An anonymous reader quotes the Washington Post: Marine scientists have found that parts of Australia’s Great Barrier Reef have recorded their highest level of coral cover since monitoring began nearly four decades ago, although they warn that the reef’s recovery could soon be reversed by global warming. The Australian Institute of Marine Sciences, a government agency, began monitoring Earth’s largest reef system 36 years ago. Its latest report shows that the northern and central parts of the reef are recovering after an “extensive series” of disturbances over the past decade, said Mike Emsley, a senior scientist at the institute. The results of the institute’s annual study show that the reef is “still alive and resilient, and it can recover from disturbances if it has the chance,” Emslie said in an interview Thursday.
News of recovery in the northern and central parts of the reef was partially offset by the conclusion of a report on the loss of coral cover in the southern region. There, the reef has fallen victim to an outbreak of spiny starfish, which feed exclusively on live coral, scientists say. About half of the reefs were surveyed before the last coral bleaching in February and March. Emslie said researchers won’t know the full extent of coral cover lost in the event until next year. The sheer size of the Great Barrier Reef system – it spans about 1,700 miles and is so large that it can easily be seen from space – means that research is carried out for seven to 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 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 declined from 38 percent in 2021 to 34 percent this year. Much of the reef’s recent recovery has been driven by the fast-growing Acropora species, whose delicate branches and table corals have graced countless tourist postcards. Marine scientists worry that these corals are among the most vulnerable to the effects of global warming, including marine heat waves, coral bleaching and destructive waves, such as waves from tropical cyclones.
