Age and Length Composition of Columbia Basin Spring and Summer Chinook Salmon at Bonneville Dam in 1993
Abstract
Representative samples of the 1993 Columbia Basin spring and summer Chinook populations were obtained at Bonneville Dam. This year marked the seventh year spring Chinook, and fourth year summer Chinook salmon were 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. Five-year-old fish were estimated to comprise 53% of the spring Chinook and 39% of the summer Chinook population. Four-year-old fish were estimated to comprise 45% of the spring Chinook and 47% of the summer Chinook population. Two-, three-, and six-year-old fish were estimated to comprise the remaining 2% of the spring Chinook, and 14% of the summer Chinook population. Difference in age class returns were used to predict spring Chinook population sizes for 1994.
Authors
Citation
Fryer, J.K. and M. Schwartzberg. 1994. Age and length composition of Columbia Basin spring and summer Chinook Salmon at Bonneville Dam in 1993. Columbia River Inter-Tribal Fish Commission Technical Report 94-1. Portland, OR. 37p.