Stream reaches within the Russian River watershed that are expected to provide habitat for juvenile and adult Coho Salmon AND Steelhead Trout. It is expected that all Coho Salmon streams are also inhabited by Steelhead Trout. But not all Steelhead Trout streams are inhabited by Coho Salmon. A separate feature class named "Steelhead Streams" in this geodatabase includes the full extent of expected Steelhead habitat. The stream reaches in this feature class are duplicated in the Steelhead feature class, which also includes additional streams that are expected to provide habitat for Steelhead Trout but not Coho Salmon.

Data was derived for and published in the report: Implementation of California Coastal Salmonid Monitoring in the Russian River Watershed (2015-2019), Final Report to the California Department of Fish and Wildlife, Fisheries Restoration Grants Program, Grantee Agreement: P1430411, February 28, 2019:

https://www.sonomawater.org/media/PDF/Environment/Fisheries/reports/cmp-report-2019_ADA.pdf

Data in this feature class is based on review of known or suspected habitat for Coho Salmon and Steelhead Trout by the Sonoma County Water Agency and California Sea Grant.

Data was originally published on February 28, 2019.

Background:

Federally endangered Coho Salmon and threatened Steelhead Trout are large, charismatic fish that play crucial roles in both stream and ocean ecosystems. They transport nutrients, help keep insect populations under control, and serve as food for larger fish and mammals. They also have many known habitat requirements (e.g. cool streams with unobstructed flow, good water quality, gravel beds and plenty of large debris) that impact their survival and make them strong indicators of stream health and environmental change.

Coho Salmon and Steelhead Trout habitat are monitored in order to detect trends in the distribution and abundance of the species at key life stages in streams known to have Coho, the species of primary concern; to determine trends in fish fitness (e.g. length, weight) at key life stages; and to identify changes in Coho and Steelhead habitat.

Monitoring data helps to identify impaired habitats that hinder Coho and Steelhead recovery; guides the evaluation of stream habitat restoration and protection efforts; and assists with efforts to predict and prepare for the effects of climate change, such as changing rainfall patterns, on stream habitats and associated fish populations.

Both Coho and Steelhead populations have declined dramatically as a result of habitat loss, overfishing and changing ocean conditions. Spawning Central California Coast Coho populations are down to only about 1% of historic levels. Because the Coho have a unique life cycle where adults are normally three years old when they spawn, adults identified in a stream reach aren’t descendants of adults that were identified the previous year, or the year before that. They are offspring of adults from three years prior. This means that there are three distinct Coho “cohorts” monitored in each stream reach. Specific trends vary by cohort and by stream, but in general Coho on the West Coast are still in need of recovery actions.

For more information contact data stewards: Gregg Horton, Sonoma County Water Agency, and Mariska Obedzinski, California Sea Grant.