Jumbo Aerial | Great Barrier Reef Marine Park Authority via AP Two-thirds of Australia’s Great Barrier Reef recorded its largest amount of coral cover in nearly four decades, although the reef remains vulnerable to climate change and mass bleaching, a monitoring group said Thursday. The northern and central parts of the UNESCO World Heritage-listed reef have seen some recovery, while the southern area has suffered a loss of coral cover due to thorn star outbreaks, according to a report by the Australian Institute of Marine Science. a government agency. AIMS CEO Paul Hardisty said that while corals in the northern and central regions were a sign that the reef could recover from disturbances, the loss of corals in the southern region showed how the reef is still vulnerable to “ongoing acute and severe disturbances which occur more frequently and last longer.” The Great Barrier Reef has suffered extensive and severe bleaching due to warming oceans. The reef was hit particularly hard in 2016 and 2017 by underwater heat waves that caused bleaching phenomena. This year, it is undergoing a sixth mass bleaching due to heat stress caused by climate change. “Each summer the reef is at risk of temperature stress, bleaching and potentially mortality, and our understanding of how the ecosystem responds to this is still developing,” Hardisty said in a media release. “The 2020 and 2022 bleaching events, although extensive, did not reach the intensity of the 2016 and 2017 events, and therefore we have seen less mortality,” Hardisty said. “These latest results show that the reef can still recover during periods without intense disturbance.” The report comes after UNESCO proposed last year to add the Great Barrier Reef to a list of world heritage sites in danger. A meeting to discuss the reef’s future was due to take place in Russia in June but was canceled after the invasion of Ukraine. In the central and northern regions, hard coral cover reached 33 percent and 36 percent this year, respectively, the highest level recorded in the past 36 years of monitoring, the report said. Meanwhile, area-wide hard coral cover on reefs in the southern region has dropped to 34% this year, compared to 38% the previous year.
