Reef health update | 26 February 2026

Over the past week, sea surface temperatures across the Marine Park have remained relatively stable.

However now that we are well into summer, there is heat build-up in the system, particularly in the Far Northern and Northern regions of the Marine Park.

The USA’s National Oceanic and Atmospheric Administration (NOAA), which monitors ocean temperatures globally, has updated the coral bleaching alert levels across parts of the Marine Park, meaning the risk of coral bleaching has increased with the Far Northern region at alert level 2 and the Northern region at alert level 1. The Central region remains at warning status and Reef health monitoring is ongoing across all regions.

The Bureau of Meteorology forecasts scattered rainfall across Marine Park catchments over the coming week, with temperatures expected to remain close to monthly averages.

Temperature

Sea surface temperatures are currently around 0.7°C above average in the Southern region and between 0.8°C and 1.2°C above average in the Central, Northern and Far Northern regions.

Forecasts for March indicate that temperatures in the Far Northern region are likely to remain elevated, reaching up to 1.2°C above average, while other regions are expected to stay between 0 and 0.8°C above the long-term average.

Rainfall

From 16 to 22 February, localised heavy rainfall occurred in the Mackay–Whitsunday catchment, with weekly totals between 150 and 500mm and some daily totals exceeding 200mm.

Heavy rainfall can lead to freshwater runoff into the Marine Park, and subsequent lower salinity in Reef waters. This runoff may also carry sediments, nutrients and pesticides, placing additional stress on nearby marine ecosystems.

Reef health

Over the past week, 70 Reef Health Impact Surveys were completed across 11 reefs in the Northern, Central and Southern regions of the Marine Park, with most surveys conducted in the Northern region.

Low to high levels of coral bleaching (1–60%) were recorded on five reefs in the Northern region, and medium levels (11–30%) were recorded on one reef in the Southern region. Low level damage was reported on 23 reefs and disease on 21 reefs, mostly in the Northern region.

Additional observations from Eye on the Reef monitoring programs also reported coral bleaching on 21 of the 38 reefs surveyed. No surveyed reefs showed fully bleached or recently dead coral.

Crown-of-thorns starfish control

The Crown-of-thorns Starfish Control Program continues to manage ongoing outbreaks across the Marine Park, with updates shared in the first weekly Reef Health Update of each month.

Our response and ongoing work

Crown-of-thorns starfish (COTS) outbreaks continue across the Marine Park and specialised dive teams are working across targeted reefs to survey and cull these predatory starfish.

Management actions remain focused on supporting Reef resilience, including enforcing compliance with zoning rules and encouraging responsible use of the Marine Park.

The Reef Authority continues to work closely with the Reef Joint Field Management Program, the Crown-of-Thorns Starfish Control Program, researchers, tourism operators, contractors and partners to ensure management actions are guided by the latest data across the World Heritage Area.

Reef health update | 5 February 2026

Sea surface temperatures remain stable across the Marine Park and are only slightly above average for this time of year.

Above-average rainfall fell across all Marine Park catchments in January, with the most rain falling in the Cape York region. Water quality monitoring is ongoing to understand how these conditions may affect nearby reefs.

Summer is also a busy time for Reef wildlife. From late January through April, thousands of baby turtles are hatching and making their way to the Marine Park, with many nesting beaches and islands seeing regular activity, especially at dawn and dusk. Seabird breeding is also underway, with many species nesting on islands and feeding across the Reef during February.

Temperature

In the Far Northern region, temperatures are around 0.1°C above the long-term monthly average. The Northern, Central and Southern regions remain 0.4–0.7°C above average.

Overall, temperatures are lower than earlier in summer but still a little warmer than usual for this time of year.

Rainfall

Between 26 January and 1 February 2026, the highest recorded rainfall occurred in the Wet Tropics with some days exceeding 200mm.

With catchments already saturated, further rainfall increases the likelihood of freshwater and sediment runoff entering the Marine Park. Current forecasts indicate a high chance of continued rainfall in the coming week.

Reef health

Recent monitoring shows limited impacts from coral bleaching. Between 26 January and 1 February, 143 Reef Health Impact Surveys were completed across 14 reefs in the Marine Park, with 12 of the 14 reefs showing no or only limited coral bleaching impacts.

On the two reefs where bleaching was recorded:

• One reef in the Northern region recorded low levels of bleaching (1–10%).
• One reef in the Southern region recorded higher bleaching levels (31–60%), which is being closely monitored.

Additional observations from Eye on the Reef monitoring programs reported coral bleaching on 13 of the 20 reefs surveyed. These reports indicate that impacts remain localised, rather than widespread, at this stage of summer.

Crown-of-thorns starfish control

Crown-of-thorns starfish (COTS) outbreaks continue across the Marine Park, with the most severe outbreaks in the Southern region (Swain Reefs) and the Northern region between Cairns and Lizard Island. Specialised dive teams are working across targeted reefs to survey and cull these predatory starfish.

Crown-of-thorns starfish (COTS) management continues to deliver strong coral protection outcomes. Since July, COTS control teams have surveyed or treated 153 reefs across the Marine Park:

• 61 reefs (around 40% of those surveyed) now have COTS at sustainable levels, supporting coral growth and recovery.
• 57 reefs (around 37%) are under active culling to suppress outbreaks and protect coral.
• COTS have been detected on 35 reefs (around 23%), with control planned as resources allow.

Sea surface temperatures remain relatively stable across the Marine Park and slightly above the long-term average for this time of year.

We’ve moved some of our crown-of-thorns starfish control vessels north to respond early to a new outbreak, while keeping control efforts underway in the central and southern Reefs to protect coral cover.

High rainfall across Reef catchment areas during January has contributed to some cooling of sea surface temperatures with increased cloud cover and rain, reducing the risk of heat stress on reefs. However, this has led to flood plumes in the Northern, Central and Southern regions of the Marine Park. Water quality monitoring is underway to understand how these conditions may affect nearby reefs.

Temperature

In the Far Northern region, sea surface temperatures are around 0.2°C above long-term monthly averages. The Northern, Central and Southern regions remain 0.5–0.8°C above average, which is lower than earlier in summer but still warmer than typical for this time of year.

Rainfall

Between 19 and 25 January, a trough and tropical low brought heavy rainfall to Far Northern Queensland. Some weather stations recorded 200–300mm of rain, increasing the likelihood of freshwater runoff from Cape York catchments flowing into the Marine Park.

Reef health

From 19–25 January, 55 Reef Health Impact Surveys were completed across 12 reefs in the Northern and Central regions.

Results from recent monitoring show that nine of the 12 reefs surveyed (75%) recorded no coral bleaching impacts. This aligns with the modest levels of heat stress that have accumulated across the Reef so far this summer.

Coral bleaching was observed on three reefs:

• In the Northern region, one reef recorded low bleaching prevalence (1–10%), with only 5% of the bleached coral were fully bleached and very low levels of recent coral mortality (under 3%).

• In the Central region, two reefs recorded low to medium bleaching prevalence (1–10% to 11–30%).

Additional observations from other Eye on the Reef monitoring programs reported coral bleaching on nine of 27 reefs surveyed in the Northern region, indicating that impacts remain localised at this stage.

Flood plumes from rivers in the Wet Tropics and Mackay–Whitsunday catchments have extended into the Marine Park. These plumes, which contain freshwater and sediments, may be contributing to coral bleaching and recent mortality on some inshore reefs.

Recent satellite imagery has also identified a developing flood plume from the Fitzroy catchment flowing into Keppel Bay. The Marine Monitoring Program and survey partners will continue to assess its extent and potential impacts in the coming weeks.

Crown-of-thorns starfish control

Crown-of-thorns starfish (COTS) outbreaks continue across the Marine Park, with the most severe outbreaks in the Southern region (Swain Reefs) and the Northern region between Cairns and Lizard Island. Specialised dive teams are working across targeted reefs to survey and cull these predatory starfish.

As of 31 December 2025:

• 128 reefs have been surveyed or treated

• 44 reefs (around 34%) now have COTS at sustainable levels

• 63 reefs (around 49%) are undergoing active culling

• 21 reefs (around 17%) have COTS present, with control planned as resources allow

Crown-of-thorns starfish control program data is updated monthly, with year-to-date updates included in the first Reef Health Update each month.