Scientists from Scripps Institution of Oceanography at the University of California San Diego were able to ‘hear’ the impacts of a marine heatwave and even economic slowdowns by analyzing 15 years of ocean sounds recorded off the coast of Southern California. The recordings, collected between 2008 and 2023, allowed researchers to hear whales moving north in response to a marine heatwave that began in 2014 as well as the massive decrease in noise from container ships during the 2008 financial crisis. The findings, published June 5 in the Journal of the Acoustical Society of America, show that listening to the sea can be a tool for monitoring ocean ecosystems and even human economic activity. … The findings show how ocean soundscapes can serve as a near real-time monitoring system for marine ecosystem health, providing early warning of species displacement and habitat shifts due to climate change and increasingly frequent marine heatwaves.