Kym Jacobson (FE), Bob Emmett (FE), David Teel (CB), Paul Bentley (FE)
In an effort to better understand the critical transition that young salmon--including populations listed under the U.S. Endangered Species Act--make as they move between freshwater and marine environments, we have been studying juvenile salmon in migratory corridors of the Columbia River estuary, immediately before they enter marine environments. Our research has shown consistent species- and stock-specific migration patterns, with peak abundance of most yearling salmon (coho, yearling Chinook, steelhead, sockeye) in mid-May and extended migration of subyearling Chinook salmon throughout the summer. Most (>90%) juvenile salmon caught are of hatchery origin and originate from throughout the Columbia River basin.
Weitkamp, L.A., P.B. Bentley, and M. N. C. Litz. 2012. Seasonal and interannual variation in juvenile salmonids and associated fish assemblage in open waters of the lower Columbia River estuary, U.S.A. Fish. Bull., U.S. 110(4):426-450.