International Society for Reef Studies

(ISRS)

European Meeting

4 th – 7 th September 2002

Abstracts Volume

Hosted by:

Cambridge Coastal Research Unit

Department of Geography

University of Cambridge.International Society For Reef Studies (ISRS)

ISRS European Meeting

Robinson College, Cambridge

4 th – 7 th September 2002

Host:

Cambridge Coastal Research Unit

Department of Geography

University of Cambridge

Abstracts Volume

Editors: S. Brooks, T. Spencer, K. Teleki and M. Taylor

Local Organising Committee Scientific Committee

Sue Brooks, Birkbeck College University of London Colin Braithwaite, University of Glasgow

Annelise Hagan, University of Cambridge Sue Brooks, Birkbeck College University of London

Tom Spencer, University of Cambridge John Bythell, University of Newcastle

Michelle Taylor, UNEP-World Conservation Monitoring Centre Christian Dullo, GEOMAR

Kristian Teleki, University of Cambridge Marcos Gektidis, University of Frankfurt

Edmund Green, UNEP-World Conservation Monitoring Centre

Jason Hall-Spencer, University of Glasgow

Jane Hawkridge, Mote Marine Laboratory

Piers Larcombe, James Cook University

Martin Le Tissier, University of Newcastle

Lucien Montaggioni, Universite de Provence

Chris Perry, Manchester Metropolitan University

Brian Rosen, Natural History Museum

Tom Spencer, University of Cambridge

Kristian Teleki, University of Cambridge

Sandy Tudhope, University of Edinburgh

Helge Vogt, Independent Consultant

Elizabeth Wood, Marine Conservation Society

Rachel Wood, Schlumberger Cambridge Research

Additional support provided by the International Coral Reef Action Network (ICRAN).i

Table of Contents

Page

Abstracts: Plenary Addresses 1

Abstracts: Oral Presentations 5

Abstracts: Poster Presentations 113

Index of Authors 157.ii

Abstracts

Abstracts are presented in the order: plenary addresses, oral

presentations and poster presentations. Abstracts for both oral and

poster presentations are arranged by first author.

In most cases abstracts are printed as they have been received and have

not been edited for content. Some ‘light editing’ of titles and

affiliations has been carried out to ensure uniformity of presentation.

Neither the Cambridge Coastal Research Unit, nor the

Organising/Scientific Committee of the ISRS European Meeting accept

responsibility for content..Plenary Addresses..Plenary Address 1

Wednesday 4 th September, 2002

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

1

REEFS IN TURBID AND POLLUTED WATERS: WHY THE FUSS?

KATHARINA FABRICIUS

Australian Institute of Marine Science and Reef CRC

PMB 3, Townsville Qld 4810, Australia

k.fabricius@aims.gov.au

Great beauty, high diversity and healthy recolonisation characterise the few turbid inshore coral reefs

of the Great Barrier Reef that remain in near-pristine condition. By contrast, other inshore reefs are

severely degraded, and some consider pollution, in the form of increased supply of land-derived

nutrients, sediments and pesticides, to be a major cause of their degradation. At local scales, pollution

impacts are well documented and accepted, however, at regional scales, pollution is frequently

denied to be a cause of reef degradation, and indeed causal links have been difficult to demonstrate.

This is due to factors such as (a) a lack of historic data, (b) high spatial and temporal variability in

pollutants, (c) the background of other forms of disturbances, and (d) non- linear responses of

organisms to pollution. Overall, pollution appears to be a lesser threat for coral reefs than coral

bleaching or destructive fishing. However, unlike many other forms of disturbances, many pollutants

accumulate and are stored in the system, thus system responses may become chronic once the

system’s buffering capacity is exhausted.

Here, I will examine various links between inshore reef degradation and pollution. This will comprise

a review of field and laboratory data from many parts of the world, followed by presentation of new

experimental and reef ecological studies. It will include the characterisation of the ecological

properties of near-pristine inshore reefs, and will contrast these with reefs frequently exposed to river

plumes from agricultural areas. I will then identify the two most likely mechanisms for reef

degradation in regions exposed to pollution. Additionally, potential secondary mechanisms of

pollution will be discussed, such as the enhanced survival of crown-of-thorns larvae, which may have

profound effects on the wider ecosystem.

Pollution and reef degradation is a complex issue and there are many threads of evidence of varying

strengths to be considered, e.g. field studies with notoriously imperfect controls and laboratory

experiments that oversimplify natural systems. It is not surprising that simple hypothesis tests are

unable to resolve such complex questions. After all, it took decades of extensive and expensive

research until epidemiologists established sufficient weight of evidence linking cigarette smoking

with lung cancer– a link that is obvious in hindsight. As scientists, we need to synthesize multiple

and complex sources of information, weigh the evidence, quantify effect sizes, and predict the

ecological consequences and socio-economic costs of alternative actions. It is then up to a better

informed society to decide how much ecological change is acceptable..Plenary Address 2

Thursday 5 th September, 2002

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

2

UNNATURAL REEFS

JEREMY B. C. JACKSON

Scripps Institution of Oceanography

University of California, San Diego

La Jolla, California 92093-0244 USA

jbcj@ucsd.edu

Basic ecological understanding of coral reefs is based on an unnatural mix of mostly small species

whose trophic relations are greatly distorted by overfishing. Large megafauna, including fishes,

sharks, sea turtles, crocodiles, sea cows, and seals have disappeared from entire reef systems

worldwide. Vertebrates in general are greatly reduced and comprise less than 2% of the total free-living

animal biomass on most reefs where the structure of food webs is dominated by very small

fishes and invertebrates. The habitat complexity of reefs and seagrass beds is also greatly reduced

over wide areas. Historical analyses demonstrate that virtually all reefs are affected by overfishing

including partially protected areas like the Great Barrier Reef. Historical trajectories of the decline in

reef ecosystems in the Indo-Pacific have the same slope as those from the tropical western Atlantic.

The only difference is the initial starting date of intense exploitation that was much earlier in the

Atlantic. Successful restoration and management require a more realistic and historically informed

understanding of the ecology of pristine coral reefs that can only be obtained by a combination of

retrospective analyses, modeling, and intensive studies of ecosystem structure and function of the

very few isolated reefs that have escaped intensive exploitation..Plenary Address 3

Friday 6 th September, 2002

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

3

LINKING ZOOXANTHELLA FUNCTION TO REEF HEALTH

ANGELA E. DOUGLAS

Department of Biology

University of York,

York YO10 5YW UK

It is accepted that zooxanthella function, especially photosynthate release to the coral, underpins

shallow water coral reefs, and that the breakdown of the zooxanthella-coral symbiosis at coral

bleaching is a response to anthropogenic factors. A key development in recent years has been the

appreciation that zooxanthellae are not functionally uniform. The purpose of my talk is twofold.

First, the extent to which molecularly-distinct zooxanthellae vary in ecologically- important traits,

including photosynthetic parameters, susceptibility to bleaching and acclimatory capabilities, will be

addressed. Second, the ecological consequences of this variation at scales from the individual colony

to the reef will be explored, especially in the context of anthropogenic factors..Plenary Address 4

Saturday 7 th September, 2002

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

4

ENVIRONMENTAL VARIABILITY AND CHANGE:

HIGH RESOLUTION RECORDS FROM CORALS AND CORAL REEFS

SANDY TUDHOPE

Department of Geology & Geophysics

Edinburgh University

West Mains Road, Edinburgh EH9 3JW,

Scotland, UK

As they grow, massive reef-building corals record environmental information in the physical

structure and chemical composition of their aragonitic skeletons. This attribute, combined with

annual skeletal growth bands, rapid growth rates, and colony longevity, makes corals valuable

palaeo-environmental archives, capable of yielding records with a temporal resolution of ± a few

months over several centuries. In addition, since the aragonitic skeletons are suitable for high-precision

U-series and 14 C dating, analysis of ‘fossil’ corals provides an opportunity to extend the

records back into the late Quaternary. These palaeoenvironmental records serve two purposes.

Firstly, corals may be used to extend beyond the instrumental record of environmental change,

thereby yielding crucial new insights into the coupled processes that control climatic and

oceanographic variability and change on decadal to millennial timescales. Secondly, the records

provide an essential context against which to view the current status and predicted decline of modern

reefs.

A major research effort has been directed towards reconstructing variability in temperature, salinity

and terrestrial run-off from analysis of annually-banded massive corals. In most cases, chemical

tracers in the skeleton are used as a proxy for the environmental parameter of interest. These records

are particularly powerful for investigating interannual variability. For example, coral data has shown

that the El Niño Southern Oscillation climatic phenomenon has varied significantly in its strength

over time, with modern ENSO probably stronger than at any other time over the past 130,000 years.

Coral geochemistry is also used to reconstruct variations in ‘mean’ conditions (e.g., change in mean

temperature, salinity, rainfall etc.). This has proven to be more difficult, due to uncertainties in

assumptions about individual tracers. Nonetheless, significant progress is being made through the use

of replication of records and use of multiple and new proxies. For example, combined trace metal

and stable isotope measurements are producing consistent patterns of temperature change on decadal

to glacial- interglacial timescales; there is exciting new work on the use of barium as a proxy for

suspended sediment input to the coastal zone over the past few centuries (McCulloch et al, this

meeting); and coral growth rates are being successfully used to reconstruct SST change over the past

few centuries. Analysis of the structure, age and elevation of corals and coral reefs also continues to

yield new insights into the magnitude, timing, rates and mechanisms of sea- level change on decadal

to 10 5 year timescales.

These coral data are contributing to a picture of tropical environments that have varied substantially,

and rapidly, over much of the past few hundred thousand years. In many ways, the last few thousand

years appear anomalous, having relatively stable (warm) mean climate and sea- level, but relatively

large interannual (ENSO) variability. These data provide a crucial testing- ground for models that

attempt to predict future climate, and the impact of natural and anthropogenic environmental change

on coral reefs..Oral Presentations..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

7

SR/CA IN CORAL ARAGONITE: IS NIGHT CARBONATE A GOOD INDICATOR OF SEA

SURFACE TEMPERATURES?

Nicola Allison, Adrian Finch

School of Geography and Geosciences,

University of St Andrews, Irvine Building, St Andrews, Fife KY16 9AL, UK

na9@st-and.ac.uk

Sr/Ca in coral skeletons has potential as an indicator of past seawater conditions but exhibits

geochemical heterogeneity on a small spatial scale (<100 µm) that does not reflect variations in sea

surface temperature (SST) or chemistry. Skeletal Sr/Ca is affected by variations in skeletal

calcification rate which may be dependent on the photosynthetic activity of the zooxanthellae in coral

tissue. The skeleton deposited at night may be unaffected by these variations and may be a more

reliable indicator of SST (Cohen et al. 2001).

We used secondary ion mass spectrometry with a 10 µm diameter analysis spot to construct records

of Sr/Ca in a Porites lobata specimen from Lanakai, Oahu, Hawaii. Analyses were performed on

sections cut perpendicular to the growth surface of the coral skeleton, spanning annual bands. Parallel

tracks were analysed following fasciculi (material deposited during the day) and centres of

calcification (deposited at night).

The Sr contents of the day and night material follow similar seasonal trends but are offset with night

carbonate typically enriched by 350-400 ppm Sr. The day carbonate profile is characterised by large

spiky Sr fluctuations, which are deposited approximately days apart and are superimposed on the

general Sr seasonal trend. These fluctuations may relate to daily variations in coral calcification rate

which is in turn affected by light intensity and water temperature. The Sr range observed in day

carbonate (~900 ppm) is equivalent to ~5ºC on the Sr palaeothermometer for Porites day carbonate

(Cohen et al. 2001) which is in good agreement with the observed seasonal temperature range.

The Sr range the in night carbonate profile (~600 ppm) is much larger than that reported previously

and is equivalent to ~16ºC on the Sr palaeothermometer for night carbonate (Cohen et al. 2001).

Calcification at night is slower than in the day and previous studies suggest that the slope of the Sr-SST

relationship in night carbonate approximates to that seen in inorganic aragonite precipitates.

This is inconsistent with our data. While the Sr range in the night carbonate is reduced compared to

that of day material, some short term Sr spikes are still present. Sr varies by up to 300 ppm over

distances of <100 µm, which is nominally equivalent to <1 week skeletal growth. These spikes do

not reflect variations in SST. We suggest that while biological effects on Sr incorporation are

minimised in night carbonate, significant biological effects may still occur in this material.

Cohen AL et al., Kinetic control of skeletal Sr/Ca in a symbiotic coral: implications for the

palaeotemperature proxy, Paleoceanography, 16, 20-26, 2001..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

8

LONG TERM CHANGES IN MALDIVIAN CORAL REEF COMMUNITIES

William R. Allison

Coral Reef Research and Management

Rangas First Floor, Violet Magu, Henveyru, Male, MALDIVES

The author has studied community change in Maldivian coral reefs since 1990. Rasdu and Addu

Atolls were repeatedly surveyed during the period 1991 to 2001. Included in the survey sites at those

atolls are sites surveyed during the Xarifa (1958) and Indian Ocean (1964) expeditions. Survey

methods included line intercept and point transects, video transects, photo-quadrats and visual

surveys. The different quantitative methods were tested to assure comparable results. COADS SST

data was obtained for the period 1980 – 2000.

Comparison of 1991 survey data with the data obtained some three decades earlier showed that large

declines in coral cover had occurred at most of the Xarifa and IOE survey sites. Acroporidae and

Pocilloporidae had declined the most. Large areas of dead branching corals in growth position were

also observed in many other parts of Maldives. During the period 1991 – 1998 coral cover generally

increased in Rasdu and Addu although there was little change at most of the IOE sites in Addu and

one site in Rasdu. In April – May 1998 a large proportion of the corals in both atolls and the

Maldives died during a severe bleaching event. Hardest hit were Acroporidae, Pocilloporidae, soft

corals (except dendronepthids) and Millepora. Although mortality was very high, "extirpations" were

not observed. At a few locations coral cover and dominant type seemed to change little in 1998, but

one large patch of coral that had apparently survived since 1958 died in 1998. Large massive coral

colonies, especially Porites, declined significantly in abundance over the entire period.

Reef bleaching and mortality in 1998 were highly correlated with elevated SST's in April and May of

that year. It seems probable that the elevated SST's and bleaching observed in 1988 contributed to the

state of reef communities documented in 1991. Anthropogenic effects were also involved in some

locations, most clearly at Gan in Addu and probably at Veligandu in Rasdu..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

9

ALLOCTHONOUS STORM GENERATES DISPLACED DAMAGE ON DEEP REEFS IN

BONAIRE (N.A.)

Rolf P.M. Bak, Gerard Nieuwland

Netherlands Institute for Sea Research (NIOZ),

P.O. Box 59, 1790 AB Den Burg, Texel, The Netherlands

Shallow reefs were destroyed and deep reefs suffered high coral mortality by displaced hurricane

effects. Hurricane Lenny never came near the island of Bonaire (N.A.) but waves generated by the

storm hit the leeward coast of the island. There were three main effects on the fringing reefs: 1 where

westerly waves hit the reefs frontally all living organisms were cleaned off the reef at depths from 0

to 6 m. 2 Dislodged corals, debris and coarse sediment was deposited between 6 to 20 m on the reef

slope. 3 Fine sediment (diam 100 µm) was transported to the reef at greater depth (> 30 m). This

sediment accumulated at the deep reef in front of the damaged shallow reefs and, through deep lateral

transport along the reef slope, also at locations that were unharmed in the shallow reef. Sediment was

efficiently cleared off living surfaces by most corals at the reef slope shallower than 25 m but not at

greater depths. Surveys (random quadrats) at 35 m depth showed the impact of fine sediment to

depend on coral species, and high mortality of dominant species such as Agaricia lamarcki. The deep

reef may be a stable habitat in terms of wave movement but rare events such as sedimentation will

cause catastrophic damage..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

10

SYMBIONT COMMUNITIES IN REEF CORALS FOLLOWING THE 1997-98 EL NIÑO:

WILL RECOVERING REEFS BE MORE RESISTANT TO A SUBSEQUENT BLEACHING

EVENT?

Andrew C. Baker, Craig J. Starger, Tim R. McClanahan, Peter W. Glynn

Wildlife Conservation Society

Center for Environmental Research and Conservation, Columbia University, MC 5557, 1200

Amsterdam Avenue, New York, New York 10027, USA

Coral bleaching as a result of sustained seawater warming is a major threat to coral reef ecosystems

worldwide. The long-term capacity of reef corals to survive these episodes is likely to be dependent,

at least initially, on the diversity and specific identities of the symbiotic dinoflagellates

(“zooxanthellae”) they contain. Because different algal symbionts appear to vary significantly in their

susceptibility to bleaching, we hypothesized that the symbiont community structure of coral reefs

following a severe bleaching event: (1) differs from that of the same reefs prior to bleaching; (2)

more closely resembles the community structure of reefs found at higher temperatures; and (3) has a

higher bleaching threshold than before and is consequently more likely to survive future temperature

anomalies of similar magnitude. We tested the first two of these hypotheses by using Restriction

Fragment Length Polymorphisms (RFLPs) in large subunit ribosomal RNA genes to identify the

symbionts of reef corals from Kenya (Indian Ocean), Panama (far eastern Pacific) and Saudi Arabia

(Arabian Gulf and Red Sea) after the 1997-98 El Niño event. We found that scleractinian corals in

Kenya, Panama and the Arabian Gulf contained symbionts in two clades of Symbiodinium (C and D).

The high relative abundance of one of these clades (Symbiodinium D) in Kenya and Panama,

combined with its virtual dominance in high-temperature Arabian Gulf reefs and comparative

scarcity in Panama prior to the El Niño, suggest this symbiont lineage may have global importance in

determining the response of reef corals to future thermal bleaching events. Red Sea reefs that were

relatively unaffected by bleaching contained relatively little Symbiodinium D but also contained

significant numbers of a third Symbiodinium clade (A), perhaps due to their high latitude location.

These results indicate that, although an absolute upper limit must exist, we should not assume that

bleaching temperature thresholds remain constant over time. Recent bleaching history, regional

symbiont diversity and time between bleaching events may be important factors in determining the

long-term response of coral reefs to global climate change..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

11

BLEACHING AND LYSIS OF THE CORAL POCILLOPORA DAMICORNIS BY THE

NOVEL PATHOGEN VIBRIO CORALLILYTICUS

Yael Ben-Haim, Eugene Rosenberg

Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life

Science, Tel-Aviv University, Ramat Aviv 69978 Israel

yaelbh@post.tau.ac.il

Coral bleaching and other diseases of corals have increased dramatically during the last few decades.

A high correlation has been reported between increased sea temperature and the incidence of coral

diseases. A new coral pathogen was isolated from diseased Pocillopora damicornis corals near

Zanzibar in the Indian Ocean. Based on its 16S rDNA sequence, genomic DNA fingerprinting

analyses, and phenotypic characteristics, the pathogen was classified as a novel species of Vibrio,

named Vibrio corallilyticus. Infection of corals in controlled aquaria at 26-29°C, with a pure culture

of V. corallilyticus caused tissue lysis of P. damicornis fragments. At 29°C, lysis began as small

white spots after 3-5 days, rapidly spreading so that by 2 weeks the entire tissue was destroyed,

leaving only the intact bare skeleton. When an infected diseased coral was placed in direct contact

with a healthy one, the healthy coral lysed in 2-4 days, further indicating that the disease was

contagious. Inoculation with as few as 30 bacteria per ml was sufficient to infect and lyse corals.

Seawater temperature was a critical environmental parameter for the infectious process: infection and

lysis occurred rapidly at 27-29°C, slowly at 26°C but tissue lysis was not observed at 25°C. At 24-25°

C, pure cultures of V. corallilyticus caused bleaching of all 16 corals infected within 2-4 weeks.

The pathogen was reisolated from the diseased tissues of the infected corals. Uninoculated control

corals at 24-25°C showed no bleaching. The bacterial bleached corals contained less than 12%

zooxanthellae concentration compared to healthy corals.

During the summer of 2001 when seawater temperature in the Red Sea (Eilat, Israel) reached over

27°C, there was considerable diseased corals. High numbers of V. corallilyticus were found in

diseased tissues, whereas it was not detected in healthy corals. V. corallilyticus was found to be

geographically distributed. Five additional strains of V. corallilyticus have been isolated, three from

diseased P. damicornis in the Red Sea, and aditional two strains from bivalve larvae, from the

Atlantic Ocean (Brazil) and Europe (Kent Region). These five strains showed high genotypic and

phenotypic similarities to V. corallilyticus type strain, and all were also pathogenic to P. damicornis.

These findings support the bacterial hypothesis of coral bleaching, and indicate a relationship

between temperature and the outcome of bacterial infection of corals..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

12

DETERIORATION INDEX: A NEW APPROACH TO CORAL REEF MONITORING

O. Ben-Tzvi, Y. Loya, A. Abelson

The Institute for Nature Conservation Research,

Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel

bentz@post.tau.ac.il

Coral reefs are deteriorating globally. Concern to the future of coral reefs drove governments, NGOs

and scientists to enhance reef monitoring worldwide. Monitoring would be valuable if it can point to

changes in the state of the examined coral community. The value of this indication can be especially

high when deterioration begins, since at early stages of deterioration the chance of reversing the

process is higher. Some widely used monitoring methods compare coral community parameters such

as live cover, mortality rate, size-frequency distribution, species richness and diversity. Coral

communities differ naturally from each other due to their depth, location, exposure to water flow and

their history of disturbances. It is expected to find significant differences in all of the above-mentioned

parameters when comparing different coral communities. In many cases however, these

differences are not indicative of the state of the coral community, do it remains stable or is it

changing. Only repetitive monitoring exactly at the same site can accurately and objectively point out

if the examined reef state is changing.

Here, we suggest a practical approach that offers a solution to the above problem by providing an

indication of the relative state of the community in addition to an indication of the trend of reef health

(developing or deteriorating). This approach is based on an index (Deterioration Index; DI) that

compares community parameters (i.e. mortality and recruitment rates) within the community as

opposed to comparing the same parameter between different reefs.

The DI was developed during a study of young coral communities developed on artificially laid rocks

in shallow water along the coast of Eilat (Gulf of Aqaba), where it was relatively straightforward to

identify the disturbed communities.

Subsequently, we examined this method on natural coral reefs at Eilat and the Seychelles. The DI

values obtained at Eilat clearly indicate that some of the examined reefs are experiencing

deterioration while others are in a relatively reasonable shape. High DI values were calculated for the

southern part of Eilat’s Nature reserve (i.e. the Japanese Gardens) indicating a declining community.

This part of the Nature Reserve reef is of high species diversity and live cover. However, the

recruitment rate is very low and the mortality rate is relatively high. The DI, therefore, indicates a

problem despite the illusive image of a well-preserved reef community, as may be misinterpreted

from the high live cover and species diversity. This indication acquired from the DI during a single

monitoring occasion shows the same results obtained by the reserve management team, after a long

term monitoring.

Results from the Seychelles surveys demonstrate that most reefs were severely damaged during the

last bleaching event. The DIs obtained there, show that most of these reefs are rehabilitating.

However, at some sites the DI values were quite high. Among them are sites that were bleached and

now have a high algal cover, and sites where the bleaching rate was relatively low but now

experience low recruitment. The results show that the DI approach can serve as an efficient tool for

MPA selection and management. This is due to the low-cost, fast-yielding and reliable data, which

can be obtained by inexperienced surveyors within a short-time (one hour) training..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

13

CORAL COMMUNITIES OF THE HADRAMAUT AND SHABWA PROVINCES, YEMEN

Francesca Benzoni, Carlo Nike Bianchi, Carla Morri

Acquario Civico e Stazione Idrobiologica di Milano

Viale G. B. Gadio 2, I-20121 Milano, Italy

The coral communities of the Gulf of Aden have been traditionally believed to be sparse and poorly

developed due to the effects of the cold, nutrient-rich water of the Arabian Sea upwelling. Recent

studies, however, have shown that they are actually significant and diverse. A survey of the coasts of

Hadramaut and Shabwa provinces, Republic of Yemen, in early 1998, found extensive coral

communities at all hard-bottom sites examined along a 130 km stretch of coast, from Al Mukalla

(14 o 31’N 49 o 9’E) westwards to Belhaf (13 o 58’N 48 o 11’E). Due to the lack of detailed cartography of

the region, hard bottom sites were located within the study area by means of spot check surveys.

Coral communities were assessed using line intercept transects carried out at sites with high coral

cover at different depths. Coral life- form categories were recorded, while dominant hard and soft

corals were identified to genus level. A diverse array of coral communities was found through the

study area. The main type, particularly at depths greater than 4 m, was a high cover Porites

community, typically composed of very large massive and sub- massive colonies. Large monospecific

areas of branching corals, especially Pocillopora damicornis, were common on shallower hard

substrates, a feature these coral communities share with those of Oman to the east. Islands, both near-shore

and offshore, tended to have better developed and more diverse coral communities than were

found fringing the mainland shore. The main factors influencing the presence, structure and

composition of coral communities in the study area seem to be the presence of available substrate,

depth and distance from the Arabian Sea upwelling. At the time of the 1998 survey the Hadramaut

and Shabwa coral communities were in excellent general health conditions, with no sign of bleaching

mortality in the recent past. True coral reefs have been reported to be very rare in the northern Gulf

of Aden, and this applies to our study area as well. Nonetheless, unexpected extensive and high-cover

coral carpets have been found in Hadramout and Shabwa. These surprising features of coral

communities in Yemen, as well as the striking patterns revealed in recent years in other sites of the

Gulf of Aden claim for further investigation in the whole area..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

14

PATTERNS OF CORAL MORTALITY, SURVIVAL AND RECRUITMENT IN

MALDIVIAN CORAL REEFS, FOLLOWING THE 1998 BLEACHING EVENT

Bianchi C.N., Pichon M., Morri C., Colantoni P., Bernardini G., Benzoni F., Baldelli G.

Marine Environment Research Centre, ENEA Santa Teresa

P O Box 224, I-19100 La Spezia, Italy

The 1998 bleaching event, which followed abnormally high sea surface temperatures (up to 34 °C),

caused widespread mortality in the reefs of the Maldives. Mortality rates were highest (approaching

100 % in certain sites) for branching and tabular species of the genus Acropora, for the

Pocilloporidae and for the hydrocoral Millepora, particularly in shallow water. Mortality rates were

lower below 20 m and in general for massive species, for which colonies affected by bleaching

mostly displayed only partial discoloration of the tissues and death. No mortality at all was observed

on the octocoral Heliopora caerulea. A recent (April 2002) survey of coral populations in 12 sites

(reef slopes in inner and outer locations as well as within passes) has shown that a majority of

colonies, for nearly 140 species belonging to virtually all reef coral families and especially Poritiidae,

Agaricidae, Fungiidae, Mussidae and Faviidae, presented adult sizes and minor or no sign of

mortality - an observation which suggests that most of them had survived the bleaching event. Very

large colonies of Porites sp.p. and Diploastrea heliopora have managed to survive although only in

relatively small patches over the whole colony, with average patch size ranging from 5 to 15 cm in

diameter. Patterns of recruitment were followed through yearly surveys. As early as April 1999, two

different size classes of Acropora had settled on the reefs. Largest recruits were up to 14 cm tall,

suggesting that the first wave of recolonization arrived soon after the mortality event. No Pocillopora

recruits were observed until 2000. In 2001, Pocillopora recruits were recorded mostly above 5 m

depth on the outer slopes and in the passes, with densities up to 5 recruits m -2 . The density of recruits

was similar for Acropora, but the recruits were spread over a larger depth range, and were also

observed in other types of reef environment than outer slopes and passes. In 2002, the abundance of

Acropora recruits did not change, while a relative lower number of Pocillopora recruits were

recorded. Small- sized colonies (< 5 cm in diameter) were the most represented in both years,

suggesting renewed recruitment waves. A relative higher proportion of comparatively large-size

colonies (up to 25 cm in diameter for Acropora) would indicate rapid growth. Faviidae, Poritidae and

Agariciidae were the most abundant recruiters other than Acropora and Pocillopora, and the genera

Pachyseris and Leptoseris, in particular, showed the highest number of non-branching recruits. No

Millepora recruits have been observed to date. Overall, the se data allow for cautious optimism with

respect to the recovery capacity of Maldivian coral reefs following a major bleaching event..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

15

SEA -LEVEL CONTROL ON REEF ACCRETION:

THE HISTORY OF RIBBON REEF 5, GREAT BARRIER REEF

C. J. R. Braithwaite, H. Dalmasso , L. F. Montaggioni

Division of Earth Sciences, Glasgow University, Glasgow G12 8QQ

A new deep borehole, drilled to a depth of 210 mbsf (metres below sea floor), on Ribbon Reef 5 on

the Great Barrier Reef off Cooktown, NE Australia, reveals a shallowing- upwards succession

punctuated towards the top by a series of erosion surfaces. Reef accretion has been controlled by the

response of the system to changing sea level.

Carbonate deposition began about 770 ka ago, during isotope stage 16, with a series of debris flows.

These reflect deposition on a relatively deep slope or ramp rather than a shallow platform and are

represented in the core from 210 to around 180 mbsf. Lithoclasts indicate that carbonate deposition

began in the area before the period represented by the cored succession, and was followed by a

period of lower sea-level that resulted in erosion. However, the cored succession shows no evidence

of erosion at these depths.

Overlying carbonates, from 178- mbsf to 155 mbsf are fine-grained grainstones with few relatively

large coral fragments and rhodoliths dominated by melobesioids. These originated in water less than

about 60 m deep but deposition was probably at greater depth. From 155 mbsf the succession is

dominated by locally coarse grainstones and wackestones, again with intervals of rhodoliths. An

upward transition from melobesioids to lithophylloids implies a progressive warming and shallowing

of waters, reflecting progradation of the platform margin. Downslope sediment movement may have

resulted from local oversteepening or storm activity on the shallower platform. The corals present

from 120-95 mbsf imply derivation from shallower water, but steeply inclined laminae suggest

continuing downslope transport. Rhodoliths, Halimeda and symbiont-bearing benthic foraminifera

indicate derivation from waters less than 60 m depth.

Typical reef assemblages were probably not established until about 100 mbsf depth in the core,

isotope stage 11. Grainstones are typical of the succession from 100-74 mbsf. Coral fragments in

these are predominantly of massive forms with bored surfaces and crusts of coralline algae. They

suggest derivation from quiet and/or relatively deep (15-30 m) water.

An upwards transition to an assemblage of robust branching corals, is paralleled by a change in the

dominant algae, from melobesioids and lithophylloids to mastophoroids. These changes imply a

progressive shallowing, and deposits probably reflect reworking on a shallow slope. More coral-bearing

limestones were deposited during isotope stages 11 and 9. The lack of evidence of a

progressive shallowing to emergence implies that the upper part of the succession has been removed

by erosion. The apparently unbroken succession to 36 mbsf and the lack of evidence of emergence

below this indicates a progressive accretion in which changes in sea level in the vicinity of the

borehole did not fall below the depositional surface..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

16

CHLOROPHYLL AS AN INDICATOR OF NUTRIENT STRESS ON REEFS OF THE

GREAT BARRIER REEF

Jon Brodie, Michelle Devlin, Glenn De’ath

Australian Centre for Tropical Freshwater Research

James Cook University, Townsville, Australia

Phytoplankton chlorophyll a has been monitored monthly since 1992 at 86 stations in the Great

Barrier Reef (GBR) lagoon. The stations are located on eight transects across the shelf from 13 0 S to

23 0 S. A primary objective of the monitoring program is to detect changes in the inshore environment

of the GBR resulting from the rapidly increasing loads of nutrients being exported from the

catchment of the GBR. Data were analysed using generalized additive models and accounted for

spatial and temporal effects. In the analyses stations were grouped by ‘inshore’ (< 25 km from the

coast), likely to be influenced by terrestrial runoff, and ‘offshore’ (> 25 km), unlikely to be strongly

influenced, and by five latitudinal regions of the GBR.

Strong differences in chlorophyll a exist across the shelf with inshore stations mean concentrations in

most transects significantly greater than offshore except in the north. In northern transects mean

chlorophyll concentrations are low ( ~ 0.25 mg/L) both inshore and offshore. Mean concentrations in

offshore stations in the rest of the GBR are similar (0.15 – 0.27 mg/L) except in the Capricorn region

in the far south where offshore mean chlorophyll is 0.55 mg/L. In contrast to northern transects

inshore mean chlorophyll concentrations from Port Douglas south fall in the range 0.45 – 0.75 mg/L.

Strong seasonal effects are evident with mean summer/wet season (December – April) values ~ 50%

greater than those in winter/dry season (May – November). Significant temporal patterns in the data

over the ten year period in each transect were observed and these may be correlated with the

influence of ENSO on river discharge but analysis of this possibility is not complete.

Mean chlorophyll concentrations in inshore areas adjacent to catchments highly developed for

agricultural and urban uses are more than double mean concentrations in inshore areas adjacent to

Cape York catchments in the north which are largely undeveloped. Discharge of nitrogen and

phosphorus from developed catchments has increased approximately fourfold over the last 150 years,

with the largest increase occurring in the last 50 years. Phytoplankton appears to be responding to

this enrichment. This signal of nutrient enrichment is of significance to the ecosystem health of inner-shelf

reefs of the GBR. In addition mean concentrations of chlorophyll above 0.6 mg/L in the inshore

Townsville to Port Douglas region of the GBR are relevant to theories which link the initiation of

crown-of-thorns starfish outbreaks to nutrient enrichment..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

17

FLORIDA’S DEEP-WATER CORAL REEFS: PROTECTION, RESEARCH AND

RESTORATION

S. D. Brooke, C. Koenig, C. M. Young

Harbor Branch Oceanographic Institution, Fort Pierce, Florida 34946

The Ivory Tree Coral Oculina varicosa, forms extensive bioherms or “banks” of azooxanthellate

colonies at depths of 70-100m along the edge of the Florida Hatteras slope. Healthy reefs support

invertebrate and fish communities as diverse as those of tropical coral reefs, and are a critical

spawning habitat for a number of commercial fisheries species. In 1984 the Oculina Banks were

declared a Habitat Area of Particular Concern (HAPC) and were protected from damaging benthic

activity. During the 1990’s it became apparent that despite protected status, large areas of the banks

had been physically damaged and fisheries were in decline. In 1994, the OHAPC status was changed

to Experimental Oculina Research Reserve to protect snapper and grouper fisheries, and a coral

restoration effort was initiated. Several types and configurations of concrete structure were deployed

over several years along damaged reef tract using large concrete structures. These structures were

intended to promote coral settlement in areas of denuded substrate, but after several years, most

showed no signs of coral recruitment. In 1998, study of reproduction and larval development was

initiated in order to assess natural re-colonisation potential and optimise restoration efforts. Research

revealed that O. varicosa is a gonochoristic broadcast spawning species, with small eggs (~100mm)

and an average fecundity of 850 (sd: 478) eggs per polyp. The gametogenic cycle begins in the early

summer and spawning occurs during late summer and fall, with no obvious relationship to lunar or

tidal phase. Planulae are small, approximately 160mm in length, and settle approximately 21 days

after spawning. Larval planktonic duration was integrated with hydrodynamic information to

estimate larval dispersal potential. It appears that larvae not only have the potential to be transported

between the deep reef tracts, but may also contribute larvae to near-shore zooxanthellate populations

during summer upwelling events. Preliminary genetic research supported ecological evidence that

gene exchange occurs between deep reefs and shallow water populations of O. varicosa.

Unfortunately, despite the protected status of the Oculina banks, and reproductive criteria conducive

to re-colonisation, the Banks have not recovered, and the healthy reef tracts have been reduced to two

small areas at the southern extent of the range. Possible explanations for the continued demise and

lack of regeneration of the Oculina reefs include illegal trawling, unknown natural causes and very

low coral recruitment rate.Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

18

STUDIES ON THE ASSOCIATED COMMUNITIES OF SERPULA VERMICULARIS (L.)

REEFS (POLYCHAETA: SERPULIDAE)

Nicola Chapman, Colin Moore

Heriot Watt University,

Riccarton, Edinburgh, EH14 4AS

The serpulid polychaete, Serpula vermicularis, is a common member of the marine encrusting

community in Europe. Throughout most of its range S. vermicularis occurs in the form of individual

tubes or occasionally as intertwining bundles of a few tubes, cemented to hard substrata, such as rock

and mollusc shells. However, at just three sites in northwest Europe massive reefs, often exceeding a

height of 50 cm and a width of 60 cm, they develop in shallow, sheltered waters.

The greatest development of these serpulid reefs is found in Loch Creran, Scotland, where their

presence has been instrumental in the designation of Loch Creran as a Special Area of Conservation

(cSAC) under the EC Habitats Directive. This will necessitate the development of a programme to

monitor the status of the reef habitat, which is under potential threat from fishing, aquaculture and

mooring activities.

From previous observations by divers it is believed that serpulid reefs provide a habitat for a diverse

associated community, although no detailed studies of the community have been published. The aim

of this study is to characterise the community, to provide a monitoring baseline and to provide

information to underpin the development of a monitoring strategy. The conservation importance of

the habitat will also be assessed by comparisons with the associated community of other biogenic

reef habitats.

Ten entire serpulid reefs were removed by diver from Loch Creran, selected to represent a broad

spectrum of reef size. Reef size was measured in situ by determination of height and width and in the

laboratory by measurement of weight. Sessile and motile fauna and flora retained on a 0.5 mm screen

were identified and counted.

The presentation will describe the nature of the reef community and will illustrate the relationship

between reef size and community diversity and species richness. By employment of multivariate

statistical techniques the relationship between species composition of the community and reef size

will be examined. The conservation importance of the habitat will be discussed and the implications

of the work for future monitoring programmes established..Oral Presentation

Abstracts Volume

International Society for Reef Studies

European Meeting – Cambridge, 4-7 th September, 2002

19

TOWARD CHARACTERIZATION OF MITOCHONDRIAL HEAT SHOCK PROTEINS IN

THE SEA ANEMONE ANEMONIA VIRIDIS

Omer Choresh 1 , Abdussalam Azem 2 , Yossi Loya 1

1 Department of Zoology, 2 Department of Biochemistry, George S. Wise Faculty of Life

Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel

omerch@post.tau.ac.il

Organisms respond to stress, which causes damage to cellular proteins, by inducing synthesis of Heat

Shock Proteins (HSPs). Induction of HSPs is one of the most familiar mechanisms of reaction to

various stressful environmental conditions (e.g. adverse temperatures, increased UV irradiation,

osmotic stress and xenobiotics). These proteins play a major role in modulating protein folding,

transport and repair during normal conditions, with higher levels of their expression being induced

under stress. The relationship between environmental tolerance of organisms and the expression of

HSPs has been studied in diverse aquatic and terrestrial organisms. However, in some groups of

organisms, such as sessile marine invertebrates, some HSPs are not well characterized and their

function and significance to adaptation are not well understood. As a major step towards

characterizing the stress response of marine invertebrates, we set out to develop general protocols for

purifying the mitochondrial (mt) HSP60 and HSP70 of the sea anemone Anemonia viridis. We also

examined the role of mt-HSP60 and mt-HSP70 in adaptation of marine invertebrates to thermal stress

through a study of the influence of changes in seawater temperature on the expression of these

proteins in A. viridis. Laboratory and field experiments reveal for the first time the existence of mt-HSP60

and mt-HSP70 in sea anemones; and furthermore, that their expression varies with changes in

temperature. A. viridis displayed high levels of both proteins when extreme temperature conditions

(31°C) prevailed in stressful habitats, such as tide pools. Further, we have developed purification

methods, based on several chromatography columns and western blot analysis, fo r both mt-HSP60

and mt-HSP70. These methods allow purification of large amounts of the proteins for further

sequence analysis. We also found new antibodies that indicate changes in the expression levels of mt-HSP60

and mt-HSP70. Partial sequence data were obtained for the purified mt-HSPs. The amino acid

sequences for both proteins are homologous to amino acid residues of the mt-HSPs of several

organisms, including Drosophila and mammals, which show the proteins to be highly conserved

between organisms. However, these fragments showed less similarity when compared to plastid

HSPs from plants and to bacterial HSPs. We further found mt-HSP60 expression for the first time in

various marine invertebrates, including scleractinian corals. These results may be particularly

significant for coral reefs, which constitute one of the most spectacular and diverse ecosystems on the