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Maureen Downing-Kunz (Former Employee)

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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.
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California Water Science Center, Pacific Coastal and Marine Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
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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.
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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.
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California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary
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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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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...
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California Water Science Center
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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...
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Tule Perch

Understanding Influences on Habitat Quality for Delta Smelt and Other Imperiled Fish Populations

USGS scientists work to provide information needed to evaluate the efficacy of ongoing U.S. Burueau of Reclamation water management efforts in Bay-Delta.
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California Water Science Center
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Understanding Influences on Habitat Quality for Delta Smelt and Other Imperiled Fish Populations

USGS scientists work to provide information needed to evaluate the efficacy of ongoing U.S. Burueau of Reclamation water management efforts in Bay-Delta.
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Erodibility Data from Gust Erosion Chamber Experiments in Grizzly Bay and San Pablo Bay, California, Winter 2020

A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained from San Pablo and Grizzly (within Suisun) Bays in California. A pair of sediment cores were collected from the same approximate locations in each bay five times between January 22nd, 2020 and March 11th, 2020 for a total of 10 experiments and 20 sediment core results. Locations were chosen to capture the b
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California Water Science Center

Erodibility Data from Gust Erosion Chamber Experiments in Grizzly Bay and San Pablo Bay, California, Summer 2019

A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained from San Pablo and Grizzly (within Suisun) Bays in California. A pair of sediment cores were collected from the same approximate locations in each bay six times between June 12th, 2019 and August 15th, 2019 for a total of 12 experiments and 24 sediment core results. Locations were chosen to capture the bent
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California Water Science Center

Sediment Concentration, Water Velocity, and Suspended Particle Size and Settling Data to Estimate Estuarine Sediment Flux at Dumbarton Bridge, San Francisco Bay, CA from 2018 - 2019

Measurements of suspended sediment concentration, water velocity, suspended-sediment particle size, and suspended-sediment particle settling velocity were collected to estimate suspended-sediment flux and investigate sediment transport processes at Dumbarton Bridge in San Francisco Bay (NWIS station 373015122071000) from calendar year 2018 to 2019. Data were collected using: stationary and boat-mo
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California Water Science Center

Sediment Concentration and Velocity Data to Assess Trapping by Submerged Vegetation

The acoustic Doppler current meter (ADCP) used in this study outputs binary data files containing measurement scheme, location, time, velocity, backscatter, boat heading, depth, and other parameters. These data are provided here in the manufacturer's "classic ASCII" format, as described in READMEforADCP.txt file associated with this data release. We also collected water samples for suspended-sedim
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California Water Science Center

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
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California Water Science Center
Scientist sample for suspended sediment by boat near the Golden Gate Bridge on a calm sunny day.
Measuring suspended sediment in San Francisco Bay
Measuring suspended sediment in San Francisco Bay
Scientist sample for suspended sediment by boat near the Golden Gate Bridge on a calm sunny day.

Measuring suspended sediment in San Francisco Bay

Measuring suspended sediment in San Francisco Bay

USGS researchers collect water samples from the Research Vessel Dorah Henry to measure suspended sediment concentration in Central San Francisco Bay. Samples were collected using a D-96 sampler that collects samples over the entire depth of the water column allowing for a  depth-integrated sample.

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California Water Science Center
Scientist sample for suspended sediment by boat near the Golden Gate Bridge on a calm sunny day.

Measuring suspended sediment in San Francisco Bay

Measuring suspended sediment in San Francisco Bay

USGS researchers collect water samples from the Research Vessel Dorah Henry to measure suspended sediment concentration in Central San Francisco Bay. Samples were collected using a D-96 sampler that collects samples over the entire depth of the water column allowing for a  depth-integrated sample.

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California Water Science Center
Filter Total Items: 19

Physics to fish—Understanding the factors that create and sustain native fish habitat in the San Francisco Estuary

Executive SummaryThe Bureau of Reclamation (Reclamation) operates the Central Valley Project (CVP), one of the nation’s largest water projects. Reclamation has an ongoing need to improve the scientific basis for adaptive management of the CVP and, by extension, joint operations with California’s State Water Project. The U.S. Geological Survey (USGS) works cooperatively with the Bureau of Reclamati
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Larry R. Brown, David E. Ayers, Brian A. Bergamaschi, Jon R. Burau, Evan T. Dailey, Bryan D. Downing, Maureen A. Downing-Kunz, Frederick V. Feyrer, Brock M. Huntsman, Tamara E. C. Kraus, Tara Morgan, Jessica R. Lacy, Francis Parchaso, Catherine A. Ruhl, Elizabeth B. Stumpner, Paul Stumpner, Janet Thompson, Matthew J. Young
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Water Resources Mission Area, California Water Science Center, Pacific Coastal and Marine Science Center

South San Francisco Bay Salt Pond Restoration Project—A synthesis of Phase-1 mercury studies

The South Bay Salt Pond Restoration Project (SBSPRP) encompasses over 6,000 hectares of former salt production ponds along the south edge of the San Francisco Bay and represents the largest wetland restoration effort on the west coast of North America. A series of studies associated with Phase 1 (2010–2018) restoration activities that are focused on a historically mercury contaminated slough and s
Authors
Mark Marvin-DiPasquale, Darell Slotton, Josh T. Ackerman, Maureen A. Downing-Kunz, Bruce E. Jaffe, Amy C. Foxgrover, Fernanda Achete, Mick van der Wegen
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Water Resources Mission Area, Ecosystems Mission Area, California Water Science Center, Pacific Coastal and Marine Science Center, Western Ecological Research Center (WERC)

Suspended-sediment Flux in the San Francisco Estuary; Part II: the Impact of the 2013–2016 California Drought and Controls on Sediment Flux

Recent modeling has demonstrated that sediment supply is one of the primary environmental variables that will determine the sustainability of San Francisco Estuary tidal marshes over the next century as sea level rises. Therefore, understanding the environmental controls on sediment flux within the San Francisco Estuary is crucial for optimal planning and management of tidal marsh restoration. Her
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Daniel N. Livsey, Maureen A. Downing-Kunz, David H. Schoellhamer, Andrew J. Manning
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Water Resources Mission Area, California Water Science Center

Trapping of suspended sediment by submerged aquatic vegetation in a tidal freshwater region: Field observations and long-term trends

Widespread invasion by non-native, submerged aquatic vegetation (SAV) may modify the sediment budget of an estuary, reducing the availability of inorganic sediment required by marshes to maintain their position in the tidal frame. The instantaneous trapping rate of suspended sediment in SAV patches in an estuary has not previously been quantified via field observations. In this study, flows of wat
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Paul A. Work, Maureen A. Downing-Kunz, Judith Z. Drexler
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Water Resources Mission Area, California Water Science Center

A summary of water-quality monitoring in San Francisco Bay in water year 2017

This report summarizes the activities of the U.S. Geological Survey (USGS) San Francisco Bay Water-Quality Monitoring and Sediment Transport Project during water year 2017, including an explanation of methods employed, stations operated, and a graphical summary of data for the period of record for stations operational in water year 2017. In cooperation with partner agencies, the USGS maintains a n
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Daniel N. Livsey, Maureen A. Downing-Kunz
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Water Resources Mission Area, California Water Science Center

State of the network: Long-term, high-frequency flow and water quality data in the San Francisco Estuary, California

The USGS California Water Science Center is heavily involved in the measurement of flow and water quality parameters in the San Francisco Estuary, with support from many partner agencies. The California Department of Water Resources (DWR), through the Interagency Ecological Program (IEP) is one of those agencies. This article describes the resulting efforts and methodologies and provides examples

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Paul A. Work, Maureen A. Downing-Kunz
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Water Resources Mission Area, California Water Science Center

Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2016–17

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 estuary management, water supply, and ecological concerns. The San Francisco Bay area is home to millions of people, and the Bay teems with plants and both resident and migratory wildlife, and fish. Freshwater mixes with salt water in
Authors
Darin C. Einhell, Maureen A. Downing-Kunz, Daniel N. Livsey
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Water Resources Mission Area, California Water Science Center

Stratigraphic analysis of Corte Madera Creek flood control channel deposits

Sedimentation in a channel can reduce flood conveyance capability and potentially place nearby property and life at risk from flooding. In 1998, Marin County Public Works dredged the concrete-lined segment of Corte Madera Creek, which drains a hilly and largely urbanized watershed that terminates in San Francisco Bay, California. From then through 2015, approximately 4,100 cubic meters of sand and
Authors
Daniel N. Livsey, Paul A. Work, Maureen A. Downing-Kunz
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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
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Water Resources Mission Area, California Water Science Center

Record-high specific conductance and water temperature in San Francisco Bay during water year 2015

The San Francisco estuary is commonly defined to include San Francisco Bay (bay) and the adjacent Sacramento–San Joaquin River Delta (delta). The U.S. Geological Survey (USGS) has operated a high-frequency (15-minute sampling interval) water-quality monitoring network in San Francisco Bay since the late 1980s (Buchanan and others, 2014). This network includes 19 stations at which sustained measure
Authors
Paul A. Work, Maureen A. Downing-Kunz, Daniel N. Livsey
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Water Resources Mission Area, California Water Science Center, San Francisco Bay and Sacramento-San Joaquin Delta Estuary

Dissolved oxygen: Chapter 6

Dissolved oxygen (DO) concentration serves as an important indicator of estuarine habitat condition, because all aquatic macro-organisms require some minimum DO level to survive and prosper. The instantaneous DO concentration, measured at a specific location in the water column, results from a balance between multiple processes that add or remove oxygen (Figure 6.1): primary production produces O2
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David Senn, Maureen A. Downing-Kunz, Emily Novick
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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
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Water Resources Mission Area, California Water Science Center
USGS Science at Work in the San Francisco Bay Estuary

USGS Science at Work in the San Francisco Bay Estuary

In an article written for the Interagency Ecological Program for the San Francisco Estuary, Dr. Paul Work and Dr. Maureen Downing-Kunz, of the...

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