California Department of Fish and Wildlife (CDFW) conducts the 20-mm Survey annually to monitor the distribution and relative abundance of larval and juvenile Delta Smelt (Hypomesus transpacificus) in the upper San Francisco Bay Estuary. The survey began in 1995 and supplies near real-time catch data to water and fisheries managers as part of an adaptive management strategy to limit the risk of Delta Smelt entrainment during water exports Data collected: temperature, electro-conductivity, water transparency, turbidity, water volume, tidal stage, fish, and zooplankton.
The Fall Midwater Trawl (FMWT) is conducted to determine the relative abundance and distribution of age-0 Striped Bass (Morone saxatilis), Delta Smelt (Hypomesus transpacificus), Longfin Smelt (Spirinchus thaleichthys), American Shad (Alosa sapidissima), Splittail (Pogonichthys macrolepidotus), and Threadfin Shad (Dorosoma petenense) in the San Francisco Estuary (SFE). FMWT has sampled annually since its inception in 1967, with the exceptions of 1974 and 1979, when sampling was not conducted. As of 2023, FMWT samples 130 stations each month from September to December and a subset of these stations are used to calculate an annual abundance index. Of the 130 stations, 35 include an additional zooplankton tow to collect meso- (CB net) and macro-zooplankton (mysid net) samples to inform food availability for young fish. Zooplankton sampling began in 2011. FMWT stations range from San Pablo Bay upstream to Stockton on the San Joaquin River, Hood on the Sacramento River, and the Sacramento Deep Water Ship Channel. Sampling takes approximately 15 days per month to complete.
The FMWT conducts compliance monitoring in collaboration with USBR and DWR to meet permit obligations to the SWRCB (and DRCB) via Water Rights Decisions (D-1485 and D-1641) and USFWS-NMFS biological opinions for Delta Smelt and salmonids, and for incidental take permits issued by CDFW for operation of the State Water Project (SWP), and the USBR BA/ROD. FMWT also informs Natural Resource Agency Delta Smelt Resiliency Strategy management actions including the Suisun Marsh Salinity Control Gate re-operation, the Effects of Outflow Alteration upon Delta Smelt Habitat, Condition, and Survival, and Summer-Fall Habitat Action monitoring.
Project Objectives
• To annually measure the abundance and distribution of selected species of pelagic fishes in the estuary. • To gain understanding of the factors affecting abundance, distribution, and survival of pelagic fishes in the estuary. • To detect introductions of new exotic fish and invertebrates. • Provide baseline data to evaluate management plans and habitat restoration projects. • To measure availability of fall planktonic food resources.
The National Wetland Condition Assessment (NWCA) is a statistical survey that begins to address some of the gaps in our understanding of wetland health by providing information on the ecological condition of the nation's wetlands and stressors most commonly associated with poor condition. The NWCA is designed to answer basic questions about the extent to which our nation's wetlands support healthy ecological conditions and the prevalence of key stressors at the national and regional scale. It is intended to complement and build upon the achievements of the U.S. Fish and Wildlife Service Wetland Status and Trends Program, which characterizes changes in wetland acreage across the conterminous United States. Paired together, these two efforts provide government agencies, wetland scientists, and the public with comparable, scientifically defensible information documenting the current status and, ultimately, trends in both wetland quantity (i.e., area) and quality (i.e., ecological condition).
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 Diet and Condition study has provided information on the food habits of young pelagic fishes in the San Francisco Estuary (SFE) since 2005. This study was created to address questions of food limitation in young fish by understanding the types and amount of prey eaten among seasons and regions of the SFE. Food limitation can be an important factor to the annual recruitment success of fish that use the estuary as a nursery, such as ESA listed Delta Smelt (Hypomesus transpacificus) and Longfin Smelt (Spirinchus thaleichthys). We focus on the temporal and spatial differences in diet composition and foraging of native smelts and also non-natives such as age-0 Striped Bass (Morone saxatilis), Threadfin Shad (Dorosoma petenense), Mississippi Silversides (Menidia beryllina), Wakasagi (Hypomesus nipponensis), and age-0 American Shad (Alosa sapidissima). Data from this project has been used to inform the Fall Low Salinity Habitat Program (FLaSH), Directed Outflow Project (DOP), Management, Analysis and Synthesis Team reports, as well as life history models used for the conservation of fish and their habitats. Understanding what prey are utilized for food in the context of available prey, with the associated body-condition of fish, helps clarify the existence and timing of food limitation for young pelagic fish in the estuary. The focus of the study currently is to analyze existing diet data and report findings generated from study species, to inform Longfin Smelt foraging conditions, ongoing outflow management of Summer-Fall Habitat Action efforts, and Delta Smelt Supplementation evaluations of wild vs culture origin foraging success. Objectives 1. What are the diets of pelagic fishes (especially Delta Smelt and Longfin Smelt) in the estuary and do they vary regionally or temporally? 2. Is there evidence of reduced feeding success spatially or temporally in the estuary? 3. Is feeding success associated with changes in relative weight or condition of fish? 4. Is there seasonal and regional overlap of diets between species (with a focus on age-0 Delta Smelt, Longfin Smelt, Striped Bass, Prickly Sculpin, Pacific Herring, and Threadfin Shad)?
The Environmental Monitoring Program (EMP) has conducted the Zooplankton Study since 1972 to better assess trends in the lower trophic food web in the San Francisco Bay-Delta estuary. The study also detects and monitors zooplankton recently introduced to the estuary and determines their effects on native species. Under the auspices of the Interagency Ecological Program for the San Francisco Estuary and mandated by Water Right Decision D-1641, the EMP Zooplankton Study is part of the Environmental Monitoring Program and is conducted by the California Department of Fish and Game (CDFW), California Department of Water Resources (DWR), and the United States Bureau of Reclamation (USBR).
The CDFW Fish Restoration Program will collect fish and invertebrate data near existing and planned tidal wetlands. These data will provide information on how fish and invertebrate communities change pre-/post-restoration. While collecting these data, the variability of invertebrate catches will be assessed for each gear type to determine the optimal number of samples per sampling site.
Under the 2008, 2019, 2024 State Water Project/Central Valley Project Joint Operations Biological Opinion from United States Fish and Wildlife Service, 2009, 2019, 2024 National Marine Fisheries Service, and 2009, 2020, and 2024 State Water Project Incidental Take Permit, Department of Water Resources (DWR) is required to restore >8,000 acres of tidal wetlands in the Sacramento-San Joaquin Delta (Delta) and Suisun Marsh to improve habitat and food web resources for threatened fishes. The Fish Restoration Program is responsible for biological monitoring in these restored tidal habitats to assess their success for providing habitat and food web benefits for at-risk native fishes.
Assess the food web resources (nutrients, phytoplankton, zooplankton, and macroinvertebrates) associated with pre- and post-restoration tidal wetlands, as well as with existing reference wetlands
Assess the fish community of restoring wetlands including use by rearing salmonids and characterization of the predator and competitor communities
