This project intends to mitigate marine-derived nutrient loss resulting from salmon extinction due to hydro project development in the Boise subbasin.  We will substitute the natural nutrient cycle provided by returning anadromous fish through application of anadromous fish carcasses and salmon analogs.  To determine nutrients lost, we will treat 500m segments of small (2-3 meters wide) streams with either pasteurized fish carcasses (at roughly .5 carcasses/m2) and fish analogs and compare to control streams.   All treatments will be adding roughly 27.5g N/m2 and 5.5g P/m2 for 500 meters.  Subsequent to application of nutrient treatment, we will monitor aquatic, vegetative, and terrestrial food webs using isotope analysis of sampled species.  Data will be used to model the relative effectiveness and effects of carcass and analog treatments on ecological food webs.  We are also researching possible appropriate inorganic fertilizers to test. The results of the model will be used to choose the final mitigation treatment type most appropriate for the Boise system.