OREGON STATE UNIVERSITY/ FLICKR (CC)
Members of the Alameda Creek Alliance, a group dedicated to protecting and restoring the natural ecosystems of the Alameda Creek watershed, are celebrating the spotting of two adult steelhead trout in the lower Alameda Creek flood control channel last week – the first confirmed sighting since 2008.
“This is significant. Steelhead have been missing from the lower Alameda Creek for half a century now, and we have been working for almost twenty years to restore them,” said Jeff Miller, director of the Alameda Creek Alliance, in an interview.
Like salmon, steelhead are anadromous fish, meaning they live out their adult lives in the ocean and migrate to freshwater streams and rivers to spawn. After a surge of dam-building, water diversions, and other barriers to migration occurred in the 1960s and 1970s, steelhead trout were virtually eliminated from the Alameda Creek watershed. Yet it wasn’t until 1997 that the fish was officially listed as threatened under the Endangered Species Act. Since then, Miller and others at the Alameda Creek Alliance, which encompasses more than 2,000 community members, have been working to remove dams and build fish ladders that would enable fish like the steelhead trout to successfully migrate to their spawning habitat near Sunol Valley and Sunol Regional Park, where blockages like a BART weir, located ten miles from the creek mouth, have prevented them from for decades.
With the help of state and federal agencies, the Alameda Creek Alliance has witnessed the completion of seventeen fish passage projects in the watershed since 2001. While some projects led by the Alameda County Water District and Alameda County Flood Control District have seen delays, plans to make nearly twenty miles of Alameda Creek accessible to ocean-run fish lie ahead.
For instance, the San Francisco Public Utilities Commission has been rebuilding the Calaveras Dam since 2011 to enhance stream flow for both the infrastructure and wildlife. The project includes construction of a fish ladder and also fish screens on an associated diversion dam in the upper Alameda Creek watershed. “Once Calaveras Dam is complete, there will be more water released downstream. So in 2018, when they are done rebuilding the dam, there should be more cold water flows for steelhead to spawn,” Miller said.
According to the announcement, the agencies also plan to build two additional fish ladders around two existing rubber dams in the years 2017–2020 that would enable steelhead to bypass the BART weir in the lower creek channel. At least nine other fish passage projects are in the planning phases.
Volunteers and East Bay Parks staffers may soon attempt to capture and radio-tag the spotted steelhead trout, as well as any other fish species blocked by the BART weir, to study their migration. Using this method, 27 steelhead have been tagged in the lower Alameda Creek and have moved past barriers into the upstream Niles Canyon. In addition, six Pacific lamprey, an eel-like fish species that also migrates to freshwater for spawning, were photographed near the BART weir just last month.
The trout were identified by a fisheries biologist from the East Bay Regional Park District. Miller said the confirmed sighting puts the watershed, which covers nearly 680 square miles of the Bay Area, in a crucial moment, and fish ladders and barrier removal are needed now more than ever.
“Migratory fish have been blocked from the Alameda Creek watershed for half a century,” Miller said in a press release. “We’ve made a lot of progress on restoration and the agencies should be commended for projects completed so far, but let’s get these fish ladders built while we still have steelhead to re-inhabit the creek.”