Marine biologists have recorded the highest coral cover on Australia's Great Barrier Reef in more than a decade, according to the latest survey by the Australian Institute of Marine Science. Hard coral now covers up to 36 per cent of surveyed northern sections, levels not seen since monitoring began in the mid-1980s.

Researchers credit a run of mild summers and reduced cyclone activity for the rebound. Warmer-than-average ocean temperatures had triggered mass bleaching events in 2016, 2017, and 2020, leaving large stretches of the reef looking ghostly white. The latest data suggests that many of those areas have bounced back faster than expected.

The recovery is not uniform. Southern sections of the reef still show below-average coral cover, and crown-of-thorns starfish, a natural predator of coral, remain a concern in several zones. Scientists warn that a single prolonged marine heatwave could reverse years of progress within weeks.

Still, the findings have been welcomed by conservation groups as a sign that reefs can recover when conditions allow. The Great Barrier Reef Marine Park Authority said the results underscore the importance of reducing local stressors such as agricultural run-off and overfishing, while global efforts to limit ocean warming continue.