Parts of Australia’s Great Barrier Reef have suffered the largest coral die-off ever recorded, and scientists fear the rest of the ecosystem will suffer the same fate, according to a study from the Australian Institute of Marine Science published on Tuesday, November 19.
Carried out on twelve reefs, it reveals a mortality of up to 72% due to massive bleaching this summer and two cyclones. In an area north of the Great Reef, about a third of the hard corals have died, making up the “the biggest annual drop” since the government began monitoring this phenomenon thirty-nine years ago.
The Great Barrier Reef, which extends 2,300 kilometers along the coast of the state of Queensland (northeast Australia), is considered the largest living structure in the world. It is home to extremely rich biodiversity, with more than 600 species of coral and 1,625 species of fish. But several episodes of mass bleaching have transformed once-thriving multicolored coral beds into pale, sickly expanses.
Five episodes of mass bleaching in eight years
The dieback phenomenon is caused by an increase in water temperature, which causes the expulsion of the symbiotic algae that give the coral its bright color. If high temperatures persist, it turns white and dies. In eight years, five episodes of mass bleaching have been recorded on the Great Barrier Reef. The study published on Tuesday specifies that a fast-growing coral, theacroporaIt is the one that suffered the highest mortality rate.
The oceans manager of the NGO WWF Australia, Richard Leck, stated that the latest data confirms his “the worst fears”. “The Great Barrier Reef can recover, but its resilience has limitssaid. They can’t hit her repeatedly like that. We are rapidly approaching a tipping point. »
Mr. Leck specified that the area that was the subject of the study is “relatively small” and said he was afraid “Similar levels of mortality” for the entire Great Barrier.
