The unpredictability and variation in adult recruits for Fraser sockeye both within and among major stocks cause challenges for harvest planning and rebuilding initiatives. This multi-year project will monitor and analyze variation in biological condition of juvenile sockeye in fresh water to understand variation in stock-specific survival. This project will apply and extend the results from a previous SEF juvenile sockeye research project that found stock-specific energetic condition of juveniles reflects variation in lake primary productivity and density of juveniles within a natal rearing lake. Moreover, mechanistic links to survival were developed, such as, interannual variability in fall-fry and smolt energetic condition are consistent with density-dependent growth and survival, critical minimal energy levels are associated with swim performance and potentially survival, and interannual and stock-specific variability in the portion of individuals at or near these critical energy levels. We propose to extend and apply these results by strategically assessing stock-specific variability in biological condition of juvenile salmon from key Fraser sockeye stocks.
