Following mass bleaching in 2024 and 2025, the Great Barrier Reef has suffered the biggest declines in coral cover in recorded history according to the Australian Institute of Marine Science's (AIMS) annual survey report.
Decreases in coral cover are caused by the death of corals.
AIMS said heat stress driven by climate change was the primary cause, mass bleaching events are becoming more frequent and intense, and "the future of the world's coral reefs relies on strong greenhouse gas emissions reduction".
Compared to the 2024 levels, coral cover in the northern region dropped by a quarter (from 39.8% to 30%), the central region by 13.9% (from 33.2% to 28.6%), and the southern region by almost one third (from 38.9% to 26.9%.)
For the northern and southern regions, those losses were the largest annual declines since monitoring began nearly 40 years ago.
The Great Barrier Reef has now suffered mass coral bleaching in 1998, 2002, 2016, 2017, 2020, 2022, 2024 and 2025.
Richard Leck, Head of Oceans for the World Wide Fund for Nature Australia said the devastating coral mortality intensifies the focus on Australia's 2035 emissions reduction target, due to be announced soon.
"The evidence from AIMS' report shouts from the rooftops 'we need a strong 2035 target'.
"In one fell swoop, climate change wiped out the encouraging coral recovery of recent years.
"The Australian Government can show it's determined to give the Reef a fighting chance by announcing a strong 2035 target backed by policies to deliver big emissions reductions.
"A strong 2035 climate target will fast track Australia's transition to become a renewable energy superpower, supporting an abundance of new economic opportunities in the regions, including regional Queensland," Mr Leck said.
Just last week, the Climate Change Authority (CCA) advised:
"Limiting climate warming… to 1.5 °C now hinges on rapid, large-scale reductions in global emissions. As the home and custodian of the Great Barrier Reef, Australia can spearhead shared efforts to accelerate these necessary reductions – both through its own actions and in coordination with global partners."
"Under the Paris Agreement, Australia has committed to pursue efforts to limit warming to 1.5 °C.
"To back up that promise with action and unlock fantastic economic benefits for future generations, Australia must commit to a 2035 emissions reduction target of at least 90% by 2035 and net zero before 2040," Mr Leck said.
