THE Great Barrier Reef has lost more live coral this year than ever before in four decades of record-keeping, the Australian Institute of Marine Science has reported.

The change underlines a new level of volatility on the world’s largest coral reef, a Unesco World Heritage Site, since coral cover had been increasing since 2017.

Mike Emslie, who heads the tropical marine research agency’s long-term monitoring programme, said the live coral cover measured in 2024 was the largest recorded in 39 years of surveys.

The losses from such a high base of coral cover had partially cushioned the damaging effects of climate change on the reef ecosystem, which covers 133,000 square miles off Australia's north-east coast, he said.

“These are substantial impacts and evidence that the increasing frequency of coral bleaching is really starting to have detrimental effects on the Great Barrier Reef,” Mr Emslie said today.

“While there’s still a lot of coral cover out there, these are record declines that we have seen in any one year of monitoring.”