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 - 22 January 2021


Like the past two weeks, cloud cover continues to restrict the ability of satellites to accurately measure sea surface temperatures over much of the Reef and modelled data showing warmer areas should be interpreted with caution.

Where observations were possible in recent days, sea surface temperatures remain close to, or below, the long-term monthly average in the south and central Reef and above average in the far northern Reef. Temperatures are currently below bleaching thresholds.

We continue to receive situational reports on Reef health, and we will monitor conditions on the Reef as the summer unfolds.

As usual, local and regional weather conditions over the next few weeks will play a key role in determining overall outcomes for the Reef this summer.


The current La Niña event has likely now reached its peak, with a gradual easing expected near the end of the first quarter of 2021. We may see above-average rainfall in eastern and northern Australia into early autumn.

Ex-tropical cyclone Kimi was the first tropical cyclone to form within the Marine Park during the 2020-2021 season, bringing cloud cover and rainfall to parts of the Reef and tropical north coast.

Reef health

Recent reports made through Eye on the Reef indicate mostly scattered, isolated cases of minor coral bleaching within the Marine Park.

The Australian Institute of Marine Science long-term monitoring surveys are currently underway in the Cairns and Innisfail Sectors, with early reports from Cairns indicating only very low-level bleaching observed.

The Reef Joint Field Management Program commenced in water observations this week to reefs between Cairns and Raine Island, with reports on observations of Reef Health to follow.