Rivers of a Lost Coast

Ted Thomas and Elizabeth Scott report preliminary results show that an experimental, non-physical fish barrier is working to help keep young Chinook salmon and steelhead in a more direct path to the ocean and away from agricultural diversion and the state and federal pumping plants.  Media is invited to view the barrier project and interview participants from the agencies involved May 15 near Lathrop.

The Department of Water Resources (DWR) is piloting the “bubble curtain” barrier project that combines acoustics and a strobe-lit sheet of bubbles to create an underwater wall of light and sound at frequencies that repel juvenile Chinook salmon.

Results from three of seven planned releases of hatchery juvenile Chinook salmon implanted with acoustic tags indicate that the barrier has increased the number of fish staying in the San Joaquin River to continue their out-migration to San Francisco Bay and the ocean. Past studies have shown that salmon kept in the main stem of the San Joaquin River have better survival than those that move into the central Delta through Old River.

The four remaining releases are scheduled through late May. Receivers are stationed along the salmon out-migration path at sites along the San Joaquin River and Old River near the barrier. DWR leased the non-physical barrier equipment from EIMCO Water Technologies, LLC for the experimental project.