The survey does not capture the most recent bleaching event confirmed earlier in 2025 that struck the Great Barrier Reef as well as ecosystems off the Western Australian coastline.

The growing prevalence of bleaching events

Report co-author Daniela Ceccarelli was concerned about the growing prevalence of bleaching events.

Ceccarelli likened the fast-growing corals to grasses and bushes that shoot up first after a bushfire.

“And if you were to fly over, you’d go ‘it’s nice and green, it’s great’,” Ceccarelli said.

“But the trees are not there yet.”

Heat stress threatening coral recovery

“We don’t know that, but it’s worrying we aren’t getting a lot of time between heatwaves anymore.”

Marine experts fear corals may not adapt to and recover from the impacts of climate change. Credit: AAP

Particularly sensitive to heat stress, corals expel the algae living in their tissues when water is too warm, causing the coral to turn completely white.

Cyclones and crown-of-thorn starfish outbreaks also contribute to reef damage, but AIMS said climate change-fuelled ocean warming drove much of the 2024 coral coverage decline.

Marine experts say coral can recover from bleaching but it can be fatal if severe enough Credit: AAP

Fears over further decline in reef health

In the central region, hard corals shrunk nearly 14 per cent.