thumbnail

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

Fact Sheet 2018-3013

By:
ORCID iD , ORCID iD , ORCID iD , and ORCID iD
https://doi.org/10.3133/fs20183013

Links

Abstract

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 bay, which is subject both to riverine influences (floods, droughts, managed reservoir releases and freshwater diversions) and to marine influences (tides, waves, effects of salt water). To understand this environment, the USGS, along with its partners (see “Acknowledgements”), has been monitoring the bay’s waters continuously since 1988. Several water-quality variables are of particular importance to State and Federal resource managers and are monitored at key locations throughout the bay (fig. 1). Salinity, which indicates the relative mixing of fresh and ocean waters in the bay, is derived from specific conductance measurements. Water temperature, along with salinity, affects the density of water, which controls gravity-driven circulation patterns and stratification in the water column. Turbidity, a measure of light scattered from suspended particles in the water, is used to estimate suspended-sediment concentration (SSC). Suspended sediment affects the bay in multiple ways: attenuation of sunlight in the water column, affecting phytoplankton growth; deposition on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; deposition in ports and shipping channels, which can necessitate dredging; and often, adsorption of contaminants, affecting their distribution and concentrations in the environment. Dissolved oxygen concentration, essential to a healthy ecosystem and a fundamental indicator of water quality, is affected by water temperature, salinity, ecosystem metabolism, tidal currents, and wind. Tidal currents in the bay reverse four times a day, and wind direction and intensity typically vary on a daily cycle. Consequently, salinity, water temperature, SSC, and dissolved-oxygen concentration vary spatially and temporally throughout the bay. Therefore, continuous measurements are needed to observe these changes. The purpose of this fact sheet is to provide information about these variables, as well as internet links to access these continuous water-quality data collected by the USGS.

Suggested Citation

Buchanan, P.A., Downing-Kunz, M.A., Schoellhamer, D.H., and Livsey, D.N., 2018, Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15 (ver. 1.1, May 2018): U.S. Geological Survey Fact Sheet 2018–3013, 5 p., https://doi.org/10.3133/fs20183013.

ISSN: 2327-6932 (online)

Study Area

Additional publication details

Publication type:
Report
Publication Subtype:
USGS Numbered Series
Title:
Continuous water-quality and suspended-sediment transport monitoring in the San Francisco Bay, California, water years 2014–15
Series title:
Fact Sheet
Series number:
2018-3013
DOI:
10.3133/fs20183013
Edition:
Version 1.0: March 8, 2018; Version 1.1: May 15, 2018
Year Published:
2018
Language:
English
Publisher:
U.S. Geological Survey
Publisher location:
Reston, VA
Contributing office(s):
California Water Science Center
Description:
5 p.
Country:
United States
State:
California
Other Geospatial:
San Francisco Bay