Determining Winter Habitat and Juvenile Coho Salmon Growth Relationships in the Russian River Watershed, California

Winter habitat availability is a limiting factor for juvenile coho salmon within the southern extent of their range. However, the type of habitat limitation can vary across streams and watersheds: stream flow, food availability, and in-stream shelter could all impact the quality of habitat depending on land use, underlying geology, and watershed latitude.  Lack of overwintering habitat may especially limit survival, growth, and population recovery efforts since overwintering is an essential part of the coho salmon life cycle. Determining environmental predictors of juvenile coho salmon overwinter growth could help identify habitat limitations to growth and prioritize restoration and conservation efforts. Predictive habitat-fish models will be created for coho rearing streams in the Russian River watershed in Northern California. Preliminary habitat metrics including in-stream shelter, stream channelization, canopy coverage, water temperature, and macroinvertebrate biomass are being collected across streams and will be compared to overwinter coho salmon growth data from spring run downstream migrant smolt traps. Preliminary models will help determine the best combination or individual environmental predictor variables for future winter fish-habitat relationships and continued coho salmon recovery measures in the watershed