A school of fish swim above a staghorn (Acropora cervicornis) coral colony as it grows on the Great Barrier Reef off the coast of Cairns, Australia October 25, 2019. REUTERS/Lucas Jackson/File Photo
Hotter-than-average ocean temperatures are causing fresh damage to Australia’s iconic Great Barrier reef and prompting concerns over a new mass bleaching event that could further destroy the world’s biggest living structure.
The impact of heat stress has been detected across the site and "several locations have whole colonies bleached white,” the Great Barrier reef Marine Park Authority, or GBRMPA, a government agency, said Friday in a statement. "Corals across the marine park remain vulnerable to the ongoing elevated temperatures.”
Bleaching occurs when corals enter a stressed state, including as a result of higher ocean temperatures, and lose their symbiotic algae, increasing the chance of disease or death. Marine heatwaves have triggered five mass bleaching events since 1998, while the United Nations warned last year about the climate change-related impacts on the reef.
"Clearly bleaching is getting more frequent and more severe on the Great Barrier reef,” said David Wachenfeld, chief scientist at the GBRMPA. While more aerial surveys are needed to assess the extent of current damage, there was "certainly a risk that this is a mass bleaching event,” he said.
Weather patterns over the coming weeks will determine the extent and severity of damage to coral colonies, according to Wachenfeld.
The reef, which stretches across an area about the size of Japan, is home to more than 600 types of corals and 1,600 species of fish. It’s also among the country’s major tourism attractions, and key to the nation’s efforts to lure back foreign visitors after two years of shuttered borders.
Lobbying by Australia’s government helped prevent the world heritage site from being added to a United Nations endangered list last year, a move that would have prompted calls for additional conservation action. The U.N. in June downgraded the long-term outlook of the reef to "very poor” from "poor.”
Prime Minister Scott Morrison’s government, which faces an election by May, has been repeatedly accused both at home and internationally of not doing enough to combat climate change.
