Variation in Salmon Migration Phenology Bolsters Population Stability but Is Threatened by Drought.

ABSTRACT: Intrapopulation variation in movement is common in nature but its effects on population dynamics are poorly understood. Using movement data from 3270 individually-marked fish representing nine cohorts of coho salmon (Oncorhynchus kisutch) in California, we show that bimodal intrapopulation variation in the timing of juvenile down-migration from their natal habitat and subsequent residence in non-natal habitat affects growth, emigration timing, and the abundance and stability of adult returns. Non-natal fish (early down-migrants) exhibited more variable growth and more variable but earlier emigration to the estuary than natal fish (late down-migrants). While natal rearing was more common, non-natal fish were overrepresented among adult returns, and total returns were 1.4 times more stable t

SUBMITTER: Baker HK 

PROVIDER: S-EPMC11848020 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature