Statement: aerial surveys on the Great Barrier Reef

The Great Barrier Reef Marine Park Authority acknowledges the extreme impact COVID-19 is having on Reef industries and their communities, and we’re doing everything we can to support these industries in these difficult times.

We monitor Reef conditions very closely. We’ve been issuing weekly public reports based on forecasts, water temperature heat mapping, in-water surveys, citizen science, and aerial surveys that included an Authority staff member as an observer.

Today the ARC Centre of Excellence for Coral Reef Studies released key findings from their aerial surveys of the Great Barrier Reef.

As Australia’s lead management agency for the Reef, we are very concerned this amazing natural wonder experienced this third mass coral bleaching event in five years.

The Reef is a 344,000 square kilometre area that is bigger than Tasmania and Victoria combined. The surveys, and associated mapping produced, show the variability of bleaching across this vast area.

Across the Reef, the analysis of aerial surveys confirmed bleaching is different from 2016 and 2017 — while it is widespread, we are seeing a different pattern of bleaching within the Marine Park.

The aerial surveys looked at 1036 reefs (focusing on shallow water corals, down to five metres) and found:

  • About 40 per cent had little or no bleaching and that is good news
  • About 25 per cent of reefs were severely bleached (that is, on each reef more than 60 per cent of the corals were bleached)
  • 35 per cent had moderate levels of bleaching.

Severe bleaching was more widespread than in past bleaching events.

The aerial surveys confirmed many areas had moderate to severe bleaching. Importantly, most recognised tourism areas had no, negligible or moderate bleaching.

There are areas mostly well offshore with no or low level bleaching as well as pockets of reefs with no or low level bleaching scattered through some areas of severe bleaching (such as in the southern offshore reefs).

Bleached corals are not dead corals — on mildly or moderately bleached reefs, the majority of the Reef this summer, there is a good chance most bleached corals will recover and survive this event.

This mass bleaching reaffirms that climate change remains the single greatest challenge to the Reef and the strongest possible global efforts to reduce emissions are essential.

This action, along with delivering the work already being undertaken to enhance the resilience of the Reef at local levels, is critical for the Reef’s long-term outlook.

This includes protecting coral cover through crown-of-thorns starfish control, improved water quality, increased monitoring and effective Marine Park management, preventing illegal fishing, and developing potential new restoration and interventions that can occur within the Reef.

When it is safe to do so, the Authority will encourage people from across Australia and around the world to see the Reef, love the Reef, and importantly protect the Reef.


Great Barrier Reef Marine Park Authority

Media team (07) 4750 0846 or