Mass bleaching has destroyed as much as one third of the coral on the northern and central Great Barrier Reef in Australia, according to a research.

Australian researchers found that around 35 percent of the coral in the northern and central sections of the reef is dead or dying, Terry Hughes, a professor with James Cook University, in Queensland, said on Monday.

The findings, based on months of aerial and underwater surveys of the 2,300km reef off the country's east coast, are a major blow to the World Heritage Site that attracts about A$5bn ($3.6bn) in tourism each year.


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"This year is the third time in 18 years that the Great Barrier Reef has experienced mass bleaching due to global warming, and the current event is much more extreme than we have measured before," said Hughes.

Bleaching occurs when the water is too warm, forcing coral to expel living algae and causing it to calcify and turn white. Mildly bleached coral can recover if the temperature drops, otherwise it may die.

Although the impact has been exacerbated by one of the strongest El Nino weather systems in nearly 20 years, which recently subsided, scientists believe climate change is the underlying cause.

Findings omitted in UN report

Pollution threatens Australia’s Great Barrier Reef

The World Heritage and Tourism in a Changing Climate report, which was released on Friday with no references to Australia, has sparked outrage from climate scientists, who were not informed that their contributions had been removed.

UNESCO's World Heritage Committee last May stopped short of placing the Great Barrier Reef on an "in danger" list, but the ruling raised concern about its future.

Australia is one of the largest carbon emitters per capita because of its reliance on coal-fired power plants for electricity.

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Source: Agencies