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Studies and Surveys

  • 20-mm Survey
    This study monitors postlarval-juvenile delta smelt distribution and relative abundance throughout their historical spring range in the Sacramento-San Joaquin Delta and San Francisco Estuary...
  • Fall Midwater Trawl
    The Fall Midwater Trawl program began in 1967 and typically samples from San Pablo Bay through the Delta every month from September to December. This program was initiated to determine the relative abundance and distribution of age-0 striped bass in the estuary, but the data has also been used for other upper estuary pelagic species.
  • Fish Salvage Monitoring
    The Fish Facilities Monitoring Project manages the data collected on fish entrained and salvaged at the Skinner Delta Fish Protective Facility (SDFPF) and Tracy Fish Collection Facility (TFCF). Directed by cooperative agreements and funded by USBR and DWR, project staff are responsible for key entry, quality assurance, data processing, data reporting, and other database management activities for these facilities.
  • San Francisco Bay Study
    The San Francisco Bay Study (Bay Study) was established in 1980 to determine the effects of freshwater outflow on the abundance and distribution of fish and mobile crustaceans in the San Francisco Estuary, primarily downstream of the Sacramento-San Joaquin Delta.
  • Smelt Larva Survey
    The Smelt Larva Survey, initiated in January 2009, provides near real-time distribution data for longfin smelt larvae in the Delta, Suisun Bay and Suisun Marsh.
  • Special Studies
    Special studies are typically intended to develop information necessary to increase the proficiency and scientific output of existing long-term monitoring projects. Special studies are often developed to combat challenges that arise during species sampling, specimen preservation, and in implementing other study methodologies.
  • Spring Kodiak Trawl Survey
    The Spring Kodiak Trawl Survey runs every other week beginning January or February. Each 'Delta-wide' survey takes 4-5 days and samples 39 stations from the Napa River to Stockton on the San Joaquin River, and up to Walnut Grove on the Sacramento River.
  • Striped Bass Study
    Staff of the Striped Bass Study calculate adult striped bass abundance, relative abundance, harvest rate, and survival rate by using data from Commercial Passenger Fishing Vessels (Party Boats; CPFV), various creel surveys, and a mark-recapture program...
  • Sturgeon Study
    This study - along with the San Francisco Bay Study - provides scientists, managers, and stakeholders with white sturgeon population dynamics and status information for use when considering habitat protection, habitat restoration, and fishing regulations. Staff of the Sturgeon Study calculate abundance, relative abundance, harvest rate, and survival rate by using data from Commercial Passenger Fishing Vessels (Party Boats), various creel surveys, and a mark-recapture program.
  • Townet Survey
    Since 1959, this survey has developed indices for the abundance of young striped bass when the average size is 38 mm by sampling 31 stations from San Pablo Bay through the Delta. The original purpose was to predict recruitment to the adult stock but the index has proven valuable in gauging the environmental health of the estuary.
  • Zooplankton Study
    The Zooplankton Study has estimated the abundance of zooplankton taxa since 1972 as a means of assessing trends in fish food resources from eastern San Pablo Bay through the eastern Sacramento-San Joaquin Delta and Suisun Marsh. The study also detects and monitors zooplankton recently introduced to the estuary and determines their effects on native species.
  • Historical Surveys


Bay Delta Region (Region 3)
Regional Manager: Gregg Erickson 
Main Office: 2825 Cordelia Road, Suite 100, Fairfield, CA 94534 | (707) 428-2002
Stockton Office: 2109 Arch Airport Rd, Stockton, CA 95206 | (209) 234-3420
Email the Bay Delta Region | Program Contacts


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