Yakama Nation Mid-Columbia Coho Reintroduction Programs

By the end of the 20^th century, indigenous natural coho salmon no longer occupied the mid- and upper-Columbia river basins.  Several factors contributed towards this extirpation, which included but not limited to, construction and operation of mainstem Columbia River hydropower projects, habitat degradation, irrigation practices, release locations, harvest management, and hatchery practices. 

Yakama Nation held a vision of coho reintroduction in the Yakima, Wenatchee, and Methow basins.  Studies to determine feasibility of reintroduction in the mid-to-upper Columbia region began in the Methow River basin in 1996, followed by the Yakima and Wenatchee basins in 1999.  Reintroduction for the Methow and Wenatchee basins focused on addressing two key objectives; 1) whether a broodstock could be developed from lower Columbia River coho stocks whose progeny could survive in increasing numbers to return as adults and 2) attempt to initiate natural reproduction in areas of low risk to sensitive species while concurrently studying and determine if there were measurable interaction risks with sensitive species.

Feasibility goals have been met in the Wenatchee and Methow basins and a conceptual master plan was developed to emphasize broodstock development and transition towards natural production using a phased approach.  The phased approach is an attempt to develop a local population over time through encouraging adaptation towards predicted habitats.  Currently, both Wenatchee and Methow basins have reached the second phase of broodstock development and are seeing positive trends towards establishing coho populations through increasing adult returns.  Since the program’s inception, adult coho returns have ranged from 1,751 to 21,905 with a mean of 8,989 fish (as per Rock Island Dam counts).  

Within the Yakima River basin, specific tributaries are the current focus for reintroduction efforts.  Taneum Creek is a moderately sized (fifth order) stream located on the Eastern slopes of the Cascade Range in central Washington State.  Beginning in 2006, research was initiated to investigate spawning success of hatchery coho salmon and their future interactions with resident fish.  Approximately 300 adult hatchery coho salmon were captured and relocated into three, 100 meter sections of Taneum Creek.  Spawner success has ranged from 49% in 2007 to 89% in 2010.  Naturally reared coho parr have been pit tagged each summer to monitor parr-to-smolt survival.  Survival estimates have ranged from 9-13% to McNary Dam.  During the 2010 spring out-migration, approximately 33% of the 1,800 PIT tagged parr were detected leaving the system.