Statement: coral bleaching on the Great Barrier Reef

Australia’s lead management agency for the Great Barrier Reef can confirm mass bleaching is occurring on the Great Barrier Reef, with very widespread bleaching detected.

The Great Barrier Reef Marine Park Authority is drawing on the most current information from in-water and aerial observations and building on the best available science and technology to understand current conditions.

With aerial surveys being completed this week, we will better understand the extent and severity of this bleaching event. Further analysis will continue over the coming weeks.

For the last two weeks, the Authority had an observer on the aerial surveys, which are being conducted by the Australian Research Council Centre of Excellence for Coral Reef Studies at James Cook University.

While there has been some cooler weather of late, the heat accumulation, particularly through February, led to bleaching which is now being observed through aerial surveys.

So far, observations from the aerial surveys over the vast area of the Reef — some 344,000 square kilometres —are:

  • Mostly confirming the worst bleaching is on reefs that suffered the highest heat stress this summer, which extended across large areas of the Reef.
  • Detecting a wide variety of bleaching severity — ranging from no bleaching to the most severe category. Some southern areas of the Reef that had little or no bleaching in 2016 and 2017 have now experienced moderate or severe bleaching.
  • Showing, importantly, key tourism reefs in the Northern and Central areas of the Reef experienced only moderate bleaching, from which most corals should recover.
  • Detecting moderate and severe bleaching on coastal and mid-shelf reefs in the far north where the corals remaining after the 2016 and 2017 events are relatively heat-tolerant.
  • Identifying pockets of the Reef that remain unaffected with healthy areas of reefs.

Over the summer the Authority was looking at in-water and aerial surveys, citizen science, and forecast and heat mapping tools from the Bureau of Meteorology and US National Oceanic and Atmospheric Administration.

Once the aerial surveys are complete we will be able to compare this event to those of 2016 and 2017.

It is important to remember bleached corals are not dead corals — on mildly or moderately bleached reefs there is a good chance most bleached corals will recover and survive this event.

Equally, on severely bleached reefs, there will be higher mortality of corals.

Ongoing long-term monitoring of Reef health by the Australian Institute of Marine Science will be key in continuing to understand the longer-term health of the Great Barrier Reef and the consequences of successive coral bleaching events.

The Great Barrier Reef remains under pressure from heat stress that accumulated over the 2019/20 summer, particularly in February and early March 2020, and resultant bleaching that is occurring.

The Great Barrier Reef Marine Park Authority continues to monitor the situation and provide up-to-date information for the public through the Authority’s Reef Health Updates.

Actions to support the resilience of the Reef are now more important than ever.

Climate change remains the single greatest challenge to the Reef. While the strongest possible global efforts to reduce emissions are essential, it is critically important we continue to deliver the work already being undertaken to enhance the resilience of the reef.

The Australian Government is investing $1.9 billion in protecting the Great Barrier Reef through world-leading science and practical environmental outcomes to support the $2.7 billion Reef 2050 Plan in conjunction with the Queensland Government.

This investment — which will double the on-ground Reef Joint Field Management Program to $38 million per year — will see more rangers on the water to increase compliance and reef management activities.

Additional investments to protect coral cover through crown-of-thorns starfish control, water quality programs, marine science, state-of-the-art monitoring of reef environments and reef adaptation are also playing key roles in supporting the Reef.

Great Barrier Reef Marine Park Authority - media team: (07) 4750 0846 or media@gbrmpa.gov.au