Sydney: Lizard Island on Australia's Great Barrier Reef has suffered one of the world's worst coral die-offs, with 92 per cent of surveyed corals lost after the 2024 bleaching event, new research has revealed. 

Researchers used drone imagery to assess the Fourth Global Coral Bleaching Event in 2024 at Lizard Island, where 96 per cent of corals were bleached and mortality averaged 92 per cent, with some sites losing over 99 per cent of corals, according to a statement released recently by Australia's Griffith University.

"This marks one of the highest coral mortality rates ever documented globally," said the study's lead researcher Vincent Raoult from Griffith University's School of Environment. Raoult described the mortality as "unprecedented," especially given that Lizard Island experienced less heat stress than other parts of the Great Barrier Reef.

Drone technology enabled precise mapping of the widespread bleaching, said Jane Williamson from the Macquarie University in Sydney, also the study's senior author, who stressed the urgent need for climate action, warning that repeated heatwaves could irreversibly damage coral reefs, Xinhua news agency reported.

Lizard Island's reefs remain fragile after years of repeated damage, such as bleaching, cyclones, and Crown-of-Thorns outbreaks, and scientists will monitor them through 2026 for signs of recovery, according to the study published in Coral Reefs, the journal of the International Coral Reef Society.

"Prolonged heat stress throughout the Far Northern and Northern regions of the reef caused widespread bleaching," said the reef snapshot published by the Great Barrier Reef Marine Park Authority, Australian Institute of Marine Science and Commonwealth Scientific and Industrial Research Organization, earlier in April.

Coral bleaching is a phenomenon that occurs when coral experiencing heat stress expel the symbiotic algae living in their tissue and turn completely white. Bleaching is not fatal in itself but bleached coral are more likely to starve and can take a decade or longer to recover. (IANS)