Cooler weather is expected to reduce the threat of mass bleaching on the Great Barrier Reef this summer.

Cloud and rain in recent weeks has caused “substantial cooling” of heat-stressed corals, according to the Great Barrier Reef Marine Park Authority (GBRMPA). 

There has been strong concern that the Reef would suffer its sixth major mass bleaching outbreak this summer after record high temperatures in December, but this has given way to cautious optimism that it may now escape a major event. 

“While the forecast for the rest of the month remains for above average temperatures, it is expected this will only be about half a degree warmer,” GBRMPA says.

“The current thermal anomaly and the forecasts have resulted in a diminished risk of mass bleaching on the reef this summer.”

Still, the authority warns that weather over the next few weeks will be “critical in determining the final outcome”.

Last year, UNESCO called for the reef to be placed on the World Heritage Committee’s list of sites “in danger”, but this was rejected by the committee. 

It will reconsider the reef’s plight at a meeting scheduled for July in Russia.