September 11, 2024 — The Salish Sea—the inland coastal waters of Washington and British Columbia—is home to two unique populations of fish-eating orcas, the northern resident and the southern resident orcas. Human activity over much of the 20th century, including reducing salmon runs and capturing orcas for entertainment purposes, decimated thei4rrrr numbers. This century, the northern resident population has steadily grown to more than 300 individuals, but the southern resident population has plateaued at around 75. They remain critically endangered.
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 the southern residents’ plight. 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 fis