Professor Jane Williamson from the School of Natural Sciences at Macquarie University, senior author on the study, said the findings underscored the urgent need for action on climate change.
The research team used high-resolution drone imagery to map coral bleaching in March 2024, returning in June to assess survival and mortality rates across the same reef areas.
“Using drone-derived imagery, we followed the amount of bleached and living coral during and after the bleaching event,” said Professor Williamson. “Use of this technology lets us upscale the effects of the bleaching event over larger areas but still in high precision.”
The team recorded the highest coral bleaching mortality on the Great Barrier Reef, with over 92% of corals experiencing mortality.
“Our results are concerning for coral resilience, considering the increasing frequency and intensity of extreme heat events predicted for the near future, with potentially irreversible consequences for reef ecosystems such as those studied in our Great Barrier Reef,” Williamson added.
More alarming still is that coral mortality actually exceeded 99% in some areas measured.
Coral reefs at Lizard Island have experienced repeated disturbances over the past decade, including severe bleaching in 2016 and 2017, cyclones, and Crown-of-Thorns outbreaks. These events have only compounded the ecosystem’s vulnerability, despite some signs of recovery in recent years.
The team behind the assessment are now running additional surveys at Lizard Island to track the recovery, if any, of corals into 2026 as part of an Australian Museum Lizard Island Critical Grant.
Click here for more from the Oceanographic Newsroom.