Modelling migratory behaviour and habitat use of fish in a large, uninterrupted river network: A case study of a migratory salmonid

Abstract Bull trout ( Salvelinus confluentus ) research has historically focused on highly impacted systems or occurred in a reactionary manner following overharvest. Here, we used telemetry and multi‐state capture–recapture modelling to inform management decision‐making for this migratory, conservation‐listed species British Columbia's upper Fraser River watershed (UFW). Our work reduced critical information gaps surrounding the seasonal migration patterns, distribution, survival rates of fluvial bull within region. By using results an existing microsatellite DNA analysis, were able assign each tagged individual one five spawning populations. This assignment allowed us investigate potential differences migratory behaviour habitat use among different We identified that majority UFW made repeated, long‐distance migrations (>300 km direction) appropriate spawning, overwintering foraging habitats. The populations did not vary their transition probabilities at spatial scale investigated, suggesting key habitats are important multiple also detected post‐spawning distribution patterns suggest exploit resource pulses during salmon smolt outmigration. highlight importance protecting, restoring maintaining diverse assemblage complex natural connections between them (e.g. tributary larger rivers) supports life histories. provides valuable prioritizing conservation actions identifying restoration opportunities both across species' range.