Great Barrier Reef avoids mass bleaching but endures heat, floods and cyclone damage, report finds

The Great Barrier Reef sidestepped another mass coral bleaching event over summer but faced a punishing season of heat, storms and flooding, according to the Great Barrier Reef Marine Park Authority’s latest Snapshot. An environmental group said the findings underscored the need for stronger action from the Australian and Queensland governments.

The Reef Snapshot: Summer 2025–26, released last night, reports sea surface temperatures were above average across the marine park from December to March. The heat triggered significant coral bleaching in the Northern Region and localised bleaching in parts of the Far Northern, Central and Southern regions.

The Snapshot suggests two cyclones likely exposed reefs to damaging waves, and an April Reef Health Update confirms powerful waves from Cyclone Narelle caused severe coral damage in the Far Northern Region and into the Northern Region near Cairns. Reef-wide flooding, driven by above-average rainfall, carried polluted runoff into inshore coral systems, the Snapshot notes.

The authority also reports two widespread outbreaks of crown-of-thorns starfish now affecting all regions. “The Great Barrier Reef avoided another mass coral bleaching event after the devastating back-to-back bleaching events of the previous two summers, but there has been no reprieve from climate change,” said Dr Max Hirschfeld, Great Barrier Reef Water Quality Manager at the Australian Marine Conservation Society (AMCS).

He said significant bleaching in the Northern Region and extensive coastal flooding had exacerbated the Reef’s water pollution crisis. Hirschfeld said this was the fourth consecutive year of above-average rainfall and flooding, with this summer’s inundation spreading across the entire Reef coast and lasting for three months rather than shorter, distinct events.

He warned pollutants such as sediment, fertilisers and pesticides can impair the growth, reproduction and health of corals and seagrasses, with knock-on effects for fish, dugongs, turtles and other marine life. AMCS called for stronger climate and water quality measures.

Hirschfeld said the Australian and Queensland governments need to do more to address climate change and should stop approving new fossil fuel developments.

He said the Crisafulli government had committed to a 75% cut in climate pollution by 2035 but had not produced a plan to reach that target, adding that the state’s renewable energy target had been dropped and projects that would reduce greenhouse gas pollution were increasingly being blocked or shelved.

These claims were made by AMCS. On local threats, Hirschfeld urged a focus on restoring wetlands that filter pollutants and replanting vegetation along riverbanks to curb erosion and sediment flows into the Reef.

He said the Queensland government’s plan to reduce water pollution on the Reef has yet to be released after the previous plan expired in 2022, and called for funding the next five-year phase of the State’s Reef Water Quality Program. He said the plan should be clear and fully costed, with an investment roadmap and timelines showing how much will be spent, where and how, and when targets will be met.

Hirschfeld likened the cumulative effect of pollution on marine life to human exposure to smog in heavily polluted cities—an ongoing stress that weakens resilience over time. He said protecting the Reef and the 77,000 jobs it supports requires urgent, coordinated action within the state’s control, alongside efforts to limit climate pressures.