This project deployed an acoustic telemetry array to track White Sturgeon movement and habitat use in the San Joaquin River Restoration Area downstream of the Eastside Bypass Control Structure in Merced County, in order to inform fish passage design improvements to that structure for the benefit of White Sturgeon, Green Sturgeon, and spring-run Chinook salmon.
Location: San Joaquin River Restoration Area, at and downstream of the Eastside Bypass Control Structure (EBCS), Merced County. The EBCS is located within the Eastside Bypass, part of the State’s flood bypass system. The study area extends from the EBCS downstream to the confluence of the San Joaquin River and Merced River near Hills Ferry, and includes the area adjacent to the Merced National Wildlife Refuge. The East Side Bypass Control Structure is one of three key barriers to fish passage for salmon along the San Joaquin River between Friant Dam and the ocean. The San Joaquin River ultimately flows west to the Sacramento-San Joaquin Delta and San Francisco Bay.
Historical Fish Presence: White Sturgeon have been detected at the entrance of the Restoration Area near Hills Ferry through a 2016–2018 USFWS tagging study that identified twelve individuals, and the 2019 capture of two White Sturgeon and one Green Sturgeon at Hills Ferry suggests active use of the Restoration Area by sturgeon. Spring-run Chinook salmon were extirpated from the San Joaquin River upstream of the Merced River confluence for over 60 years due to Friant Dam and downstream water diversions, with the first returning adult spring-run Chinook documented in 2019 by the San Joaquin River Restoration Program.
Project Lead: U.S. Fish and Wildlife Service (USFWS), Lodi Fish and Wildlife Office
Project Partners: California Department of Fish and Wildlife (CDFW), La Grange Office; U.S. Bureau of Reclamation; San Joaquin River Restoration Program; The Fishery (local sturgeon farm, used for surgical training)
CFPF Funding: $100,000.00
Project Description: An understanding of when, where, and how White Sturgeon use the Restoration Area downstream of the EBCS is needed to ensure that planned modifications to the structure and construction of an engineered rock ramp will facilitate upstream migration and habitat use by White Sturgeon and other native fishes. The project deploys and maintains an acoustic receiver array, tags adult White Sturgeon, and tracks their movements relative to flow, temperature, and other parameters. As of April 2024, 27 receivers were maintained and one new receiver installed near the Merced National Wildlife Refuge. A total of 776 detections had been recorded across the array, with gill netting for tagging underway since late February 2024.
Expected Completion: Fall 2024
Project Effectiveness: Results of the telemetry study are presented to the Eastside Bypass Improvements working group and the SJRRP Science Meeting, with final findings published on the San Joaquin River Restoration Program website.