Researchers say that 2010 is a devastating year for coral in the oceans of the world due to bleaching observed due to the effects of an El Nino event. Bleaching of the coral has been observed in every major sea and ocean where it occurs, from the Persian Gulf to southeast Asia, the Central Pacific to the Caribbean.

“We're looking at an event of the same magnitude, with temperatures on a par with what we saw in 2005," said Mark Eakin, coordinator of the US National Oceanic and Atmospheric Administration's Coral Reef Watch program based in Silver Springs, Maryland. "As far as corals are concerned, 2010 is, in places, as bad as or worse than 2005."

Unusually warm waters in the tropical Atlantic Ocean and Caribbean Sea caused among the worst bleaching events in 2005, damaged most of the coral. More than 80% of the corals surveyed were bleached and nearly 40 per cent of them died at many sites. Researchers published their paper in PLoS ONE1 this week. "Severe, widespread bleaching spells trouble for tropical marine ecosystems in general," said Eakin.

This year, the damage has been caused by the after effects of El Nino event. Scientists are also warning that corals could be damaged further due to the La Nina effect in 2010-11.

"What is much more predictable and more likely is that we will have a year much worse than 2005 between now and, say, 2015 or 2020," said Paul Sammarco at the Louisiana Universities Marine Consortium in Chauvin, who researches environmental impacts on coral reefs.