Salmonid Population and Life History Research in Tributary Stream and River Habitats and Response to Dam Removal

Science Center Objects

Juvenile anadromous salmonids all spend some portion of their lives in freshwater. This time may vary from days to years depending upon species and run. Spring Chinook Salmon and Coho salmon generally spend one year in freshwater and Steelhead may spend up to five years in freshwater prior to beginning their journey to sea. Several projects at WFRC – CRRL are investigating populations, life-histories, habitat, and potential limiting factors on the freshwater rearing juvenile salmonids. Much data on salmonid ecology and life-histories is gathered through tagging fish with Passive Integrated Transponder (PIT) tags. Instream PIT tag detection systems are a tool we have employed in many watersheds throughout the west and continue to do so in several local watersheds including the Wind River and Rock Creek, WA.

A project in the Wind River, WA is focusing on steelhead populations, life histories, habitat, and limiting factors as part of a multi-agency effort to restore steelhead populations in the Wind River.  These efforts are contributing to a greater understanding of the diversity of Steelhead life-histories and the factors driving different life-history expressions in a wild Steelhead population. Of interest are migratory parr and their fates compared to headwater rearing parr that do not migrate until smolting. Efforts to date have demonstrated that parr Steelhead migrate from headwater rearing areas as young as age-0 and do so throughout the year.

A portion of the Wind River work has focused on interaction between juvenile Steelhead an introduced run of hatchery spring Chinook salmon, which has demonstrated little effect of hatchery Chinook spawning on wild Steelhead populations. Our sampling efforts provide data to inform life-cycle modeling, estimate life-stage specific survival, and identify potential population bottlenecks. Additionally, these data are contributing to evaluation of the Steelhead response to the removal of Hemlock Dam from Trout Creek, which occurred in 2009.

An ongoing project is juvenile salmonid monitoring in the White Salmon River following removal of Condit Dam in 2011. Condit Dam had completely blocked the White Salmon for nearly 100 years. Our goals are to assess smolt production from upstream of rkm 2.3, juvenile salmonid distribution in the watershed, and juvenile salmonid abundance at sites in Buck and Rattlesnake Creeks as natural recolonization occurs. Species recolonizing the White Salmon include Steelhead, Coho salmon, and both spring and fall Chinook salmon. Data collected on populations, behavior, and genetics will help evaluate dam removal as a restoration and conservation strategy, assess the efficacy of a natural recolonization strategy for anadromous salmonids, and inform managers of the status of ESA listed salmonid stocks.

Clearing snow from solar panels

Clearing snow from solar panels which provide power to an instream Passive Integrated Transponder tag detection system in the Wind River, WA. The system detects tagged juvenile and adult Steelhead for population assessment and migratory data. Credit: Brad Liedtke, USGS. (Public domain.)