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Bay-Delta

The Sacramento-San Joaquin River Delta and San Francisco Bay make up the "Bay-Delta.” The USGS monitors flow, water quality, and other dynamics in the Bay-Delta system. Data are gathered and reported in a variety of ways including sediment sampling, mapping surveys, and data collected every 15 minutes at stationary monitoring sites.

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In situ chlorophyll fluorometer validation and comparison study

The Sacramento-San Joaquin Delta (Delta) supplies drinking water to much of California. The Delta also provides irrigation water to the Central Valley and is an important habitat to many aquatic and terrestrial species. In the past decade, there has been an increase in harmful algal blooms (HABs) in the Delta. While some HABs are nontoxic, others contain cyanobacteria that can produce dangerous...
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In situ chlorophyll fluorometer validation and comparison study

The Sacramento-San Joaquin Delta (Delta) supplies drinking water to much of California. The Delta also provides irrigation water to the Central Valley and is an important habitat to many aquatic and terrestrial species. In the past decade, there has been an increase in harmful algal blooms (HABs) in the Delta. While some HABs are nontoxic, others contain cyanobacteria that can produce dangerous...
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Emergency Drought Barrier’s Impacts on cyanoHABs and Water Quality

Drought is making the Delta Saltier. Less freshwater coming from watershed runoff and reservoir releases means that more salty water flows into the Sacramento San Joaquin Delta (Delta) from the Pacific Ocean. Changes in Delta salinity have far-reaching impacts, affecting the water supply for agriculture, drinking, wildlife, and Delta ecosystems.
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Emergency Drought Barrier’s Impacts on cyanoHABs and Water Quality

Drought is making the Delta Saltier. Less freshwater coming from watershed runoff and reservoir releases means that more salty water flows into the Sacramento San Joaquin Delta (Delta) from the Pacific Ocean. Changes in Delta salinity have far-reaching impacts, affecting the water supply for agriculture, drinking, wildlife, and Delta ecosystems.
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Delta Wetlands and Resilience: Blue Carbon and Marsh Accretion

Blue carbon ecosystems (BCEs) are coastal ecosystems, such as tidal marshes, mangroves, and seagrasses, with manageable and atmospherically significant carbon stocks and fluxes. The tidal marshes and scrub-shrub wetlands in the Sacramento-San Joaquin Delta (Delta) of California are examples of BCEs. The Delta is a 2,400 square kilometer tidal freshwater region located at the landward end of the...
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Delta Wetlands and Resilience: Blue Carbon and Marsh Accretion

Blue carbon ecosystems (BCEs) are coastal ecosystems, such as tidal marshes, mangroves, and seagrasses, with manageable and atmospherically significant carbon stocks and fluxes. The tidal marshes and scrub-shrub wetlands in the Sacramento-San Joaquin Delta (Delta) of California are examples of BCEs. The Delta is a 2,400 square kilometer tidal freshwater region located at the landward end of the...
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Identifying the Source and Taxa That are Producing Microcystins Detected in San Francisco Bay

Microcystins are toxins produced by cyanobacteria (previously known as blue-green algae ) that are harmful to humans and other animals. In 2012, microcystins began to be detected in San Francisco Bay (SFB). This was unexpected because most microcystin producing cyanobacteria live in freshwater. On-going microcystin-related work has focused on monitoring the presence of microcystins in water and...
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Identifying the Source and Taxa That are Producing Microcystins Detected in San Francisco Bay

Microcystins are toxins produced by cyanobacteria (previously known as blue-green algae ) that are harmful to humans and other animals. In 2012, microcystins began to be detected in San Francisco Bay (SFB). This was unexpected because most microcystin producing cyanobacteria live in freshwater. On-going microcystin-related work has focused on monitoring the presence of microcystins in water and...
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Biogeochemistry Group

The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
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Biogeochemistry Group

The Biogeochemistry (BGC) Group uses an interdisciplinary approach to address surface water quality issues and food web dynamics throughout California, particularly in the Sacramento-San Joaquin Delta and San Francisco Bay.
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Flow and Water Quality Data in the San Francisco Estuary

The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. Water flow and water quality in the San Francisco Bay-Delta Estuary are important to the economies of both California and the nation. The Bay-Delta system provides water to more than 25 million California residents and vast farmlands, as well as key habitat for birds, fish, and other...
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Flow and Water Quality Data in the San Francisco Estuary

The San Francisco Bay and Sacramento-San Joaquin Delta form one of the largest estuaries in the United States. Water flow and water quality in the San Francisco Bay-Delta Estuary are important to the economies of both California and the nation. The Bay-Delta system provides water to more than 25 million California residents and vast farmlands, as well as key habitat for birds, fish, and other...
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Longfin Smelt Distribution in the Coastal Pacific Ocean

Longfin Smelt ( Spirinchus thaleichthys ) is a pelagic fish species found in waters along the Pacific coast, from Alaska to central California. Its complex life cycle makes it vulnerable to threats in both freshwater and at sea. Longfin Smelt is listed as a threatened species by the state of California.
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Longfin Smelt Distribution in the Coastal Pacific Ocean

Longfin Smelt ( Spirinchus thaleichthys ) is a pelagic fish species found in waters along the Pacific coast, from Alaska to central California. Its complex life cycle makes it vulnerable to threats in both freshwater and at sea. Longfin Smelt is listed as a threatened species by the state of California.
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Assessing Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta

Sediments represent an important pool of nutrients in the Sacramento-San Joaquin Delta (Delta). The exchange of nutrients between the water column and the benthos impacts water quality and effects phytoplankton, harmful algal blooms, aquatic vegetation, and drinking water quality. To date, there is very limited information about nutrient pools in Delta sediments, nor how these nutrients are...
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Assessing Sediment Nutrient Storage and Release in California's Sacramento-San Joaquin Delta

Sediments represent an important pool of nutrients in the Sacramento-San Joaquin Delta (Delta). The exchange of nutrients between the water column and the benthos impacts water quality and effects phytoplankton, harmful algal blooms, aquatic vegetation, and drinking water quality. To date, there is very limited information about nutrient pools in Delta sediments, nor how these nutrients are...
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Ecosystem Engineering Impacts of Water Primrose in the Sacramento-San Joaquin Delta

Many non-native fish, invertebrates, and plants have colonized the Sacramento-San Joaquin Delta (Delta) of California, the landward most region of the San Francisco Estuary. Included among these invasive species is the water primrose ( Ludwigia spp . ), an aggressive floating aquatic plant that is native to South and Central America and parts of the US, but invasive in California. Water primrose...
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Ecosystem Engineering Impacts of Water Primrose in the Sacramento-San Joaquin Delta

Many non-native fish, invertebrates, and plants have colonized the Sacramento-San Joaquin Delta (Delta) of California, the landward most region of the San Francisco Estuary. Included among these invasive species is the water primrose ( Ludwigia spp . ), an aggressive floating aquatic plant that is native to South and Central America and parts of the US, but invasive in California. Water primrose...
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Sediment transport, streamflow, and climate change: long-term resilience of the Bay-Delta

Sediment supply is important to the health of the Sacramento-San Joaquin River Delta and San Francisco Bay (Bay-Delta) ecosystem. Sediment eroded from upland source areas in the Sacramento and San Joaquin watersheds is transported through the rivers to the Bay-Delta where it is deposited in mudflats and tidal wetlands, which in turn helps protect against the effects of sea-level rise. Sediment...
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Sediment transport, streamflow, and climate change: long-term resilience of the Bay-Delta

Sediment supply is important to the health of the Sacramento-San Joaquin River Delta and San Francisco Bay (Bay-Delta) ecosystem. Sediment eroded from upland source areas in the Sacramento and San Joaquin watersheds is transported through the rivers to the Bay-Delta where it is deposited in mudflats and tidal wetlands, which in turn helps protect against the effects of sea-level rise. Sediment...
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High Resolution Temporal and Spatial Mapping of Mercury and Methylmercury in Surface Waters of the Sacramento – San Joaquin Delta

Mercury (Hg) is a contaminant of significant concern in the San Francisco Bay-Delta estuary and watershed (Bay-Delta). The formation, fate, and transport of methylmercury (MeHg), a particularly toxic organic form of Hg that readily bioaccumulates in wildlife, has been studied extensively throughout the system. However, there is widespread recognition of the need for more comprehensive monitoring...
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High Resolution Temporal and Spatial Mapping of Mercury and Methylmercury in Surface Waters of the Sacramento – San Joaquin Delta

Mercury (Hg) is a contaminant of significant concern in the San Francisco Bay-Delta estuary and watershed (Bay-Delta). The formation, fate, and transport of methylmercury (MeHg), a particularly toxic organic form of Hg that readily bioaccumulates in wildlife, has been studied extensively throughout the system. However, there is widespread recognition of the need for more comprehensive monitoring...
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Evaluating the effects of wastewater-derived nutrients on phytoplankton abundance and community structure in the San Francisco Estuary and Delta

Planned upgrades to the Sacramento Regional wastewater treatment plant (SRWTP) will substantially reduce nutrient discharge and also alter the types and amounts of nutrients being distributed across the San Francisco Delta and Estuary (Delta). One highly anticipated outcome of lower nutrients is improved productivity in the phytoplankton communities that supply aquatic food webs, which should...
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Evaluating the effects of wastewater-derived nutrients on phytoplankton abundance and community structure in the San Francisco Estuary and Delta

Planned upgrades to the Sacramento Regional wastewater treatment plant (SRWTP) will substantially reduce nutrient discharge and also alter the types and amounts of nutrients being distributed across the San Francisco Delta and Estuary (Delta). One highly anticipated outcome of lower nutrients is improved productivity in the phytoplankton communities that supply aquatic food webs, which should...
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