A tropical low is developing in the Coral Sea off the east coast of North Queensland. The Bureau of Meteorology advises there is currently a low to moderate chance of it developing into a tropical cyclone. Increased wave action from this system may affect some shallow reef habitats.

Monsoonal activity and the tropical low are expected to bring heavy rainfall to most Marine Park catchments. This increases the risk of flooding and freshwater runoff into the Marine Park.

SeaWeek 2026 is being celebrated from 28 February to 8 March, with this year’s theme “Caring for Planet Water”. The week highlights the importance of ocean literacy and the role healthy oceans play in regulating climate, supporting biodiversity and sustaining communities. It’s a timely reminder of the connection between weather, water quality and Reef health, and the shared responsibility to care for our marine environment.

Temperature

Heat stress continues to build across parts of the Marine Park. Some reefs in the far northern and northern regions are experiencing conditions that may lead to bleaching in heat-sensitive corals.

Over the past week, sea surface temperatures in the far northern region increased from 29.5°C to 30°C and are now about 1.5°C above the long-term monthly average. Sea surface temperatures in the north regions are also about 1.5°C above the long-term monthly average while those in the Central and Southern regions remained relatively stable at 0.8°C to 1°C above average.

Rainfall

Rainfall was average across most Marine Park catchments over the past week. However, monsoonal activity and the tropical low are expected to bring heavier rainfall in the coming week.

Reef health

Over the past week, 91 Reef Health Impact Surveys were completed across six reefs in the northern and central regions.

Low levels of coral bleaching (1–10%) were recorded on four northern reefs and one central reef. One northern reef also recorded low levels of physical damage (e.g. from anchors). No disease was recorded in surveys.

Eye on the Reef monitoring programs also reported coral bleaching on 12 of the 28 reefs surveyed. No surveyed reefs showed fully bleached or recently dead coral colonies.

Crown-of-thorns starfish control

As of 28 February 2026, the Crown-of-Thorns Starfish Control Program and Reef Joint Field Management Program response teams have surveyed and, where needed, culled starfish on 157 reefs this financial year.

Of these reefs:

• Crown-of-thorns starfish are at sustainable levels on 61 reefs (39%).
• Active culling is underway on 57 reefs (36%) to suppress outbreaks.
• Starfish have been detected on 39 reefs (25%), and these reefs will be targeted for culling based on priority and actioned when operationally feasible.

The program uses a science-based prioritisation process to focus effort on reefs with high ecological and economic value, with the aim of maximising coral protection.

Our response and ongoing work

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 from across the World Heritage Area.

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 – 12 February 2026

Summary

Sea surface temperatures have increased slightly across the Far North, North and Central regions over the past week, with little change in the southern region. Temperatures are tracking slightly above the long-term average with the Northern region (Cooktown – Innisfail) experiencing above-average conditions.

The Bureau of Meteorology has forecast a tropical low (23U) to form in the Coral Sea. There is a low chance (5–10%) it will develop into a tropical cyclone by the weekend. The system is expected to remain offshore and may bring localised rainfall to Marine Park catchments in the coming week.

The breeding season continues across the Reef, with turtle hatchlings emerging from nests and making their way to the sea from late January through April, especially at dawn and dusk. Seabirds are also nesting and feeding across island and reef habitats, and many fish species are spawning and laying eggs during the warm summer months, taking advantage of the productive wet season conditions.

Temperature

Sea surface temperatures are currently around 0.4–0.5°C above the long-term average in the Far Northern, Central and Southern regions. The Northern region is averaging around 1°C above the long-term monthly average.

While there has been some accumulation of heat stress, particularly in northern Reef waters, this remains below the level where we would expect to see significant coral bleaching impacts.

Rainfall

From 2–8 February, rainfall was lower than expected in the Marine Park catchments, with average rainfall occurring in the Wet Tropics and Mackay–Whitsundays. Heavy rainfall is currently forecast in areas which may be affected by the Tropical Low 23U.

Reef health

America’s National Oceanic and Atmospheric Administration’s (NOAA) coral bleaching alert level for the Northern region has moved from bleaching watch to bleaching warning, meaning coral bleaching is possible, following the recent temperature increases. Monitoring is ongoing across the Marine Park.

During the past week, 86 Reef Health Impact Surveys were completed across 10 reefs in the Northern, Central and Southern regions.

Low to medium levels of coral bleaching (1–30%) were recorded on four reefs in the Northern region and one reef in the central region. Most surveyed reefs showed no to low levels of bleaching.

Additional observations from Eye on the Reef monitoring programs reported coral bleaching on 11 of the 26 reefs surveyed. Impacts remain localised and are being closely monitored.

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

Marine Monitoring Program teams and partners are sampling water quality and tracking flood plumes in the Burdekin. On Magnetic Island, training is underway to support local citizen scientists to help monitor water quality.

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 efforts remain focused on supporting Reef resilience, including enforcing zoning rules, encouraging responsible use of the Marine Park and responding early to emerging risks.

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 decisions are guided by up-to-date information.

For more information, visit - www.gbrmpa.gov.au/learn/reef-health/reef-health-updates