Skip to main content
U.S. flag

An official website of the United States government

David Schoellhamer (Former Employee)

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
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
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: 151

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
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
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
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
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
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.
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
By
Water Resources Mission Area, California Water Science Center

Estimation of historic flows and sediment loads to San Francisco Bay,1849–2011

River flow and sediment transport in estuaries influence morphological development over decadal and century time scales, but hydrological and sedimentological records are typically too short to adequately characterize long-term trends. In this study, we recover archival records and apply a rating curve approach to develop the first instrumental estimates of daily delta inflow and sediment loads to
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
By
Water Resources Mission Area, California Water Science Center

Optimum sampling strategy for sediment-associated pesticides in Suisun Bay

The purpose of this study was to develop a twice-a-day sampling strategy for suspended solids concentration at Mallard Island that best reproduces the residual (tidally averaged) near-surface suspended solids concentration computed using the entire time series (96 sampling times per day) for high delta discharge conditions and to use this stratgy for sampling sediment-associated pesticides vvaried

Tidal and vertical variability of floc characteristics

No abstract available.

1993 Annual Report: San Francisco estuary regional monitoring program for trace substances

This first annual report of the San Francisco Estuary Regional Monitoring Program contains the results of monitoring measurements made in 1993. Measurements of conventional water quality parameters and trace contaminant concentrations were made at 16 stations throughout the Estuary three times during the year: the wet period (March), during declining Delta outflow (May), and during the dry period

Science and Products