Evaluation of juvenile salmonid outmigration and survival in the lower Umatilla River Basin: annual report, 1998-1999

摘要

Large runs of salmon (Oncorhynchus spp.) and steelhead (O. mykiss) once supported productive Tribal and sport fisheries in the Umatilla River. By the 1920s, unscreened irrigation diversions, reduced in-stream flows, poor passage conditions, and habitat degradation had extirpated the salmon run and drastically reduced the summer steelhead run (CTUIR and ODFW 1989). Reintroduction of chinook salmon (O. tshawytscha) and coho salmon (O. kisutch) and enhancement of summer steelhead populations in the Umatilla River was initiated in the early and mid-1980s (CTUIR and ODFW 1989). Measures to rehabilitate the fishery and improve flows in the Umatilla River are addressed in the original Northwest Power Planning Council's Columbia River Basin Fish and Wildlife Program (NPPC 1987). These include habitat enhancement, hatchery production, holding and acclimation facilities, flow enhancement, passage improvement, and natural production enhancement. Detailed scope and nature of the habitat, flow, passage, and natural production projects are in the Umatilla River basin fisheries restoration plans (CTUIR 1984; Boyce 1986). The Umatilla Hatchery Master Plan (CTUIR and ODFW 1990) provides the framework for hatchery production and evaluation activities. Many agencies cooperate, coordinate, and exchange information in the Umatilla basin to ensure successful implementation of rehabilitation projects, including the Oregon Department of Fish and Wildlife (ODFW), the U.S. Bureau of Reclamation (USBR), the Bonneville Power Administration (BPA), National Marine Fisheries Service (NMFS), Oregon Water Resources Department (OWRD), the Confederated Tribes of the Umatilla Indian Reservation (CTUIR), and local irrigation districts (West Extension, Hermiston, and Stanfield-Westland). The Umatilla River Operations Group and the Umatilla Management, Monitoring and Evaluation Oversight Committee coordinate river and fisheries management and research in the Umatilla River basin.