The objective of this project is to enrich the nutrient base in the South Fork Nooksack ecosystem through dispersal of hatchery derived salmon carcasses. Dramatic decreases in salmonid spawner abundances have reduced MDN inputs to freshwater ecosystems, leading to diminished stream productivity and initiating a negative feedback loop that contributes further to salmonid decline. This project will be implemented according to WA Dept. of Fish and Wildlife and National Marine Fisheries Service Guidance. Nooksack Displaced workers will collect, freeze and stor a portion of the hatchery carcasses at a commercial cold storage facility beginning in late fall 2002 while the remaining portion will be distribued immediately without freezing. From November 2002 through March 2003, Nooksack workers will disperse approximately 12,000 carcasses to reach a target density of approximately 600 carcassess per mile within the project reach specified by WDFW. Actual dispersal quantities are dependent upon returning salmon to hatcheries in the fall. The carcassess will be tahhed and released from four access points along the South Fork Nooksack River (RM13, 20, 25, and 30). Since thawed carcassess typically settle out within oone mile whereas frozen carcasses float drift further downstream, a mix of frozen and thawed carcassess will be used to ensure adequate distribution throughout the reach. Landowners and other interested parties will be informed before implementation with a press release and signage at dispersal points. Nutrient enrichment through carcass dispersal benefits a variety of terrestrial and aquatic organisms. Salmonids directly consume both eggs and carcasses; in one study for example, MDN increased as much as 39% in the muscle tissue of juvenile salmonids following carcass placement (Bilby et al 1998). Carcasses that are not directly consumed provide indirect benefit through incorporation into trophic pathways, which leads to increased productivity. Sections of the South Fork Nooksack proposed for carcass enrichment provide transportation, holding, rearing and spawning habitat for chinook fry and yearling spring chinook, abundances of which are critically low in the South Fork Nooksack. Since increased survival of salmonids in both freshwater and marine enfvironments is assoicaited with larger sizes, augmentation of the food base for juvenile salmonids rearing in these reaches is likely to increase smolt production from the South Fork Nooksack. Other species can alos benefit from carcasses deposited by floods in the terrestrial envirnoment; Cederholm et al. (1989) found at least 22 species of birds and mammals that depend on salmon carcasses as a food source. Project monitoring: Carcasses will be marked prior to dispersal so that they can be identified in the field. Dispersal will be monitorined with foot survey by displaced workers and the restoration coordinator, during which carcass location will be mapped. Data will be used to qualitatively ascertain within reach retention and extent of movement downstream. In addition, data from ongoing screw trap operations will be used to compare smolt length, survival and % MDN between years with and without carcass enrichment. Such comparison is necessarloily qualitative as differences in growth and survival are confounded by a host of other factors. Watershed Analysis reference: This reach of the South Fork Nooksack between RM12 and 31 has the highest density of South Fork chinook spawning, Juvenile salmon rear throughout these waters, with coho and spring chinook having year round habitation. United States Fish and Wildlife Service, Partners for Fish and Wildlife Grant Number 134100027
