WA coral not immune to big bleaching event

Coral along Western Australia's Kimberley coast is not immune to an unprecedented bleaching event affecting northern Australian waters, with a recent study discovering climate change may overwhelm the organisms' unique defence system.

The James Cook University study found when corals were exposed to a slight rise in water temperature, they were able to use it as a "practice run" to prepare ahead of a significant increase.

Despite their defence mechanism, the research found corals are reaching a tipping point as temperatures continue to increase, from which they may not be able to recover.

The study looked at 27 years of satellite data for sea surface temperatures, previous coral bleaching events and how corals responded to different ocean warming conditions.

It found an increase of just 0.5C could be enough to overwhelm coral, leading to extensive bleaching around Australia.

Australia is also in the midst of the El Nino Southern Oscillation, which is causing increased water temperatures.

University of Western Australia professor Malcolm McCulloch said the study was crucial in understanding coral's tolerance to warming oceans.

"In fact it now appears that what is happening in the Great Barrier Reef and also our reefs of North Western Australia, may even be worse than even these pessimistic findings," Prof McCulloch said.

The research predicted different sections of the Great Barrier Reef will lose their protective mechanisms at different rates.

"Our models suggest reefs that lose their thermal protection in the future will degrade faster and stay in a degraded state for a longer period," Dr Juan Ortiz from Queensland University said.

"While reefs that maintain their protection have a better chance of maintaining coral cover if carbon emissions are reduced in the near future."

The findings will help scientists better understand coral's capacity to survive bleaching events.