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Phytoplankton Species Composition, Abundance and Cell Size in San Francisco Bay: Microscopic Analyses of USGS Samples, beginning in 2014 (ver. 2.0, April 2019)

Metadata Updated: October 28, 2023

This Data Release makes available measurements of phytoplankton species composition, abundance and cell size made on samples collected in San Francisco Bay (CA) from January 2014 through December 2018. Whole water phytoplankton samples were collected at least monthly at fixed sampling stations along a 145-km transect where the variability of salinity, temperature, turbidity and nutrient concentrations reflected a broad range of environmental factors that regulate phytoplankton growth and abundance. A map and table of sampling locations are included in this Data Release. Immediately after samples were collected, they were preserved with acid Lugol’s solution. The samples were analyzed by BSA Environmental Services, Inc following the McNabb (1960) filter method. Following standard methods, at least 400 natural units (colonies, filaments, and unicells) were enumerated to the lowest possible taxonomic level from each sample. In 2014 and 2015, abundances were estimated by random field counts with at least 100 cells of the most numerous taxon counted. From 2016 onward, the 400 natural unit tally was met using two separate random field count efforts: (1) at least 100 natural units of organisms smaller than or equal to 5 μm were identified and enumerated; and (2) at least 300 natural units of organisms larger than 5 μm were identified and enumerated. The 2016 method was adopted to maximize detection of large but rare cells. For all data, cell volumes for each taxon were estimated with the formulas for solid geometric shapes that most closely matched the cell shape according to Hillebrand et al. (1999). Cell volume calculations were based on measurements of up to ten organisms for the most abundant taxa. The Biovolume (cubic microns per ml) of each taxon was computed as the product of abundance (cells per ml) and cell volume (cubic microns per cell). In order to assess replication of results, 10 duplicate samples were collected and analyzed in 2017 and are reported here. Hillebrand, H., Dürselen, C.-D., Kirschtel, D., Pollingher, U. and Zohary, T. 1999. Biovolume Calculation for Pelagic and Benthic
Microalgae. Journal of Phycology, 35: 403–424. doi:10.1046/j.1529-8817.1999.3520403.x McNabb, C. D. 1960. Enumeration of freshwater phytoplankton concentrated on the membrane filter. Limnol. Oceanog., 5: 57-61.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Metadata Created Date June 1, 2023
Metadata Updated Date October 28, 2023

Metadata Source

Harvested from DOI EDI

Additional Metadata

Resource Type Dataset
Metadata Created Date June 1, 2023
Metadata Updated Date October 28, 2023
Publisher U.S. Geological Survey
Identifier USGS:598b755de4b09fa1cb0eadd9
Data Last Modified 20200818
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context
Metadata Catalog ID
Schema Version
Catalog Describedby
Harvest Object Id 7e2a94da-e13f-4938-85b7-c80e770028eb
Harvest Source Id 52bfcc16-6e15-478f-809a-b1bc76f1aeda
Harvest Source Title DOI EDI
Metadata Type geospatial
Old Spatial -122.47167,37.47167,-121.68833,38.15167
Publisher Hierarchy White House > U.S. Department of the Interior > U.S. Geological Survey
Source Datajson Identifier True
Source Hash cef276674919e999228fe5c6d2fc5d1e9d0bec39499c9b032ade32f77855a582
Source Schema Version 1.1
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