Great Barrier Reef Has Most Coral In Decades

An anonymous reader quotes a report from the Washington Post: Marine scientists have found that parts of Australia's Great Barrier Reef have recorded their highest levels of coral cover since monitoring began nearly four decades ago, although they warn the reef's recovery could be swiftly undone by global warming. The Australian Institute of Marine Science, a government agency, began monitoring Earth's largest reef system 36 years ago. Its latest report indicates that the northern and central parts of the reef are on the mend after an 'extensive bout' of disturbances over the past decade, said Mike Emslie, a senior research scientist at the institute. The results of the institute's annual survey show that the reef 'is still vibrant and still resilient, and it can bounce back from disturbances if it gets the chance,' Emslie said in an interview Thursday.

News of the recovery in the reef's northern and central parts was partly offset by the report's finding that there was a loss of coral cover in the southern region. There, the reef fell prey to an outbreak of crown-of-thorns starfish, which feed exclusively on live coral, the scientists said. About half of the reefs were surveyed before the most recent coral bleaching event in February and March. Emslie said researchers won't know the full extent of the coral cover lost from that event until next year. The sheer size of the Great Barrier Reef system -- it spans some 1,700 miles and is so large it can easily be spotted from space -- means the survey is staggered over seven or eight months of the year.

Among the 87 reefs surveyed for the latest report, average hard coral cover in the north increased to 36 percent, up from 27 percent in 2021, and to 33 percent in the central Great Barrier Reef from 26 percent last year. Average coral cover in the southern region decreased from 38 percent in 2021 to 34 percent this year. Much of the recent reef recovery was driven by the fast-growing Acropora species -- whose delicate branching and table corals have adorned countless postcards for tourists. Marine scientists worry that these corals are some of the most vulnerable to the impacts of global warming, including marine heat waves, coral bleaching and damaging waves, such as those generated during tropical cyclones.

Read more of this story at Slashdot.