At least 35 percent of corals in parts of Australia’s Great Barrier Reef are dead or dying from mass bleaching caused by global warming, scientists said Monday. The assessment was made following months of aerial and underwater surveys after the worst bleaching in recorded history first became evident in March as sea temperatures rise.

Global warming was wreaking havoc on the World Heritage-listed site, said Terry Hughes, director of the Australian Research Council Centre of Excellence for Coral Reef Studies at the James Cook University. “We found on average, that 35 percent of the corals are now dead or dying on 84 reefs that we surveyed along the northern and central sections of the Great Barrier Reef, between Townsville and Papua New Guinea,” he said in a statement. READ MORE