Fishery and Hatchery Effects on an Endangered Salmon Population with Low Productivity

We estimated the natural spawner–fry stock–recruitment relationship and juvenile survival rates for Sacramento River winter Chinook Salmon Oncorhynchus tshawytscha in California and used these estimates to examine the expected numbers of spawners and fishing mortality under different fishing mortality rates and levels of hatchery supplementation. A stochastic, age-structured population dynamics model was fit to fry and female spawner abundance data for the years 1996–2010. Estimated survival rates of fry through the end of the first year in the ocean were generally Received February 21, 2013; accepted December 14, 2013.