Southeast Asia's coral reefs are the most important and also the most threatened in the world, with 88 percent severely at risk from human activities, according to new research.

The ominous statistics are the findings of a unique collaboration between 35 scientists from across the region, the United States, Australia and Britain, who compiled a vast database on the region's coral reefs.

A report on the research, published by environmental think-tank the World Resources Institute and released in Malaysia this week, said the main threats are overfishing, destructive fishing, and sedimentation and pollution from land-based sources.

"Coral reefs are the cornerstone of the economic and social fabric of Southeast Asia, yet they are the most threatened reefs in the world," said Lauretta Burke, a co-author of Reefs at Risk in Southeast Asia.

Southeast Asia is considered the global epicenter of marine diversity, with its nearly 100,000 square kilometers of coral reefs, or 34 percent of the world's total, housing over 600 of the 800 reef-building coral species in the world.

"It is not unusual to find a greater variety of species around a single island in this region than can be found on all the coral reefs in the Caribbean," the report says.

It estimates that the sustainable value of Southeast Asia's coral reef fisheries is 2.4 billion dollars annually. If ecosystem services like tourism and shoreline protection are included, the figure is greater.

The total economic value for Indonesia, with the largest coral reef systems in the region, is estimated at 1.6 billion dollars annually. The Philippines comes second with an annual estimated value of 1.1 billion dollars.

Overfishing

According to the report, more than 90 percent of the coral reefs in Cambodia, Singapore, Taiwan, the Philippines, Vietnam, China, and the Spratly Islands are threatened, along with more than 85 percent of the reefs of Malaysia and Indonesia.

Indonesia and the Philippines hold 77 percent of the region's coral reefs and nearly 80 percent of all the threatened reefs.

The report concludes that overfishing threatens about 64 percent of reefs. The figure in Cambodia, Japan and the Philippines exceeds 70 percent.

"If fishing in Southeast Asia is not reduced to more sustainable levels, both coral reefs and food security will be further imperiled," said Mark Spalding, a co-author of the report.

Destructive fishing practices, like the use of poison and dynamite, threaten an estimated 56 percent of the region's coral reefs, particularly in the Spratly and Paracel Islands in the South China Sea, and in Vietnam.

Sedimentation and pollution associated with coastal development and changes in land use place 37 percent of the region's reefs at risk.

Recommendations

The report makes a number of recommendations:

- Expanding the protected areas network for coral reefs. Currently, only eight percent of the region's reefs are in marine protected areas.

- Reducing overfishing through improved management and the development of alternative livelihoods.

- Regulating the international trade in live reef organisms. The total value of the trade in live reef fish exceeds one billion dollars a year, with Southeast Asia supplying up to 85 percent of the fish in the aquarium trade and nearly all of the live reef food fish.

- Improving the management of existing marine protected areas, which will require political and financial commitments from government, private organizations, and the tourism industry.

There are 646 marine protected areas in the region, but of the 332 whose management status could be determined, only 14 percent were rated as effectively managed.

The report finds that although management requires additional investments, the cost of inaction is even higher. Over a 20-year period, current levels of blast fishing, overfishing, and sedimentation could cost Indonesia and the Philippines more than 2.5 billion dollars each.