Coral reef (Photo: Peter Mumby).

Water rise threatens coral reefs

CCRES Chief Scientist Professor Peter Mumby has co-authored a Nature paper showing how at risk tropical coral reefs in the Indian and western Atlantic oceans are.

According to the report, more than three-quarters of 200 tropical Indian and western Atlantic ocean coral reefs surveyed are likely to be 50-plus centimetres deeper beneath the water’s surface by the year 2100.

The research team involving Professor Mumby of The University of Queensland said modelling suggested this would “open higher wave-energy windows” that would in turn increase sediment mobility, shoreline change and island overtopping.

“Climate-driven perturbations, specifically coral bleaching, can drive major declines in reef accretion potential,” Prof Mumby said. “The most worrying end-point scenario is that if predictions of increasing bleaching are realised and result in more frequent mortality, reefs may become locked into permanent low-accretion-rate states, leading to increasing rates of submergence under all sea-level-rise scenarios. Ocean acidification and thermal impacts on calcification represent additional threats.”

Peter added that efforts to improve coral resilience at local scales will remain important to minimise the rate at which the reefs become submerged. “The more coral there is, the greater the rate at which reefs can keep up with rising sea level,” he said.

A copy of the full report, ‘Loss of coral reef growth capacity to track future increases in sea level’, is available on Nature’s website.