This data release contains one data table and a data dictionary for the California Department of Water Resources and the United States Bureau of Reclamation’s Environmental Monitoring Program (EMP) Generalized Random Tessellation Stratified (GRTS) program.

This data release contains eleven data tables and a data dictionary for the Department of Water Resources' and the Bureau of Reclamation’s Environmental Monitoring Program's (EMP) Benthic Monitoring program.

This data release contains eleven data tables and a data dictionary for the Department of Water Resources' and the Bureau of Reclamation’s Environmental Monitoring Program's (EMP) Benthic Monitoring program.

Declining phytoplankton biomass and the resulting stress on the food web has been suggested as one contributor to the decline of Delta Smelt and other fish species in the San Francisco Bay (SFB) and the Sacramento San Joaquin River Delta. Filter feeding by two species of bivalves, Corbicula fluminea and Potamocorbula amurensis, has been shown to control phytoplankton growth rate in the SFB and Delta and both are thought to be partially responsible for the reduction in food for pelagic species. Phytoplankton growth rate is dependent on spatially and temporally varying nutrient concentrations, light availability, transport time, and pelagic and benthic grazing losses. Bivalve grazing has the potential to limit primary production at phytoplankton source locations and to limit effective connectivity of habitats by grazing in the conduits that connect different habitats. It is important to determine the factors that control the success of each species of bivalve if we are to understand when and where the pelagic food web is most affected by bivalve grazing. Therefore, we need to protect, build, or restore habitat that is likely to produce phytoplankton for local consumption and export. Benthic communities are a good monitor of acutely and chronically stressful environments because they are stationary, accumulate contaminants, and respond to low and high phytoplankton biomass. Changes in the benthic community structure occur normally, and benthic species distributions are dependent on the physical habitat (substrate and depth), physiological limits, and predators. Therefore, seasonal and interannual differences in freshwater flow result in both seasonal and episodic changes in species abundance and community composition. The Sacramento Watershed has experienced below normal rainfall and dry conditions with sporadic wet years for the past decade. However, heavy rainfall in water year 2017 (October 2016 to September 2017) ended a five-year drought and set the record for California’s wettest year since 1983. The severity and duration of a potential change in the benthic community as a result of this increase in freshwater is still unknown, yet it is unlikely for such a drastic change in salinity as this to go unnoticed. This dataset includes data from 2015 to 2018, encompassing a period of drought before Water Year 2017, as well as the year following Water Year 2017.

Declining phytoplankton biomass and the resulting stress on the food web has been suggested as one contributor to the decline of Delta Smelt and other fish species in the San Francisco Bay (SFB) and the Sacramento San Joaquin River Delta. Filter feeding by two species of bivalves, Corbicula fluminea and Potamocorbula amurensis, has been shown to control phytoplankton growth rate in the SFB and Delta and both are thought to be partially responsible for the reduction in food for pelagic species. Phytoplankton growth rate is dependent on spatially and temporally varying nutrient concentrations, light availability, transport time, and pelagic and benthic grazing losses. Bivalve grazing has the potential to limit primary production at phytoplankton source locations and to limit effective connectivity of habitats by grazing in the conduits that connect different habitats. It is important to determine the factors that control the success of each species of bivalve if we are to understand when and where the pelagic food web is most affected by bivalve grazing. Therefore, we need to protect, build, or restore habitat that is likely to produce phytoplankton for local consumption and export. Benthic communities are a good monitor of acutely and chronically stressful environments because they are stationary, accumulate contaminants, and respond to low and high phytoplankton biomass. Changes in the benthic community structure occur normally, and benthic species distributions are dependent on the physical habitat (substrate and depth), physiological limits, and predators. Therefore, seasonal and interannual differences in freshwater flow result in both seasonal and episodic changes in species abundance and community composition. The Sacramento Watershed has experienced below normal rainfall and dry conditions with sporadic wet years for the past decade. However, heavy rainfall in water year 2017 (October 2016 to September 2017) ended a five-year drought and set the record for California’s wettest year since 1983. The severity and duration of a potential change in the benthic community as a result of this increase in freshwater is still unknown, yet it is unlikely for such a drastic change in salinity as this to go unnoticed. This dataset includes data from 2015 to 2018, encompassing a period of drought before Water Year 2017, as well as the year following Water Year 2017.

This data release contains ten data tables and a data dictionary for the Technical Assistance Agreement (TAA) between the U.S. Geological Survey and the San Francisco Estuary Institute titled "Lower San Francisco Bay Bivalve Grazing Rates”. The data are provided in comma-delimited value spreadsheets as well as Microsoft Excel Worksheet formats.

This data release contains ten data tables and a data dictionary for the Technical Assistance Agreement (TAA) between the U.S. Geological Survey and the San Francisco Estuary Institute titled "Lower San Francisco Bay Bivalve Grazing Rates”. The data are provided in comma-delimited value spreadsheets as well as Microsoft Excel Worksheet formats.

This data release contains eight data tables and a data dictionary for the SF Bay-Delta Priority Ecosystems Science Program - Biophysical Controls on Erosion and Near-Bed Turbulence: Strengthening Sediment Transport Modeling in San Francisco Bay. The data are provided in comma-delimited value spreadsheets as well as Microsoft Excel Worksheet formats.

This data release contains eight data tables and a data dictionary for the SF Bay-Delta Priority Ecosystems Science Program - Biophysical Controls on Erosion and Near-Bed Turbulence: Strengthening Sediment Transport Modeling in San Francisco Bay. The data are provided in comma-delimited value spreadsheets as well as Microsoft Excel Worksheet formats.

Benthic invertebrate communities are monitored because the composition of those communities can affect and be affected by the water quality of an aquatic system. Benthic communities use and sometimes regulate the cycling of essential elements (for example, carbon). Benthic invertebrate taxa may also indicate acute and chronic stressors in an environment because they accumulate contaminants and can respond – sometimes dramatically - to oligotrophic and eutrophic conditions. Benthic communities affect water quality by grazing pelagic food resources and increasing the rate of nutrient regeneration through feeding and bioturbating sediments. South San Francisco Bay is a system dependent on phytoplankton as the base to the food web. Despite abundant nutrients, South San Francisco Bay has had limited phytoplankton production in the last several decades owing to poor light conditions caused by high turbidities, and high grazing losses from the water column by benthic invertebrates and zooplankton. However, the balance of biogeochemical conditions in most springs accommodates a short phytoplankton bloom in South San Francisco Bay. This balance between available light, nutrients, and grazing has maintained the phytoplankton biomass in South San Francisco Bay at low levels relative to other high-nutrient urban estuaries. The role of benthic invertebrates during these episodic spring events, as well as in other seasons, remains of great interest to water-quality and biological resource managers.