The Napa River watershed provides a range of habitat types for fish–from the steep, cold, fast-moving waters in the mountain streams, to the flat, warm, salty and tidal waters of the esturary. Twelve native fish species can be found in the upper, nontidal portion of the Napa River (upstream of the Trancas bridge), including several threatened and/or rare species such as steelhead trout, fall-run Chinook salmon, and Pacific and river lamprey. Non-native fish species also reside in the watershed. Fourteen species are found in the upper Napa River watershed during most years, although none are found in high gradient mountain streams.
Human development and introduction of non-native fish species has impacted the Napa River and its fish. The Napa River system has changed from being dominated by pools and riffles to a morphology dominated by large, deep pools with increased water temperatures and slow-moving water. As a result, the most sensitive species–the steelhead trout, coho salmon, and Chinook salmon–have undergone significant declines in population size.
Download report on native and exotic populations: Fishes of the Napa River Watershed (pdf)
Native fish found in Napa County waterways (currently or historically):
Pacific Staghorn Sculpin
Steelhead Trout are an important component of California’s diverse wildlife heritage. They are a good indicator of the health of aquatic systems because they use all portions of a river system, and require cool, clean water. Steelhead are a sport fish, with about 100,000 steelhead anglers throughout the state. If the current population of steelhead in California were to double, the state’s economy from fishing revenue would increase by an estimated 37.5 million dollars.
Swimming with Salmon and Steelhead in the Napa River