Researchers at the University of New Hampshire have developed a new method for measuring the impacts of marine heatwaves to provide more detailed information about their effects on marine life.
The study, published in the Journal of Animal Ecology, examined how researchers can better understand the impacts of marine heatwaves and calculate the survival rate of marine organisms. The researchers said the new methods are needed because marine heatwaves are becoming more frequent as climate change progresses.
“Traditional statistical methods fall short because they ignore the biological responses of organisms,” said Easton White, a scientist at the New Hampshire Agricultural Experiment Station. “Our physiological framework, which we present in this paper, takes into account how marine organisms respond to both the intensity and duration of heat stress and provides a much clearer understanding of the deadly effects of marine heat waves.”
It is already known that marine heatwaves have impacts on marine life, which have had a direct impact on the fishing industry.
A 2019 Northeast Pacific heatwave known as the “Blob” impacted fish stocks in Alaska’s Bering Sea. The Blob had severe negative consequences for some commercial fisheries, and research showed that the heatwave was responsible for a sharp decline in snow crab in the Bering Sea, forcing regulators to close the fishery for the 2022-2023 season.
White said the new research and strategy could be crucial to predicting the impacts of marine heatwaves and mitigating their consequences.
“By understanding the specific survival thresholds for different marine species, our research can shed light on how different heatwave profiles affect marine life,” said Andrew Villeneuve, a doctoral student in UNH’s marine biology program. “This understanding is key to developing more effective conservation and management strategies to protect vulnerable marine ecosystems.”
The researchers examined both acute marine heatwaves – where there was a sharp increase in temperature for a short period of time – and longer-term, chronic heat events. Their research identified cases where the effects of both long-term heatwaves and short-term heatwaves with higher temperatures overlapped.
“While most research attention has focused on chronic marine heatwaves, we show that more frequent but neglected acute marine heatwaves can also have similar deadly effects,” the researchers write. “Crucially, a statistical definition of marine heatwaves does not accurately categorize biological mortality.”
Understanding the heat waves will help researchers and scientists respond better, the researchers said.
“For example, if a particular marine species is found to be particularly vulnerable to short, intense heat waves, conservation efforts could focus on creating refuges or cooler microhabitats during these heat periods to ensure their survival,” Villeneuve said.
