May 9, 2023--For the second time this century, there will be no commercial or recreational fishing for salmon in California waters. To find out what caused the decline of Chinook salmon here, we turn to Dr. Nathan Mantua of the NOAA Fisheries Science Center. Dr. Mantua brings us the big picture, describing how the complex life cycle of these great fish exposes them to threats from changes in rivers and in the Pacific ocean. It's a remarkable story with a surprising twist, as a seemingly healthy ocean producing abundant anchovies is leading to a vitamin deficiency that kills the young fish.