CORAL REEF DEGRADATION IN THE INDIAN OCEAN Status Report 2000 DRAFT – 1 – CORAL REEF DEGRADATION IN THE INDIAN OCEAN Status reports and project presentations 2000 Published by CORDIO SAREC Marine Science Program Department of Zoology Stockholm University 106 91 Stockholm Sweden ISBN 91-973959-1-9 Maps by Jeanette Bergman Weihed, Tellurit Datorgrafik Layout by Tryckfaktorn AB, Hans Melcherson Printed by Stenby Offset, Västerås, 2000 – 2 – Foreword The temperatures of the world’s oceans are increasing at an accelerat- ing rate. Recent estimates indicate that the magnitude of these increas- es might be as much as several degrees over the next century and un- doubtedly, the impacts of these changes on the Earth’s ecosystems are likely to become increasingly obvious. Coral reefs have already shown dramatic responses to the increasing ocean temperatures. Under nor- mal temperature conditions, reef-building corals, which form the foun- dation of coral reefs, are living very near the maximum sea tempera- tures that they can tolerate. If they are exposed to even modest increas- es in sea temperatures, perhaps only 1° C - 2° C, they become stressed and often ‘bleach’. This bleaching of corals is a response to stress, and it occurs when the symbiotic unicellular algae (zooxanthellae) that lives within the tissues of the coral polyp, are expelled or lost. The coral can survive for short periods without these zooxanthellae but unless the stress that caused the bleaching subsides and new zooxanthellae are incorporated into the tissue of the coral, the coral will die. For several months in early 1998, the temperature of surface waters (< 10 m) over much of the world’s tropical oceans increased between 3° C and 5° C. As a result, corals on reefs throughout the world bleached and, unfor- tunately, many died. The mortality of corals was particularly serious in the central and western Indian Ocean, where as many as 50% to 95% of all corals died. The impacts of the 1998 coral mortality are a matter of great con- cern. Coral reefs are one of the most diverse, productive and complex ecosystems on the planet. They are the home of hundreds of thousands of species, many of which are unknown to science. They are highly productive, providing food and shelter for most of the fish species caught in shallow tropical coastal waters. As a consequence, the impacts of such widespread coral mortality will have a direct bearing on critical marine and coastal biodiversity and fragile ecosystems that are affected. From a socio-economic perspective, the impacts of coral mortality are far reaching, affecting food security as well as local and national econo- mies that are dependent on reef-based tourism and industry. It is par- ticularly worrying that models, based on the IPCC Scenario A (dou- – 3 – bling of atmospheric carbon dioxide levels by 2100), that forecast fu- ture climatic conditions predict that the temperature tolerances of reef- building corals will be exceeded permanently within the next few dec- ades. Considering these grave predictions, it is a matter of great impor- tance that we, as custodians of the planet, learn all that we can about the ecological and socio-economic implications of climate change. The CORDIO Program was launched in 1999 to obtain valuable data that will enable us to determine the consequences of increasing ocean tem- peratures. This report presents the results of work conducted within the first 18 months of the CORDIO Program and makes an important contribution to our knowledge of the problems caused by climate change. In gathering such data the CORDIO Program fulfils an im- portant role and warrants full support. ARNE JERNELÖV Secretary General, FRN (Swedish Council for Planning and Co-ordination of Research) INDU HEWAWASAM Senior Environmental Specialist, World Bank MICHAEL STÅHL Head of Division, Sida (Swedish International Development Co-operation Agency) KARI ALANKO Director of the Southern Africa Unit Ministry of Foreign Affairs Finland MÅNS LÖNNROTH Director, MISTRA (Foundation for Strategic Environmental Research) LARS KRISTOFERSON Secretary General, WWF-Sweden – 4 – Address by the Global Coral Reef Monitoring Network (GCRMN) During the severe El Niño and La Niña events of 1998, mine whether rehabilitation is necessary and possible; many coral reefs in the Indian Ocean and the Arabian assess the socio-economic impacts; and determine what region suffered unprecedented levels of coral bleaching alternative livelihood activities are possible for the peo- and mortality. It was under El Niño conditions that se- ple of the region. Thus, CORDIO became the first vere bleaching occurred in the Indian Ocean countries large-scale, ocean-wide project that took a holistic ap- of Comores, India, Kenya, the Maldives, Oman, Sey- proach to assess coral reefs and interact with the people chelles, Sri Lanka, and Tanzania, and the UK territories who depend on them. of the Chagos banks. During the La Niña events in the The CORDIO Program is now being welcomed as second half of the year, there was extensive bleaching in an operational component of the International Coral the Arabian Gulf and reefs of the southern Red Sea. Reef Initiative (ICRI), which was formed as a direct re- Coral mortality exceeded 50% on many of these reefs, sponse to alarming reports of increasing degradation of and in some countries like the Maldives and Seychelles, coral reefs. Such concerns were a theme at the United virtually all corals in shallow water died. Nations Conference on Environment and Development These events sounded the alarm for the future of in 1992, and was again stressed by Small Island Devel- coral reefs and particularly for the many communities of oping States at a meeting in Barbados, 1994. The inter- people in the Indian Ocean dependent on these reefs for national community responded by forming ICRI with their livelihoods. But there was a glaring problem; there key countries being Australia, France, Jamaica, Japan, was insufficient information on the extent and status of Philippines, Sweden, UK and USA along with the the reefs in the wider Indian Ocean and also very little World Bank, UNEP, IOC/UNESCO, UNDP, IUCN understanding of how people of the region interacted and WWF. The first operational unit of ICRI was initi- with these reefs. Our knowledge of coral reefs of the In- ated in 1995 with the formation of the Global Coral dian Ocean was much poorer than of those of Southeast Reef Monitoring Network (GCRMN). The GCRMN Asia, the Pacific and the Caribbean, where considerable aims to determine the status of coral reefs around the research and monitoring has been conducted. world by networking existing monitoring activities, es- This lack of knowledge was immediately recognized tablishing new monitoring where necessary, and raising by Sweden and the World Bank and they reacted with awareness amongst all stakeholders of the need for en- amazing speed to implement the CORDIO project hanced reef conservation. Thus, the goals of CORDIO (Coral Reef Degradation in the Indian Ocean) with and the GCRMN have considerable overlap and a stra- funding from the governments of Sweden and the tegic partnership was formed early to maximise efforts Netherlands through a Trust Fund with the World in the Indian Ocean. Bank. CORDIO has five basic elements: to assess the ex- The GCRMN operates through independent Nodes tent of the bleaching; measure rates of recovery; deter- of neighbouring countries that co-ordinate training, – 5 – monitoring, data analysis and report writing to deter- neously tackles coral reef ecosystem problems over oce- mine the status of coral reefs. There are three functional anic scales and integrates this with socio-economic as- Nodes in the Indian Ocean: South Asia, Western Indian sessment of the user communities. A search for solutions Ocean, and Eastern Africa. While there had been con- is an integral feature within the project. I was invited to siderable coral reef monitoring in Eastern Africa (espe- participate in the meeting held in Lamu, Kenya in Feb- cially Kenya and Tanzania), a co-ordinating Node had ruary 2000 and was impressed with the strong sense of not been formed. This role was taken on by CORDIO teamwork and co-operation amongst participants from which is funding and co-ordinating monitoring for both all Indian Ocean countries, external agencies and do- the GCRMN and CORDIO within Kenya, Mozam- nors. Thus, I can predict that the CORDIO project will bique and Tanzania, with South Africa assisting and serve as a new model to tackle global environmental and hopefully Somalia to participate in the future. social problems such as those caused by climate change, Thus, the partnership between the CORDIO and by sharing knowledge and experience amongst the con- GCRMN programmes has been established on the basis cerned scientific and policy-making community over of mutual goals and methods. The GCRMN will assist much larger scales than many current projects that CORDIO with the first two objectives: assessing reef work only with small areas within a single country. status and observing recovery. What has been estab- lished under CORDIO should serve as an example for CLIVE WILKINSON other parts of the world. This is a project that simulta- Global Coordinator GCRMN – 6 – Table of contents FORWARD 3 Status of the coral reefs of Maldives after the bleaching event in 1998 64 ADDRESS BY THE GLOBAL CORAL REEF Hussein Zahir MONITORING NETWORK (GCRMN) 5 The status of the coral reefs of India following the EXECUTIVE SUMMARY 9 bleaching event of 1998 69 Lida Pet-Soede, Mohideen Wafar, K. Venkataraman, SYNTHESIS 12 P.T. Rajan and Dan Wilhelmsson Indian Ocean Islands - Summary 75 SECTION I - STATUS REPORTS Susie Westmacott and Jean-Pascal Quod East Africa - Summary 23 David Obura The reefs of the granitic islands of the Seychelles 77 Kenya, reef status and ecology 25 John Turner, Rebecca Klaus and Udo Engelhardt David Obura, Jacqueline N.