Hard coral cover across Australia's Great Barrier Reef has dropped sharply following a record bleaching event in 2024, the Australian Institute of Marine Science (AIMS) reported on Wednesday.
Two of the reef's three regions recorded their largest annual declines in coral cover since monitoring began nearly 40 years ago, according to AIMS' annual survey report.
The 2024 bleaching event, triggered by climate change-induced heat stress, was the main driver of the losses, AIMS said. Cyclones and outbreaks of crown-of-thorns starfish also contributed.
AIMS noted that this was the fifth mass bleaching event to impact the region since 2016 and the largest ever recorded on the Great Barrier Reef. The report warned that such events are becoming more frequent,while recovery periods are shrinking.
"We are now seeing increased volatility in the levels of hard coral cover. This is a phenomenon that emerged over the last 15 years and points to an ecosystem under stress," said AIMS long-term monitoring programme leader Mike Emslie.
"We have seen coral cover oscillate between record lows and record highs in a relatively short amount of time, where previously such fluctuations were moderate," he added.
The findings are based on surveys carried out between August 2024 and May 2025. Of the 124 reefs assessed, nearly half (48%) showed adecline in coral cover, while only 10% showed gains.
Despite the setbacks, Ems lie noted that the reef still retains more coral cover than many reef systems globally.
Located off Australia's north-east coast, the Great Barrier Reef is the world's largest coral reef system, home to about 400 types of coral, around 1,500 fish species and 4,000 mollusc types. —dpa
Oman Observer is now on the WhatsApp channel. Click here
