Ex-Tropical Cyclone Koji formed on 10 January 2026 and made landfall between Ayr and Bowen on 11 January as a category 1 system. The system moved through the Central region of the Marine Park between Ayr and Mackay, bringing heavy rainfall. Early reports indicate flood plumes have formed in the Marine Park from nearby catchments, and flood warnings remain in place. Freshwater runoff into the Marine Park is expected to continue, and river plumes are being surveyed by the Marine Monitoring Program.

Temperature

From 5 to 11 January 2026, sea surface temperatures dropped slightly by 0.2−0.3°C across the Marine Park but remain approximately 0.4−0.9°C above average in all regions.

In the Northern, Central and Southern regions of the Marine Park, temperatures are not high enough to build up heat stress.

In the Far Northern region, heat stress is still building with most reefs under a Bleaching Warning or Watch level, meaning coral bleaching is possible. A few reefs near the Torres Strait boundary are under Bleaching Alert Level 1, meaning there’s a risk of some reef-wide bleaching if warm conditions continue.

Rainfall

During the reporting period, rainfall exceeded 200mm in many parts of the Cape York, Wet Tropics and Burdekin catchments, with some rainfall stations recording over 300mm in the Mackay−-Whitsundays region.

Reef health

During the survey period, 33 Reef Health Impact Surveys were carried out on three reefs in the Far Northern and Northern regions, and no coral bleaching was observed. However, bleaching was reported eight times through 23 surveys from other Eye on the Reef monitoring programs, across the Northern, Central and Southern regions.

Due to the high rainfall in the catchments adjacent to the Marine Park, early satellite imagery and reports from the ongoing water quality monitoring conducted by the Marine Monitoring Program indicate flood plumes have developed in the Marine Park across the affected catchments.

Crown-of-thorns starfish control

As of 31 December 2025, crown-of-thorns starfish (COTS) outbreaks are impacting reefs throughout the Marine Park, with the most severe outbreaks occurring in the Southern region (Swain Reefs) and in the Northern region between Cairns and Lizard Island. The COTS Control Program and Reef Joint Field Management Program (RJFMP) COTS response teams have actioned 128 reefs for surveillance and culling where required.

- COTS are at sustainable levels for coral growth and recovery at 44 actioned reefs

- Cull operations are currently active at 63 reefs to suppress outbreaks and protect coral from starfish predation.

- COTS have been detected on 21 reefs and culling will be initiated when resources are available.