trends
both don’t continue then the decrease in aragonite saturation will be even greater (arag = -0.43)
and the resulting decrease in calcification will be -20.6%. These anticipated changes in the carbonate system of the GOAE will be unaffected by the abstraction of water to the RDC.
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Addressing best option for RDC intake
Based on the analysis and assessment of the various aspects of the RDC presented in the previous
chapters, we can immediately eliminate the "no-go" options which we identify as any combination of
intake configuration, location, and depth which are located within the photic zone. In the following
chapter we therefore address the issue of the best option for a "go" decision.
Best option for intake configuration
The two options for intake configuration considered were an open channel at the surface and a submerged intake. While there are certainly engineering considerations that must be taken into account
for either option, these are beyond the scope of our study which focuses on the environmental issues
and impacts of the proposed water abstraction. In this respect there is a clear preference for a submerged intake under the assumption that it is located at an appropriate depth, as explained in the
next subsection. The reasons for not recommending a surface intake are the following:
(1) Considerations concerning morphology
An open channel at the surface requires significant construction and development of infrastructure
which will permanently affect the landscape.
(2) Considerations concerning water circulation
The largest disturbance of the circulation resulting from abstraction of water will occur when the intake is located in shallow water. In this respect there is little difference between a surface intake and
a submerged shallow intake. The induced currents will be felt throughout the entire water column in
the vicinity of the intake, and as with all options, the effects will be felt up to a few hundred meters
from the intake. This may pose certain hazards to various surface operations such as boating, fishing, and recreational activities.
(3) Considerations concerning water quality
In shallow water the entire water column will be affected by the induced currents. In very shallow water around a surface intake the likelihood that the abstraction will cause resuspension of the sediments is much higher than even for a shallow submerged intake. This will lead to reduced water
quality at the intake. In additional a surface intake may entrain floating or buoyant pollutants such as
hydrocarbons which are not found at depth.
(4) Considerations concerning the ecosystem
A major conclusion of this study is that any intake for water abstraction should be located well below
the maximum depth of the photic layer. In this respect the impact of a surface intake on the ecosystem will be similar to the impact of a shallow submerged intake and is therefore not recommended.
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Best option for intake location
Concerning intake location, eastern candidate site is recommended for following reasons:
(1) Considerations concerning morphology
Since it is recommended to locate the intake well below the photic zone (see below), the relatively
steeper bottom slope of eastern intake area versus northern intake implies that the desired depth
can be achieved closer to shore.
(2) Considerations concerning water circulation
The local currents along the east shore tend to be stronger than along the north beach and therefore
the disturbance caused by the abstraction would be less significant.
(3) Considerations concerning water quality
a.
The proposed northern intake is located in relatively shallow water (bottom depth of 17.5 m
with the intake located 9.5 m above the bottom), this characteristic, coupled with the presence of relatively fine sediments in the north, increase the likelihood that the currents induced by the abstraction will re-suspend the sediments. This may augment the damage to
the local benthic community and the sea grass meadows. It could also adversely affect the
invertebrate larvae population in this area. Finally, this may also lead to reduced water
quality at the intake.
b.
During southerly storms, the typical wind speed is around 5 m/s. If we consider the most
extreme southerly winds of 10-15 m/s, which occur at most once or twice a year (between
October and May) and last for a period of 12 hours or less (meteorological data recorded at
IUI station in Eilat), the estimated maximum significant wave height at the northern end of
the Gulf could reach 2.6-4.3 m. These waves would break in water depth of less than 6 m
and could cause some sediment resuspension in the nearshore zone. Thus wind and wave
induced sediment resuspension is in general not expected to be a major factor even in the
vicinity of the shallower northern intake location, except for the rare occasions when the
water remains turbid for about 2-3 days after such storms (e.g., visual observations at the
IUI station).
c.
After extreme events such as infrequent winter flooding some suspended sediments are introduced along the northern shore. These sediments may remain suspended in the water
column for a few days (visual observations at the IUI station) and could be an issue for operation of the intake. However such events occur only once every few years.
d.
Several sources of potential contamination exist in the upper Gulf of Aqaba, close to the
proposed northern intake, such as the cities of Eilat and Aqaba with their marinas, beaches
and hotel areas. Untreated sewage spills to the Gulf due to failure of Eilat municipal
wastewater treatment plant are not infrequent, while emission of contaminants from the
boats and yachts contribute to the depletion of local water quality. The new touristic developments of Ayla Oasis and Saraya Aqaba, presently under construction, are likely to add
new potential contamination sources to the present situation. In this context the eastern intake, being far from relevant potential contamination sources (especially when considering
the planned re-location of Aqaba port to the south) is by far a safer choice in terms of abstracted water quality.
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(4) Considerations concerning bottom habitats
a.
While in the past the sea grass meadows near Tala Bay (located south of Aqaba and previously known as the Big Bay) may have been a thriving sea grass site, after the construction of the Tala Bay resort, many of these sea grasses deteriorated (M. Khalaf personal
observation). This indicates the clear risks posed by development and construction in the
sea to the health of these meadows. Today the sea grass meadows in the “hotel area” located near the northern site is in much better condition. It is therefore important to preserve
this important habitat from further anthropogenic disturbance.
b.
At the eastern candidate site a barren submerged area (approximately 35-40 m) was found
near the study site of Thermal Power Station, starting from 2m depth to more than 40m
depth. This area was destroyed by previous construction and development activities and
has never recovered. Given the already deteriorated state of the natural ecosystem at this
site, the construction of intake facilities here is preferable over the option of building it in a
pristine, undisturbed habitat.
(5) Considerations concerning fish communities
a.
The Northern Intake Site is dominated by well-developed sea grass meadows that can
serve as nursery area for the successful recruitment, nursery and development of juvenile
fishes, particularly for economically important species. This site can support fishery stock
along the Jordanian coast. It is of great importance to protect this valuable fishery resource
and to minimize any adverse impacts on the fishing community and industry in the city of
Aqaba that may arise from any sea-based facilities including the RDC project.
b.
Teixeirichthys jordani (Jordan`s damselfish) lives in aggregations over sea grass areas and
sandy bottoms. Juveniles are often found among the spines of the sea urchins in the studied area. This species is only observed in this site only along the Jordanian coast. This
should be taken into consideration if this site is to be decided as intake site.
c.
The fish Chromis pelloura which is found at the eastern intake site is an endemic species
to the Gulf of Aqaba, it is highly abundant in the northern zone of the eastern intake site at
15m depth. It has also been reported during previous monitoring programs in the Tala Bay
area as well as at Phosphate Loading berth site.
d.
At the eastern candidate site, the northern area show higher quality conditions in terms of
number of species and number of individuals. The southern zone is of lesser importance. If
this site will be selected as the intake site and the destroyed area mentioned above is not
sufficient for construction and deployment of the intake, then it is recommended expand the
construction and operation into the southern zone of the site rather than the middle or
northern zone.
(6) Considerations concerning larvae spatial distribution
The measurements indicate that larvae and plankton are more abundant at the northern site than
at the eastern site. Therefore the adverse impact of abstraction from the north will be higher.
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Best option for intake depth
Based on the model simulations, the analysis of the available, and the new insights gained from the
additional data collected within the framework of this project, it is recommended that the intake be
located well below the deepest extent of the photic zone. To locate the intake within the photic zone
would lead to a "no-go" recommendation. The maximum depth of the photic zone varies with the
seasons as well as interannually. In Figure 5-1 we show the monthly variations of the depth of the
1% light level and the light attenuation coefficient for 2010 based on data collected at Station A as
part of the NMP. The average depth is 86.3 m and it ranges from 59 m during the late winter bloom
in March to 111 m in August. Considering the typical vertical extent of the current disturbance induced by the abstraction from the deep intake, which is +/-20 m, the implication is that the intake
should be located even deeper than the proposed 120 m. In addition, during the summer months, the
water column is stratified, and a typical deep chlorophyll maximum (DCM) develops at 60 – 100 m
depth (see paragraph 2.2). Furthermore, chlorophyll-a is found in minute but measureable concentrations below the above mentioned depths of the photic layer, often at 120 m and occasionally even
at 150 m. Thus based on the range of the photic layer depth, the chlorophyll-a concentrations, and
our objective to avoid withdrawing water from the 60-120 m layer (where larvae are common), it is
recommended to locate the intake at a depth of at least 140 m (bottom depth of 160-165 m). We are
aware of high variability in plankton numbers, of the significant augmentation of larvae densities
close to the shore and of other possible source of errors in the estimation. In addition to that, since
our results show that larvae are also present down to a depth of 180 m (limit of our sampling), to further refine and corroborate the selection of the precise depth, from an environmental point of view,
we recommend conducting additional sampling, very focused in the vicinity of the proposed intake,
down to a depth of approximately 250 m. Abstraction of water from this depth, which is within the
nutricline will result in higher nutrient levels in abstracted water. The nutrient load to the RDC from
such an intake depth is likely less than an order of magnitude greater than the estimate made for the
120 m intake depth, i.e. 0 102 tons of dissolved inorganic nitrogen and phosphate.
Finally to avoid entraining mature larvae and larvae that actively seek proximity to the bottom, we
recommend the intake to be located 25 m above bottom.
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Figure 5-1 Monthly variations of the depth of the 1% light level (red line) and the light
attenuation coefficient in m-1 (blue line) at Station A during the year 2010.
Abstraction rate
One of the major goals of the proposed RDC is to provide, through desalination, much needed fresh
water to meet the increasing needs of the population this very dry region. In this respect it is clear
that to anticipate future needs it is most sensible to strive for the maximum availability of fresh water.
For this reason in most of our analysis, especially concerning the impacts on water quality and the
ecosystem, we concentrated on the maximum abstraction rate of 2 billion m3/yr. In this sense our
recommendations are cautious and conservative and represent a worst case option.
The impacts of varying abstraction rates were assessed mainly in terms of the speed of the currents
induced by the abstraction. Not surprisingly, for any given intake configuration, location, and depth
the impacts will increase with increasing abstraction rates.
Modeling results at lower abstraction rates carried out according to the ToR and the agreed scenarios allow to evaluate different combination of intake configuration, location, and depth and could certainly be refined in a future study, running modeling scenarios aimed at directly supporting next design phases.
Summary
1. The motivation for this study is a concern the RDC operation would lead to adverse ecological and environmental changes, consisting of: seawater warming, changes in the circulation,
and changes in coral reefs and other benthic habitats due to the abstraction of larvae.
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2. Water exchange between the Red Sea and the Gulf of Aqaba/Eilat is several orders of magnitude larger than the RDC abstraction, resulting in no significant effect on warming of the
water in the northern Gulf due to climate change.
3. Modeling simulations show that the effects on of RDC on the circulation will be local (~ 300
m around the intake).
4. Modeling simulations show that intake will pump water from a layer extending up to 20 m
above and below the intake depth, except for a short period towards the end of winter.
5. The vast majority of larvae (vertebrate and invertebrate) are found within the photic layer (i.e.
shallower than 100-120m). The proportion of larvae found below that depth rarely exceed
10%, except during the four winter months, when vertical mixing may extend a few hundred
meters in depth (depending how cold the winter is).
6. Larvae of corals (“planulae”) were rarely observed in our net tows, indicating their rarity in
the layer sampled (>25 m above bottom).
7. Off the coral reefs, there is a tendency of larval abundance to be higher closer to shore along
the east coast (MSS station) but not the west coast (NR station).
8. Larvae are found in significant number across the gulf, including the deep waters along the
gulf’s centerline, suggesting that dispersal is not necessarily restricted to narrow long-shore
routes (termed “corridors”).
9. There is no apparent genetic structure across the northern GOA, suggesting that both sides
are drawing larvae from a common and well-mixed pool.
10. Given point number 8, water drawn by the intake will be replaced by water with similar larval
concentrations (note that the abstraction of larvae by the intake is expected to have a significant effect on their abundance in the down-current region only if the water compensating for
the volume abstracted originates in regions where the larvae are rare).
11. Modeling simulations indicate that the intake will abstract much less than 1% of the larvae
released in water parcels that flow toward the intake from 3 kilometers upstream.
12. Together with the aforementioned rarity of larvae at depth below the photic layer, with an intake at >120 m depth, the RDC will abstract an insignificant amount (<<1 %) of the larvae
flowing toward the intake region across the entire water column.
13. Long term data from the Israeli National Monitoring Program, as well as several similar studies in other coral reefs in the world, indicate that the supply of larvae is not a limiting factor
for corals in Eilat. It is yet unknown whether the lack of larval limitation also applies for fish
and other invertebrates in GOAE. Hence, a cautionary approach is recommended.
14. The overall synthesis of the available data lead us to recommend that the minimal depth of
the intake should be at 140 m, raised at least 25 m above bottom, and located at the designated area on the east coast.
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Gulf scale assessment and risks
In this study, the potential sources of concern of the RDC abstraction were the effects on: the circulation (local, regional, and gulf wide), the water column structure and mass balances, and the coral
reefs and fish fauna.
Despite the fact that the collection and analysis of Best Available Data and the new surveys and experimental activities have been limited to the Israeli and Jordanian coastline and the northern tip of
the GOAE, the results of the modeling study and the assessment are exhaustive and allow us to exclude any risk for the environment at the gulf wide scale, which may involve the Egyptian and Saudi
Arabian coastal areas and territorial waters (Figure 6-1).
Israel
Jordan
Egypt
Saudi Arabia
Figure 6-1 Countries facing the GOA and relative contribution to coastline.
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This conclusion is valid provided that the recommendations on best location and best depth are respected and provided that no major future developments affecting water abstraction / water discharge and pollution loads will happen in the Egyptian and Saudi Arabian coastal area.
In the latter case, a specific evaluation on potential cumulative effects with RDC is recommended.
More specifically, in the configuration with the eastern intake, a water depth of at least 140 m and an
abstraction rate of 2 billion m3/y:
-
the effects on the circulation will be local, limited to a few hundreds meters from the intake;
-
abstraction will be less than 0.5% the amount of water exchanged though the strait of Tiran;
therefore the impact on circulation and heat budget at the scale of the whole gulf will be negligible;
-
the effect of RDC on heat flux and water column structure and stability will be negligible;
-
the nutrient abstraction is less than 1% of the total flux through the Tiran strait; this abstraction may be marginally beneficial for the coral reefs;
-
the larvae (fish and invertebrates) abstraction is very limited and will not induce negative effects on coral reefs and pelagic communities, neither regional nor Gulf wide scales:
-
the abstraction is not expected to affect connectivity between populations in the area;
-
effects on benthic habitats and fish communities, including economically important species,
will be local and limited to the construction phase and site.
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Next steps recommended
In order to assist the next design, testing and realization phases of RDC we recommend to:
1)
maintain a continuous long term monitoring program in the northern Gulf;
2)
carry out detailed monitoring at the selected intake site;
3)
carry out a detailed modeling and near field study at the selected intake site.
Concerning the long-term monitoring, we urge the authorities responsible for the operation of the
RDC to maintain a continuous monitoring program which will provide science-based information on
its potential environmental effects. Especially, we recommend that the future monitoring program will
measure the currents around the intake and away from it, will provide monthly profiles of key oceanographic parameters including physical (C,T,D), chemical (nutrients, oxygen, pH, heavy metals and
other pollutants) and biological (plankton, primary production) parameters and will routinely measure
the abundance of coral reef larvae and the abundance and diversity of corals, fish, and other benthic
invertebrates in the coral reefs and other benthic communities near and away from the intake.
We also recommend initiating an additional small-scale study prior to final selection of the intake site
and depth. That study should focus on the habitats and processes across the immediate vicinity of
the proposed intake site (eastern intake), with the aim of assisting in the precise design, location,
and construction of the intake. This additional study should provide:
-
detailed hydrographic conditions at the site;
-
small-scale circulation and internal-wave regime at the proposed intake site;
-
the quantitative characterization of the local benthic community, including corals, other invertebrates, fishes, sea grasses, and soft-bottom fauna down to 200 m depth;
-
the distribution of larvae across the entire water columns, including the 25m above-bottom
layer, extending to a depth of 250 m.
The additional study should provide a small-scale model to describe the near field behavior around
the intake and assist in the evaluation and optimization of the possible intake. This study should also
assist the evaluation and optimization of the possible intake of a Pilot Project, if implemented (the
Feasibility Study Consultant provided information concerning a pilot project having a subsurface intake at the northern intake location, between the Ayla property development project in Aqaba and the
Jordan / Israeli international border, with an abstraction rate of 4 to 40 million m3/year).
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References
Abu-Hilal, A. 1993. Observations on heavy metal geochemical association in marine sediments of
the Jordan Gulf of Aqaba. Marine Pollution Bulletin 26: 85-90.
Ajiad, A. M. and Mahasneh, D.M. (1987) Redescription of Ariomma brevimanus ( Klunzinger, 1884) a
rare stomateoid from the Gulf of Aqaba (Red Sea). Cybium 10/ 2: 135-142.
Ajiad, A.M. (1987) First record of Aulacocephalus temmincki Bleeker, 1857, from the Red Sea and
four rare species from Aqaba, Jordan. Cybium 11/1: 104-105.
Ajiad, A.M. and Al- Absy, A.H. (1986) First record of Lycodontis elegans (Pisces: Muraenidae) from
the Red Sea. Cybium 10/ 3: 297-298.
Ajiad, A.M., Jafari, R. and Mahasneh, D. (1987) Thyrsitoides jordanus ( Teleosti: Gempylidae): A
new species from the Gulf of aqaba (Red Sea). J. mar. biol. Ass. India 24/1-2: 12-14.
Al-Absy, A.H. (1988) Review of the goatfishes (Pisces: Perciformes: Mullidae) in the Gulf of Aqaba,
Red Sea. Fauna of Saudi Arabian, 9: 152-168.
Al-Khashman O. (2007). The investigation of metal concentrations in street dust samples in Aqaba.
Environ Geochem Health (2007) 29:197-207).
Allen G.R., Steene R., and Allen, M. (1998) Guide to angelfishes and Butterflyfishes. Odyssey Press.
ALLEN, G. R. (1984): Lutjanidae. - In: FISCHER, W. & BIANCHI, G. [Eds.]: FAO species identification
sheets for fishery purposes. Western Indian Ocean fishing area 51. Vol. III: [pag. var.]; Rome (FAO).
Al-Masri M, Alawi M, Rasheed M (2009). Degradation of Organochlorine pesticides in carbonate sediments from the Gulf of Aqaba. Res. J. Env. Toxicology, 3:147-158.
Al-Moghrabi SM. 1997. Bathymetric distribution of Drupella cornus and Coralliophilaneritoidea in the
Gulf of Aqaba (Jordan). Proc 8th Int Coral Reef Symp 2, 1345-1350.
Al-Najjar T., 2000. The seasonal dynamics and grazing control of Phyto- and mesozooplankton in
the northern Gulf of Aqaba. Journal Seasonal feasts and festivals. Volume & Page Numbers Volume
579, Number 1.
Al-Zibdah Mohammad (2009). SYNOPSIS on AQUCULTURE in JORDAN. A report submitted to
Thailand Agency for International Cooperation during a training course on marine finfish hatcheries.
13pp. 1-31/May 2009, Songkhla, Thailand.
Al-Zibdah, M. and N. Odat. ( 2007). Fishery status, growth, reproduction biology and feeding habit of
two Scombrid fish from the Gulf of Aqaba, Red Sea. Lebanese Science Journal, 8(2), 3-20.
Al-Zibdah, M., M. Khalaf and N. Odat. (2006). The fishery status in Jordan’s Gulf of Aqaba, Red Sea.
Dirasat, pure sciences. 33(1), 127-141.
Al-Zibdah, Mohammad (2008). Community structure of fishes in relation to coastal industrialization
on Jordan’s Gulf of Aqaba, Red Sea. J.J. Appl. Sci. Vol. 10, No.1, 59-70.
RSS-REL-T005.0
page 188 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Antonius A, Riegl B. 1998. A possible link between coral diseases and a corallivorous snail (Drupella
cornus) outbreak in the Red Sea. Atoll Res Bull 447, 1-9.
ARON, A. & GOODYEAR, R. H. (1969): Fishes collected during a mid-water trawling survey of the Gulf
of Elat and the Red Sea. – Israel Journal of Zoology, 18: 237-244.
ASEZA (2008). Jordan’s National Programme of Action for the Protection of the Marine Environment
from Land-Based Activities.
Assaf, G., and J. Kessler (1976), Climate and energy exchange in Gulf of Aqaba (Eilat), Mon.
Weather Rev., 104, 381–385.
Atkinson MJ, Bilger RW (1992) Effects of water velocity on phosphate-uptake in coral reef-flat communities. Limnol Oceanogr 37:273-279
Atkinson MJ, Birk Y, Rosenthal H (eds), 2001.Evaluation of Pollution in the Gulf of Eilat, a technical
report for the Israeli Ministries of Infrastructure Environment and Agriculture.
Atkinson MJ, Kotler E, Newton P (1994) Effects of water velocity on respiration, calcification, and
ammonium uptake of a Porites compressa community. Pac Sci 48:296-303
Ayre DJ, Miller KJ. 2004. Where do clonal coral larvae go? Adult genotypic diversity conflicts with reproductive effort in the brooding coral Pocillopora damicornis. Mar Ecol Prog Ser 277, 95–105.
Badran M.I. and Al Zibdah M.K., 2005. Environmental Quality of Jordanian Coastal Surface Sediment, Gulf of Aqaba, Red Sea. AMBIO: A Journal of the Human Environment 34(8):615-620. 2005
Badran, M. I. (2001). Dissolved oxygen, Chlorophyll a and Nutrients: Seasonal Cycles in waters of
the Gulf Aqaba, Red Sea. Aqua. Ecosys. Health Manag., 4, 139-150.
Badran, M. I. (2001). Dissolved oxygen, Chlorophyll a and Nutrients: Seasonal Cycles in waters of
the Gulf Aqaba, Red Sea. Aqua. Ecosys. Health Manag., 4, 139-150.
Badran, M.I. and P. Foster. (1998). Environmental quality of the Jordanian cosatal waters of the Gulf
of Aqaba, Red sea. Aqua. Ecosys. Health Manag., 1: 75-89.
BARANES, A. & GOLANI, D. (1991): The Mesobenthic Fish Assemblage of the northern Red Sea. - Abstracts. VII. Congress of European Ichthyologists - Den Haag: 8.
Baranes, A. and Golani, D. (1993) An annotated list on deep –sea fishes collected in the northern
Red Sea, Gulf of Aqaba. Israel J. Zool. 39: 299-336.
Bein A, Magal E and Yechieli Y (2004) IET Recommendation No. a2, Nutrient flux into the Gulf of Eilat through the groundwater system, In: Evaluation of Fish Cages in the Gulf of Eilat, a technical report for the Israeli Ministries of Infrastructure Environment and Agriculture, Atkinson MJ, Birk Y,
Rosenthal H (eds), www.sviva.gov.il
Benayahu, Y. and Loya, Y. 1977b. seasonal occurrence of benthic-algae communities and grazing
regulation by sea urchin at the coral reefs of Eilat, Red Sea. Proc. 3ed int. coral reef symp. Miami,
USA, 1:384-389.
Benayahu, Y., Loya, Y., 1977a. Space partitioning by stony corals, soft corals and algae in the
northern Gulf of Eilat, Red Sea. Helogländer Wiss. Meeresunters. 30, 362-382.
RSS-REL-T005.0
page 189 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Ben-Sasson, M., S. Brenner, and N. Paldor (2009), Estimating air-sea heat fluxes in semienclosed
basins: The case of the Gulf of Elat (Aqaba), J. Phys. Oceanogr., 39, doi:10.1175/2008JPO3858.1.
Ben-Tuvia, A. and Trewavas,E. (1986/1987) Atrobucca geniae, a new species of sciaenid fish from
the Gulf of Elat (Gulf of Aqaba), Red Sea. Israel J. Zool. 34(1-2): 15-21.
Ben-Tuvia, A; Diamant, A; Baranes, A. and Golani, D. (1983) Analysis of a coral reef fish community
in shallow –waters of Nuweiba, Gulf of Aqaba, Red Sea. Bull Inst Oceanogr Fish 9: 193-206.
Ben-Tzv, O, Kiflawi M, Gaines SD, Sheehy MS, El-Zibdah M, Paradis GL, Abelson A. 2008. Tracking
recruitment pathways of Chromis viridis in the Gulf of Aqaba using otolith chemistry. Mar Ecol Prog
Ser 359, 229-238.
Berman, T., N. Paldor, and S. Brenner (2000), Simulation of wind-driven circulation in the Gulf of Elat
(Aqaba), J. Mar. Syst., 26, 349–365.
Berman, T., N. Paldor, and S. Brenner (2003). The seasonalty of the tidal circulation in the Gulf of
Elat. Isr. J. Earth Sci., 52, 11-19.
Biton, E. and H. Gildor (2011), The general circulation of the Gulf of Eilat/Aqaba revisited: The interplay between the exchange flow through the Straits of Tiran and surface fluxes, J. Geophys. Res.,
accepted pending revision.
Biton, E. and H. Gildor (2011a), Stepwise seasonal restratification and the evolution of salinity minimum in the Gulf of Eilat/Aqaba, J. Geophys. Res., in press.
Biton, E. and H. Gildor (2011b), The coupling between exchange flux through a strait and dynamics
in a small convectively driven marginal sea: The Gulf of Eilat/Aqaba, J. Geophys. Res., in press.
Biton, E., J. Silverman, and H. Gildor (2008a), Observation and modeling of pulsating density current, Geophys, Res. Lett., 35, doi:10.1029/2008GL034, 123.
Black R, Johnson MS. 1994. Growth rates in outbreak populations of the corallivorous gastropod
Drupella cornus (Roding 1798) at Ningaloo reef, Western Australia. Coral Reefs 13, 145-150.
BLEEKER, P. (1854-57): Nieuwe nalezingen op de ichthyologie van Japan. – Verhandelingen van het
Bataviaasch Genootschap van Kunsten en Wetenschappen, 26: 1-132.
BLOCH, M. E. & SCHNEIDER, J. G. (1801): M. E. Blochii, Systema Ichthyologiae iconibus cx illustratum.
Post obitum auctoris opus inchoatum absolvit, correxit, interpolavit Jo. Gottlob Schneider, Saxo. Berolini. Sumtibus Austoris Impressum et Bibliopolio Sanderiano Commissum. - i-lx + 584 p.; Berlin
Blumberg, A.F. and G.L. Mellor (1987). A description of a three dimensional coastal ocean circulation
model. In: Three dimensional coastal ocean models, N. Heaps, editor, American Geophysical Union,
Washington, DC, 1-16.
Botha C. (2000). Cathodic protection for ships. Mechanical Technology: May 2000, 31-35.
Bouchon-Navaro, Y. (1980) Quantitative distribution of the Chaetodontidae on a fringing reef of the
Jordanian coast (Gulf of Aqaba, Red Sea). Mar. Biol. 63/: 79-86.
Bouchon-Navaro, Y. and Bouchon, C. (1989) Correlations between chaetodontid fishes and coral
communities of the Gulf of Aqaba (Red Sea). Envior. Biol. Fish. 25/1-3: 47-60.
RSS-REL-T005.0
page 190 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Brenner, S. (2003) High-resolution nested model simulations of the climatological circulation in the
southesastern Meditteranean Sea. Annales Geophysicae, 21, 267-280.
Brewer P. G., Goyet C., Friedrich G. (1997). Direct observations of oceanic CO2 increase revisited.
Proc. Natl. Acad. Sc., 94:8308-8313.
Brochovich, E.; A. Baranes & M. Goren. (2000) Reef fish communities and biodiversity in Eilat`reefs. Red Sea program, Center for Tropical marine Ecology (ZMT), Bremen, p 79-89.
Buochon-Navaro, Y. and Harmelin-Vivien, M.L. (1981) Quantitative distribution of herbivorous fishes
in the Gulf of Aqaba (Red Sea). Mar. Biol. 63: 79-86.
Carlson, D., E. Fredj, H. Gildor, and V. Rom-Kedar (2010), Deducing an upper bound to the horizontal eddy diffusivity using a stochastic Lagrangian model, Environmental Fluid Mechanics, 10, 499520, DOI 10.1007/s10652-010-9181-0.
Carlson, D., P. A. Muscarella, H. Gildor, B. L. Lipphardt, Jr., and E. Fredj (2010a), How useful are
Progressive Vector Diagrams for studying coastal ocean transport?, Limno. Oceanog. Methods, 8,
98-106.
Carpenter, K; Krupp, F; Jones, D.J and Zajonz, U. (1997) FAO Species Identification Guide for Fishery Purposes. The living Marine Resources of Kuwait, Eastern Saudi Arabia, Bahrain, Qatar and the
United Arab Emirates. 311 pp. FAO, Rome.
CARUSO, J. H. (1989): Comments on the taxonomic status of Lophiodes quinqueradiatus (Brauer),
with the first record of Lophiomus setigerus (Vahl) from the Red Sea (Pisces: Lophiidae). – Copeia,
1989 (4): 1072.
Chen Y., Mills J., Street J., Golan D., Post A., Jacobson M. and Paytan A. (2007). Estimates of atmospheric dry deposition and associated input of nutrients to Gulf of Aqaba seawater. J. Geophys.
Res., 112, D04309.
Clark, E; Ben-Tuvia, A. and Steintz, H. (1968) Observations on a coastal fish community, dahlak Archipelago, Red Sea. Sea. Fish. Res. Stn. Haifa Bull. 49: 15-31.
COMPAGNO, L. J. V. & RANDALL, J. E. (1987): Rhinobatos punctifer, a new species of guitarfish (Rhinobatiformes: Rhinobatidae) from the Red Sea, with notes on the Red Sea batoid fauna. – Proceedings of the California Academy of Sciences, 44 (14): 335-342.
COMPAGNO, L. J. V. (1983): The shark fauna of the Red Sea. - Bulletin of the Institute of Oceanography and Fisheries, 9: 381-406.
COMPAGNO, L. J. V. (1984): FAO species catalogue No. 125. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1 - Hexanchiformes to Lamniformes: 1-249. Part 2. Charcharhiniformes: 250-655; Rome (FAO Fisheries Synopsis).
Connell, J. H. 1978. Diversity in tropical rain forest and coral reefs. Science 199:1302-1310
Connolly, S. R. and A. H. Baird (2010) Estimating dispersal potential for marine larvae: dynamic
models applied to scleractinian corals. Ecology 91:3572-3583.
Corander J, Marttinen P, Sirén J, Tang J. 2008. Enhanced Bayesian modelling in BAPS software for
learning genetic structures of populations. BMC Bioinformatics 9:539.
CUVIER, G. & VALENCIENNES, A. (1837): Histoire naturelle des poissons. Tome douzième. Suite du
RSS-REL-T005.0
page 191 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
livre quatorzième. Gobioïdes. Livre quinzième. Acanthoptérygiens à pectorales pédiculées. - i-xxiv +
1-507 + 1 p., Pls. 344-368 [Val.]; Paris-Strasbourg.
Debelius H. (1993) Indian Ocean Tropical Fish Guide, Aquaprint Verlags GmbH, Germany, 298p.
Dennison WC, Barnes DJ (1988) Effect of water motion on coral photosynthesis and calcification. J
Exp Mar Biol Ecol 115:67-77.
Dor, M. (1984) Checklist of the fishes of the Red Sea. Jerusalem, 437 p.
Dubinky, Z., and N. Stambler (2010) Coral Reefs: An Ecosystem in Transition. Springer.
Edwards AJ, Head S. 1987. Key environments Red Sea. Pergamon Press. 441 pages.
EEA (2009). EMEP/EEA Air Pollutant Emission Inventory Guidebook 2009.
Eilat Ashkelone Pipeline co. Operations Division (2004). Port of Eilat. Information, operational procedures and regulation handbook).
English, C.; Wilkinson, C. and Baker, V. (eds). (1994) Survey manual for tropical marine resources.
Australian Institute of Marine Science, Townsville, 368p.
Entchchev, A., and K. Korotenko (2004), Stratification and tidal current effects on larval transport in
the eastern English Channel: Observations and 3D modelong. Environ. Fluid Mech., 4, 305-331.
ESCHMEYER, W. N. [Ed.] (1998): Catalog of fishes. – 3 vols., 2905 p.; San Francisco (California
Academy of Sciences, Special Publication).
Eschmeyer, W.N. (1990) Catalog of the Genera of Recent Fishes. Spec. Publ. California Academy of
Sciences, San Francisco, 695 p.
Farstey, V., B. Lazar, A. Genin. 2002. Homogeneous vertical distribution of zooplankton in a deep
mixed layer. Marine Ecology Progress Series 238: 91-100.
Fischer, H. B., E. J. List, J. Imberger, R. C. Y. Koh, and N. H. Brooks. (1979). Mixing in Inland and
Coastal Waters. Academic Press, New York, NY. 483 pp.
Fischer, W. and Bianchi, G. (eds.). (1984) FAO species identification sheets for fishery purposes,
Western Indian Ocean. Rome, 5 vols.
Fishelson, L. (1971) Ecology and distribution of the benthic fauna in the shallow waters of the Red
Sea. Ma. Bilo. 10: 113-133.
Fishelson, L; Poper, D. and Avidor, A. (1974) Biosociology and ecology of Pomacentrid fishes
around the Sinai Peninsula ( northern Red Sea) J. Fish. Biol. 6: 119-133.
Folmer O, Black M, Hoeh W, Lutz R, Vrijenhoek R. 1994. DNA primers for amplification of mitochondrial cytochrome coxidase subunit I from diverse metazoan invertebrates.Mol Mar Biol Biotechnol 3,
294-299.
FORSSKÅL, P. (1775): Descriptiones animalium avium, amphibiorum, piscium, insectorum, vermium;
quae in itinere orientali observavit. Post mortem auctoris edidit Carsten Niebuhr. - 1-20 + i-xxxiv + 1164; Hauniae.
Fricke H. W., Vareschi E., Schlichter D. (1987). Photoecology of the coral Leptoseris fragilis in the
Red Sea twilight zone (an experimental study by submersible). Oecologia (Berlin), 73:371-381.
RSS-REL-T005.0
page 192 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Fricke, H. W, and B. Knauer (1986) Diversity and spatial pattern of coral communities in the Red Sea
upper twilight zone. Oecologia 71:29-37.
Fricke, H.W. (1977) Community structure, social organization and ecological requirements of coral
reef fishes (Pomacentridae). Helgol Wissenschaftliche Meeresunters 30: 412-426.
FRICKE, R. (1986): Callionymidae. – In: SMITH, M. M. & HEEMSTRA, P. C. [Eds.]: Smiths' Sea Fishes:
770-774; Johannesburg (Macmillan).
FRICKE, R. (1999): Fishes of the Mascarene Islands (Réunion, Mauritius, Rodriguez). An annotated
checklist with descriptions of new species. - i-viii + 1-759; Königstein (Koeltz Scientific Books).
FRICKE, R. (2000): Invalid neotypes. - Copeia, 2000 (2): 639-640.
Froese, R. and D. Pauly, Editors. (2000) FishBase 2000: Concepts, design and data sources.
ICLARM, Los Baños, Laguna, Philippines, 344p.
Froukh, F. (2001) Studies on taxonomy and ecology of some fish larvae from the Gulf of Aqaba.
Faculty of science. University of Jordan. Master thesis, p 128.
Fuchs Y, Douek J, Rinkevich B, Ben-Shlomo R. 2006. Gene diversity and mode of reproduction in
brooded larvae of the coral Heteroxenia fuscescens. J Heredity 97, 493-498.
GEBCO. http://www.gebco.net.
Genin, A., B. Lazar, and S. Brenner (1995), Vertical mixing and coral death in the Red-Sea following
the eruption of Mount-Pinatubo, Nature, 377, 507–510.
Genin, A., Lazar, B., Brenner, S., 1995. Vertical mixing and coral death in the Red Sea following the
eruption of Mount Pinatubo. Nature 377, 507-510.
Gertman I. and Brenner S. (2004). Analysis of water temperature variability in the Gulf of Eilat.
GILBERT, C. R. (1967): A revision of the hammerhead sharks. – Proceedings of the U.S. National Museum, Smithsonian Institution, 119 (3539): 1-88.
Gildor, H. E. Fredj, and A. Kostinski (2010), The Gulf of Eilat/Aqaba: a Natural Driven Cavity? Geophy. Astro. Fluid Dyn., doi: 10.1080/03091921003712842.
Gildor, H., E. Fredj, J. Steinbuck, and S. Monismith (2009), Evidence for submesoscale barriers to
horizontal mixing in the ocean from current measurements and aerial-photographs, J. Phys. Oceanogr., 39, 1975-1983, doi:10.1175/2009JPO4116.
Glynn PS (1997) Bioerosion and coral-reef growth: A dynamic balance, p 68-94. In: Birkeland C (ed),
Life and Death of coral reefs. Chapman and Hall, New-York.
GOHAR, H. A. F. & MAZHAR, F. M. (1964): The Elasmobranchs of the north-western Red Sea. – Publications of the Marine Biological Station Ghardaqa, 13: 3-144.
Golani, D and Diamant, A. (1999) Fish colonization of an artificial reef in the Gulf of Eilat, Northern
Red Sea. Environ. Biol. Fish. 54: 275-282.
Golani, D; Orsi-Relini, L; Massuti, E and Qugnard, J. (2002) CIEM Atlas of exotic species in the Mediterranean. CIESM. Monaco, p 254.
RSS-REL-T005.0
page 193 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Goren, M and Dor, M. (1994) An update checklist of the fishes of the Red Sea. CLOFERS
II.- Jerusalem, 120 p.
Goren, M. (1973) Zoogeography of the fishes of the Indian Ocean. The Biology of the Indian Ocean.
Springes-Verlag: 451-464.
Goren, M. (1984a) A new species of Oplopomps Smith 1959 from Elat, northern Red Sea (Pisces:Gobiidae). Senckenberg. Biol. 65(1-2): 19-23.
Goren, M. (1984b) Three new species and two new records for the Red Sea of invertebrate associated gobies (gobiidae, Pisces0. Cybium 8(1): 71-82.
Goren, M. (1989) Oplopomus reichei (Pisces: Gobiidae) new record from the Red Sea. Israel J. Zool.
34: 149-153.
Goren, M. (1992) Obliquogobius turkayi, a new species of gobiid fish from the deep water of the central Red Sea (Pisces: Gobiidae). Senckenberg. Marit. 22(3-6): 265-270.
Graham DE. 1978. The isolation of high molecular weight DNA from whole organisms or large tissue
masses. Analyt. Biochem. 85, 609-613.
GRIFFITH, E. & SMITH, C. H. (1834): The class Pisces, arranged by the Baron Cuvier, with supplementary additions, by Edward Griffith, F.R.S., &c. and Lieut.-Col. Charles Hamilton Smith, F.R., L.S.S.,
&c. &c. - 680 p.; London.
GUICHENOT, A. (1863): Faune ichthyologique. - In: MAILLARD, L. [Ed.]: Notes sur l'ile de la Réunion
(Bourbon). Tome II, Annexe C: 1-32; Paris.
Gulf of Aqaba and northern Red Sea. Meereswissenschaftliche Berichte (Marine Science Report).
50, 1-120.
Gulf of Eilat Monitoring and Research Program. IET Project n° 12. 13 p.
Hadas O. and Erez J. (2004). IET Report. on Nitrogen fixation in the northern GOAE. In: Evaluation
of Fish Cages in the Gulf of Eilat, a technical report for the Israeli Ministries of Infrastructure Environment and Agriculture, Atkinson MJ, Birk Y, Rosenthal H (eds), www.sviva.gov.il
Hall, J. K. Ben-Avraham, Z. (1978). Bathymetric Chart of the Gulf of Elat. Geological Survey of Israel,
Scale 1:250,000, Contour interval 50 m.
Haney, R.L. (1971). Surface thermal boundary condition for ocean circulation models. J. Phys.
Oceanogr., 1, 241-248.
Harmelin-Vivien, M.L and Bouchon-Navaro, Y. (1981) Trophic relationships among chaetodontid
fishes in the Gulf of Aqaba (Red Sea). Proc. Int. Coral Reef Symp. No. 42: 537-544.
Harmelin-Vivien, M.L. (1989) Reef fish community structure: an Indo-Pacific comparison. In: Harmelin-Vivien ML, Bourlière F (eds) Vertebrates in complex tropical systems. Springer, Berlin Heidelberg
New York, p 21-60.
Harmelin-Vivien, M.L. (1997) Ichtyofauna des recifs corallines de Tulear (Madagascar): ecologie et
relations trophiques. Sc. D. Thesis, University of Marseille, 165 pp.
RSS-REL-T005.0
page 194 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Hassan M, Kotb MMA, Al-Sofyani AA. 2002. Status of Coral Reefs in the Red Sea and Gulf of Aden,
In: C.R. Wilkinson (ed.), Status of coral reefs of the world 2002. GCRMN Rep, AustInstit Mar Sci,
Townsville. Chapter 2, pp 45-52.
Herut B. and Cohen Y. (2004) IET Recommendation No. 7, In: Evaluation of Fish Cages in the Gulf
of Eilat, a technical report for the Israeli Ministries of Infrastructure Environment and Agriculture, Atkinson MJ, Birk Y, Rosenthal H (eds), www.sviva.gov.il
Hiatt, R. W. and Strasburg, D.W. (1960) Ecological relatonship of the fish fauna of the Marshall Island. Ecol. Monog. 30:65-127.
Holborn K, Johnson MS, Black R. 1994. Population genetics of the corallivorous gastropod Drupella
cornus at Ningaloo reef, Western Australia. Coral Reefs 13, 33-39.
HUBBS, C. L. & LAGLER, K. F. (1958): Fishes of the Great Lakes region. – 213 p.; Ann Arbor, Michigan
(University of Michigan Press).
Hughes, T. P., and J. E. Tanner (2000) Recruitment failure, life histories, and long-term decline of
Caribbean corals. Ecology 81:8, 2250-2263
Hughes, T.P., , A. H. Baird, E. A. Dinsdale, N. A. Moltschaniwskyj, M. S. Pratchett, J. E. Tanner, and
B. L. Willis (2000) Supply-side ecology works both ways: the link between benthic adults, fecundity,
and larval recruits. Ecology 81:2241-2249.
Hulings, N.C. (1989) A review of marine science research in the Gulf of Aqaba. The University of
Jordan Press. Amman, Jordan, 267 p.
HUTCHINS, J. B. (1984): Balistidae. - In: FISCHER, W. & BIANCHI, G. [Eds.]: FAO species identification
sheets for fishery purposes. Western Indian Ocean fishing area 51. Vol. I: [pag. var.]; Rome (FAO).
Imberger, J. and J.C. Patterson (1990), Physical Limnology, Advances In Applied Mechanics,
27, 303-475
Ismail NS, Elkarmi AZ, Moghrabi SM. 2000. Population structure and shell morphometrics of the corallivorous gastropod Drupella cornus (Gastropoda: Prosobranchia) in the Gulf of Aqaba, Red Sea.
Ind J Mar Sci29, 165-170.
Jackson, G. A. and R. R. Strathmann (1981) Larval Mortality from Offshore Mixing as a Link between
Precompetent and Competent Periods of Development. Am. Nat. 118:16-26.
Johnson MS, Cumming RL. 1995. Genetic distinctness of three widespread and morphologically variable species of Drupella (Gastropoda, Muricidae). Coral Reefs 14, 71-78
Johnson MS, Holborn K, Black R. 1993.Fine-scale patchiness and genetic heterogeneity of recruits
of the corallivorous gastropod Drupella cornus.Mar Biol 117, 91-96.
JORDAN, D. S. & EVERMANN, B. W. (1903): Descriptions of new genera and species of fishes from the
Hawaiian Islands. - Bulletin of the U.S. Fishery Commission, 22 [1902]: 161-208.
Jost L. 2008. GST and its relatives do not measure differentiation. Mol Ecol 17, 4015-4026.
Kanan, N.M. (1998) Studies on planktivorous fish ecology in coral reef of the Gulf of the Gulf of Aqaba. Master thesis, p. 119.
RSS-REL-T005.0
page 195 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Kaplan, D. M., and F. Lekien (2007), Spatial interpolation and filtering of surface current data based
on open-boundary modal analysis, J. Geophys. Res., 112, C12007, doi:10.1029/2006JC003984.
Karhan SU, Yokes MB. 2009. Additional records of the alien gastropod, ErgalataxjunionaeHouart,
2008 (Gastropoda: Muricidae), from the eastern Mediterranean. Medit Mar Sci 10, 137-142.
Kaufman, L.S. and Ebersole, J. P. (1984) Microtopography and the organization of two assemblages
of coral reef fishes in the Wes Indies. J. Exp. Mar. Biol. Ecol. 78: 253-268.
Khalaf M.A and M. Crosby (2005) Assemblage structure of butterflyfish and their use as indicators of
Gulf of Aqaba benthic habitat in Jordan. Aquatic conservation, S27-SS43.
Khalaf M.A. & M. Abdalla (2005). Community structure of butterflyfish in the Red Sea and Gulf of
Aden. Aquatic conservation, S77-S89.
Khalaf, M. A and Disi, A.M. (1997) Fishes of the Gulf of Aqaba. Marine Science Station. No. 8, p 252.
Khalaf, M.A (2000) Fishery Statistical reports of Jordan. Submitted to PERSGA office, Jeddah. (Report).
Khalaf, M.A (2004). Fish fauna along the Jordanian Coast - Gulf of Aqaba. Journal of Faculty of Marine Science 15:23-50.
Khalaf, M.A and F. Krupp (2008). A new species of the genus Symphysanodon (Perciformes: Symphanodontidae) from the Gulf of Aqaba, Red Sea. Aqua 14/2:85-88.
Khalaf, M.A and Kochzius, M. (2002) Community structure and biogeography of shore fishes in the
Gulf of Aqaba, Red Sea. Helgol. Mar. Res. 55: 252-284.
Khalaf, M.A. (2005). Five additional records of fishes from the Gulf of Aqaba, including Mola mola
(Forsskäl, 1775), new for the Red Sea, Zoology in the Middle East, 34:45-42.
Khalaf, M.A. and Kochzius, M. (2002b) Changes in trophic community structure of shore fishes at an
industrial site in the Gulf of Aqaba, Red Sea. Mar. Ecol. Prog. Ser. 10: 239-250.
Khalaf, M.A. and Krupp, F. (2003) Two new records of fishes from the Red Sea. Zoology in the Middle East 30: 55-59.
Khalaf, M.A. and U. Zajonz (2007). Fourteen additional fish species recorded from below 150m
depth in the Gulf of Aqaba, including Liopropoma lunulatum (Pisces: Serranidae), new record for the
Red Sea. Fauna of Arabia 23:421-433.
Khalaf, M.A.; Disi, A.M. and Krupp, F. (1996) Four new records of fishes from the Red Sea. Fauna of
Saudi Arabia. 15: 402-406.
Kiflawi, M., Belmaker, J., Brokovich, E., Einbinger, S. and Holzman, R. 2006. The determinants of
species richness of a relatively young coral-reef ichthyofauna. Journal of Biogeography 33, 12891294.
Kinsey DW, Davies PJ (1979) Effects of elevated nitrogen and phosphorus on coral reef growth.
Limnol Oceanog 24:935-940
Klausewitz, W. (1964) Die Erforschung der Ichthyofauna des Roten Meers. In Klunzinger CB (1870,
reprint) Synopsis der Fische des Rothen Meers. J. Cramer, Weinheim, p V-XXXVI.
KLAUSEWITZ, W. (1981): Tiefenwasser- und Tiefseefische aus dem Roten Meer. IV. Neunachweis
RSS-REL-T005.0
page 196 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
von Lophiodes mutilus (Alcock), mit Bemerkungen über Lophius (Chirolophius) quinqueradiatus
Brauer und Chirolophius papillosus (Weber) (Pisces: Lophiiformes: Lophiidae). – Senckenbergiana
maritima, 13 (4/6): 193-203.
KLAUSEWITZ, W. (1986): Zoogeographic Analysis of the Vertical Distribution of the Deep Red Sea Ichthyofauna, with a New Record. - Senckenbergiana maritima, 17 (4/6): 279-292.
Klausewitz, W. (1989) Evolutionary history and zoogeography of the Red Sea ichthyofauna. Fauna
of Saudi Arabia 10: 310-337.
Kleypas, J. A., J. W., McManus, and L. A. B., Meñez (1999b), Environmental limits to coral reef development: Where do we draw the line? Amer. Zool., 39, 146 – 159.
Klinker, J., Z. Reiss, C. Kropach, I. Levanon, H. Harpaz, E. Halicz, and G. Assaf (1976), Observations on the circulation pattern in the Gulf of Elat (Aqaba), Red Sea, Isr. J. Earth. Sci., 25, 85–103.
Kochzius, M., Soller, R., Khalaf, M.A, and Blohm, D. (2003) Molecular phylogeny of the lionfishes
genera Dendrochirus and Pterois (Scorpaenidae, Pteroinae) based on mitochondrial DNA sequences. Mol. Phylo-genet. Evol. 28: 396-403.
KOTLYAR, A.N. (1986): Systematics and distribution of species of the genus Hoplostethus Cuvier
(Beryciformes, Trachichthyidae). - Trudy Instituta Okeanologii, Akademiya Nauk SSSR (Transactions
of the Institute of Oceanology, Academy of Sciences of the USSR), 121: 97-140.
KRUPP, F. (1987): Tiefenwasser- und Tiefseefische aus dem Roten Meer. XV. The Occurrence of
Cynoglossus acutirostris Norman, 1939 in the Red Sea (Pisces: Cynoglossidae). - Senckenbergiana
maritima, 14 (3/4): 249-259.
Krupp, F. (1989) Beobachtungen an Fahnenbarschen im Roten Meer, Natur. Und. Museum 119(8):
262-266.
Krupp, F. and Paulus, T. (1991a) Territoriality and courtship in the coral-reef fish Pseudanthias
heemstrai (Performes: Serranidae). Revue fr. Aqariol. 18/2: 43-46.
Krupp, F; Zanjonz, U and M. Khalaf. 2009. A new species of the deepwater cardinalfish genus
Epigonus (Perciformes: Epigonidae) from the Gulf of Aqaba, Red Sea. Aqua vol. 15:4-15.
Labiosa, R.G. and K.R. Arrigo (2003), The interplay between upwelling and deep convective mixing
in determining the seasonal phytoplankton dynamics in the Gulf of Aqaba: Evidence from SeaWiFS
and MODIS. Limnol. And Oceanogr, 48, 2355-2368
LAST, P. R. & STEVENS, J. D. (1994): Sharks and rays of Australia. - 513 p.; Australia (CSIRO).
Lazar B, Erez J (2004) IET Recommendation No. 7, In: Evaluation of Fish Cages in the Gulf of Eilat,
a technical report for the Israeli Ministries of Infrastructure Environment and Agriculture, Atkinson
MJ, Birk Y, Rosenthal H (eds), www.sviva.gov.il
Lazar B, Loya Y (1991) Bioerosion of coral reefs. A chemical approach. Limnol Oceanog 36:377-381
Lazar B., Erez J., Silverman J., Rivlin T., Rivlin A., Dray M., Meeder E. and Iluz D. (2009). Recent
environmental changes in the chemical-biological oceanography of the Gulf of Aqaba (Eilat). In: Aqaba-Eilat, the Improbable Gulf. Environment, Biodiversity and Preservation, (Ed., F.D. Por). Magnes
Press, Jerusalem.
RSS-REL-T005.0
page 197 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Lazar B., Erez J., Silverman J., Rivlin T., Rivlin A., Dray M., Meeder E. and Iluz D. (2009). Recent
environmental changes in the chemical-biological oceanography of the Gulf of Aqaba (Eilat). In: Aqaba-Eilat, the Improbable Gulf. Environment, Biodiversity and Preservation, (Ed., F.D. Por). Magnes
Press, Jerusalem.
Lekien, F. and H. Gildor (2009), Computation and approximation of the length scales of harmonic
modes with application to the mapping of surface currents in the Gulf of Eilat, J. Geophys. Res., 114,
C06024, doi: 10.1029/2008JC004742, 2009.
Lekien, F., C. Coulliette, R. Bank, and J. E. Marsden (2004), Open-boundary modal analysis: Interpolation, extrapolation, and filtering, J. Geophys. Res., 109, C12004, doi:10.1029/2004JC002323.
Lesser MP, Weis VM, Patterson MR, Jokiel PL (1994) Effects of morphology and water motion on
carbon delivery and productivity in the reef coral, Pocillopora damicornis (Linnaeus): diffusion barriers, inorganic carbon limitation, and biochemical plasticity. J Exp Mar Biol Ecol 178:153-179.
LESUEUR, C. A. (1822): Description of a Squalus, of a very large size, which was taken on the coast
of New-Jersey. – Journal of the Academy of Natural Sciences Philadelphia, 2: 343-352.
Lindell D, Post AF (1995). Ultra phytoplankton succession is triggered by deep winter mixing in the
Gulf of Aqaba (Eilat), Red Sea. Limnol Oceanogr 40:1130-1141.
Loya Y, Solodkin LB (1971) The coral reefs of Eilat (Gulf of Eilat, Red Sea). Symp Zool Soc Lond
28:117–139.
Loya, Y. (1972) Community structure and species diversity of hermatypic corals at Eilat, Red Sea.
Mar. Biol. 13:100-123.
LUBBOCK, R. & RANDALL, J. E. (1978): Fishes of the genus Liopropoma (Teleostei: Serranidae) in the
Red Sea. – Zoological Journal of the Linnean Society, 64: 187-195.
Magalon H, Adjeroud M, Veuille M. 2005. Patterns of genetic variation do not correlate with geographical distance in the reef-building coral Pocillopora meandrina in the South Pacific. Mol Ecol 14,
1861–1868.
Mahasneh, I. A., 1984. The physiological ecology of the marine phytoplankton in the Jordanian Gulf
of Aqaba. Masters Thesis, Yarmouk University, Irbid, Jordan.
Manasrah, R. 2002. The general circulation and water masses characteristics in the
Manasrah, R. S., M. Badran, H. U. Lass, and W. Fennel (2004), Circulation and winter deep-water
formation in the northern Red Sea, Oceanologia, 46, 5–23.
Marshall, N.B. (1952) The ´Manihine Expedition to the Gulf of aqaba 1948-1949`. IX. Fishes. Bull.
Brit. Mus. (Nat. Hist.), Zool. 1(8): 221-252.
Marubini F, Davies PS (1996) Nitrate increases zooxanthelae population and reduces skeletogenesis in corals. Mar Biol 127:319-328.
Mass, T., A. Genin, U. Shavit, M. Grinstein, and D. Tchernov (2010) Flow enhances photosynthesis
in marine benthic autotrophs by increasing the efflux of oxygen from the organism to the water. Proceedings of the National Academy of Sciences of the USA (PNAS) 107: 2527-2531.
MATSUURA, K. 2001. Balistidae. Triggerfishes. In: CARPENTER, K.E. & NIEM, V. [Eds.]: FAO species
identification guide for fishery purposes. The living marine resources of the Western Central Pacific.
RSS-REL-T005.0
page 198 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Vol. 6. Bony fishes part 4 (Labridae to Latimeriidae), estuarine crocodiles: 3911-3928; Rome (FAO).
McClanahan TR. 1997. Dynamics of Drupella cornus populations on Kenyan coral reefs. Proc 8th Int
Coral Reef Symp, pp. 633-638.
Meir E, Tollrian R, Rinkevich B, Nurnberger B. 2005. Isolation by distance in the scleractinian coral
Seriatopora hystrix from the Red Sea. Mar Biol 147, 1109-1120.
Mellor, G.L. and Yamada, T. (1982). Development of a turbulence closure model for geophysical fluid problems. Rev. Geophys. Space Phys., 20, 851-875.
Mellor, G.L., Ezer, T., and Oey, L.-Y. (1994). The pressure gradient conundrum of sigma coordinate
ocean models. J. Atmos. Oceanic Technol., 11, 1126-1134.
Mellor, G.L., Ezer, T., and Oey, L.-Y. (1994). The pressure gradient conundrum of sigma coordinate
ocean models. J. Atmos. Oceanic Technol., 11, 1126-1134.
Mergner H (1971) Structure, ecology and zonation of Red Sea reefs (in comparison with South Indian and jamaican reefs). Symp. Zool. Soc. Lond. 28: 141-161.
Michalakis Y, Excoffier L. 1996. A generic estimation of population subdivision using distances between alleles with special reference for microsatellite loci. Genetics 142, 1061-1064.
Miller MP. 1997. Tools for Population Genetic Analyses (TFPGA). Department of Biological Sciences, Northern Arizona University, Flagstaff.
Monismith, S. G., and A. Genin (2004), Tides and sea level in the Gulf of Aqaba (Eilat), J. Geophys.
Res., 109, doi:10.1029/2003JC002,069.
Monismith, S.G. And T. Maxworthy (1989), Selective Withdrawal And Spin-Up Of A Rotating Stratified Fluid, J. Fluid Mech., 199, 377-401.
Monsen, N.E., J.E Cloern, L.V. Lucas, and S.G. Monismith (2002), A comment on the use of flushing
time, residence time, and age as transport time scales, Limno. Oceanogr., 47, 1545-1553.
Moyer JT, Emerson WK, Ross M. 1982. Massive destruction of scleractinian corals by the muricid
gastropod, Drupella, in Japan and the Philippines. The Nautilus 96, 69-82.
mum in the Gulf of Eilat/Aqaba, J. Geophys. Res., in press.
Murray, S., A. Hecht, and A. Babcock (1984), On the mean flow in the Tiran Strait in winter, J. Mar.
Res., 42, 265–284.
MYERS, R. F. (1999): Micronesian Reef Fishes. A Field Guide for Divers and Aquarists. – 216 p.;
Guam (Coral Graphics).
Myers, R.F. (1991) Micronesian Reef Fishes: A practical Guide to the Identification of the Inshore
Marine Fishes of the Tropical Central and Western Pacific. Coral Graphica, USA, 298 p.
Nakamura T, Yamasaki H, van Woesik R (2003) Water flow facilitates recovery from bleaching in the
coral Stylophora pistillata. Mar Ecol Prog Ser 256:287-291
NAKAMURA, H. (1935): On the two species of the thresher shark from Formosan waters. - Memoirs of
the Faculty of Sciences, Taihoku Imperial University Formosa, 14 (1): 1-6.
RSS-REL-T005.0
page 199 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Natour, R. M. and Neinhuis, H. (1980). Some phytoplanktonic studies in Aqaba Gulf of Jordan. Nova
Hedwigia, 33: 433-443.
Nei M. 1978. Estimation of average heterozygosity and genetic distance from a small number of individuals. Genetics 89, 583-590.
Nielsen, J.G. (1993) Peter Forsskål – a pioneer in Red Sea ichthyology. Israel J. Zool. 39: 283-286.
NORMAN, J. R. (1939): Fishes. – In: The John Murray Expedition 1933-34. Scientific Reports, 7 (1): 1116; London (British Museum of Natural History).
Oceanogr., 1, 241-248.
Ofer Ben-Tzvi, M. Kiflawi, S. D. Gaines, M. Al-Zibdah, M. S. Sheehy, G. L. Paradis, A. Abelson
(2008). Tracking recruitment pathways of chromis viridis in the Gulf of Aqaba using otolith chemistry.
Mar Ecol Prog Ser. Vol. 359: 229–238.
Öhman, M. C., Rajasuriya A and Ólafsson, E. (1997) Reef fish assemblages in north-west Sri Lanka:
distribution patterns and influences of fishing practices. Env. Biol. Fish. 49:54-61.
OLFERS, J. F. M. VON (1831): Die Gattung Torpedo in ihren naturhistorischen und antiquarischen
Beziehungen erläutert. - 35 p.; Berlin.
Olson, D.B., Backus, R.H. 1985. The concentrating of organisms at fronts: A cold-water fish and a
warm-core Gulf Stream ring. J. Mar. Sci. 43, 113-137.
Olson, D.B., Hitchcock, G.L., Mariano, A.J., Ashjian, C.J., Peng, G., Nero, R.W. Podesta, G.P. 1994.
Life on the edge: marine life and fronts. Oceanography, 7, 52-60.
Orlanski, I. (1976), A simple boundary condition for unbounded hyperbolic flows. J. Computational
Phys., 21, 251-269.
ORMOND, R. F. C. & EDWARDS, A. J. (1987): Red Sea Fishes. – In: EDWARDS, A. J. & HEAD, S. M.
[Eds.]: Key Environments, Red Sea: 252-287; Exeter (Pergamon Press).
Paetkau D. et al. 1995. Microsatellite analysis of population structure in Canadian polar bears. Mo.
Ecol 4, 347-354.
Paldor, N. and D. A. Anati (1979). Seasonal variations of temperature and salinity in the Gulf of Elat.
Deep-Sea Res., 26/6A, 661–672.
PARENTI, P. & RANDALL, J.E. (2000). An annotated checklist of the species of the labroid fish families
Labridae and Scaridae. - Ichthyological Bulletin J.L.B. Smith Institute of Ichthyology, 68: 1-97.
Paris, C. B. and R. K. Cowen (2004) Direct Evidence of a Biophysical Retention Mechanism for Coral Reef Fish Larvae. Limnol. Oceanogr. 49:1964-1979.
Park SDE. 2001.Trypanotolerance in West African cattle and the population genetic effects of selection. University of Dublin.
Parrish, J.D. (1989) Fish communities of interacting shallow-water habitats in tropical oceanic regions. Mar. Ecol. Prog. Ser. 58: 143-160.
Paulus, T. (1992) Syngnathus safina n. sp. And first record of S. macrophtalmus Duncker, 1915 from
the Gulf of Aqaaba, Red Sea (Pisces: Osteichthyes: Syngnathidae). Senckenbergiana boil. 72(1/3):
27-33.
RSS-REL-T005.0
page 200 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Paulus, T. (1993) Morphologie und Okologie syntop lebender. Syngnathidae (Pisces: Teleosti) de
Roten Meers. Ph.D. thesis, Universitat Mainz., Germany, 160 p.
Peakall R, Smouse PE. 2006. GENALEX 6: genetic analysis in Excel. Population genetic software
for teaching and research. Mol Ecol Notes 6, 288-295.
Perkol-Finkel, S. and Y. Benayahu (2004) Community structure of stony and soft corals on vertical
unplanned artificial reefs in Eilat (Red Sea): comparison to natural reefs. Coral Reefs 23:195-205.
Perkol-Finkel, S. and Y. Benayahu (2007) Differential recruitment of benthic communities on neighboring artificial and natural reefs. J. Exp. Mar. Biol. Ecol. 340:25-39.
Perkol-Finkel, S., N. Shashar, and Y. Benayahu (2006) Can artificial reefs mimic natural reef communities? The roles of structural features and age. Marine Environmental Res. 61:121-135.
Piry S, Alapetite A, Cornuet JM, Paetkau D, Baudouin L, Estoup A. 2004. GENECLASS2: A software
for genetic assignment and first-generation migrant detection. J Heredity 95, 536-539.
Plähn, O., B. Baschek, T. H. Badewien, M. Walter, and M. Rhein (2002), Importance of the Gulf of
Aqaba for the formation of bottom water in the Red Sea, J. Geophys. Res., 107,
doi:10.1029/2000JC000,342.
POST, A. & SVOBODA, A. (1980): Strandfunde mesopelagischer Fische aus dem Golf von Akaba. –
Archiv für Fischereiwissenschaft, 30 (2/3): 137-143.
Pritchard JK, Stephens M, Donnelly P. 2000. Inference of population structure using multilocus genotype data. Genetics 155, 945–959.
RANDALL, J. E. & TAYLOR, L. R. (1988): Review of the Indo-Pacific fishes of the serranid genus Liopropoma, with descriptions of seven new species. - Indo-Pacific Fishes, 16: 1-47.
RANDALL, J. E. (1986a): Sharks of Arabia. - 148 p.; London (Immel Publishing).
RANDALL, J. E. (1998): Revision of the Indo-Pacific squirrelfishes (Beryciformes: Holocentridae: Holocentrinae) of the genus Sargocentron, with descriptions of four new species. - Indo-Pacific Fishes,
27:1-105.
RANDALL, J. E., GOLANI, D. & DIAMANT, A. (1989). Sargocentron marisrubri, a new squirrelfish (Beryciformes: Holocentridae) from the Red Sea. - Israel Journal of Zoology, 35: 187-198.
RANDALL, J.E. & GREENFIELD, D. W. (1996): Revision of the Indo-Pacific holocentrid fishes of the genus Myripristis, with descriptions of three new species. - Indo-Pacific Fishes, 25:1-61.
Randall, J.E. (1983) Red Sea reef fishes. London; Immel publishing.
RANDALL, J.E. (1986b). Labridae. – In: SMITH, M. M. & HEEMSTRA, P. C. [Eds.]: Smiths' sea fishes:
683-706; Berlin (Springer-Verlag).
Randall, J.E. (1994) Twenty-two records of fishes from the Red Sea. Fauna of Saudi Arabia 14: 259275.
Randall, J.E. (1995) The compleye Divers’ & Fishermen’s Guide to Coastal Fishes of Oman. Crawford House Publishing Pty Ltd. Australia. 439pp.
RSS-REL-T005.0
page 201 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Randall. J.E and Khalaf, M.A. (2003) Redescription of the Labrid fish Oxycheilinus orientalis (Günther), a Senior Synonym of O. rhodochrous (Günther), and first record from the Red Sea. Zool. Stud.
42 (1): 135-139.
Rasheed M., Badran M.I., Richter C., Huettel M. (2002) Effect of reef framework and bottom sediment on nutrient enrichment in a coral reef of the Gulf of Aqaba, Red Sea. Mar. Ecol. Prog. Ser.,
239, 277–285.
Rasheed M., Badran M.I., Richter C., Huettel M. (2002) Effect of reef framework and bottom sediment on nutrient enrichment in a coral reef of the Gulf of Aqaba, Red Sea. Mar. Ecol. Prog. Ser.,
239, 277–285.
Raymond ML, Rousset F. 1995. An exact test for population differentiation. Evolution 49, 1280-1283.
Reese, E.R. 1981. Predation on coral by fishes of the family chaetodontidae: implications for
conservation and mangement of coral reef ecosystem. Bull.mar. Sci. 31:594-604.
Reiss, Z. and Hottinger, L. (1984) The Gulf of Aqaba. Ecological micropaleontology. Ecological study
50. Springer-Verlag, Berlin, 354 p.
Richter C, Wunsch M, Rasheed M, Kotter I, Badran MI (2001) Endoscopic exploration of Red Sea
coral reefs reveals dense populations of cavity-dwelling sponges. Nature 413:726-730.
Richter C, Wunsch M, Rasheed M, Kotter I, Badran MI (2001) Endoscopic exploration of Red Sea
coral reefs reveals dense populations of cavity-dwelling sponges. Nature 413:726-730.
Richter, C., and A. Abu-Hilal (2006). Seas of the Arabian Region.Chapter 34. In: The Sea: The Global Coastal Ocean, Interdisciplinary Regional studies and Synthesis.Volume 14 Part B. Edited by Allan R. Robinson and Kenneth H. Brink. Pp 1373-1412. Harvard University Press, Cambridge, MA.
Ridderhinkof and Zimmerman (1992), Chaotic stirring in a tidal system, Science, 258:1107–1111.
Ridderhinkof and Zimmerman (1992), Chaotic stirring in a tidal system, Science, 258:1107–1111.
Rilov, G. and Benyahu, Y. (1998) Vertical artificial structures as an alternative habitat for coral reef
fishes in disturbed areas. Mar Environ. Res. 45: 431-451.
Rilov, G. and Benyahu, Y. (2000) Fish assemblages on natural versus verical artificial reefs: the rehabilitation perspective. Mar. Biol. 136: 931-942.
Rinkevich B. 2005. What do we know about Eilat (Red Sea) reef degradation ? A critical examination
of the published literature. J Exp Mar Biol Ecol 327, 183-200.
Roberts C.M, Shepherd, A.R.D., and Ormond, R.F.G. (1992) Large scale variation in assemblages
structure of Red Sea butterflyfishes and angelfishes. J. Biogeor. 19:239-250.
Roberts, C.M. and Ormond, R.F.G. (1987) Habitat complexity and coral reef diversity and abundance
on Red Sea fringing reefs. Mar. Ecol. Prog. Ser. 41:1-8.
Sade R., Hall J.K., Tibor, G., Niemi, T.M., Ben-Avraham, Z., Al-Zoubi, A., Hartman, G., Akawi, E.,
Abueladas, A. and Amit, G. (2008). The Israel national bathymetric survey: Northern Gulf of Aqaba/Eilat poster. Israel Journal Earth Sciences 57:139-1444.
Sano, M., Shimizo, M. and Nose, Y. (1984) Changes in structure of coral reef fish communities by
destruction of hermatypic corals: Observational and experimental views. Pac. Sci. 38 (1):51-79.
RSS-REL-T005.0
page 202 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Scheer, G. 1971. Coral reefs and coral genera in the Red Sea and the Indian Ocean. In : Regional
variation in Indian Ocean Coral reefs. Symp. zool. Soc. Lond., 28 : 329-367
Schick A. and Lekach J., 1993. An evaluation of two ten-year sediment budgets, Nahal Yahel, Israel.
Physical Geography, 1993, 14, 3, pp. 225-238
Schoepf V, HerlerJ Zuschin M. 2010. Microhabitat use and prey selection of the coral-feeding snail
Drupella cornus in the northern Red Sea.Hydrobiologia 641, 45-57.
Schumacher, H., Krupp, F. and Randall, J.E. (1989) Pseudanthias heemstrai, a new species of
anthiine fish (Perciformes: Serranidae) from the Gulf of Aqaba, Red Sea. Fauna of Saudi Arabia 10:
338-346.
Sebens, K.P. (1991) Habitat structure and community dynamics in marine benthic systems. In: Bell,
S.S., McCoy, E.D., Mushinskey, H.R. (eds.), Habitat Structure: the Physical Arrangement of Objects
in Space. Chapman and Hall, New York, p. 211-234.
Shafir S, Gur O, Rinkevich B. 2008. A Drupella cornus outbreak in the northern Gulf of Eilat and
changes in coral prey.Coral Reefs 27, 379.
Shanks, A.L., Largier, J., Brink, L., Brubaker, J., Hooff, R. 2000. Demonstration of the onshore
transport of larval invertebrates by the shoreward movement of an upwelling front. Limnol. Oceanogr. 45, 230-236.
Silverman J. and Gildor H. (2008) The residence time of an active versus a passive tracer in the Gulf
of Aqaba: A box model approach. Journal of Marine Systems, 71:158 – 170.
Silverman J., Lazar B., Cao L., Caldeira K. and Erez J. (2009). Coral reefs may start dissolving when
atmospheric CO2 doubles. Geophysical Research Letters, 36, L05606, DOI 10.1029/2008GL036282.
Silverman J., Lazar B., Erez J. (2007a). Community metabolism of a coral reef exposed to naturally
varying dissolved inorganic nutrient loads. Biogeochemistry, DOI 10.1007/s10533-007-9075-5.
Silverman J., Lazar B., Erez J. (2007b). The effect of aragonite saturation, temperature and nutrients
on the community calcification rate of a coral reef. J. Geophys. Res., 112, C05004, doi
10.1029/2006JC003770.
Silverman J., Lazar B., Erez J. (2007b). The effect of aragonite saturation, temperature and nutrients
on the community calcification rate of a coral reef. J. Geophys. Res., 112, C05004, doi
10.1029/2006JC003770.
SMITH, M. M. & HEEMSTRA P. C. (1986). Balistidae. – In: SMITH, M. M. & HEEMSTRA, P. C. [Eds.]:
Smiths' sea fishes: 876-882; Berlin (Springer-Verlag)
Smith, M.M. and Heemstra, P.C.(eds.).(1986) Smiths´ sea fishes. Berlin; Springer-verlag, 1047.
Souter PB, Henriksson O, Olsson N, Grahn M. 2009. Pattern of genetic structuring in the coral Pocillopora damicornis on reefs in East Africa. BMC Ecol 9:19.
Spigel, R.H. and B. and Farrant (1984), Selective Withdrawal Through A Point Sink And Pycnocline
Formation In A Linearly Stratified Flow , J. Hydraulic Res., 22, 35-51.
Stambler N. (2006). Light and picophytoplankton in the Gulf of Eilat (Aqaba). J Geophys Res,
111(C):11009, doi:10.1029/2005JC003373.
RSS-REL-T005.0
page 203 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
Starger CJ, Barber CH, Ambariyanto, Baker AC. 2010. The recovery of coral genetic diversity in the
Sunda Strait following the 1883 eruption of Krakatau. Coral Reefs 29, 547–565.
Starger CJ, Yeoh SSR, Dai CE, Baker AC, Desalle R. 2008. Ten polymorphic STR loci in the cosmopolitan reef coral,Pocillopora damicornis Mol Ecol Resources 8, 619–621.
STEINDACHNER, F. & DÖDERLEIN, L. (1883): Beiträge zur Kenntniss der Fische Japan's (I.). –
Denkschriften der Akademie der Wissenschaften Wien, 47 (1. Abth.): 211-242.
Steinitz, H. and Ben-Tuvia, A. (1995) Fishes from Eylath (Gulf of Aqaba), Red Sea. Second report.
Sea. Fish. Res. Sta. Haifa Bull., 11: 3-15.
Stoddart JA. 1984. Genetic differentiation amongst populations of the coral Pocillopora damicornis
off Southwestern Australia. Coral Reefs 3, 149–156.
Suari, Y. (2011). Modeling the impact of terrestrial nutrients input on the southeastern Levantine
planktonic ecology. Ph.D. Thesis, Bar Ilan University, under review.
Sutton, M. (1985) Patterns of spacing in a coral reef fish in two habitats on the Great Barrier Reef.
Anim. Behav. 33: 1322-1337.
Thomson, R.E., and W. J. Emery (2005), Data Analysis Methods in Physical Oceanography, Elsevier Science.
Torontese E. (1968) Fishes from Eilat (Red Sea). Sea Fish. Res. Haifa. 51:6-30.
TORTONESE, E. (1954): Spedizione subaquata italiana nel Mar Rosse. Ricerche zoologische. IV. Plagiostomi. – Rivista di ”Biologia Coloniale”, 14: 1-21.
Tortonese, E. (1983) List of fishes observed near Jeddah (Saudi Arabia). J. Fac. Mar. Sci. Jeddah
3:105-110.
Turner SJ. 1992. The egg capsules and early life history of the coral1ivorous gastropod Drupella
corn us (Roding, 1798). The Veliger 35, 16-25.
Turner SJ. 1994. The biology and population outbreaks of the corallivorous gastropod Drupella on
Indo-Pacific reefs Oceanogr. Mar Biol Ann Rev 32, 461-530.
Underwood, A. J. and G. Fairweather (1989) Supply-side ecology and benthic marine assemblages.
Trends Ecol. Evol. 4:16-29.
UNEP/IUCN. (1988) Coral reefs of the world. UNEP Regional Seas Directories and Bibliographies.
IUCN, Gland, Switzer-land and Cambridge, UK/UNEP, Nairobi, Kenya.
USEPA (2003). Discharge As-sessment Report Hull Coating Leachate
USEPA, 1983. Results of the Nationwide Urban Runoff Program. Volume I - Final Report.
VAHL, M. (1797): Beskrivelse tvende nye arter af Lophius (L. stellatus og L. setigerus). - Skrifter
naturhistorike det kongelige Danske Videnskabernes Selskab Kiøbenhavn, 4: 212-216.
van Oosterhout C, Hutchinson WF, Wills DPM, Shipley P. 2004. MICRO-CHECKER: software for
identifying and correcting genotyping errors in microsatellite data. Mol Ecol Notes 4, 535–538.
Van Treeck P, Schuhmacher H. 1997. Initial survival of coral nubbins transplanted by a new coral
transplantation technology: options for reef rehabilitation. Mar Ecol Prog Ser 150, 287-292.
RSS-REL-T005.0
page 204 of 205
Thetis SpA
The Interuniversity
Sciences In Eilat
A qaba
VARI, R. P. (1984): Teraponidae. In: FISCHER, W. & BIANCHI, G. [Eds.]: FAO species identification
sheets for fishery purposes. Western Indian Ocean fishing area 51. Vol. IV: [pag. var.]; Rome (FAO).
Veron J. 2000. Corals of the world Townsville, Qld.: Australian Institute of Marine Science.
Veron, J.E.N. (1986) Corals of Australia and the Indo-Pacific. Angus & Robertson Publishers, London, UK.
Vichi M., N. Pinardi and S. Masina (2007a) A generalized model of pelagic biogeochemistry for the
global ocean ecosystem. Part I: Theory. J. Marine Systems, 64(1-4), pp 89-109.
Vichi M., S. Masina and A. Navarra (2007b) A generalized model of pelagic biogeochemistry for the
global ocean ecosystem. Part II: numerical simulations. J. Marine Systems, 64(1-4), pp 110-134.
Vos P, Hogers R, Bleeker M, Reijans M, van de Lee T, Hornes M, Frijters A, Pot J, Peleman J, Kuiper M, Zabeau M. 1995. AFLP: a new technique for DNA fingerprinting. Nucleic Acids Res 23, 4407414.
Wahbeh, M. I. and M. I. Badran., 1990. Distribution of chlorophyll, organic carbon, protein, biomass
and trace element in the microplankton of Aqaba (Jordan). Dirasat., 17: 161-167.
Wahbeh, M.I and Ajiad, A. (1987) Some fishes from the Jordanian coast of the Gulf of Aqaba. Dirasat 1: 137-154.
Wahbeh, M.I. (1981) Distribution, biomass, biometry and some associated fauna of the seagrass
community in the Jordanian Gulf of Aqaba. Proc 4th Int Coral Reef Symp. 2:453-459
Wahbeh, M.I. (1992) Some aspects of reproduction and growth of three species of fusilier (Pisces:
Caesionidae) from Aqba, Red Sea, Jordan. Dirasat, 19B: 157-172.
Wahbeh, M.I. and Ajiad, A. (1985) The food and feeding habits of the goatfish, Parupeneus barberinus (Lacèpède), from Aqaba, Jordan. J. Fish Biol., 27: 147-154.
Weir BS, Cockerham CC. 1984. Estimating F-statistics for the analysis of population structure. Evolution 38, 1358-1370.
Wheeler, A. (1985) The world Encyclopedia of fishes. London, 368 P, 501 Pls.
Wolf-Vecht, A., N. Paldor, and S. Brenner (1992), Hydrographic indications of advection/convection
effects in the Gulf of Elat, Deep Sea Res., 39, 1393–1401.
Wood, I.R. (2001), Extensions to the theory of selective withdrawal, J. Fluid Mech., 448, 315-333
Yeh C, Yang C, Boyle T. 1999. Popgene Version 1.31. University of Alberta, Canada.
Zibdeh, M; Khalaf, M.A; and Al-Najjar, T. (2003) Environment, social and cultural implications of Aqaba fishers and fishing industry in Aqaba. Report to UNESCO office Amman.
Zuschin M, Stachowitsch M. 2007. The distribution of molluscan assemblages and their postmortem
fate on coral reefs in the Gulf of Aqaba (northern Red Sea).Mar Biol 151, 2217-2230.
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