By Abbey Cannan
A study by an international team of researchers including The University of Western Australia reveals the damage marine heatwaves are causing to the marine environment wherever they occur.
The research, published today in Nature Climate Change, is the first to use the same methods and metrics to quantify and contrast the magnitude and impact of several prominent marine heatwaves. It demonstrates periods of extreme temperatures can cause rapid loss of marine habitat, local extinctions, reduced fisheries catch and altered ocean food webs.
One of the lead authors, Associate Professor Thomas Wernberg, from UWA’s Oceans Institute and School of Biological Sciences, said the study demonstrated that regardless of where marine heatwaves had occurred, they had negative and often detrimental effects on all kinds of marine organisms, including plankton, seaweed, coral, fish, birds and mammals.
“The study identifies species and ecosystems at their warm range margins as being particularly at risk, which is perhaps not surprising as they live close to their upper thermal tolerance,” Associate Professor Wernberg said.
“The major concern is that the oceans have warmed significantly as a consequence of man-made climate change, so that marine heatwaves have become more frequent. Just as atmospheric heatwaves can destroy crops, forests and animal populations, marine heatwaves can devastate ocean ecosystems.
“Across Australia we have seen severe impacts of extreme events and marine heatwaves for a range of locations and organisms – coral reefs, mangroves, seagrass beds and kelp forests have all been severely impacted in recent years.”
The authors conclude that climate change will continue to increase the severity of marine heatwaves, and the associated impacts on marine biology could have far-reaching consequences for marine ecosystems and the many benefits humans derive from the oceans.