Age and Length Composition of Columbia Basin Spring and Summer Chinook Salmon at Bonneville Dam in 1992
Abstract
Representative samples of the 1992 Columbia Basin spring and summer Chinook populations were obtained at Bonneville Dam. 1992 marked the sixth year spring Chinook, and third year summer Chinook Salmon were so sampled. Fish were trapped, anesthetized, sampled for scales and biological data, allowed to revive, and released. The scales were examined to estimate the age of the fish. Four-year-old fish were estimated to comprise 78% of the spring Chinook and 47% of the summer Chinook population. Five-year-old fish were estimated to comprise 18% of the spring Chinook and 34% of the summer Chinook population. Two-, three-, and six-year-old fish were estimated to comprise the remaining 4% of the spring Chinook, and 19% of the summer Chinook population. Difference in age class returns were used to predict spring Chinook population sizes for 1993.
Authors
Citation
Fryer, J.K., and M. Schwartzberg. 1993. Age and length composition of Columbia Basin spring and summer Chinook Salmon at Bonneville Dam in 1992. Columbia River Inter-Tribal Fish Commission Technical Report 93-3. Portland, OR. 36p.