Standard methods for assessing marine heatwaves may be hiding the scale of global warming: researchers at the Virginia Institute of Marine Science have developed a concept that accounts for warming periods before and after heatwaves, infohub.kz reports.
Scientists from the Virginia Institute of Marine Science (VIMS) and the Batten School of Coastal & Marine Sciences at William & Mary have proposed a new approach to assessing marine heatwaves. The results are published in the journal Communications Earth & Environment. According to ScienceDaily, traditional analysis of isolated temperature spikes ignores prolonged periods of anomalous water warming that occur before and after them.
A team led by Ricardo Utzig Nardi and assistant professor Piero Mazzini analyzed two decades of data from 20 U.S. estuaries, covering more than 2,580 marine heatwaves. They found that periods of elevated temperatures can last for weeks and months, and standard assessment methods underestimate the total thermal impact on ecosystems by an average of more than 150%.
The researchers classified events into two types: "single" events, with a warming period of about 60 days, and "compound" events, lasting about 90 days. Compound events generate three times more thermal load.
The authors emphasize that prolonged thermal exposure exacerbates oxygen depletion and triggers harmful algal blooms, threatening coral reefs and seagrasses. The new approach will allow scientists to plan laboratory experiments more accurately and help environmental agencies protect coastal resources.