Using Hatchery Supplementation to Sustain Fisheries In a Barrier-Constrained River System

The Upper Yakima River in south-central Washington State, USA is heavily managed for irrigation with three major storage reservoir dams in the upper watershed and five major irrigation diversion dams in the lower watershed.  In addition, salmon from the Yakima River encounter 4 major hydroelectric dams on the Columbia River while migrating to and from the Pacific Ocean.  Not surprisingly, salmon populations in the Yakima River were severely depressed with many populations extirpated by the mid-1980s.  To reverse salmon declines in the Yakima River Basin, the Yakama Nation and collaborators are using a combination of hatchery supplementation and habitat restoration.  The Cle Elum Supplementation Research Facility (CESRF) spring Chinook (O. tshawytscha) salmon hatchery program began in 1997. This program was designed to test whether artificial propagation can be used to increase natural production and harvest opportunities while limiting ecological and genetic impacts (RASP 1992). It is an integrated hatchery program (Mobrand et al. 2005) because only natural-origin broodstock are used and returning hatchery-origin adults are allowed to spawn in the wild. The program uses the adjacent, unsupplemented Naches River population as an environmental and wild control system.  This talk will present results to date from this innovative project.