Status of the Worlds Coral Reefs
Executive Summary

STATUS OF THE WORLD’S REEFS

The first and second global GCRMN/Reef Check surveys showed that most of the world’s reef corals are in good to excellent condition, because they are either remote from human populations, or are under good management, such as the Great Barrier Reef. But these surveys also showed that management at most marine parks is failing to stop the loss of high value, edible species, and that greater attention is needed to improve management. The ecological balance in many of the world's best reefs has been altered by the removal of high-value organisms.

A recent estimate by the World Resources Institute in Washington suggested that as many as 56% of the world’s reefs are threatened. Finally, there are those reefs that have been severely damaged or destroyed. Approximately 10% of the world’s reefs fit into this category, being mined for sand and rock, reclaimed for development (particularly for airports), or have been buried under sediment washing into the sea from inappropriate land use.

Fortunately most reefs have a high capacity for recovery, and if pressures are reduced or removed, many damaged reefs will rebound to a healthy status.

Status of Middle East Coral Reefs

The Red Sea reefs are only affected in a minor way by human disturbances. Consequently the reefs are in near-pristine condition, and few threats loom on the horizon. Reefs on the Arabian Sea coast are heavily influenced by cool upwellings, which limit coral growth and favour the growth of large algae. But these reefs are only marginally affected by human activities, and remain in good condition. The shallow fringing reefs in the Arabian Gulf are impacted by high sediment, and large fluctuations in temperature and salinity, hence they are not well developed. Also they have been severely impacted by coral bleaching in recent years. There is little active coral-reef management in the region, however, there are projects to increase management capacity and conserve some valuable reefs. An imminent threat to these reef systems is oil pollution from increasing tanker traffic.

Status of Western Indian Ocean Coral Reefs

The status of reefs ranges from those in virtually pristine condition, such as the atolls in mid-ocean, to reefs that are heavily impacted by human activities, such as those fringing the coast of East Africa and Madagascar. Extensive clearing of land and forests in Kenya, Tanzania, and Madagascar has led to excessive sediment runoff, which has damaged many reefs. In addition, there is over-fishing, including the use of explosives, so that these reefs are in medium to poor condition. Some reefs on Mauritius have been impacted by sediment runoff from sugar-cane farming, and by over-fishing, whereas the reefs of the Comoros and Seychelles are mostly in good to very good condition, except immediately adjacent to large population centres. Reef management is not well developed, and fisheries and coastal development are poorly regulated. Rapidly increasing populations and tourism are contributing to reef destruction. Recently there has been significant progress in reef management in the Seychelles, Mauritius, Kenya, and Tanzania, particularly in establishing marine protected areas for tourism. Efforts at increasing community-level management are proving successful in some areas of Kenya and Tanzania.

Status of South Asian Coral Reefs

The coral reefs of South Asia vary considerably. In the Maldives, Laccadive/Lakshadweep and Chagos atolls, the status of the oceanic reefs is very good, and virtually undisturbed reefs fringe the Andaman and Nicobar Islands. In contrast, the fringing reefs and patch reefs off India and Sri Lanka are predominantly in poor condition, and increased sedimentation, pollution, coral mining, and intensive fishing, including for the aquarium industry, are major problems. Tourism in now the mainstay of the economy in the Maldives, and is increasing in Sri Lanka and the Andaman Islands. Virtually all reefs in South Asia (except Chagos) have suffered major damage from coral bleaching in 1998. Environmental awareness is increasing, and reef management gradually improving.

Status of Southeast Asian Coral Reefs

Approximately 30% of the coral reefs of the world are in Southeast Asia, the global centre of biodiversity for hard corals and many other reef animals and plants. But the populations and economies of the region are growing rapidly, mainly in coastal areas, and the result is non-sustainable use and degradation of many reefs, particularly those close to major populations. Some remote reefs may still be healthy, but fishers are moving throughout the region, taking fish by destructive means, especially cyanide. The demand for healthy reefs for tourism may increase reef conservation, because tourism can generate long-term sustainable income if managed carefully. Many reefs have been monitored and show a steady decline in live coral cover over the last 15 years. As a response, more marine protected areas have been gazetted, but less than 10% are well managed. Although awareness of the importance of reefs is increasing, recent economic problems may mean that reef conservation receives a lower priority.

Status of Australian Coral Reefs

The major stresses to Australian reefs are natural, such as cyclones, coral bleaching and crown-of-thorns starfish. Human stresses are very light, except on some reefs close to the land, because population density is low, the economic status is high, and there is low fishing pressure. Major research is underway to ensure fishing is sustainable for target species, total catch and for reef health. All Australian reefs are under efficient management with strong local support, with good compliance achieved more by education and involvement, than by enforcement. The bulk of the Great Barrier Reef is in good condition because most of it is remote from land influences, but inner shelf reefs may have suffered impacts resulting from enhanced sediment and nutrient runoff caused by cattle grazing and sugar cane growing. However the farming industry is working out of both self interest and concern for the environment to reduce the impacts of sediment and nutrient runoff. All tourist resorts are now required to treat sewage so as to avoid any runoff, and to manage areas of reefs that they use. Reefs off Western Australia are in good health as they are generally not impacted by land influences, and there have been no impacts attributed to petroleum exploration or fishing. There is strong recognition by government that the tourism and resource values of coral reefs are particularly high, which means that management receives sufficient attention.

Status of Northwest Pacific Reefs

Reefs of China, Japan, and Taiwan are normally impacted by typhoons and crown-of-thorns starfish, and recently have been severely damaged by sediment, pollution, and over-fishing, including blast and cyanide fishing. Reefs of the Marianas have likewise deteriorated and both coral and fish populations reduced. However, the reefs of Palau, the Federated States of Micronesia, and the Marshall Islands are in good health, except those around population centres where there is sediment and nutrient pollution. The traditional low-level fishing activity has increased dramatically in response to enormous demand from Asia and America. Giant clams, sea cucumbers, trochus shells, lobsters, and top quality fish are often severely depleted, even on remote reefs. Reef conservation is inadequate, although management is improving in all countries. However, far greater efforts are required to arrest the continuing trend of reef degradation.

Status of Southwest and East Pacific Reefs

About 99% of all southwest and east Pacific reefs are remote from urban pollution and sediment degradation, and structurally they remain in good to excellent condition. Reefs near large towns provide benefits in subsistence fishing, recreation, tourism, and shoreline protection, but these reefs are being chronically degraded. There is often significant over-fishing, and giant clams, sea cucumbers, and trochus shells are now rare. Sharks and lobsters have been removed from most remote reefs. This is an increasing trend, and involves cyanide and dynamite fishing for Asian markets. The largest natural threats are from storms and strong wave action, along with crown-of-thorns starfish. Concern is increasing about global climate change, coral bleaching, and stronger El Niño events. Rising sea levels will damage the shores high islands that are rapidly subsiding, and may destroy low coral islands and jeopardise their island cultures. Management is required to reduce or divert increasing population pressures, and integrate traditional management of reef resources into ‘modern’ methods.

Status of Central American Coral Reefs

The Pacific coast reefs of Central America are small, have low diversity, and are being heavily impacted by natural and human pressures. Previous large-scale damage from crown-of-thorns starfish and El Niño bleaching is being compounded by sediment runoff from poor land-use practices. The reefs are remote from external sources of coral larvae, are continually stressed by cold upwellings, and damaged by bio-eroding animals; their potential for natural recovery is very poor. There is little active conservation and very few reefs are protected.

Caribbean reefs off Belize, and well offshore to the south, have high biodiversity and are in good to excellent condition. Most reefs were heavily damaged by coral bleaching, diseases, and death of the long-spined sea-urchin, but recovery has been good to patchy. Recovery has been poor on reefs being polluted by increased sediment and nutrient runoff resulting from poor land use, and/or where reefs were over-fished, for example the reefs off southern Panama. The severe coral bleaching of many reefs which started in mid-1998 continues, and there is major mortality. Hurricanes also pose a significant threat to reefs north of 15ºN. Many of the marine protected areas exist only on paper, but a major project (Mesoamerican Barrier Reef Initiative) aims to increase monitoring and management of reef resources.

Status of Northern Caribbean Coral Reefs

Most reefs in the northern Caribbean are in fair to relatively good condition, with a few degraded reefs. Some reefs are limited by natural conditions, including hurricanes, and human pressures vary from very high (e.g. off Haiti, and Veracruz in Mexico), to low (e.g. Flower Garden Banks, parts of the Bahamian and Cuban archipelagos). Coral diseases, such as white-band disease, have reduced coral cover on many reefs and the death of the algal-grazing urchin, Diadema antillarum, has resulted in proliferation of fleshy algae, particularly near sources of pollution and in highly fished areas. Stocks of reef fish also vary with socioeconomic conditions and the level of effective management. People are becoming more aware of the ecological and socioeconomic values of reefs, and conservation and sustainable management efforts are increasing.

Status of Central Caribbean Coral Reefs

Awareness of the need for reef conservation is particularly high on Bonaire and the Cayman Islands because reef tourism is a dominant part of the economy. These reefs are essentially healthy with few pressures. However, off the mainland (Colombia and Venezuela) and on Jamaica, reefs have been damaged so that there are fewer fish, more algae, and less coral cover, and current conservation efforts are insufficient to prevent ongoing damage from sediment, nutrient pollution, and over-fishing. Corals have also suffered from bleaching, diseases, and Diadema die-off. Cayman and Bonaire have well-developed reef management strategies, which are being used as examples for the rest of the Caribbean.

Status of Eastern Caribbean Coral Reefs

The Lesser Antilles include high volcanic islands with very narrow continental shelves, and some low coral islands with wider shelves. There are some excellent coral reefs, which are normally stressed by sediment runoff from heavy rains, and by hurricanes. Recently, coral bleaching, coral diseases, tourism, and fishing pressure have resulted in some degradation in many areas, but there are few long-term studies to determine the status of reefs or the trends in their condition. The number of reefs under active and effective management has increased, and the need for better management is being recognised. Community-based management on St Lucia may prove to be a model for the region.

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Last updated - 7 December 98

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