Corals may be better placed to cope with the gradual acidification of the world's oceans than previously thought giving rise to hopes that coral reefs might escape climatic devastation.
In new research published in the journal Nature Climate Change, an international scientific team has identified a powerful internal mechanism that could enable some corals and their symbiotic algae to counter the adverse impact of a more acidic ocean.
As humans release ever-larger amounts of carbon dioxide into the atmosphere, besides warming the planet, the gas is also turning the world's oceans more acidic at rates thought to far exceed those seen during past major extinctions of life. This has prompted strong scientific interest in finding out which species are most vulnerable, and which can handle the changed conditions.
In groundbreaking research, a team of scientists from Australia's ARC Centre of Excellence for Coral Reef Studies, at the University of Western Australia and France's Laboratoire des Sciences du Climat et de l'Environnement, has shown that some marine organisms that form calcium carbonate skeletons have an in-built mechanism to cope with ocean acidification which others appear to lack.
"The good news is that most corals appear to have this internal ability to buffer rising acidity of seawater and still form good, solid skeletons," says Professor Malcolm McCulloch of CoECRS and UWA. "Marine organisms that form calcium carbonate skeletons generally produce it in one of two forms, known as aragonite and calcite.
"Our research broadly suggests that those with skeletons made of aragonite have the coping mechanism while those that follow the calcite pathway generally do less well under more acidic conditions."
The aragonite calcifiers such as the well-known corals Porites and Acropora have molecular 'pumps' that enable them to regulate their internal acid balance, which buffers the
|Contact: Malcolm McCulloch|
ARC Centre of Excellence in Coral Reef Studies