NOAA - Marine Heatwave Confirmed Along GBR From Torres Strait To Brisbane (In Mid-Winter)

A marine heatwave has broken out along more than 2,000km of the Queensland coast, raising concerns for the health of corals on the Great Barrier Reef and other ocean life. Satellite data managed by the US National Atmospheric and Oceanic Administration (NOAA) shows the heatwave started to emerge at the end of June.

About 1m sq km of ocean north-east of the continent are now under heatwave conditions, the data shows. Experts said the heatwave could increase the risk of coral disease and would probably affect fish populations that would need to work harder to find food under warmer conditions.

The Bureau of Meteorology briefed the Great Barrier Reef Marine Park Authority (GBRMPA) about the raised ocean temperatures on Friday. A marine heatwave happens when temperatures over an area are in the hottest 10% ever recorded for that time of year and then stay there for at least five days. The NOAA data goes back to 1981.

Experts said the impacts of marine heatwaves in the winter are less dramatic than in summer, when they can damage or kill corals and underwater forests of kelp and seagrass. Dr Alex Sen Gupta, an associate professor at the UNSW Climate Change Research Centre and marine heatwave expert, said: “If you look globally, we’re seeing more marine heatwaves now than we have ever seen before. “It’s exceptional at the moment. It’s definitely warm in the [water] north-east [of Australia]. There’s bound to be impacts to animals and plants because of these warmer temperatures.”

EDIT

https://www.theguardian.com/environment/2023/jul/22/marine-heatwav-in-north-east-queensland-sets-off-alarm-over-health-of-great-barrier-reef