* Local coral unusually resilient to climate change

* Researchers say management crucial to conservation By Daniel Wallis

NAIROBI, April 24 (Reuters) - A network of "super-reefs" off east Africa are unusually resilient to climate change and could provide important lessons for coral conservation in other parts of the world, researchers said on Friday.

Experts say the planet has lost about a fifth of its corals and warn that many of the remaining reefs could die in the next 20 to 40 years, unless greenhouse gas emissions are reduced.

A study coordinated by the Wildlife Conservation Society said the Indian Ocean reefs -- in a triangle off Tanzania between northern Mozambique, Madagascar and southern Kenya -- should be a high priority for future scientific work.

"Northern Tanzania's reefs have exhibited considerable resilience and in some cases improvements in reef conditions despite heavy pressure from climate change impacts and overfishing," said Tim McClanahan, the study's lead author.

"This gives cause for considerably more optimism that developing countries, such as Tanzania, can effectively manage their reefs in the face of climate change."

The experts found Tanzania's corals recovered quickly from a 1998 "bleaching" event -- when colourful algae in corals die -- that wiped out up to 45 percent of the region's coral.

Researchers attributed the recovery in part to management measures, including closures to commercial fishing.

They also found the reefs' structure played a major role in their resiliency. Tanzania's reefs are particularly complex, with unusual water current and temperature variations.

Scientists warn further coral loss would have alarming consequences for the half billion people who depend on reefs for their livelihood. They cannot say how much of the loss in recent years is due to global warming, but agree climate change is the biggest threat to reefs.

A report last December said the impact on coral from rising sea surface temperatures and seawater acidification, were made worse by factors such as overfishing, pollution and invasive species. [ID:nLA616621]

Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and providing sources of food, pharmaceuticals and jobs. (Editing by Farah Master)

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