Damaged by divers, pollution and climate change, coral reefs may soon be protected through debt forgiveness. The US Congress is expected to approve a bill that would cancel foreign debt in developing countries in exchange for coral reef and rainforest conservation.

The Tropical Forest and Coral Conservation Act of 2007 sailed through the Senate's foreign-relations committee on 11 September. The full Senate and House of Representatives should take up the bill soon, and it could reach President George W. Bush ? a supporter ? by the end of 2007, says Mark Helmke, a senior adviser for Senator Richard Lugar (Republican, Indiana), one of the bill's sponsors. The bill provides $75 million to pay off debts owed to the United States over the next three years.

Indonesia could be the first country to swap national debt for corals. Credit: B. COLE/NATUREPL.COM

Congress passed a similar bill in 1998 that has channelled $137 million to protect rainforests in developing countries such as Panama, Bangladesh and Botswana. Under the deal, countries in debt to the US Agency for International Development give money to local conservation groups. In return, the United States cancels the same amount of debt. For example, in 2003, the US government cancelled $10 million in debt owed by Panama to protect the Chagres National Park. The money is being spent on projects such as park-boundary enforcement to stem illegal farming and training locals as ecotourist guides.

Indonesia is likely to be the first country to take up the debt-for-coral swap. Its Coral Triangle, home to more than 600 species of coral and 3,000 species of fish, is under threat from pollution, overfishing and bleaching ? a situation exacerbated by global warming.

?Corals are in a tricky position because of climate change,? says Lara Hansen, chief scientist for climate change with the conservation group WWF in Washington DC, which has helped to broker rainforest protection. ?Even if you protect a coral spatially, you still have this massive threat.? But any measure that relieves stress on reefs will buffer against damage from warming, she adds.