Raised water temperature has been blamed for the demise of 90% of the Indian Ocean's surface coral. University of Warwick's Dr. Charles Sheppard warned that the rest could die by 2030. He regards coral reefs as the rainforests of the sea because of the quantity and complexity of life they harbour.

If global warming causes the surface waters of the world's oceans to warm permanently, it could mean the end of coral altogether. This, in turn, would threaten the survival of the many thousands of species of fish and seaweed which depend on coral reefs, and of the 500 million coastal peoples who live within 60 miles of a reef and depend on those fish and weeds for food.

Coral reefs protect adjacent coasts from the worst effects of sea surge and storm damage. They are also a major source of new drugs. Half of all new cancer drug research is based on marine organisms, and AZT, the drug given to people with HIV, is based on chemicals from a Caribbean reef sponge.

Ed.- Coral is actually an animal, related to the sea anemone, whose excretions form spiny external skeletons.