Jeffery Rutter, University of Washington, School of Aquatic and Fishery Sciences
James Anderson, University of Washington, School of Aquatic and Fishery Sciences
Richard Zabel, NOAA, Northwest Fisheries Science Center
This project will develop a theoretical framework for identifying the mechanisms influencing marine carrying capacity for juvenile salmon. It will analyze tagging and run-size databases and will develop and test new models to determine whether adult return numbers are related to smolt production in Chinook populations in the Columbia River basin. The results will inform management strategies to improve the outlook for wild salmon. Though the study focuses on Columbia River Chinook, its theoretical framework will apply to all anadromous fishes.
A central element of many strategies for recovering wild salmon populations has been to increase production of outmigrating smolts and larger juveniles in hatcheries. However, these increases appear to have had little effect on the number of adults returning. This suggests that density-dependent processes limit the production of adults.