New research led by the University of Washington and the National Oceanic and Atmospheric Administration has revealed how underwater noise produced by humans may help explain why southern resident orca populations have not recovered from historic lows. In a paper published Sept. 10 in Global Change Biology, the team reports that underwater noise pollution — from both large and small vessels — forces northern and southern resident orcas to expend more time and energy hunting for fish. The din also lowers the overall success of their hunting efforts. Noise from ships likely has an outsized impact on southern resident orca pods, which spend more time in parts of the Salish Sea with high ship traffic.
