Technical Abstract: We examined how biomass of marine-derived nutrients (MDN), in the form of spawning Pacific salmon, influenced the nutritional status and nitrogen stable isotope ratios (d15N) of stream-dwelling fishes. We sampled coho salmon (Oncorhynchus kisutch) parr and juvenile Dolly Varden (Salvelinus malma) during spring and fall from 11 south-central Alaskan streams that varied widely in spawning salmon biomass (0.1 to 4.7 kg m-2). Growth rate (as indexed by RNA-DNA ratios), energy density, and d15N enrichment in spring-sampled fishes increased with spawner biomass, indicating the persistence of spawner effects >6 months after salmon spawning. Point estimates suggest that spawner effects on nutrition were substantially greater for coho salmon than Dolly Varden (268% and 175% greater for growth and energy, respectively). Although the data were less conclusive for fall- than spring-sampled fish, they do suggest spawner effects were also generally positive during fall, soon after salmon spawned. In a follow-up analysis where growth rate and energy density were modeled as a function of d15N enrichment, results suggested that both increased with MDN assimilation, especially for coho salmon. Despite the variation in geomorphic features, ambient nutrient levels, and species composition of spawning salmon at our sites, spawner biomass appears to be an important factor in determining growth and energy among stream-dwelling fishes. Our results highlight the importance of maintaining large salmon runs in systems where the maintenance or recovery of stream-dwelling salmonid populations is a priority.