Coral Reef Degradation in the Indian Ocean Editors: Olof Lindén, David Souter, Status Report 2002 Dan Wilhelmsson & David Obura The Netherlands Finland Coral Reef Degradation in the Indian Ocean Status Report 2002 The coral reefs of the Indian Ocean are extremely diverse ecosystems and play a key Program co-ordination role in the productivity of the coastal areas. In CORDIO addition, these reefs are essential for the food Olof Lindén David Souter security of a large proportion of the human Department of Biology and Environmental Science population, for the protection of coastlines and University of Kalmar as a valuable tourist attraction. Unfortunately, a 391 80 Kalmar number of threats that have caused serious Sweden (e-mail: [email protected], [email protected]) declines in the distribution and condition of these reefs during recent decades. In particular, CORDIO East Africa Region the El Niño event of 1997/98 produced David Obura extremely high water temperatures that caused P.O.Box 10135 Bamburi, Mombasa bleaching and mortality of corals on a global Kenya (e-mail: [email protected], scale. CORDIO is a collaborative program [email protected]) involving research groups in 11 countries and CORDIO South Asia Region was created in 1999 to help mitigate the Dan Wilhelmsson widespread degradation of the coral reefs South Asia Co-operative Environment Programme throughout the central and western Indian Ocean. (SACEP) This report presents a summary of the results 10 Anderson Road Colombo 5 obtained during 2001 and 2002. Sri Lanka (e-mail: [email protected], CORDIO is an operational program under the [email protected]) International Coral Reef Initiative (ICRI). CORDIO is supported by Sida (Swedish CORDIO Indian Ocean Islands Jean Pascal Quod ARVAM (Agence pour la Recherche et International Development Cooperation la Valorisation Marine)14, Rue du Stade de l’Est, Agency), the Dutch Trust Fund of the World 97490 Sainte Clotilde Bank, The Government of Finland, IUCN and La Réunion (e-mail: [email protected]) WWF. CORDIO Socio-economic project Herman Cesar IVM-VU (A-670), Vrije Universiteit De Boelelaan 1087 1081 HV Amsterdam the Netherlands (e-mail: [email protected]) Website: www.cordio.org ISBN 91–973959–2–7 Coral Reef Degradation in the Indian Ocean Status Report 2002 EDITORS: OLOF LINDÉN, DAVID SOUTER, DAN WILHELMSSON & DAVID OBURA The Netherlands Finland Coral Reef Degradation in the Indian Ocean Status Report 2002 © 2002 CORDIO and the authors ISBN 91-973959-2-7 Published by CORDIO Department of Biology and Environmental Science University of Kalmar SE–391 80 KALMAR Sweden Maps Tommy Holmberg Production Bo Heurling AB Printed in Italy 2002 by Eurolitho, Milano, through Italgraf, Västerås, Sweden Contents Foreword 7 David O. Obura, Innocent N. Wanyonyi Executive Summary 9 & Jelvas M. Mwaura Participatory Monitoring of Part I East Africa 13 an Artisanal Fishery in Kenya 70 David Obura: M. H. Schleyer & L. Celliers Status of Coral Reefs in East Africa 15 A Consideration of the Biodiversity Mohammed S. Mohammed, and Future of Southern African Coral Reefs 83 Christopher Muhando & Haji Machano Coral Reef Degradation in Tanzania: Part II South Asia 91 Results of Monitoring 1999–2002 21 Dan Wilhelmsson Christopher A. Muhando & Baraka L. Kuguru Coral Reef Degradation in South Asia 93 The Status of Corallimorpharia Sarang Kulkarni & Alok Saxena on Coral Reefs of Tanzania 31 The Conservation Status of Coral Reefs Christopher A. Muhando of Andaman and Nicobar Islands 103 Seawater Temperature on Shallow Reefs J. K. Patterson Edward Off Zanzibar Town, Tanzania 40 The Coral Reefs of the Tuticorin Coast David Obura of the Gulf of Mannar, South-East India 114 Status of Coral Reefs in Hussein Zahir Kiunga Marine Reserve, Kenya 47 Status of the Coral Reefs of Maldives 119 Helena Motta, Marcos A.M. Pereira H. Zahir, S. Clark, R. Ajla & M. Saleem 125 & Michael H. Schleyer Spatial and Temporal Patterns of Coral Reef Degradation in Mozambique, Coral Recruitment Following Results of the Monitoring 1999–2000 55 a Severe Bleaching Event in the Maldives 125 Jacqueline Uku, Samuel Ndirangu & Charles Muthama Hussein Zahir Trends in the Distribution of Macroalgae Assessing Bioerosion and Its Effect in a Bleached Kenyan Reef Ecosystem 61 on Reef Structure Following a Bleaching Event in the Maldives 135 Arjan Rajasuriya Charles R.C. Sheppard Status Report on the Condition Island Elevations, Reef Condition of Reef Habitats in Sri Lanka, 2002 139 and Sea Level Rise in Atolls of Chagos, Chintha Perera, Dan Wilhelmsson & Arjan Rajasuriya British Indian Ocean Territory 202 Reef Fisheries and Udo Engelhardt, Martin Russell & Bertrand Wendling Coral Reef Degradation in Sri Lanka 149 Coral Communities around Dan Wilhelmsson, S. S. K. Haputhantri, the Seychelles Islands 1998–2002 212 Arjan Rajasuriya, Shamen P. Vidanage Ben Stobart, Raymond Buckley, Larry LeClair, Kristian Monitoring the Trends of Marine Teleki, Nigel Downing, David Souter & Martin Callow Ornamental Fish Collection in Sri Lanka 158 Aldabra: Monitoring the Path to Recovery 232 Helen Perks Future Effects of Climate Change on Part IV Thematic Reports 249 Coral Reefs and Mangroves in South Asia 167 Herman Cesar, Lida Pet-Soede, Susie Westmacott, Stephen Mangi, & Annabelle Aish Part III Indian Ocean Islands 177 Economic Analysis of Coral Bleaching Jean Turquet, Lionel Bigot, Harold Cambert, in the Indian Ocean – Phase II 251 C. Conand, Remi Garnier, Emile Mirault Jerker Tamelander & David Obura & Jean Pascal Quod Coral Reef Rehabilitation: 2001 Bleaching on Acropora Dominated Reefs Feasibility, Benefits and Need 263 in Réunion 179 David Kirugara & Peter Wawiye Jean Pascal Quod, Youssouf Dahalani, Lionel Bigot, UV-Radiation and Recruitment of Jean Benoit Nicet, Said Ahamada& Jean Maharavo Microalgal Assemblages in a Coastal Lagoon 272 Status of Coral Reefs at Réunion, Mayotte and Madagascar 185 F. J. Webster & K. McMahon Adresses to Authors 281 An Assessment of Coral Reefs in Northwest Madagascar 190 6 Foreword In addition to being magnificent ecosystems full of life particularly badly affected by this El Niño and most of and colour, coral reefs are critical to the food security of the corals in East Africa and in central and northern coastal people in large parts of the world. It has been Indian Ocean bleached and died during this event. Since estimated that around 50% of the fish catch from several the early 1990s Sida, IUCN and a few other organiza- countries in the tropics are directly related to coral reefs. tions such as UNEP has supported capacity building in The productivity of these ecosystems is phenomenal. marine science and management in the East African One square kilometre of coral reef can provide food for region. Institutions that took part in this capacity build- several hundred people per year. In addition the reefs ing reported much of the early data showing the extent provide shelter for larval stages of a number of different of the coral bleaching in 1998. It is interesting to note fish and other organisms. Furthermore we know that that the flow of data and information regarding the along coasts where coral reefs have been destroyed, impacts of the El Niño of 1998 came from the East floods and storms easily wash the coastline away. It is African region to the rest of the world and not the other therefore with great concern that we learn about the way around. At the same time as the reported informa- destruction of coral reefs around the planet. It is obvious tion is worrying indeed, we are convinced that is an that a number of human activities are to blame, includ- encouraging sign of the growing capacity in the field of ing fishing using destructive fishing methods including environmental science at local institutions in the region. dynamite, and pollution and sedimentation from land. As a result of the region-wide bleaching of 1998, Sida During the last decades it has becom obvious that cli- decided to support the CORDIO program, which was mate change is a factor playing an increasing role in the launched early in 1999. The purpose of CORDIO, stress on coral reefs. If the trend towards increasing which also was supported by several other Swedish and temperatures on the planet continues, the background international organizations, is to obtain data regarding sea surface temperatures is likely to raise to levels where the ecological and socio-economic consequences of the bleaching – a general sign of stress affecting corals – will mortality of corals, particularly focusing on vulnerable become regular phenomena within a few decades. groups of the coastal human population. This report A climate related phenomenon; the El Niño of 1998 presents the results of the work conducted under the caused massive coral bleaching, which killed a large por- CORDIO program during the last 18 months. The tion of the corals on the planet. The Indian Ocean was results make an important contribution to our knowl- 7 edge of some of the very worrying problems caused by will stimulate national and international efforts to better climate change. manage coral reefs. Action is needed at all levels, from The scientific assessments carried out under the assisting local communities with co-management agree- CORDIO program is done by local scientists and ex- ments, via national programs for capacity building and perts in 11 countries around the Indian Ocean. COR- strengthening of institutions to improve management DIO is therefore an example of a locally driven regional and enforcement, to truly global initiatives like managing initiative to provide valuable data for not only the coun- the trade in coral reefs products or reducing the release tries of the region but for the world at large. It is impor- of greenhouse gases that are linked to coral bleaching. tant that such networks are maintained as it is only We need to conserve coral reefs because of their magnifi- through long-term data series that we are able to assess cent biodiversity, unparalleled beauty, enormous tour- the state of the environment and the potential threat to ism potential and particularly because well managed the society from environmental change.