Boat noise hampers orcas’ hunting ability

The noise from passing ships is hindering the ability of orcas to find their prey in the Pacific Northwest. Orcas use ultrasonic echolocation to hunt fish—they communicate and coordinate their hunting through clicks. Researchers placed tracking and noise recording devices on northern and southern resident killer whales in the Salish Sea that sits between British Columbia and Washington state between 2009 and 2014. They found that louder ship noise resulted in longer hunting times for the orcas (Orcinus orca). “Vessel noise negatively impacts every step in the hunting behavior of northern and southern resident orcas: from searching to pursuing and finally capturing prey,” said lead author Jennifer Tennessen, a senior research scientist at the University of Washington’s Center for Ecosystem Sentinels, in a press release. “It shines a light on why southern residents in particular have not recovered. One factor hindering their recovery is availability and accessibility of their preferred prey: salmon. When you introduce noise, it makes it even harder to find and catch prey that is already hard to find.”

Read more at Mongabay.