The phenomenon, known as coral bleaching because the reefs turn bone white when the colourful algae that give the coral its colour and food is lost, has been reported throughout south east Asia, the Indian Ocean and the Pacific. Divers and scientists have described huge areas of previously pristine reef being turned into barren white undersea landscapes off the coast of Thailand and Indonesia.
The popular island tourist destination the Maldives have also suffered severe bleaching. Reefs in the Caribbean could also be under threat.
High ocean temperatures this year are being blamed for the bleaching, which experts fear could be worse than a similar event in 1998 which saw an estimated 16 per cent of the world's reefs being destroyed. Dr Mark Eakin, coordinator of the National Oceanic and Atmospheric Administration's Coral Reef Watch, said: "The bleaching is very strong throughout south east Asia and the central Indian Ocean. "The reports are that it is the worst since 1997/1998. This is a really huge event and we are going to see a lot of corals dying."
Coral reefs provide refuge and food to nearly a quarter of all marine species, making them among the most biologically diverse habitats on the planet. Bleaching can also rob fish and other species of important shelter and food sources. Although reefs can often recover from bleaching, it leaves the coral vulnerable to damage from storms, infections and other environmental stress, increasing the risk of deaths. Coral reef monitoring teams have reported mass bleaching of coral reefs off the coast of Thailand, Malaysia, Vietnam, Cambodia and Indonesia while the Maldives, Sri Lanka and reefs off the coast of east Africa have also been hit.
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http://www.telegraph.co.uk/earth/earthnews/7896403/Coral-reefs-suffer-mass-bleaching.html