Reef health

Fact or fiction: coral bleaching 101

Do you know what is fact or fiction?

As Australia’s lead management agency for the Reef, we monitor Reef conditions very closely throughout the year. From May to November each year, we issue regular Reef health reports. Over summer, we issue weekly public reports on the conditions of the Reef.

These updates are based on forecasts, water temperature heat mapping, in-water surveys, citizen science and aerial surveys. The current updates are available below and past Reef health updates are also available.

In addition to our regular updates, we’ve released:


Reef health update —  1 April 2021

Temperature and rainfall

Reef temperatures remain below bleaching thresholds.

Sea surface temperatures are mostly average to slightly above average, with the warmest temperatures found in the Cairns–Cooktown region and at inshore and mid-shelf areas in the central and southern areas.

The Bureau of Meteorology moved its ENSO outlook to inactive, indicating an end to the 2020–21 La Nina event.

A subtropical low is forecast to develop over the central Coral Sea on Friday or Saturday, however it is not expected to become a severe tropical storm.

The Bureau of Meteorology continues to forecast warmer than average conditions and above average sea surface temperatures between April and June, particularly in the northern tropics.

Rainfall over the next three months is also likely to be above average for large parts of north-eastern Australia, however this signal is mostly from April.

Reef management

Great Barrier Reef Marine Park Authority staff joined industry leaders, experts, and Traditional Owners at the International Crown-of-thorns Starfish Forum in Cairns this week to discuss latest research findings and strategies for improved management.

Compliance flights conducted between Cooktown and Princess Charlotte Bay (26 to 28 March) observed no signs of coral bleaching on offshore reefs and only low to moderate bleaching on some inshore and mid-shelf reefs.