Study tells of growing threat to coral reefs

A quarter of the world's coral reefs have been lost to climate change and to human activity. and further losses are certain, according to a new report.

Climate change in particular will accelerate the breakdown of reef ecosystems, leading to species loss. The Pew Centre on Global Climate Change report on coral reefs was released yesterday at the American Association meeting in Seattle. It makes grim reading for those seeking to protect an ecosystem that is described as the most biologically diverse on the planet.

The report outlines how increased carbon dioxide output will push up ocean water temperatures, leading to coral "bleaching" which can weaken and kill these sensitive animals.

The higher carbon dioxide content of the air will also alter the water chemistry of the oceans. More dissolved carbon dioxide will increase the acidity of the water, robbing it of dissolved carbonate. This is an essential building block of calcium carbonate, used by coral and other organisms to grow their skeletons and build reefs.