Parts of Australia’s large coral barrier, famous for vibrant colors and biodiversity, suffered in 2024 the largest decline ever recorded in history, after a marine heat wave has whitening several coral bands, according to a new report.
In 2024, when the world underwent a rare global coral mass bleaching event, Recife recorded its worst summer. The increase in water temperature, combined with the El Niño climate phenomenon, generated stress in the corals and led them to lose their color.
An official analysis released on Thursday (6) shows that the great barrier of corals lost between a quarter and one third of the coral cover in three main regions, according to AIMS (Australian Institute of Marine Sciences).
In some areas, reefs lost up to 70% of living corals.
The mass bleaching of 2024 “had the largest impact ever registered in (large coral barrier)”, concluded the report. “The declines in the north and south have been the largest in a single year since the start of monitoring 39 years ago.”
Massive coral loss
A CNN He checked widespread bleaching visits to – and Recife de Ningaloo, on the west coast of Australia, in 2025. At the time, a scientist described the devastation as “subacous forest fires.”
Massive loss in the 2,300 kilometers ecosystem is especially discouraging after significant growth in recent years, with some corals had helped Recife recover from the previous bleaching.
But these corals “were known to be extremely vulnerable and was a matter of time until they lost these gains,” the report said. These fears materialized last year, with rapid growth corals among the most impacted.
“This raises the prospect that the great coral barrier can reach a point where it won’t recover,” the report warned.
Marine devastation
With almost 345,000 square kilometers, the large coral barrier is the largest reef with these animals in the world, home to over 1,500 fish species and 411 hard coral species.
The region contributes billions of dollars to the Australian economy each year, mainly through tourism, and is widely promoted to foreign visitors as one of the country’s greatest natural wonders – and the world.
But activists and scientists warn have warned in the last decade that the future of Recife is at risk.
In the Great Barrier of Coral had already been observed in 1998, 2002, 2016, 2017, 2020 and 2022. Corals can recover from bleaching if temperatures return to normal, but die if the water remains warmer than normal.
Water temperatures increased again earlier this year during the Australian summer, reaching peak in March and causing even more bleaching – although their impacts have not been fully measured and have not been included in this report.
Oceans now store 90% of the excess heat of global warming – recording consecutive temperature records over the past eight years.
Reef protection measures
The destruction of marine ecosystems would represent a death sentence for about a quarter of all species that depend on the reefs to survive, warns scientists. Reefs also provide vital protection for coastal, reducing the impact of floods, cyclones and sea level elevation.
Blancing is “a call to action,” said the Queensland Conservation Council, a non-profit organization, on Wednesday (6), after the report.
The board, the maximum agency of dozens of environmental groups of Queensland, has asked state and national leaders to close the coal power plants.
Australia is in a transition to renewable energy, as well as other developed nations, but critics say this is not happening with the speed necessary.
“It is unlikely that the coral reefs of the future will look like those of the past. Biodiversity loss seems inevitable,” says the report, who calls for further research on reef adaptation and protection while the world works to reduce greenhouse gas emissions.
