CANBERRA, April 17 (Xinhua) -- A majority of Australia's iconic Great Barrier Reef experienced coral bleaching in the summer of 2023-24, a government report has found.
Federal government agencies the Great Barrier Reef Marine Park Authority, the Australian Institute of Marine Science (AIMS) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) on Wednesday published the Reef Snapshot for 2023-24.
According to the report, coral bleaching was observed on 73 percent of surveyed reefs in the marine park area. It marks the fifth widespread bleaching event on the reef since 2016.
Coral bleaching is a phenomenon whereby coral experiencing heat stress expels the symbiotic algae living in its tissue, turning the coral white. Bleached coral is not dead but is more likely to die from starvation due to a disruption in its photosynthesis process.
The Australian report was published two days after the U.S. National Oceanic and Atmospheric Administration declared a fourth global mass bleaching event since 1998.
"Climate change is the greatest threat to the Great Barrier Reef, and coral reefs globally," Roger Beeden, the reef authority's chief scientist, said in a media release on Wednesday.
"The Great Barrier Reef is an incredible ecosystem, and while it has shown its resilience time and time again, this summer has been particularly challenging."
The report said 39 percent of monitored reefs in the park suffered from very high or extreme bleaching in the summer of 2023-24.
Bleaching is considered very high when at least 61 percent of coral on a reef is bleached and extreme at 90 percent and above.
David Wachenfeld, research program director at AIMS, said that divers have already observed coral mortality from the summer bleaching event in every region of the reef.
He said the extent of heat stress and findings of aerial surveys indicated that it was one of the most extensive bleaching events in the 40 years AIMS has been monitoring the reef. ■
