Declining Chinook salmon (Oncorhynchus tshawytscha) abundance across the Pacific Northwest is an issue of great concern ecologically, culturally, and economically. Growth and survival during the first summer is vitally important to juvenile Chinook as it influences not only life history decisions (to smolt or not to smolt) but also subsequent river and ocean survival. Working with scientists from NOAA’s Northwest Fisheries Science Center, I developed a food web model using Ecopath with Ecosim of a representative stream in the Salmon River basin to evaluate potential species-specific and food web effects of three management strategies: (1) adding carcasses or carcass analogs to promote primary production and detrital availability lost due to declining salmon returns, (2) removal of invasive brook trout (Salvelinus fontinalis) that are both competitors with and predators on juvenile Chinook salmon, and (3) stocking hatchery fish into streams to supplement wild production.

Overall, juvenile Chinook salmon responded strongly to increases in basal resources. Removing brook trout had little effect on potential production for juvenile Chinook salmon, but sculpin (Cottus spp.) responses were strong, primarily due to the high degree of diet overlap and predation by brook trout on sculpin. Supplementation with hatchery-origin juveniles depressed production of wild juvenile Chinook, especially at the densities commonly applied in streams in this region. Our results suggest that efforts to enhance basal resources are likely to be most effective in promoting juvenile Chinook salmon production, along with nearly all groups in our model system. Removal of invasive brook trout is unlikely to substantially affect salmon but could have a disproportionately large effect on non-game species that are generally overlooked in single species management approaches.