Australia’s Great Barrier Reef suffers “extensive bleaching” caused by above-average ocean temperatures, announced Friday, March 25, the authority responsible for this reef. Aerial surveillance flights have noted discoloration of the coral, “confirming a vast bleaching phenomenon, the fourth since 2016”according to the Great Barrier Reef Marine Park Authority (GBRMPA), responsible for managing the world’s largest coral reef system.
The corals suffered despite a cooling phenomenon in the southern summer by La Niña, a cyclical climatic phenomenon – contrary to that of El Niño – which results in a cooling of the Pacific Ocean.
This phenomenon of decline of the Great Barrier Reef is caused by the rise in water temperature – a consequence of global warming –, which leads to the expulsion of the symbiotic algae giving the coral its bright color.
Although bleached corals are under stress, they can still recover if conditions improve, the GBRMPA pointed out: “The weather conditions for the next two weeks are crucial in determining the extent and severity of coral bleaching in the Marine Park. »
“The colors replaced by a ghostly white”
The study into the massive bleaching phenomenon was released four days after the United Nations began inspecting the Great Barrier Reef to assess whether the World Heritage-listed site is protected from climate change.
“The beloved bright colors of the Great Barrier Reef are being replaced by (…) a ghostly white », lamented Martin Zavan, an activist for Greenpeace Australia. He urged the government to show the areas affected by this phenomenon to the UN mission which is currently inspecting the reef rather than the scenic areas which have not been affected. “If the government is serious about allowing the UN mission to get a full picture of the state of the reef, it needs to take the mission to the north and center of the reef”Mr. Zavan said.
The UNESCO mission aims to assess whether the Australian government is doing enough against threats to the Great Barrier Reef, before the World Heritage Committee decides in June whether to list it ” in danger “.
In July 2021, the World Heritage Committee decided not to classify the site ” in danger “, to everyone’s surprise and against the recommendation of Unesco. Australia launched a billion-dollar Reef 2050 protection plan after the United Nations threatened in 2015 to downgrade the site.
The Great Barrier Reef is home to some 1,500 species of fish and 4,000 types of molluscs. In recent years, it has also been affected by several cyclones, in addition to being threatened by agricultural runoff and by the purple acanthaster, a coral-eating starfish.