CORDIO Status Report 2000

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BENTHIC COMMUNITIES Benthic community structure has been recorded by a number of methods with varying comparability. They include a rapid assessment method (IUCN/UNEP in Obura et al., 1998) used in northern Kenya in 1998, a variety of line transect methods (McClanahan & Shafir, 1990; Obura, 1995; Obura, in prep), and video transects. Results from all these methods are reported here, with reasonable comparability amongst the line transect and video methods. The rapid assessment method was used for a particular site in 1998 and provided the first documentation of bleaching in Kenya and northern Tanzania (Obura et al., 1998). Kenyan reefs were some of the worst hit of the region, by El Niño bleaching and mortality, with many reefs estimated to have suffered levels of 50% to 90% coral mortality (Wilkinson, 1998; Obura, 1999; Mc- Clanahan et al., 1999). Transect-based monitoring of reefs following the first estimations has confirmed the general loss of corals countrywide (Figure 1). McClanahan (this volume) reports an average decline in coral cover from 30% to 11% (Figure 1a) on lagoon patch reefs < 1m deep at MLW along the southern Kenya Figure 1. Benthic cover on Kenyan reefs before, 12 months after and 18 months after the 1998 bleaching event. Data shown for shallow and deep reefs in northern and southern Kenya. A) southern shallow reef records, source: McClanahan/CRCP, this volume and records from 1992 – press. B, C and D – shorter term records of deeper sites and northern reefs, sources: Obura, 1995; Obura et al., 1998, <strong>CORDIO</strong>. Cover (%) 60 50 40 30 20 10 70 A) South Shallow 60 B) North Shallow 50 Cover (%) 40 30 20 10 0 0 Cor-Live Cor-Dead Inverts Alg-Cor Alg-Fle AlgTRF Cor-Live Cor-Dead Inverts Alg-Cor Alg-Fle AlgTRF 50 40 70 C) South Deep 60 D) North Deep 50 Before After - 12 months After - 18 months Cover (%) 30 20 10 Cover (%) 40 30 20 10 0 0 Cor-Live Cor-Dead Inverts Alg-Cor Alg-Fle AlgTRF Cor-Live Cor-Dead Inverts Alg-Cor Alg-Fle AlgTRF – 27 –
coast. Coral cover decreased on both protected and unprotected reefs, with concomitant increases in algal cover depending on the status of herbivore communities (see McClanahan & Mangi, this volume). Monitoring of reefs in northern parts of Kenya (in the Kiunga Marine Reserve) and in a few fore reef sites in both northern and southern parts of Kenya has been established more recently. Monitoring in the remote northern sites has involved collaborations among many organisations, including, Kenya Wildlife Service, WWF, UNEP, FAO, CRCP, and recently, <strong>CORDIO</strong> (reported in Obura et al., 1998). Transect surveys of deeper reef sites in the Malindi and Watamu areas are based on sites established in Obura (1995). Coral mortality shows the same patterns at these additional sites (Figure 1b, c, d), with coral cover falling from levels of 30% (southern, deep reefs) and approximately 10% (northern reefs) to about 5% at all sites. Lower pre-bleaching coral cover on northern Kenya reefs is thought to be due to a gradual transition from the coral-reef dominated East African fauna in the south, to the cold-water influence of the Somali upwelling system further north (Samoilys, 1988; McClanahan, 1988; 1990). While coral bleaching and mortality in shallow waters in this northern region were as dramatic as southern areas, deeper corals suffered less mortality (though > 50% bleaching was observed, pers. obs., J. Church, pers. comm.), and the small losses in coral cover were not distinguishable due to the differences in methods used in the before/after surveys. Kenya’s network of Marine Protected Areas has offered a large-scale experiment for studies of the effects of protection on reef ecology (e.g. McClanahan et al., 1999) and has been the focus of over 15 years of coral reef monitoring and analysis of a variety of threats (Coral Reef Conservation Project, McClanahan & Obura, 1995). Analysis of the El Niño effects in relation to other stresses, and in the context of protection status (Mc- Clanahan & Mangi, this volume) will give critical support to calls for placing increased areas of coral reefs under protective management (Introduction, this volume). CORALS The condition of corals was observed during and following the El Niño, to record species-specific differences in response to the stress. The frequency of normal, bleached and dead corals for species that were observed during and after the El Niño are given in Table 1. The table partitions species first by the severity and rapidity of their bleaching response, then by mortality levels. The Acroporidae were the most affected group of cnidarians, showing rapid bleaching and mortality at levels approaching or at 100% even before the end of the El Niño event. The second group that showed high levels of bleaching included some species that also suffered close to 100% mortality (Galaxea astreata), other acroporids that suffered high but not complete mortality, and a number of other groups (Fungia spp., Coscinaraea sp., anemones) that had high levels of bleaching, but low mortality levels. Other acroporids, all pocilloporids sampled and most Millepora spp. showed variable bleaching during the event and high mortality subsequently. The remaining groups in the table exhibited variable and moderate to low bleaching and mortality levels, and included predominantly faviids, acroporids in the genera Montipora and Astreopora, agariciids, poritids and most of the octocorals and zoanthids. Almost all of the coral species that suffered high bleaching and mortality rates are fast growing with branching morphologies, which enable them to dominate reef communities through sexual and asexual reproduction and competitive overgrowth. Many of the surviving species are massive or sub-massive in morphology and slower growing, or only attain small sizes and don’t tend to dominate reef communities. These patterns in the bleaching response of coral species are reflected in cluster analysis groupings from a subset of 16 coral species and one soft coral genus (Sinularia) from the same data set. The primary division separates the fast growing, low resistance species from the others (A, Figure 2), with the main distinction between groups B and C being in higher mortality but less tendency to bleach, and also higher levels of variation in response, in – 28 –
Page 2 and 3: CORAL REEF DEGRADATION IN THE INDIA
Page 4 and 5: Foreword The temperatures of the wo
Page 6 and 7: Address by the Global Coral Reef Mo
Page 8 and 9: Table of contents FORWARD 3 ADDRESS
Page 10 and 11: Executive Summary The World Conserv
Page 12 and 13: to date. Working group discussions
Page 14 and 15: Biophysical Generally, region-wide
Page 16 and 17: species exhibit different tolerance
Page 18 and 19: er-term, “shifting baselines” i
Page 20 and 21: flow diagram presented below. CORDI
Page 22 and 23: SECTION I Status Reports - 21 -
Page 24 and 25: East Africa - Summary DAVID OBURA C
Page 26 and 27: Kenya, reef status and ecology DAVI
Page 30 and 31: Figure 2. Three strategies for blea
Page 32 and 33: % cover % cover 16 14 12 10 8 6 4 2
Page 34 and 35: Table 3: Population densities and s
Page 36 and 37: Assessment of coral reef degradatio
Page 38 and 39: Table 1. Reef stations surveyed in
Page 40 and 41: live coral cover for Mbudya Marine
Page 42 and 43: Table 5. Some environmental paramet
Page 44 and 45: Coral reef monitoring and managemen
Page 46 and 47: L impopo Maputo Sa ve River Riv er
Page 48 and 49: category) and size classes (total n
Page 50 and 51: The status of South African coral r
Page 52 and 53: South Asia - Summary DAN WILHELMSSO
Page 54 and 55: SRI LANKA Most shallow coral reef h
Page 56 and 57: corals in Sri Lanka is relatively h
Page 58 and 59: Figure 1. Distribution of coral ree
Page 60 and 61: Kandakuliya Most of the nearshore r
Page 62 and 63: shallow water (0 m - 3 m) on the re
Page 64 and 65: Rajasuriya, A & De Silva, M.W.R.N.
Page 66 and 67: In each of these regions three reef
Page 68 and 69: Table 4. Summary data from transect
Page 70 and 71: The status of the coral reefs of In
Page 72 and 73: Relative importance in total landin
Page 74 and 75: Small pelagics Large pelagics Demer
Page 76 and 77: Indian Ocean Islands - Summary SUSI
Page 78 and 79:
The reefs of the granitic islands o
Page 80 and 81:
onies damaged was recorded using th
Page 82 and 83:
FAMILY GENUS SPECIES DEAD SURVIVING
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FAMILY GENUS SPECIES DEAD SURVIVING
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Figure 10. Recruit on consolidated
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Reef systems of the islands of the
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Figure 2. Coral condition by locati
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At the Bank’s northern and southe
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chelles (Turner et al., this volume
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the shallow bays of Balaclava Marin
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Development of a geographical infor
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2 1,8 1,6 Mean Bleaching Score 1,4
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Meteorological data from the period
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Figure 16. Total sunshine (hrs) per
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solar irradiance. In Thailand, loca
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Harriott, V.J. 1985. Mortality rate
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Table 1. Location of CORDIO monitor
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Figure 1. Recovery from settlement
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that due to its low impact, dead co
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Map of the Western Indian Ocean wit
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In April 1998, close to the peak of
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Pachyseris, Turbinaria spp.) and en
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Partial mortality of Favites flexuo
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REFERENCES Barnes, J., Bellamy, D.J
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SECTION II Environmental Monitoring
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Sea surface temperature in the west
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Temperature and water exchange in a
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Figure 2a. Time series temperature
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ACKNOWLEDGEMENTS I would like to th
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Figure 2. Settlement plates for cor
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REFERENCES CARICOMP. 1994. Manual o
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Figure 2. Two possible recoveries f
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SECTION III Thematic/Research Repor
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Socio-economic assessment of the im
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to escape predation (Williams, 1991
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Table 4 Demersal fish landings in 1
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mersal species have not been heavil
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Therefore, it must be concluded tha
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▲ Level of importance 35 30 25 20
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very few come specifically for reef
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Percentage 28% Food and beverages w
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Anonymous. 1998b. Basic Fisheries S
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has a 4 m tidal range) dominated by
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Table 1. Comparison of the gross be
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Greenstein, B.J., Curran, H.A. & Po
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to assess ciguatera risk by impleme
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Evaluation of succession and coral
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within each depth zone (5 m and 10
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The taxonomic patterns of coral rec
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dives, this study has demonstrated
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Bioerosive processes An important a
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each of the three different fish co
Page 182 and 183:
Figure 1. Coral fragments transplan
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Pavona Echinopora 50 100 50 100 Gro
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A low-tech method for reef rehabili
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Impacts of bleaching on coral commu
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anching and massive corals (Plate 1
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es, metal bars and PVC surfaces. No
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strate that supports a low percenta
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egeneration and prevent further des
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APPENDICES - 197 -
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Coral Reef Degradation in the India
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LIST OF PARTICIPANTS LIONEL BIGOT A
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AGNETHA NILSSON Programme Officer U
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DR. SUE WELLS Co-ordinator, E.A. Ma
Page 208 and 209:
- 207 -
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