West coast reefs warming up

Scientists are keeping a close eye on reefs along the west coast of Australia, with sea surface temperatures reaching levels where some coral bleaching is occurring. 

The thermal stress has been accumulating over the high-risk summer period and is expected to continue until April, according to forecasts from the Bureau of Meteorology (BoM). 

Australian Institute of Marine Science’s (AIMS) coral ecologist Dr James Gilmour said the areas of concern include reefs in the Pilbara, Ningaloo, Shark Bay and the Abrolhos.

“Low level bleaching has already been observed in parts of Exmouth Gulf and in the Dampier Archipelago, which were reported by officers from the Department of Biodiversity Conservation and Attractions (DBCA),” he said.

 “While cloud cover and rainfall from a recent tropical low has reduced some heat stress, the risk of bleaching will continue in the coming weeks in central to southern Western Australian reefs.”

The recurring threat of bleaching to WA coral reefs has galvanised collaborative efforts across government and research institutions, drawing on the most current observations and forecasts based on data provided by BoM, National Oceanic and Atmospheric Administration (NOAA), CSIRO, the Integrated Marine Observing System (IMOS) and the University of Western Australia (UWA).

“In the coming weeks, we’ll have many eyes on the reef to report coral bleaching and in-water surveys will be conducted by several research agencies, including AIMS, DBCA and CSIRO,” Dr Gilmour said.

“This week we are conducting in-water surveys around Ningaloo – this monitoring will extend to other reefs at risk in the coming weeks.

“We are encouraging people who are visiting these reefs to download our app ArcGIS Collector and report any sightings of coral bleaching.”  

Currently, on the other side of Australia, temperatures are below bleaching thresholds for the most part of the Great Barrier Reef.

The 2020-2021 summer has been characterised by a La Niña event, which is forecasted by BoM to last until Autumn. 

This climate driver has meant above average rainfall has been likely for eastern and some northern parts of Australia, meaning a lower risk of bleaching in the Kimberley and the Great Barrier Reef.