New AIMS report confirms worst annual coral declines on record for Great Barrier Reef

The Australian Institute of Marine Science (AIMS) has today released its Long Term Monitoring Program (LTMP) report which confirms the Great Barrier Reef has suffered the largest annual declines in coral cover in two of its three regions since monitoring began.

The Australian Government has until February 2026 to improve its Reef protection policies or risk a World Heritage 'In Danger' listing for the Reef.

Following the release of the AIMS report, the Australian Marine Conservation Society (AMCS) noted “the choices the Australian Government makes in the next 12 months will decide the Reef's fate.”

According to the AIMS report, the Great Barrier Reef has suffered the largest annual declines in coral cover in two of its three regions since monitoring began in 1986.

Coral cover plummeted by about a quarter in the northern region (Cape York to Cooktown), almost 14% in the central region (Cooktown to Proserpine), and nearly a third in the southern region (Proserpine to Gladstone), the largest annual decline ever recorded there.

For the first time, substantial bleaching impacts were recorded in the southern Reef, showing that almost the entire system has been hit hard, not just isolated areas.

The Reef has now endured five mass bleaching events since 2016 - including back‑to‑back events in 2024 and 2025 - a clear sign that climate change is overwhelming the Reef's ability to recover.

This devastating update comes just days after the Climate Change Authority warned that the Reef cannot survive without urgent climate action. It also comes as the Australian Government decides its 2035 emissions reduction targets - with a 90% cut critical to protecting the Reef. UNESCO has given Australia until February 2026 to improve Reef protection policies or risk a World Heritage 'In Danger' listing.

The Australian Marine Conservation Society (AMCS) is urging the Federal Government to:

• Commit to at least a 90% cut in emissions by 2035

• End approvals for new coal and gas projects

• Tackle local threats including water pollution, deforestation in reef catchments and coral harvest

Australian Marine Conservation Society (AMCS) Great Barrier Reef Campaigns Manager Dr Lissa Schindler notes "For those of us who dived on the Reef during the 2024 bleaching event, we knew it was devastating. Now the data confirms just how bad it was.

"The most alarming finding is the pattern – the Reef is lurching from record highs to record lows – a hallmark of an ecosystem in crisis.

"As custodians of the Reef and one of the wealthiest nations on Earth, Australia has both the responsibility and the ability to lead on climate action. Yet, we remain among the world's highest per capita carbon polluters, and we're still approving new coal and gas projects. That must stop.

"The Federal Government is currently setting its 2035 climate targets – a decision that will define the future of the Great Barrier Reef and Australia's role in the unfolding climate crisis. Australia must commit to an emissions reduction of 90% by 2035, in line with the science to give our Reef a chance for the future.

"They must also commit to addressing local threats like reducing water pollution, phasing out coral harvest for the aquarium trade, and finalising the gill net fishing ban by 2027.

"The Reef's future is still in our hands, but the choices Australia makes in the next 12 months will decide its fate. We must act now – for the Reef and for future generations".

AIMS' Long-Term Monitoring Program
AIMS' Long-Term Monitoring Program measures the status and trend of reefs in the Great Barrier Reef World Heritage Area.

Each year, the AIMS team of marine scientists spend more than 120 days at sea surveying between 80 and 130 reefs along the length and breadth of the Reef. Over its 35+ year history, the Program has surveyed more than 490 reefs, across a range of environmental gradients within the Reef - for example, across gradual changes in water clarity, wave energy and latitude. AIMS also monitors in different management zones.

The result is the most comprehensive and extensive record of coral status on any reef ecosystem in the world. The data are an essential resource for governments, the science community and everyone involved in its management and protection.

Access AIMS Long Term Monitoring Program (LTMP) report

Image. One Tree Island in Southern Great Barrier Reef. Credit: AIMS/ LTMP