Source: The Age 
Marine reserves across the globe should be extended because coral reefs are more susceptible to environmental change than previously thought, researchers say.
Researchers from Townsville's James Cook University (JCU) said their study had major implications for the long-term survival of corals after disproving current conservation theories.
The research, published in the international science journal Nature, tested the "neutral theory of biodiversity", which argues that coral species colonise reefs randomly.
However, studies of 180 sites from Sulawesi to French Polynesia found location and environmental change, caused by events such as cyclones, played an important role in determining the success of coral reefs.
"Our study found much more variability in coral reefs than expected and we think this is because of the influence that environmental conditions have on reefs," the study's lead author Maria Dornelas said in an interview.
"The implications for conservation are that preserving isolated reefs is too risky, because sooner or later that reef is going to be hit by a disturbance.
"And unless there are nearby healthy reefs to repopulate it, it was a waste of time to actually protect that reef."
Ms Dornelas, from JCU's ARC Centre of Excellence for Coral Reef Studies, said protected marine areas should be networked and extended across national borders to help reefs cope with environmental changes expected with global warming.
The centre's Dr Sean Connolly, who also worked on the study, said corals were not always suited to a particular condition or location.
They needed to disperse their offspring widely to ensure their survival when conditions changed, he said.
"Most marine protected areas around the world are too small and too isolated to preserve the links between populations on different reefs," Dr Connolly said.
"This increases the risk that a rare group of animals could go extinct unless they can colonise a more favourable reef."
© 2006 AAP