Analysis finds endangered orcas eat range of Chinook salmon

SEATTLE – A new analysis shows the endangered orcas that spend time in Washington state waters depend on Chinook salmon from a wide range of rivers in Puget Sound as well as along the West Coast.

The Seattle Times reports that the whales eat Chinook salmon from rivers in Puget Sound, including urban rivers such as the Duwamish and Puyallup. Also important are Chinook runs from the Fraser River in British Columbia, the Columbia and Snake rivers, and the Sacramento River in California’s Central Valley.

Scientists from NOAA Fisheries and the Washington Department of Fish and Wildlife used drone surveys and DNA analysis of poop and food scraps to rank the relative importance of rivers for the orcas’ diet.

The orcas eat mostly Chinook salmon, rather than marine mammals. They’re struggling in part because they don’t have enough food to eat.