Getty imagesAccording to a new report, parts of the Great Barrier Reef have faced the biggest annual decline in coral cover, as the records started about 40 years ago.
Both the northern and southern branches of the huge Australian rock faced their best coral bleaching, Australian Institute of Marine Science (AIMS) found.
Reefs have been defeated in recent months by tropical cyclones and crown-off-thorns starfish outbreaks, which feasts on coral, but the heat stress-inspired heat stress is the main reason, AIMS said.
The AIMS warns that the habitat may reach a tipping point, where coral may not heal enough between terrible events and faces the future “unstable”.
The AIMS surveyed the health of 124 coral reefs between August 2024 and May 2025. It has been surveying since 1986.
Often the world’s largest living structure is dubbed, the Great Barrier Reef expands a 2,300 km (1,429-mile) tropical coral, with a surprising array of biodiversity. Frequent bleaching incidents are changing the huge swatches of coral white once.
Coral is important for the planet. The surname of the sea architect, it forms the giant structures that are an estimated 25% of all marine species.
Bleaching occurs when the coral becomes stressed and becomes white because the water that remains in it is very hot.
Getty imagesThe stressed coral will probably die if it experiences a temperature of 1C (1.8F) above its thermal range for two months. If the water is 2 C more, it can survive around a month.
Unusually hot tropical water triggers Comprehensive coral bleaching on Great Barrier Reef in 2024 And in the first few months of 2025, the sixth such incident since 2016.
Also climate change, Natural weather patterns like El Nino Can also play a role in large -scale bleaching events.
Reef has “experienced unprecedented levels of heat stress, which has been the most spatial and severe bleaching,” found in the report.
According to the report, any recovery may take years and depended on the future coral breeding and minimal environmental disturbances.
Among the latest AIMS survey results, the most affected coral species were acropora, which are susceptible to heat stress and preferred food of crown-kantte starfish.
Dr. Mike Amsley told ABC News, “These are the fastest to grow corals and are first to go.”
He said, “The Great Barrier Reef is such a beautiful, iconic place, it is really, really worth fighting. And if we can give it a chance, an inherent ability to fix it is shown,” he said.
The Australian government has some success with the Crown-Off-Thorns Starfish Kalinga program, which has killed more than 50,000 starfish by injecting them with vinegar or ox bile.
The AIMS report stated, “Crown-off-theorns due to starfish control activities, there were no ability, installed, or severe outbreaks of the Crown-off-Thorns starfish recorded on Central GBR Reefs in 2025.
Jiva is a native of the Great Barrier Reef and capable of eating huge amounts of coral. But their number has increased significantly since the 1960s, land-based agricultural run-off nutrients are considered to be the most possible cause.
Richard Lake from the Global Environmental Charity WWF said that the report shows that the reef is “ecosystem under incredible stress” and scientists are worried that when “Reef does not bounce back that way,” he told the news agency AFP.
Lake said that some coral reefs worldwide are already beyond recovery, warning the Great Barrier Reef may face the same fate without ambitious and rapid climate action.
The Great Barrier Reef is heritage-listed for over 40 years, but UNESCO has warned that the Australian icon is “in danger” from warming seas and pollution.
