An unlikely source is revealing some secretive habits of whales: the group tasked with monitoring nuclear weapons testing. The underwater hydrophone network of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) was designed to listen for massive explosions, but its sonic sensors more often pick up the peaceful rumblings of the world’s largest animals. Now scientists are exploiting this unique data set to estimate fin whale population sizes and movements, which could improve the species’ uncertain conservation prospects.
