Reef health update | June 2026

**Reef health update | June 2026** While heat stress has eased across the Great Barrier Reef Marine Park from summer, sea surface temperatures remain slightly above average in some regions for this time of year. Climate conditions remain neutral; however, there are increasing signs that an El Niño may develop later this year, bringing drier conditions to northern Queensland in the months ahead. As winter settles across the Reef, seasonal wildlife sightings are increasing. The annual humpback whale migration is now underway, with thousands of whales expected to travel through the Marine Park on their journey from Antarctic feeding grounds to breeding and calving areas in tropical waters. Dwarf minke whales are also beginning to arrive in northern Reef waters, while manta ray sightings have increased during these cooler months. The return of these iconic species is one of the Reef's great natural spectacles and a reminder of the importance of protecting marine habitats. Visitors are encouraged to enjoy wildlife encounters responsibly by giving animals space to behave naturally and safely. **Temperature** Sea surface temperatures in the Far Northern and Northern regions remain approximately 0.5–0.8°C above long-term monthly averages. Temperatures in the Central and Southern regions are closer to average, sitting around 0.2°C above normal. The Bureau of Meteorology forecasts sea surface temperatures to remain above average through winter and into August. Climate forecasts suggest an El Niño may develop later this year, which can increase the likelihood of warmer and drier conditions across northern Queensland. However, other climate factors, such as conditions in the Indian Ocean and tropical weather systems that influence rainfall and cloud cover, also affect local weather, so conditions may vary across the Reef catchment.   **Rainfall** The Indian Ocean Dipole, which can influence regional rainfall patterns is currently neutral and forecasts remain uncertain. Should both El Niño and a positive Indian Ocean Dipole develop during winter and spring, northern Queensland could experience drier-than-average conditions over the coming months. **Reef health** Over the past month, 521 Reef Health Impact Surveys were conducted across 43 reefs; - In the Far Northern region, one reef was surveyed, recording no coral bleaching and low levels of coral damage. - In the Northern region, 24 reefs were surveyed. Coral bleaching was recorded on 18 reefs, ranging from low (1–10%) to moderate (11–30%) prevalence. Coral damage was recorded on 20 reefs. - In the Central region, 8 reefs were surveyed. Three reefs recorded low levels of coral bleaching and 7 reefs recorded low coral damage. - In the Southern region, 10 reefs were surveyed. Eight reefs recorded low to moderate coral bleaching prevalence and four reefs recorded low coral damage. Coral disease was recorded on 20 reefs across the Marine Park during the reporting period. Additional Eye on the Reef monitoring programs reported coral bleaching on 29 of 41 reefs surveyed during May. The coral bleaching observed across the Marine Park is likely associated with prolonged heat exposure experienced during summer, while much of the coral damage recorded in the Far Northern and Northern regions is consistent with impacts from Severe Tropical Cyclone Narelle.