Restoring Sockeye Salmon to the Deschutes River Basin, Oregon

The Deschutes - Metolius River Basin in north Central Oregon was historically home to a run of Sockeye salmon (Oncorhynchus nerka). This run was extirpated in the last century, primarily due to passage issues to Suttle Lake, the natal nursery lake located 157 river miles upstream from the Columbia River.   The Pelton Round Butte Hydroelectric Complex, a series of three hydroelectric dams and their resultant reserviors, was constructed in 1957-1964 at river mile 100 on the Deschutes River.  Lake Billy Chinook (LBC) is the uppermost and largest of the three reservoirs and currently supports a naturally spawning population of kokanee (landlocked sockeye salmon).  Efforts are currently in process to develop an anadromous sockeye salmon population from the established resident populations of kokanee, utilizing the newly constructed Surface Water Withdrawal / Fish Transfer Facility in the forebay of LBC and / or Suttle Lake.  In spring 2009, a small number of O. nerka smolts (981) were collected at the outlet of Suttle Lake and released into the lower Deschutes River downstream of the PRB Project.  In spring 2010, approximately 50,000 smolt-size O. nerka were captured at the and released into the lower Deschutes River.   Adult returns from these smolt releases are expected beginning in 2011 and 2012.  Ultimate success of this reintroduction will require informed management decisions, particularly information about the status and trends of the kokanee populations in the LBC / Suttle Lake system that are being used to support the efforts. Current and ongoing data collection of kokanee population dynamics include spawning escapement of LBC kokanee into the Metolius River, juvenile outmigration from Suttle Lake and LBC, reservoir recruitment of juveniles to LBC, hydroacoustic surveys, and genetic analyses. All these data will contribute to attempts of creating a life history model of O. nerka in the Deschutes Basin. This presentation summarizes past data collection efforts, present population statuses, future goals, and a discussion of the many challenges faced by fisheries managers in the Deschutes River Basin.