WASHINGTON — Nearly 60 per cent of the world’s coral reefs are being threatened by human activity, says a senior associate of the environmental think-tank World Resources Institute (WRI).

Although they cover less than one per cent of the earth’s surface, coral reefs are “the most productive ecosystem in the sea” and yield approximately $375 billion in goods and services each year, according to the Cousteau Society.

Coral reefs and associated seagrass and mangrove communities also protect thousands of miles of coastline from tropical storms and wave damage. Despite their commercial and ecological importance, however, destructive human practices are undermining their survival.

The identification of the threats to reefs, as well as discussion of policies and practices to mitigate the ongoing damage, was the focus of the conference “Coral Reefs at Risk: Challenges and Solutions,” convened in Washington on June 6 as part of Capitol Hill Oceans Week.

Lauretta Burke of the WRI opened the forum by emphasising the need for additional investigation of the status of coral reefs. She estimated that less than 10 per cent of the world’s reefs have been monitored, with significantly fewer subjected to repeated evaluations that would document evolutionary trends. Although Burke stressed the importance of gathering more information, the available analysis indicates that the world’s reefs are dying.

Citing the 1998 report “Reefs at Risk”, Burke noted that 58 per cent of the world’s reefs and most US reefs are threatened, particularly US reefs in the Caribbean. The study found that more than 60 per cent of all reefs in the Caribbean are at risk, with most of those in Jamaica, Haiti, the Dominican Republic, Puerto Rico and the Lesser Antilles under high threat.

According to Dr John Pandolfi of the Smithsonian Institution, there is overwhelming historical evidence that human activity is largely responsible for the growing risk to the long-term survival of reefs.

Pandolfi contrasted the abundance of marine life predating human interaction with the relative paucity today to conclude that the “the exponential increase in human exploitation, consumption and development has altered our coral reef environment”. He identified over-fishing and destructive fishing practices, extensive coastal development, and land-based sources of pollution as contributing to the destruction of the marine ecosystems that support reefs.

Over-fishing and destructive fishing — fishing with poisons or explosives — are among the most pervasive threats to reefs. Assessing the damaging impact of these practices, Pandolfi said that the disruption of the delicate oceanic balance frequently begins with fishing that eliminates large marine fauna such as whales and sharks and then cascades down to reefs, which are often overrun as the fish or other marine life that consume seaweed and algae are depleted.

As part of a complex ecosystem, the decline of reefs is not an isolated phenomenon. Rather, their demise serves as an important indicator of the deteriorating health of the oceans. As Dr John Ogden of the Florida Institute of Oceanography explained, “reefs are the poster child,” but “the real problem is with the oceans, and this nation has to get a grip on it”.

Given the connectivity of reefs with other marine life and coastal development, Ogden said, efforts to reduce or reverse the risks to reefs require an inclusive approach. He called for “broad programmatic attention” to address the overarching problem of human disturbance of marine ecosystems. Once the United States implements a comprehensive ocean use strategy to address over-fishing and poor land use practices affecting its coastal waters, he added, other nations are likely to follow suit.