Spawning Distribution of Fall Chinook Salmon in the Snake River : Annual Report 2000.
From 1997 to 2000, we collected data on the spawning distribution of fall chinook salmon above Lower Granite Dam as part of a five-year evaluation of three acclimation/release facilities: Pittsburgh Landing, Captain John, and Big Canyon Creek. The use of multiple facilities is intended to distribute spawning throughout the habitat normally used in the Snake and Clearwater rivers, and our study was designed to determine if this is achieved. In the Snake River, spawning normally occurs throughout a 100 mile reach. Pittsburgh Landing is located within the upper half of this reach, and Captain John is located within the lower half. In the Clearwater River, most spawning occurs within the lower 41 miles and the Big Canyon Creek facility is located therein. Our approach for determining spawning distribution was to first trap returning fish at Lower Granite Dam, identify their origin (all yearling fish were externally marked before they were released), and use radio tags and redd searches to determine where they spawned. Thus far we radio tagged 203 adult fish that were initially released at the acclimation sites. We confirmed the spawning location of 74 of these fish, 42 from releases at Pittsburgh Landing, seven from Captain John, and 25 from releases at the Big Canyon Creek facility. All of the fish from Pittsburgh Landing spawned in the Snake River, 86% within the upper half of the Snake River study area, and 14% in the lower half. Of the adult fish from Captain John, roughly 71% spawned in the lower half of the Snake River study area, 14% spawned in the upper half, and 14% spawned in the Clearwater River. Of the adult fish from releases at Big Canyon Creek, 80% spawned in the Clearwater River and 20% spawned in the Snake River (four in the lower half and one in the upper half). To augment the study, we determined the spawning locations of 16 adult fish that were directly released as subyearlings at or near the three acclimation sites. Ten of the fish were from Pittsburgh Landing, three from Big Canyon Creek, and three from the Captain John area. All of the fish from Pittsburgh Landing spawned in the Snake River (nine in the upper half, and one in the lower half). All of the fish from Big Canyon Creek spawned in the Clearwater River, and all of the fish from Captain John area spawned in the lower half of the Snake River study area. We also tagged and tracked six adult natural fish. These fish were initially captured and PIT-tagged in the Snake River when they were juveniles, and, based on our observations, all spawned in the Snake River and did not wander into other rivers after crossing Lower Granite Dam. Our results indicate that the supplementation program will accomplish its objective in terms of spawning distribution, although currently the sample size for some groups is too small for the results to be conclusive. To finish the study we plan to tag 340 fish in the fall-winter of 2001-2002, and complete the final report by November 2002.
- Research Organization:
- Bonneville Power Administration, Portland, OR (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- 00004700
- OSTI ID:
- 799226
- Report Number(s):
- DOE/BP-00004700-1; TRN: US200221%%2030
- Resource Relation:
- Other Information: PBD: 1 Aug 2001
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fall Chinook Acclimation Project; Pittsburg Landing, Captain John Rapids, and Big Canyon, Annual Report 2002.
Fall Chinook Acclimation Project; Pittsburg Landing, Captain John Rapids, and Big Canyon, Annual Report 2003.