Great Barrier Reef health update

Reef Health update | 29 January 2025 © Great Barrier Reef Marine Park Authority

As the lead managers of the Great Barrier Reef, the Reef Authority keeps an eye on the Reef year-round — with efforts stepped up over summer, a typically high-risk period from extreme weather.

The Reef Authority releases updates on the health of Reef which includes; sea surface temperatures, rainfall and floods, cyclones, crown-of-thorns starfish outbreaks, and coral disease.

These updates are based on forecasts, water temperature heat mapping, in-water surveys, citizen science and aerial surveys.

Reef Health update | 29 January 2025

An increase in activity of the monsoon trough across northern Australia is expected to provide a reprieve from hot weather over the coming weeks and could potentially mitigate the impacts of higher sea surface temperatures across the Reef.

Monsoonal conditions bringing wind and rain will potentially reduce elevated sea surface temperatures across the northern and central regions of the Great Barrier Reef Marine Park.

Heat stress is currently highest in the Far North of the Marine Park, progressively declining toward the south, with the Southern region showing the lowest level of accumulated heat stress.

Temperatures

Despite promising forecasts, sea surface temperatures are currently between 1 to 2 degrees Celsius above average, with the highest temperature anomalies recorded in the Northern and Central regions. These higher-than-average temperatures are expected to persist throughout summer, with the peak in March - although local weather conditions across the region will continue to influence outcomes for the Reef during this period.

Air temperatures continue to be above average throughout the Great Barrier Reef catchments but are also expected to ease with the onset of the low-pressure system across the region.

Rainfall

Above average rainfall is expected to continue throughout January. Rainfall is likely to be above average across much of northern and eastern Australia, with the likelihood of above average rainfall exceeding 80% in parts of northern and central Queensland for February through to April.

Reef health

Forty-two reefs were surveyed across the Marine Park over the past fortnight with low prevalence of coral bleaching reported, mainly in the Central and Northern regions.

Crown-of-thorns starfish outbreaks remain the most severe in the Southern Region (Swain Reefs) and the Northern 'initiation zone' (Port Douglas to Lizard Island), with isolated outbreaks offshore Townsville and the Whitsundays.

The Crown-of-thorns Starfish Control Program is prioritising reducing spawning populations in the "initiation zone" to prevent further spread of this coral-eating species, with concern the increasing population in this area may trigger waves of secondary outbreaks.

Reef management

As the lead managers of the Reef, we are working closely with our partners to monitor conditions across the Marine Park during these high-risk summer months.

We also use a range of management actions to support and build Reef resilience, including enforcing compliance with our zoning plan and ensuring people enjoy the Reef in a responsible way.

You too can help by reporting any incidents through the Eye on the Reef app, which is available for download on Google Play or Apple Store.