Data on denitrification and ecological characteristics of nontidal floodplains, Chesapeake Bay watershed, USA, 2013-2016
This data set presents attributes of floodplain ecosystem characteristics including floodplain soil denitrification, floodplain soil biogeochemistry, floodplain vegetation, floodplain sedimentation, floodplain and channel morphometry, stream discharge and water quality, floodplain climate, floodplain physiographic region, and catchment land cover. Attributes are associated with 18 floodplains of the Chesapeake Bay watershed. For many of these attributes, mean values are summaries of multiple measurements made within each floodplain site.
Isotopic and chemical composition (δ13C, Δ14C, δ15N, C:N, SUVA254nm, % HPOA) of aquatic carbon and field conditions (water temperature, pH, discharge) in the Upper Mississippi River Basin, October 2014 – February 2016
This dataset contains stable isotope (δ13C) and radioisotope (Δ14C) compositions of dissolved inorganic carbon, dissolved organic carbon, particulate organic carbon, and bed material organic carbon samples collected from rivers in the Upper Mississippi River Basin between October 2014 and February 2016. Rivers were sampled at USGS gaging stations: Minnesota River at Fort Snelling State Park, MN (gage #05330920), Mississippi River at Hwy 610 in Brooklyn Park, MN (gage #05288500), St. Croix River at Prescott, WI (gage #05344490), Mississippi River at Prescott, WI (gage #05344500), and Chippewa River at Durand, WI (gage #05369500). One site was also sampled at a location that is not co-located with a gaging station:...
Shallow Sediment Geochemical Data for the Cache Creek Settling Basin, Yolo County, California, 2010–17
This dataset includes shallow surface sediment (top 0–2 cm interval) constituent concentration data (primarily) and microbial methylmercury production potential rate data (limited) collected from the Cache Creek Settling Basin (CCSB), Yolo County, California, between April 2010 and July 2017. The dataset includes up to 706 observations (including field replicates) per sediment parameter, reflecting 93 unique sampling locations, with each location having been sampled from 1 to 28 times (excluding field replicates) over this 8-year period. There were four spatially intensive field campaigns conducted (February–March 2013, May 2013, October–November 2014, and January–March 2015), during which at least 90 sites were...
Data for Biogeochemical and Physical Processes Controlling Mercury Methylation and Bioaccumulation in Lake Powell, Glen Canyon National Recreation Area, Utah and Arizona, 2014-2015
This dataset includes the field measurements and laboratory analyses of surface water, seston, and sediment collected from Lake Powell, within Glen Canyon National Recreation area (GLCA), during high flow (May-June 2014) and low flow (August 2015) conditions. The study area includes 12-13 sampling sites that follow a transect spanning the entire length of the reservoir from the Colorado River inflow to the Glen Canyon dam, as well as the San Juan River arm, the Escalante River arm and West Canyon. Bed sediment samples were analyzed for mercury speciation, methylmercury production and degradation rates, total reduced sulfur, iron speciation, organic content, and 16S rRNA gene templates as a proxy for microbial abundances....
This dataset contains water chemistry measurements for all wetlands in the Cottonwood Lake Study Area, Stutsman County, North Dakota.
Mercury speciation and other constituent data from deep sediment cores in Alviso Slough, South San Francisco Bay, California, 2012-16.
This dataset includes mercury and other constituent concentration and physical properties data for seven deep sediment profiles (ranging from 79 cm to 214 cm in length) collected from the thalwag of Alviso Slough, a major tributary to South San Francisco Bay (California, USA). Field sampling occurred during May 2012 (4 sites) and January 2016 (3 sites). Each profile was comprised of 1–4 core sub-sections, which were collected from adjacent boreholes with 10–18 cm of vertical overlap. This data product includes two data tables (*.csv): 1) ‘T1_ALSL_DC_Sed_Data.csv’, the deep core analytical results; 2) ‘T2_ALSL_DC_QA_Data.csv’, quality assurance data. The two image files, ‘ALSL_DC_Log_2012.pdf’ and ‘ALSL-DC_Log_2016.pdf’,...
This dataset contains water chemistry measurements for groundwater wells in the Cottonwood Lake Study Area, Stutsman County, North Dakota.
USGS Measurements of Dissolved and Suspended Particulate Material Selenium in Lake Koocanusa in the Vicinity of Libby Dam (MT), 2015-2017 (update)
IMPORTANT NOTE: Data and supporting information from samples collected during 2015-16 can be can be accessed from this link. The U.S. Geological Survey is studying Lake Koocanusa, a border reservoir between British Columbia in Canada and Montana, in collaboration with the Montana Department of Environmental Quality and the U.S. Environmental Protection Agency (Region 8). This work is part of a multi-agency project to apply an ecosystem-scale selenium modeling methodology (Presser and Luoma, 2010) to the lake to support development of site-specific selenium guidelines for the protection of aquatic life. A conceptual model framework was published in 2017 (Jenni, Naftz, and Presser, 2017) to serve as a coherent and...
USGS Measurements of Dissolved and Suspended Particulate Material Selenium in Lake Koocanusa in the Vicinity of Libby Dam (MT), 2015-2016
IMPORTANT NOTE: An updated version that contains data from samples collected during 2017 can be accessed from this link. The U.S. Geological Survey is studying Lake Koocanusa, a border reservoir between British Columbia in Canada and Montana, in collaboration with the Montana Department of Environmental Quality and the U.S. Environmental Protection Agency (Region 8). This work is part of a multi-agency project to apply an ecosystem-scale selenium modeling methodology (Presser and Luoma, 2010) to the lake to support development of a site-specific selenium guideline for the protection of aquatic life. This Data Release makes available measurements taken during the periods of May, 2015 to October, 2015 and April,...
This dataset contains in situ specific conductance, pH, and temperature measurements from groundwater wells in the Cottonwood Lake Study Area, Stutsman County, North Dakota.