Emeritus Scientist
Office of the Chief Operating Officer
Email:
jecloern@usgs.gov
Office Phone:
650-329-4594
ORCID:
0000-0002-5880-6862
Supervisor:
Dorothea (Dot) J Lundberg
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The U.S. Geological Survey maintains a program of water-quality studies in San Francisco Bay (CA) that began in 1969. This U.S.G.S. Data Release archives and makes available all measurements from 2016-2021, and is a continuation of the previously published 1969-2015 dataset (Cloern and Schraga, 2016; Schraga and Cloern, 2017). 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). The sampling was conducted at least monthly at 37 fixed sampling locations along a 145-km transect from lower South San...
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Phytoplankton photosynthesis drives many biogeochemical and ecological processes in lakes, estuaries, and the ocean. For example, dynamic changes in pH, trace metal speciation, and concentrations of dissolved gases (oxygen, carbon dioxide, methane), inorganic nutrients (nitrate, phosphate, silicate), and organic compounds (amino acids, organosulfur compounds) are all closely associated with fluctuations in phytoplankton photosynthesis. Trophic linkages also exist, between the phytoplankton as primary producers and populations of consumer organisms including bacteria, zooplankton, benthic invertebrates, and fish. Our scientific understanding of lakes and estuaries as dynamic ecosystems is therefore dependent upon...
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This Data Release makes available measurements of phytoplankton species composition, abundance and cell size made on samples collected in San Francisco Bay (CA) from April 1992 through March 2014. Phytoplankton samples were collected at 31 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 (map of sampling locations is available on the project website at: https://sfbay.wr.usgs.gov/access/wqdata/overview/wherewhen/stnmap.html). Whole water samples were preserved with acid Lugol’s solution, and 2 to 50 ml aliquots were settled in chambers for 6 to 24...
Categories: Data;
Tags: Aquatic Biology,
California,
Ecology,
San Francisco Bay,
USGS Science Data Catalog (SDC), All tags...
Water Quality,
diatom,
dinoflagellate,
estuary,
microalgae,
microscopy,
phytoplankton,
taxonomy, Fewer tags
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This dataset is a compilation of multiple studies over different periods and in many environments as described below. These data were collected to measure temporal fluctuations in plant isotopic composition associated with seasonal cycles of growth and environmental variability. In 1990, 1992, and 1998-2000, a total of 868 samples were collected and analyzed to determine carbon and nitrogen mass and 13C:12C and 15N:14N ratios by mass spectrometry. Intensive sampling was done in 1999 when species of vascular plants common to wetlands of northern California were sampled biweekly to monthly for one year along a gradient of habitats (salt-marsh creek, freshwater brackish marsh, seasonal wetland) within the San Francisco...
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