The steelhead trout is a remarkable trout species that lives in both freshwater and ocean environments. Steelhead trout are born in freshwater streams/rivers, where they typically spend their first year, then migrate to the ocean where they spend most of their adult life. Adult steelhead trout are anadromous, meaning they migrate up freshwater streams and rivers to spawn.
Steelhead trout are native to streams and rivers along the Pacific Coast from Mexico to Alaska. Populations of southern steelhead historically existed in all of the larger watersheds within Santa Barbara County (Stoecker 2002).
The Santa Ynez River is reported to have had the largest population of steelhead in all of Southern California, with estimates of 13,000 to 25,000 adults returning in the 1943-1944 run (Titus 1994).
Although the range of steelhead trout is still very large, from Alaska to northern Baja, populations in the southern portion of their range have been severely reduced. Since the beginning of the century it is estimated that steelhead populations in Southern California have been reduced to less than one percent of their former population size (Stoecker 2002).
Due to this significant reduction, the Southern California steelhead trout population (which includes Santa Barbara County) has been federally designated as an endangered species by the National Marine Fisheries Service.
Mission Creek is considered the most viable stream for steelhead trout restoration within the City of Santa Barbara. Mission Creek has an existing population of rainbow trout, contains high quality spawning and rearing habitat within the stream channels in the mid and upper watershed, and has a documented historic run of steelhead trout.
Over the last ten years, Southern California steelhead trout have been observed attempting to migrate and spawn within the lower section of Mission Creek. During the winter of 2007-2008, six steelhead trout that measured over sixteen inches each were documented in the lower section of Mission Creek.
Although steelhead trout are frequently spotted in Mission Creek, they are unable to migrate upstream and spawn due to barriers within the creek channel. Currently, there are 12 significant anthropogenic (manmade) barriers to steelhead trout migration in Mission Creek.
The Creeks Division has already removed barriers at the Tallant Road Bridge and the Upper and Lower Caltrans Channels. Removing these barriers provides access for steelhead trout to 3.9 miles of creek channel, which includes 2 miles of moderate to high quality spawning and rearing habitat (Stoecker 2002).