The Great Barrier Reef Marine Park Authority has officially declared a mass bleaching event, the fourth in six years.

Aerial surveys have now been completed, revealing bleaching has occurred right across the Marine Park.

Chief Scientist Dr David Wachenfeld says the bleaching has occurred despite La Nina conditions over Summer, which would usually deliver lower temperatures and plenty of cloud cover.


“This assessment of bleaching at multiple reefs in all four management areas confirms a mass coral bleaching event,” he said.

“The Great Barrier Reef Marine Park acknowledges that this news comes at a time when Reef-dependent industries are working hard to re-establish themselves following the impacts of COVID-19.


“Impacts from climate change and extreme weather are a reminder of the importance of global greenhouse gas emissions reduction and strong marine management actions that support the resilience of this magnificent ecosystem.

“We encourage people to come and see the Reef, love the Reef and help us to protect the Reef.”

Almost 750 reefs were surveyed from the sky.

Research Scientist Dr Neil Cantin says the method allows for bleaching diagnoses in up to five metres of water depth.

“In the Far North, we’re seeing a range of bleaching severity ranging from minor to severe,” he said.

“Coral bleaching is most severe through the northern and central sectors of the Marine Park.

“We're seeing severe bleaching on both the inshore and through to the offshore reefs.

“What we’re seeing is that more than half of the living coral cover that we can see from the air is severely bleached, completely white and can have signs of fluorescence in the colours of pink, yellow and blue.


Reefs in the southern sector are showing more minor signs of bleaching.

The Authority will now further assess the impacts by getting dive teams in the water to find out how deep the bleaching extends.

That process will continue throughout the year.


Main points

  • All four sectors of the Great Barrier Reef have bleached corals
  • The most impacted regions are the central and northern regions
  • A mass bleaching event has been declared
The reef remains a resilient and beautiful ecosystem.
Dr David Wachenfeld
Chief Scientist, GBRMPA
The corals are producing these fluorescent pigments in an attempt to protect their tissue from the heat and from the intense sun during these marine heatwaves.
Dr Neil Cantin
Research Scientist, AIMS