Adult Returns of Volitionally Migrating and Pond-Sedentary Hatchery-Reared Steelhead Smolts

Abstract

Adult return rates of steelhead Oncorhynchus mykiss that volitionally emigrated as smolts were compared with those of pond-sedentary juveniles forced from a raceway after being allowed 6 weeks of volitional migration opportunity. In 5 years of releases, an average of 7.2% of the smolts remained in the raceway after the volitional migration opportunity. Adult returns of volitional and pond-sedentary fish were statistically similar in all but 1 year of release; in that year, pond-sedentary returns were significantly greater than those from the volitional release. The results suggest that pond-sedentary juvenile steelhead should not be destroyed or placed in nonanadromous waters out of concern for poor adult survival.