Welcome to our Special Studies Research Program at DWR. Dr. Peggy Lehman and Dr. Cynthia LeDoux-Bloom, collaborate with other scientific experts from State and Federal agencies, and national and international academic institutions, stakeholders and businesses to design and implement diverse scientific studies using state-of-the art technology, such as the flowCAM and biotelemetry with fishes, to answer current ecosystem questions in the San Francisco Estuary Watershed. They partner with the Interagency Ecological Program, the CALFED Science Program and the Bay-Delta Science Consortium and lead interdisciplinary research studies crucial to water operations management and restoration planning and implementation.

Photos by Peggy Lehman, Bill Templin and Anke Mueller-Solger

Special  Study: Habitat Use of Sub-adult Striped Bass Implanted with Acoustic Transmitters - Dr. Cynthia LeDoux-Bloom

The distribution of sub-adult striped bass Morone saxatilis changes seasonally in the San Francisco Estuary Watershed. We investigated the distribution, habitat use and movement patterns of sub-adult striped bass (sexual immaturity) over a 17 month period from June 2010-Novemeber 2011. Sub-adult striped bass (n=99) were surgically implanted with acoustic transmitters and tracked by a large, stationary acoustic receiver array located in the San Francisco Estuary Watershed and nearshore Pacific Ocean.

In fall, sub-adult striped bass were widely distributed from the bays to rivers. Between fall and winter, the distribution shifted toward the ocean, likely in response to decreasing water temperatures in the rivers.

In winter, detections of fish decreased and fish were typically found in or near the bays, while some fish emigrated to the ocean. In spring, detections increased as fish began to return from the ocean and moved about the bays, delta, and watershed.

In late spring, early summer, the fish were distributed from the bay to 325 km upstream in the Sacramento River. In summer 2010, most fish were distributed in the Sacramento River, while in 2011; most fish were distributed in the bays. Differences in distribution between individual fish and schools and emigration into the ocean during some years may help explain the erratic population fluxes observed in sub-adult striped bass inhabiting the SFEW.

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