Abu dhabi: A marine heatwave off the Western Australian coast was the longest, largest, and most intense on record for the area, scientists said on Tuesday. The heatwave resulted in the most widespread coral bleaching event ever recorded for Western Australia, according to the Australian Institute of Marine Science (AIMS). Experts had reported bleaching and mortality across systems up to 1,500 kilometres apart, AIMS said.
According to Emirates News Agency, AIMS senior research scientist James Gilmour highlighted that reefs which had previously escaped bleaching were affected. "There has been little reprieve this time for any of our north-west reefs. Areas which had given us hope because they'd rarely or not bleached before like the Rowley Shoals, north Kimberley and Ningaloo have been hit hard this time," Gilmour stated.
For individual coral reefs, experts are still analysing the Degree Heating Weeks (DHW) - a measure of heat stress on corals. Gilmour noted that eight DHWs is the level generally considered severe enough to cause coral mortality. Early estimates indicate over 15 DHWs on all reefs and up to 30 DHWs at some Pilbara reefs, he said, expressing concern for the future of Australia's coral reefs.
Last week, AIMS reported that hard coral cover across the Great Barrier Reef had dropped sharply following a record bleaching event in 2024.