It’s the fourth global bleaching event since 1998, and has now surpassed bleaching from 2014-17 that hit some two-thirds of reefs, said the ICRI, a mix of more than 100 governments, non-governmental organizations and others. And it’s not clear when the current crisis, which began in 2023 and is blamed on warming oceans, will end.

“We may never see the heat stress that causes bleaching dropping below the threshold that triggers a global event,” said Mark Eakin, executive secretary for the International Coral Reef Society and retired coral monitoring chief for the U.S. National Oceanic and Atmospheric Administration.

“We’re looking at something that’s completely changing the face of our planet and the ability of our oceans to sustain lives and livelihoods,” Eakin said.