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USGS Measurements of Water Quality in San Francisco Bay (CA), 1969-2015 (ver. 4.0, March 2023)


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Cloern, J.E., and Schraga, T.S., 2016, USGS Measurements of Water Quality in San Francisco Bay (CA), 1969-2015 (ver. 4.0, March 2023): U. S. Geological Survey data release,


The U.S. Geological Survey maintains a program of water-quality studies in San Francisco Bay (CA) that began in 1969. This USGS data release archives and makes available all measurements from 1969-2015. Water-quality constituent measurements include salinity, temperature, light attenuation coefficient, and concentrations of chlorophyll-a, dissolved oxygen, suspended particulate matter, and dissolved inorganic nutrients (nitrate, nitrite, ammonium, phosphate and silicate). Since the mid-1990s, sampling was conducted at least monthly at 37 fixed sampling locations along a 145-km transect from lower South San Francisco Bay to the lower Sacramento River. A map and table of sampling locations are included in the Attached Files section. [...]


Point of Contact :
Tara Schraga
Originator :
James Cloern, Tara Schraga
Metadata Contact :
James Cloern
Publisher :
U. S. Geological Survey
Distributor :
U.S. Geological Survey - ScienceBase
USGS Mission Area :
Water Resources
SDC Data Owner :
Office of the Associate Director for Water

Attached Files

Click on title to download individual files attached to this item.

“Map of Stations”
830.77 KB application/pdf
“Table of Station Locations”
2.52 KB text/csv
“Data 1969-2015”
13.82 MB text/csv
VersionHistory.txt 2.59 KB text/plain
sfbaymap.jpg thumbnail 362.75 KB image/jpeg


The dataset was collected to measure spatial and temporal patterns of water-quality variability in San Francisco Bay as a component of long-term research to understand how estuarine-coastal ecosystems change in response to human activities and climate variability.
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  • USGS Data Release Products

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Revision 4.0 by Tara Scharaga on March 30, 2023. To review the changes that were made, see “VersionHistory.txt” in the attached files section. In May 2017, the data authors discovered that a small subset of the silicate measurements made between January 2011 and February 2014 have questionable reliability. The authors removed these data in the revised file: "SanFranciscoBayWaterQualityData1969-2015v3.csv". On 27 December 2016, the data authors discovered that the data file associated with this data release had an error. The original data file had inconsistencies in the format of dates. The author corrected that error in the attached data file "SanFranciscoBayWaterQualityData1969-2015v2.csv".

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