Coral decline warns of ocean changes: Australian scientists

SYDNEY, January 2, 2009 (AFP) – A sharp slowdown in coral growth on Australia’s Great Barrier Reef since 1990 is a warning sign that precipitous changes in the world’s oceans may be imminent, scientists said Friday.

Rising sea temperatures are blamed on global warming caused by the build-up in the atmosphere of greenhouse gases such as carbon dioxide — which is also blamed for higher acidity in sea water.

A UN report warned in 2007 that the Great Barrier Reef, described as the world’s largest living organism, could be killed by climate change within decades.

The World Heritage site and major tourist attraction, stretching over more than 345,000 square kilometres (133,000 sq miles) off Australia’s east coast, could become “functionally extinct”, the report said.

The journal Science is published by the American Association for the Advancement of Science.

Strong evidence points to the cause being a combination of warmer seas and higher acidity from increased levels of atmospheric carbon dioxide, Australian Institute of Marine Science researchers reported.

“The data suggest that this severe and sudden decline in calcification is unprecedented in at least 400 years,” said Glenn De’ath, pri