Australia conference on ocean acidification

Terra Daily: Acid oceans will be among the issues explored by Australia's leading coral scientists at a national public forum at the Shine Dome in Canberra tomorrow. The Coral Reef Futures 07 Forum is on October 18-19, 2007 and is hosted by the ARC Centre of Excellence for Coral Reef Studies (CoECRS).

…."Analysis of coral cores shows a steady drop in calcification over the last 20 years," says Professor Ove Hoegh-Guldberg of CoECRS and the University of Queensland. "There's not much debate about how it happens: put more CO2 into the air above and it dissolves into the oceans. "When CO2 levels in the atmosphere reach about 500 parts per million, you put calcification out of business in the oceans." (Atmospheric CO2 levels are presently 385 ppm, up from 305 in 1960.)

"It isn't just the coral reefs which are affected - a large part of the plankton in the Southern Ocean, the coccolithophorids, are also affected. These drive ocean productivity and are the base of the food web which supports krill, whales, tuna and our fisheries. They also play a vital role in removing carbon dioxide from the atmosphere, which could break down."

Professor Hoegh-Guldberg said an experiment at Heron Island, in which CO2 levels were increased in the air of tanks containing corals, had showed it caused some corals to cease forming skeletons. More alarmingly, red calcareous algae - the 'glue' that holds the edges of coral reefs together in turbulent water - actually began to dissolve. "The risk is that this may begin to erode the Barrier of the Great Barrier Reef at a grand scale," he says.

"As an issue it's a bit of a sleeper. Global warming is incredibly serious, but ocean acidification could be even more so."

…Globally, the welfare of 500 million people is closely linked to the goods and services provided by coral reef biodiversity. Uniquely among tropical and sub-tropical nations, Australia has extensive coral reefs, a small population of relatively wealthy and well-educated citizens, and well developed infrastructure. Coral reef research is one area where Australia has the capability, indeed the obligation, to claim world-leadership.