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David Schoellhamer (Former Employee)

Science and Products

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Map of San Francisco Bay

San Francisco Bay Wetlands Priority Ecosystem Studies

The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
By
California Water Science Center
link

San Francisco Bay Wetlands Priority Ecosystem Studies

The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
Learn More
link
Invasive Aquatic Vegetation

Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems

The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
By
California Water Science Center, Pacific Coastal and Marine Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
link

Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems

The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
Learn More
link
Estuary and bird

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.
By
California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
link

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.
Learn More
link
USGS research vessel mapping in Alviso Slough in south San Francisco Bay

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in deciding...
By
California Water Science Center
link

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in deciding...
Learn More

ADCP Data in Support of Water and Suspended-Sediment Flux Measurements at the Golden Gate, 2016-2017

Field observations of water and suspended-sediment fluxes at the Golden Gate were made over one ebb tide and one flood tide on three occasions: 1) 21-22 March 2016, following a large storm event that triggered the first flow into Yolo Bypass flood control structure since 2011; 2) 23 June of 2016, during a period of low freshwater inflow and 3) 27-28 February 2017, following several large storms of
By
California Water Science Center
Filter Total Items: 150

Sediment supply to San Francisco Bay, water years 1995 through 2016: Data, trends, and monitoring recommendations to support decisions about water quality, tidal wetlands, and resilience to sea level rise

Knowledge of the status and trends of sediment supply to San Francisco Bay is critically important for management decisions about dredging, marsh restoration, flood control, contaminants, water clarity (in relation to primary production), and sea level rise. Several sitespecific studies of sediment supply to San Francisco Bay have been conducted, but no synthesis of recent studies is available. Th
Authors
David H. Schoellhamer, Lester McKee, Sarah Pearce, Pete Kauhanen, Micha Saloman, Scott Dusterhoff, J. Letitia Grenier, Mathieu D. Marineau, Philip Trowbridge
By
Water Resources Mission Area, California Water Science Center

Measurements of erosion potential using Gust chamber in Yolo Bypass near Sacramento, California

This report describes work performed to quantify the erodibility of surface soils in the Yolo Bypass (Bypass) near Sacramento, California, for use in the California Department of Water Resources (DWR) Yolo Bypass D-MCM mercury model. The Bypass, when not serving as a floodway, is heavily utilized for agriculture. During flood events, surface water flows over the soil, resulting in the application
Authors
Paul A. Work, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay (bay) as part of a multi-agency effort to address management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the bay teems both with resident and with migratory wildlife, plants, and fish. Freshwater mixes with salt water in the ba
Authors
Paul A. Buchanan, Maureen A. Downing-Kunz, David H. Schoellhamer, Daniel N. Livsey
By
Water Resources Mission Area, California Water Science Center

Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 3
Authors
David H. Schoellhamer, Andrew J. Manning, Paul A. Work
By
Water Resources Mission Area, California Water Science Center

Primary production in the Delta: Then and now

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it i
Authors
James E. Cloern, April Robinson, Amy Richey, Letitia Grenier, Robin Grossinger, Katharyn E. Boyer, Jon Burau, Elizabeth A. Canuel, John F. DeGeorge, Judith Z. Drexler, Chris Enright, Emily R. Howe, Ronald Kneib, Anke Mueller-Solger, Robert J. Naiman, James L. Pinckney, Samuel M. Safran, David H. Schoellhamer, Charles A. Simenstad
By
Water Resources Mission Area, California Water Science Center

The effect of submerged aquatic vegetation expansion on a declining turbidity trend in the Sacramento-San Joaquin River Delta

Submerged aquatic vegetation (SAV) has well-documented effects on water clarity. SAV beds can slow water movement and reduce bed shear stress, promoting sedimentation and reducing suspension. However, estuaries have multiple controls on turbidity that make it difficult to determine the effect of SAV on water clarity. In this study, we investigated the effect of primarily invasive SAV expansion on
Authors
E.L. Hestir, David H. Schoellhamer, Jonathan Greenberg, Tara L. Morgan-King, S.L. Ustin
By
Water Resources Mission Area, California Water Science Center

Review of suspended sediment in lower South Bay relevant to light attenuation and phytoplankton blooms

Lower South Bay (LSB), a shallow subembayment of San Francisco Bay (SFB), is situated south of the Dumbarton Bridge, and is surrounded by, and interconnected with, a network of sloughs, marshes, and former salt ponds undergoing restoration (Figure ES.1). LSB receives 120 million gallons per day of treated wastewater effluent from three publicly owned treatment works (POTWs) that service San Jose a
Authors
David H. Schoellhamer, Gregory Shellenbarger, Maureen A. Downing-Kunz, Andrew J. Manning
By
Water Resources Mission Area, California Water Science Center

Recent advances in understanding flow dynamics and transport of water-quality constituents in the Sacramento–San Joaquin River Delta

This paper, part of the collection of research comprising the State of Bay–Delta Science 2016, describes advances during the past decade in understanding flow dynamics and how water-quality constituents move within California’s Sacramento– San Joaquin River Delta (Delta). Water-quality constituents include salinity, heat, oxygen, nutrients, contaminants, organic particles, and inorganic particles.
Authors
David H. Schoellhamer, Scott Wright, Stephen G. Monismith, Brian A. Bergamaschi
By
Water Resources Mission Area, California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Primary production in the Sacramento-San Joaquin Delta: A science strategy to quantify change and identify future potential

No abstract available.
Authors
April Robinson, Amy Richey, James E. Cloern, Katharyn E. Boyer, Jon Burau, Elizabeth A. Canuel, John F. DeGeorge, Judith Z. Drexler, E. R. Howe, Ronald Kneib, Anke Mueller-Solger, James L. Pinckney, Robert J. Naiman, David H. Schoellhamer, Charles A. Simenstad
By
Water Resources Mission Area

Suspended-sediment dynamics in the tidal reach of a San Francisco Bay tributary

To better understand suspended-sediment transport in a tidal slough adjacent to a large wetland restoration project, we deployed continuously measuring temperature, salinity, depth, turbidity, and velocity sensors in 2010 at a near-bottom location in Alviso Slough (Alviso, California, USA). Alviso Slough is the downstream reach of the Guadalupe River and flows into the far southern end of San Fran
Authors
Gregory Shellenbarger, Maureen A. Downing-Kunz, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center

Modeling tidal freshwater marsh sustainability in the Sacramento-San Joaquin Delta under a broad suite of potential future scenarios

In this paper, we report on the adaptation and application of a one-dimensional marsh surface elevation model, the Wetland Accretion Rate Model of Ecosystem Resilience (WARMER), to explore the conditions that lead to sustainable tidal freshwater marshes in the Sacramento–San Joaquin Delta. We defined marsh accretion parameters to encapsulate the range of observed values over historic and modern ti
Authors
Kathleen M. Swanson, Judith Z. Drexler, Christopher C. Fuller, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Suspended-sediment trapping in the tidal reach of an estuarine tributary channel

Evidence of decreasing sediment supply to estuaries and coastal oceans worldwide illustrates the need for accurate and updated estimates. In the San Francisco Estuary (Estuary), recent research suggests a decrease in supply from its largest tributaries, implying the increasing role of smaller, local tributaries in sediment supply to this estuary. Common techniques for estimating supply from tribut
Authors
Maureen A. Downing-Kunz, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center

Science and Products

link
Map of San Francisco Bay

San Francisco Bay Wetlands Priority Ecosystem Studies

The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
By
California Water Science Center
link

San Francisco Bay Wetlands Priority Ecosystem Studies

The U.S. Fish & Wildlife Service's (USFWS) San Francisco Bay National Wildlife Refuge manages wildlife at a number of salt ponds that the Cargill Corporation currently operates for salt production. A number of these ponds probably will be purchased by the USFWS. With acquisition, the USFWS will be responsible for maintenance or restoration of thousands of hectares of wetlands, an extremely complex...
Learn More
link
Invasive Aquatic Vegetation

Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems

The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
By
California Water Science Center, Pacific Coastal and Marine Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
link

Ecosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems

The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
Learn More
link
Estuary and bird

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.
By
California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
link

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.
Learn More
link
USGS research vessel mapping in Alviso Slough in south San Francisco Bay

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in deciding...
By
California Water Science Center
link

Improved Lower South Bay suspended-sediment flux measurements

Tidal marshes provide animal habitats and prevent erosion. Expanding towns and cities have claimed major parts of San Francisco Bay’s marshland. Sediment deposits are essential to rebuilding tidal marshes and keeping existing marshes intact. In the southern part of the Bay, the largest tidal wetland restoration project on the west coast is underway. Sediment flux measurements are key in deciding...
Learn More

ADCP Data in Support of Water and Suspended-Sediment Flux Measurements at the Golden Gate, 2016-2017

Field observations of water and suspended-sediment fluxes at the Golden Gate were made over one ebb tide and one flood tide on three occasions: 1) 21-22 March 2016, following a large storm event that triggered the first flow into Yolo Bypass flood control structure since 2011; 2) 23 June of 2016, during a period of low freshwater inflow and 3) 27-28 February 2017, following several large storms of
By
California Water Science Center
Filter Total Items: 150

Sediment supply to San Francisco Bay, water years 1995 through 2016: Data, trends, and monitoring recommendations to support decisions about water quality, tidal wetlands, and resilience to sea level rise

Knowledge of the status and trends of sediment supply to San Francisco Bay is critically important for management decisions about dredging, marsh restoration, flood control, contaminants, water clarity (in relation to primary production), and sea level rise. Several sitespecific studies of sediment supply to San Francisco Bay have been conducted, but no synthesis of recent studies is available. Th
Authors
David H. Schoellhamer, Lester McKee, Sarah Pearce, Pete Kauhanen, Micha Saloman, Scott Dusterhoff, J. Letitia Grenier, Mathieu D. Marineau, Philip Trowbridge
By
Water Resources Mission Area, California Water Science Center

Measurements of erosion potential using Gust chamber in Yolo Bypass near Sacramento, California

This report describes work performed to quantify the erodibility of surface soils in the Yolo Bypass (Bypass) near Sacramento, California, for use in the California Department of Water Resources (DWR) Yolo Bypass D-MCM mercury model. The Bypass, when not serving as a floodway, is heavily utilized for agriculture. During flood events, surface water flows over the soil, resulting in the application
Authors
Paul A. Work, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay (bay) as part of a multi-agency effort to address management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the bay teems both with resident and with migratory wildlife, plants, and fish. Freshwater mixes with salt water in the ba
Authors
Paul A. Buchanan, Maureen A. Downing-Kunz, David H. Schoellhamer, Daniel N. Livsey
By
Water Resources Mission Area, California Water Science Center

Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 3
Authors
David H. Schoellhamer, Andrew J. Manning, Paul A. Work
By
Water Resources Mission Area, California Water Science Center

Primary production in the Delta: Then and now

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it i
Authors
James E. Cloern, April Robinson, Amy Richey, Letitia Grenier, Robin Grossinger, Katharyn E. Boyer, Jon Burau, Elizabeth A. Canuel, John F. DeGeorge, Judith Z. Drexler, Chris Enright, Emily R. Howe, Ronald Kneib, Anke Mueller-Solger, Robert J. Naiman, James L. Pinckney, Samuel M. Safran, David H. Schoellhamer, Charles A. Simenstad
By
Water Resources Mission Area, California Water Science Center

The effect of submerged aquatic vegetation expansion on a declining turbidity trend in the Sacramento-San Joaquin River Delta

Submerged aquatic vegetation (SAV) has well-documented effects on water clarity. SAV beds can slow water movement and reduce bed shear stress, promoting sedimentation and reducing suspension. However, estuaries have multiple controls on turbidity that make it difficult to determine the effect of SAV on water clarity. In this study, we investigated the effect of primarily invasive SAV expansion on
Authors
E.L. Hestir, David H. Schoellhamer, Jonathan Greenberg, Tara L. Morgan-King, S.L. Ustin
By
Water Resources Mission Area, California Water Science Center

Review of suspended sediment in lower South Bay relevant to light attenuation and phytoplankton blooms

Lower South Bay (LSB), a shallow subembayment of San Francisco Bay (SFB), is situated south of the Dumbarton Bridge, and is surrounded by, and interconnected with, a network of sloughs, marshes, and former salt ponds undergoing restoration (Figure ES.1). LSB receives 120 million gallons per day of treated wastewater effluent from three publicly owned treatment works (POTWs) that service San Jose a
Authors
David H. Schoellhamer, Gregory Shellenbarger, Maureen A. Downing-Kunz, Andrew J. Manning
By
Water Resources Mission Area, California Water Science Center

Recent advances in understanding flow dynamics and transport of water-quality constituents in the Sacramento–San Joaquin River Delta

This paper, part of the collection of research comprising the State of Bay–Delta Science 2016, describes advances during the past decade in understanding flow dynamics and how water-quality constituents move within California’s Sacramento– San Joaquin River Delta (Delta). Water-quality constituents include salinity, heat, oxygen, nutrients, contaminants, organic particles, and inorganic particles.
Authors
David H. Schoellhamer, Scott Wright, Stephen G. Monismith, Brian A. Bergamaschi
By
Water Resources Mission Area, California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Primary production in the Sacramento-San Joaquin Delta: A science strategy to quantify change and identify future potential

No abstract available.
Authors
April Robinson, Amy Richey, James E. Cloern, Katharyn E. Boyer, Jon Burau, Elizabeth A. Canuel, John F. DeGeorge, Judith Z. Drexler, E. R. Howe, Ronald Kneib, Anke Mueller-Solger, James L. Pinckney, Robert J. Naiman, David H. Schoellhamer, Charles A. Simenstad
By
Water Resources Mission Area

Suspended-sediment dynamics in the tidal reach of a San Francisco Bay tributary

To better understand suspended-sediment transport in a tidal slough adjacent to a large wetland restoration project, we deployed continuously measuring temperature, salinity, depth, turbidity, and velocity sensors in 2010 at a near-bottom location in Alviso Slough (Alviso, California, USA). Alviso Slough is the downstream reach of the Guadalupe River and flows into the far southern end of San Fran
Authors
Gregory Shellenbarger, Maureen A. Downing-Kunz, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center

Modeling tidal freshwater marsh sustainability in the Sacramento-San Joaquin Delta under a broad suite of potential future scenarios

In this paper, we report on the adaptation and application of a one-dimensional marsh surface elevation model, the Wetland Accretion Rate Model of Ecosystem Resilience (WARMER), to explore the conditions that lead to sustainable tidal freshwater marshes in the Sacramento–San Joaquin Delta. We defined marsh accretion parameters to encapsulate the range of observed values over historic and modern ti
Authors
Kathleen M. Swanson, Judith Z. Drexler, Christopher C. Fuller, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Suspended-sediment trapping in the tidal reach of an estuarine tributary channel

Evidence of decreasing sediment supply to estuaries and coastal oceans worldwide illustrates the need for accurate and updated estimates. In the San Francisco Estuary (Estuary), recent research suggests a decrease in supply from its largest tributaries, implying the increasing role of smaller, local tributaries in sediment supply to this estuary. Common techniques for estimating supply from tribut
Authors
Maureen A. Downing-Kunz, David H. Schoellhamer
By
Water Resources Mission Area, California Water Science Center
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