This is a continuation of a five-year project funded by CDWR and CDFW and the Central Valley Project Improvement Act in 2017. The objective of the project is to improve estimates of population abundances for fall, winter and spring run juvenile Chinook Salmon at Sacramento and Chipps Island by improving trawl efficiency estimates using data from releases of coded wire tags (CWT), acoustic tags (AT), and by genetically sampling the trawl catch in 2025 and 2026. The project will (1) develop statistical models for estimating trawl efficiencies using 2016-2025 data for paired AT-CWT releases of winter run and fall-run Chinook Salmon; (2) use 2016-2025 genetic sampling of trawl catch in combination with efficiency estimates to estimate population abundances of fall, spring and winter run at Sacramento and Chipps Island for 2016-2025; (3) implement trawl efficiency studies for multiple salmon runs in 2025-2026 informed by the prior results and in coordination with hatcheries for inclusion of AT fish with existing CWT releases; and (4) combine trawl efficiencies with genetic samples of trawl catch to provide estimates of fall, spring and winter-run salmon abundance (with estimated precision) entering and exiting the Delta in 2016-2025.
Description: The Enhanced Delta Smelt Monitoring (EDSM) program is a comprehensive, year-round monitoring initiative that employs multiple research crews conducting concurrent trawling operations across designated strata within the San Francisco Estuary. The program specifically targets post-larval Delta Smelt from April through June using 20mm trawling gear, while Kodiak trawling gear is utilized for the remainder of the year. Additionally, the program incorporates gear efficiency experiments and shallow water sampling protocols whenever feasible to enhance data collection. Need: The ongoing decline of the Delta Smelt population has underscored the critical need for continuous improvement in the data supporting our understanding of the ecological and anthropogenic factors influencing Delta Smelt population dynamics. The EDSM program plays a vital role in providing essential biological data that informs management strategies aimed at mitigating the adverse effects of water operations on this endangered species. By capturing data across nearly all life stages of Delta Smelt, including near-real-time information on juvenile and adult stages, the EDSM program offers significant conservation benefits. This data is promptly disseminated to the Smelt Working Group and other resource managers to facilitate informed decision-making during the critical entrainment season. Objectives: -Estimate the total abundance of Delta Smelt, including standard errors or confidence intervals, on a weekly to bi-weekly basis across various life stages (post-larvae, juveniles, sub-adults, adults) throughout the year. -Assess the spatial distribution of Delta Smelt at a management-relevant temporal and spatial resolution. -Provide data that supports management decisions and addresses scientific inquiries related to sampling efficiency, drivers of Delta Smelt population patterns, and other conservation and management-related topics.
The Environmental Monitoring Program (EMP) began in 1975 to conduct baseline and compliance monitoring of water quality, phytoplankton, zooplankton, and benthic invertebrates in the San Francisco Bay-Delta estuary. This monitoring program was designed to track the impact of water diversions to the State Water Project (SWP) and Central Valley Project (CVP) on the Bay-Delta. In the decades since, EMP scientists have monitored these constituents at fixed and floating stations throughout the estuary and ensured compliance with state and federal mandates such as Water Right Decision 1641 (D-1641). In the years and decades since its inception, EMP has become one of the cornerstones for scientists' and managers' understanding of the pace and pattern of change in this critical ecosystem. By sampling water quality and biological communities concurrently, EMP has created a dataset that is uniquely useful in better understanding causal connections between physical, biological, and biogeochemical processes.
The Delta Juvenile Fish Monitoring Program was established in the 1970s to monitor juvenile salmon abundance in the San Francisco Bay-Delta using trawling and beach seine nets. Since then the DJFMP has expanded its objective and sampling efforts, most significantly in 2016, when the Enhanced Delta Smelt Monitoring Program was initiated as part of DJFMP. Today, the DJFMP continues to document the relative abundance, distribution and survival of juvenile salmonids and other fishes in the lower Sacramento and San Joaquin rivers, Delta and San Francisco Bay for the protection, recovery and management of naturally produced salmonids and other native species in the Central Valley of California. Monitoring Data All monitoring data are collected by the Lodi Fish and Wildlife Office. Daily and weekly summary reports are available in the Lodi FWO Monitoring Data collection. Raw preliminary data files are also available. Some of the more common data requests, such as Chinook salmon, steelhead and pelagic organism decline species (e.g., Delta smelt, longfin smelt, threadfin shad and striped bass) catch data — by survey as well as the Chipps Island survival calculations — have also been compiled. If you would like additional information or want to request specific data or a specific format, please contact fish biologist Jonathan Speegle at jonathan_speegle@fws.gov. Custom data requests will be handled as soon as possible; however, response times may be delayed under certain circumstances. We encourage users to contact the data managers to discuss which dataset is best suited to your needs. Complete data files that have undergone final quality checks are available on the Environmental Data Initiative Data Portal. Type DJFMP or EDSM into the search bar to access the data sets and accompanying program metadata. These files are updated periodically as final quality-assurance and quality-control measures are completed.
