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Evaluating the reintroduction potential and limiting factors associated with anadromous fish reintroductions in the Upper Lewis River, WA

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By Northern Rocky Mountain Science Center April 12, 2016

Hydropower facilities on the Lewis River, WA eliminated historic runs of anadromous species to the headwaters of the Lewis River. As anadromous reintroductions are considered and implemented, there remains considerable uncertainty in the viability of reintroductions in reservoir and tributary systems where large populations of non-native species persist and where spawning and rearing habitat may be limited. Further, little information exists regarding how anadromous reintroductions may affect Threatened bull trout (salvelinus confluentus). This project is evaluating the reintroduction potential of Chinook salmon (oncorhynchys tshawytscha), coho salmon (O. kisutch), and steelhead (O. mykiss) into Merwin and Yale Lakes and concomitantly the interactions between reintroduced populations on native, resident populations of bull trout and cutthroat (O. clarkii clarkia) in Swift Reservoir.

Hydropower facilities on the Lewis River, WA eliminated historic runs of anadromous species to the headwaters of the Lewis River. As anadromous reintroductions are considered and implemented, there remains considerable uncertainty in the viability of reintroductions in reservoir and tributary systems where large populations of non-native species persist and where spawning and rearing habitat may be limited. Further, little information exists regarding how anadromous reintroductions may affect Threatened bull trout (salvelinus confluentus). This project is evaluating the reintroduction potential of Chinook salmon (oncorhynchys tshawytscha), coho salmon (O. kisutch), and steelhead (O. mykiss) into Merwin and Yale Lakes and concomitantly the interactions between reintroduced populations on native, resident populations of bull trout and cutthroat (O. clarkii clarkia) in Swift Reservoir.