Varying effects of anadromous sockeye salmon on the trophic ecology of two species of resident salmonids in southwest Alaska

摘要: SUMMARY 1. Anadromous salmon transport marine-derived nutrients and carbon to freshwater riparian ecosystems upon their return natal spawning systems. The ecological implications of these subsidies on the trophic ecology resident fish remain poorly understood despite broad recognition potential importance. 2. We studied within-year changes in ration size, composition stable isotope signature diets two salmonids (rainbow trout, Oncorhynchus mykiss; Arctic grayling, Thymallus arcticus) before after arrival sockeye (Oncorhynchus nerka) grounds Bristol Bay region southwest Alaska. 3. Ration size energy intake increased by 480–620% for both species arrived. However, cause increases differed between such that rainbow trout switched consuming eggs, flesh blowflies colonized carcasses, whereas grayling primarily ate more benthic invertebrates were presumably made available because physical disturbances salmon. 4. also observed an increase d 15 N post-salmon, but not grayling. This led with increasing body mass, 5. Using a bioenergetics model, we predicted salmon-derived resources contributed large majority necessary growth this community. Furthermore, model showed how seasonal diet affected ratios species. These results expand growing literature highlights different pathways whereby anadromous influence coastal ecosystems, particularly fish.