Climate change

A group of coral reefs off the Australian state of Western Australia (WA) has shown remarkable resistance to extreme marine heat, offering rare hope for reef survival under climate change, new research reveals.
Researchers from Australia's James Cook University (JCU) and partner institutions found minimal coral bleaching at the Houtman Abrolhos Islands (HAI) despite massive and deadly marine heat waves throughout 2025 that resulted in widespread coral bleaching and death along the WA coastline, said a JCU statement released Thursday.
"The temperatures have been off the scale for eight months ... what we would call catastrophic. But when we surveyed the HAI reefs, there was really no to little sign of bleaching ... it was very unexpected," said study first author Kate Quigley, research fellow at JCU.
Laboratory tests on three different coral species from the HAI reefs in the Indian Ocean off the coast of WA showed bleaching resistance was 3.7 times higher than expected, with corals surviving nearly four times longer under extreme heat stress.
Thresholds for declining photosynthetic efficiency were up to 22 times higher than expected, according to the findings published in Current Biology.
The improved photosynthetic efficiency could be linked to symbiotic algae that help sustain coral energy production, as well as the region's location at the junction of temperate and tropical waters, Quigley said.
The researchers estimate that fewer than 10 such refuges may exist globally and stressed the need to prioritize their protection alongside efforts to curb greenhouse gas emissions.