The U.S. Fish and Wildlife Service has counted 160,000 juvenile winter-run Chinook salmon in the Sacramento River this year, down from an average of 1.3 million.
A study directed by Daniele Tonina, an ecohydraulics professor at the University of Idaho, finds that spawning areas for Chinook salmon in Bear Valley Creek are disappearing due to slower rivers and lower water levels.
Warming waters and a series of dams are making the grueling migration of the Chinook salmon even more deadly — and threatening dozens of other species.
