August 27, 2008

Scientists Warn of Impending Doom for Coral Reefs

A panel of marine scientists said on Wednesday that in order to keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere.

The scientists authored a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

"The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the report warned.

The scientists said ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching.

Billy Causey of the U.S. National Marine Sanctuary Program said coral reefs are a "sentinel ecosystem," a sign that the environment is changing.

"Although ocean acidification is affecting the health of our oceans, the same thing"”increased carbon dioxide in the atmosphere"”is going to in fact be affecting terrestrial environments also," said Causey.

Marine scientists say coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue.

However, they are increasingly threatened by warming sea surface temperatures as well as ocean acidification.

The acidic levels of oceans are increasing because they have been absorbing some 525 billion tons of the greenhouse gas carbon dioxide over the last two centuries, about one-third of all human-generated carbon dioxide for that period.

The sea water combined with carbon dioxide forms carbonic acid.

Acidification in deep ocean water far from land has been well documented in the past, but a study published this year in the journal Science found this same damaging phenomenon on the Pacific North American continental shelf from Mexico to Canada, and quite likely elsewhere around the globe.

The water became so corrosive that it started dissolving the shells and skeletons of starfish, clams and corals.

The Honolulu Declaration's top long-term recommendation is to stabilize carbon dioxide emissions. The key short-term recommendation was to nurture coral reefs that seem to have natural resilience against acidification.

Causey believes managers of protected marine areas can adopt it immediately.

The Honolulu Declaration will be presented to the United Nations and to other global, regional and national forums.