More than 40% of individual corals monitored around a Great Barrier Reef island were killed last year in the most widespread coral bleaching outbreak to hit the reef system.
Scientists tracked 462 colonies of corals at One Tree Island in the southern part of the Great Barrier Reef after heat stress began to turn the corals white in early 2024. Researchers said they encountered “catastrophic” scenes at the reef.
Only 92 coral colonies escaped bleaching entirely and by July, when the analysis for the study ended, 193 were dead and a further 113 were still showing signs of bleaching.
In November the Australian Institute of Marine Science visited eight reefs in the same Capricorn-Bunker sector of the reef. They found the single largest annual decline in hard coral cover in that area since monitoring started in the mid-1980s, with coral cover dropping by 41%.
Similar falls in coral cover were also recorded by Aims scientists in parts of the northern section of the reef, where one government scientist has described seeing a “graveyard of corals”.
The US government’s Coral Reef Watch program is projecting parts of the reef, north of Cooktown, will be subjected to heat stress and potentially more widespread bleaching by mid-February.