Continuous water-quality and suspended-sediment transport monitoring in San Francisco Bay, California, water years 2020–21

U.S. Geological Survey (USGS) | December 29th, 2022

Continuous Water-Quality and Suspended-Sediment Transport Monitoring in the San Francisco Bay, California, Water Years 2011–13

U.S. Geological Survey (USGS) | September 23rd, 2014

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of peop

The U.S. Geological Survey (USGS) monitors water quality and suspended-sediment transport in the San Francisco Bay. The San Francisco Bay area is home to millions of people, and the bay teems with both resident and migratory wildlife, plants, and fish. Fresh water mixes with salt water in the bay, which is subject both to riverine and marine (tides, waves, influx of salt water) influences. 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 causes gravity driven circulation patterns and stratification in the water column. Turbidity is measured using light-scattering from suspended solids in water, and is used as a surrogate for suspended-sediment concentration (SSC). Suspended sediment often carries adsorbed contaminants; attenuates sunlight in the water column; deposits on tidal marsh and intertidal mudflats, which can help sustain these habitats as sea level rises; and deposits in ports and shipping channels, which can necessitate dredging. Dissolved oxygen, which is essential to a healthy ecosystem, is a fundamental indicator of water quality, and its concentration 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 change on a daily cycle: consequently, salinity, water temperature, suspended sediment concentration, and dissolved oxygen concentration vary spatially and temporally throughout the bay, and continuous measurements are needed to observe these changes. The purpose of this fact sheet is to inform the public and resource managers of the availability of these water-quality data.

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

U.S. Geological Survey (USGS) | April 28th, 2020

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 add

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 the Bay and is subject to riverine influences (floods, droughts, managed reservoir releases, and freshwater diversions) and marine influences (tides, waves, and effects of salt water). To understand this environment, the USGS along with its cooperators (see “Acknowledgments”), has been monitoring the Bay’s waters continuously since 1988.

Control of the Clear Lake Gnat in California

Entomological Society of America (ESA) | August 1st, 1951

Critical Aquifer Overdraft Accelerates Degradation of Groundwater Quality in California's Central Valley During Drought

American Geophysical Union (AGU) | September 1st, 2021

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. 

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. This study examined 30 yr of data from California's Central Valley to find dramatic groundwater-level declines during drought were associated with worsening groundwater quality. This likely happens because increased pumping during drought can draw shallow, contaminated groundwater to depths commonly tapped by public drinking water wells. This is the first study of its kind to show direct linkages between drought and groundwater quality at such a broad spatial scale

Critical Assessment of the Delta Smelt Population in the San Francisco Estuary, California

University of California, Davis (UC Davis) | July 1st, 2005

Cruise Plan: 2016 Regional Monitoring Program (RMP) Bivalve Deployment Cruise

San Francisco Estuary Institute (SFEI) | June 2nd, 2016

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) bivalve deployment cruise. This Cr

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP) bivalve deployment cruise. This Cruise Plan was developed based upon the decisions of the RMP Technical Review Committee in 2002 to reduce the number of bivalve transplant stations from twelve to nine, utilize deployment cages rather than bags at all stations, and deploy only Mytilus californianus. These changes went into effect with the 2003 program and continued through the 2012 deployments. In 2014, the RMP Technical Review Committee reduced bivalve deployment transplant stations from 9 to 7 stations, 3 of which are back-up deployment sites. In addition, as instituted initially with the 2006 deployments, there is no mid-deployment maintenance cruise, as previous analyses showed no difference in bivalve growth or survival between maintained and unmaintained deployments. 

Cruise Plan: 2016 Regional Monitoring Program (RMP) Bivalve Retrieval Cruise

San Francisco Estuary Institute (SFEI) | September 27th, 2016

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) bivalve retrieval cruise. This Cruise Plan

This report details plans associated with the biennial Regional Monitoring Program for Water Quality in San Francisco Bay (RMP) bivalve retrieval cruise. This Cruise Plan was developed based upon the decisions of the RMP Technical Review Committee in 2002 to reduce the number of bivalve transplant stations from twelve to nine, utilize deployment cages rather than bags at all stations, and deploy only Mytilus californianus. These changes went into effect with the 2003 program and continued through the 2012 deployments. In 2014, the RMP Technical Review Committee reduced bivalve deployment transplant stations from 9 to 7 stations, 3 of which are back-up deployment sites. In addition, as instituted initially with the 2006 deployments, there is no mid-deployment maintenance cruise, as previous analyses showed no difference in bivalve growth or survival between maintained and unmaintained deployments. 

Cruise Report 2016 Regional Monitoring Plan (RMP) Bivalve Deployment Cruise, June 28 – July 1, 2016

San Francisco Estuary Institute (SFEI) | July 7th, 2016

This report describes activities associated with the 2016 bivalve deployment cruise of the Regional Monitoring Program (RMP). Measurement of contaminant concentrations in

This report describes activities associated with the 2016 bivalve deployment cruise of the Regional Monitoring Program (RMP). Measurement of contaminant concentrations in transplanted bivalves accumulated during dry season deployment is designed to provide long-term data on the bioaccumulation of select trace elements and trace organic compounds in tissue throughout the Estuary. 

Cruise Report: 2016 Regional Monitoring Program (RMP) Bivalve Retrieval Cruise, September 30 – October 13, 2016

San Francisco Estuary Institute (SFEI) | November 3rd, 2016

This report describes activities associated with the 2016 bivalve retrieval cruise of the Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP)

This report describes activities associated with the 2016 bivalve retrieval cruise of the Regional Monitoring Program for Water Quality in the San Francisco Estuary (RMP). Measurement of contaminant concentrations in transplanted bivalves accumulated during dry season deployment is designed to provide long-term data on the bioaccumulation of trace elements and trace organic compounds in tissue throughout the Estuary.