The Great Barrier Reef is undergoing its fifth major bleaching event since 2016, according to the latest snapshot. 

The Reef Snapshot 2023−24 says this year’s severe weather events, including two cyclones and numerous floods, have significantly compounded the stresses on the reef, contributing to extensive coral bleaching.

The collaborative report by the Reef Authority, the Australian Institute of Marine Science (AIMS), and the CSIRO highlights an alarming increase in the frequency and intensity of disturbances affecting the reef compared to previous years. 

Survey data reveals 73 per cent of reefs are showing signs of coral bleaching within the Marine Park, while damage is recorded in the Torres Strait too. 

“The southern regions of the Marine Park have been hit hardest, experiencing unprecedented levels of heat stress,” according to the report.

“Climate change is the greatest threat to the Great Barrier Reef, and coral reefs globally. This summer has been particularly challenging,” says Dr Roger Beeden, the Reef Authority’s Chief Scientist.

The report also covers efforts to mitigate damage, including the control of crown-of-thorns starfish, a major predator of coral. 

Tourism operators have played a crucial role too, conducting thousands of reef health surveys and contributing data to the 'Eye on the Reef' system.

According to Dr David Wachenfeld of AIMS, the full impact of recent events on coral mortality will be clearer with ongoing research, “but the preliminary data indicates this is one of the most extensive bleaching events on record”.