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Bay-Delta

The Sacramento-San Joaquin River Delta and San Francisco Bay collectively make up the "Bay-Delta." Much of the fresh water used for agriculture, municipal and industrial use in central and southern California passes through the Delta, where it is subjected to tidal forcing and other inputs that impact its quality. The USGS monitors the magnitude of the flows through the Delta, and the qua

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Subsidence in the Sacramento-San Joaquin Delta

The Sacramento-San Joaquin Delta is part of the San Francisco Estuary, home to a diverse flora and fauna, including several threatened and endangered species, has a large area of prime farmland, and serves as the hub of California's freshwater-delivery system that moves water from the wet north to the dry southern part of the State.
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Subsidence in the Sacramento-San Joaquin Delta

The Sacramento-San Joaquin Delta is part of the San Francisco Estuary, home to a diverse flora and fauna, including several threatened and endangered species, has a large area of prime farmland, and serves as the hub of California's freshwater-delivery system that moves water from the wet north to the dry southern part of the State.
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Mercury and Dissolved Organic Matter in Delta Wetlands

Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar, metacinnabar...
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Mercury and Dissolved Organic Matter in Delta Wetlands

Between 1860 and 1914, hydraulic mining activities sent more than 800,000,000 cubic yards of mercury-laden sediment into the Delta altering the landscape, water flows, and contributing to the leveeing and reclamation of the Delta's marshes. Transport of mercury from historic mining areas continues today. The sedimentary supply of mercury to the Delta and in Delta sediments (cinnabar, metacinnabar...
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Sources of Disinfection Byproduct-forming Material in the State Water Project

Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water-treatment process. The amount of DBPs that form is a function of the amount and source of the DOC, both of which...
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Sources of Disinfection Byproduct-forming Material in the State Water Project

Water from the Sacramento-San Joaquin Delta contains high concentrations of disinfection byproduct-forming (DBP-forming) materials when treated for potable use. DBPs form when dissolved organic compounds (DOC) in water react with disinfectants such as chlorine and ozone during the water-treatment process. The amount of DBPs that form is a function of the amount and source of the DOC, both of which...
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Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses

The project is part of an overarching Interagency Ecological Program (IEP)/Department of Water Resources (DWR) study that is focused on understanding the processes by which the Yolo Bypass may provide a fall food web supply for the Cache Slough Complex and downstream regions of the Sacramento/San Joaquin Delta. Several studies conducted since 2011 have shown that phytoplankton blooms can be...
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Pesticide Occurrence in California – Yolo Bypass Pesticide Analyses

The project is part of an overarching Interagency Ecological Program (IEP)/Department of Water Resources (DWR) study that is focused on understanding the processes by which the Yolo Bypass may provide a fall food web supply for the Cache Slough Complex and downstream regions of the Sacramento/San Joaquin Delta. Several studies conducted since 2011 have shown that phytoplankton blooms can be...
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Water-Quality Inventory Pesticides in the Golden Gate National Recreation Area

In 1998, all urban creeks in the San Francisco Bay Area were added to the Clean Water Act Section 303d list due to known or suspected diazinon impairment. Diazinon is an organophosphorus insecticide used on lawns, and fruit and vegetables. This pesticide has since been "phased out" and has not been available for purchase since late 2004. Diazinon use is declining and is being replaced by other...
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Water-Quality Inventory Pesticides in the Golden Gate National Recreation Area

In 1998, all urban creeks in the San Francisco Bay Area were added to the Clean Water Act Section 303d list due to known or suspected diazinon impairment. Diazinon is an organophosphorus insecticide used on lawns, and fruit and vegetables. This pesticide has since been "phased out" and has not been available for purchase since late 2004. Diazinon use is declining and is being replaced by other...
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Variability of Salinity and Temperature In San Francisco Bay

The USGS has been collecting specific conductance (salinity) and water temperature data in San Francisco Bay (SF Bay) since 1990. Data are typically collected at 5-10 fixed locations throughout the bay, every fifteen minutes, every minute of the day.
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Variability of Salinity and Temperature In San Francisco Bay

The USGS has been collecting specific conductance (salinity) and water temperature data in San Francisco Bay (SF Bay) since 1990. Data are typically collected at 5-10 fixed locations throughout the bay, every fifteen minutes, every minute of the day.
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High-Speed Mapping of Nutrient Distributions and Water Quality Survey - Lower South San Francisco Bay

This project aims to characterize spatial heterogeneity for key water quality parameters, and pilot the use of underway-flowthrough mapping of biogeochemical properties as a cost-effective approach to monitoring.
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High-Speed Mapping of Nutrient Distributions and Water Quality Survey - Lower South San Francisco Bay

This project aims to characterize spatial heterogeneity for key water quality parameters, and pilot the use of underway-flowthrough mapping of biogeochemical properties as a cost-effective approach to monitoring.
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Assessment of Baseline Conditions in Liberty Cut

Monitoring habitat quality in the San Francisco Estuary (SFE) and Sacramento-San Joaquin Delta has been limited to mostly monthly discrete measurements of biologically relevant parameters (e.g. phytoplankton, dissolved organic matter (DOM), nutrients) that cannot fully characterize the physical and biogeochemical variability.
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Assessment of Baseline Conditions in Liberty Cut

Monitoring habitat quality in the San Francisco Estuary (SFE) and Sacramento-San Joaquin Delta has been limited to mostly monthly discrete measurements of biologically relevant parameters (e.g. phytoplankton, dissolved organic matter (DOM), nutrients) that cannot fully characterize the physical and biogeochemical variability.
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Phytoplankton production and nutrient transformations in shallow water wetland habitats

The objectives of this study are to quantify and characterize (1) phytoplankton production on Liberty Island, (2) utilization and transformation of nutrients, and (3) attenuation/loss of phytoplankton as the material is transported from Liberty Iisland into Cache Slough.
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Phytoplankton production and nutrient transformations in shallow water wetland habitats

The objectives of this study are to quantify and characterize (1) phytoplankton production on Liberty Island, (2) utilization and transformation of nutrients, and (3) attenuation/loss of phytoplankton as the material is transported from Liberty Iisland into Cache Slough.
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Development of unimpaired flows for mountain basins draining to the Bay Delta

The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A...
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Development of unimpaired flows for mountain basins draining to the Bay Delta

The objective of this study is to develop daily historical climate surfaces and simulate unimpaired basin discharge, including surface water flow and baseflow, from all basins that drain to the Bay Delta. Basin drainage will be calibrated to DWR reconstructed flows, and comparisons of results will be made with other independently developed watershed models for basins in which they coincide. A...
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Interactions Between Physical Processes and Suspended Sediment Quality in Relation to Spawning Migrations of Delta Smelt

The proposed study is designed to better establish relationships between patterns of delta smelt abundance and properties of suspended particles as measured by optical and acoustical techniques.
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Interactions Between Physical Processes and Suspended Sediment Quality in Relation to Spawning Migrations of Delta Smelt

The proposed study is designed to better establish relationships between patterns of delta smelt abundance and properties of suspended particles as measured by optical and acoustical techniques.
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Causes and Relevance of Phytoplankton Blooms in the Northern Sacramento-San Joaquin Delta

Phytoplankton are an important part of aquatic food webs and ecosystems. These single-celled plants grow faster in the stronger light of spring or summer, resulting in population explosions called phytoplankton blooms. These blooms in turn feed zooplankton (free-floating aquatic microorganisms), providing food for many aquatic species, including fish, shrimp, crabs, and other invertebrates.
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Causes and Relevance of Phytoplankton Blooms in the Northern Sacramento-San Joaquin Delta

Phytoplankton are an important part of aquatic food webs and ecosystems. These single-celled plants grow faster in the stronger light of spring or summer, resulting in population explosions called phytoplankton blooms. These blooms in turn feed zooplankton (free-floating aquatic microorganisms), providing food for many aquatic species, including fish, shrimp, crabs, and other invertebrates.
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