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The goal of this study was to develop a suite of inter-related water quality monitoring approaches capable of modeling and estimating the spatial and temporal gradients of particulate and dissolved total mercury (THg) concentration, and particulate and dissolved methyl mercury (MeHg), concentration, in surface waters across the Sacramento / San Joaquin River Delta (SSJRD). This suite of monitoring approaches included: a) data collection at fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, b) spatial mapping using boat-mounted flow-through sensors, and c) satellite-based remote sensing. The focus of this specific Child Page is to present all field and laboratory-based data associated with...
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The Sacramento / San Joaquin River Delta (SSJRD) is contaminated with legacy mercury (Hg) from historical mining and mineral processing activities throughout the watershed, as well as from contemporary atmospheric and industrial inputs. The current project was designed for the purpose of developing high-resolution spatial and temporal models for estimating concentrations of mercury species in surface waters of the SSJRD. The field component of the project brings together three high-resolution platforms for collecting water-quality data (fixed continuous monitoring stations (CMS) outfitted with in-situ sensors, spatial mapping using boat-mounted flow-through sensors, and satellite-based remote sensing) coupled with...
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The urbanized area of downtown Menlo Park is subject to persistent flooding and sediment deposition by San Francisquito Creek in South San Francisco Bay. To mitigate these events, a suite of cores was collected in 2002 at the mouth of the creek to determine sediment depositional rates on the delta. One of those cores (721-1) was selected for microbiological (pollen, diatoms, and foraminifera) and geochemical analyses to reconstruct a depositional record over the past two millennia. This data release provides radiocarbon dates, census counts of benthic foraminifera, diatoms, and palynomorphs, and the measurement of anthropogenic metals and other elements in sediments from this core.
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Geochemical data are reported for surface sediments and long sediment cores from Bellingham Bay, Whatcom County, Washington, collected in early February 2020 after flood conditions on the Nooksack River. Data include total organic carbon content (TOC), carbonate content (CaCO3), ratios of stable carbon 13/12 isotopes (d13C), ratios of total carbon to total nitrogen (C:N), short-lived cosmogenic radionuclide activities (Beryllium-7, Cesium-137, and excess Lead-210), and elemental chemistry.
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Fine-sediment elemental chemistry and short-lived cosmogenic radionuclides (Beryllium-7, Cesium-137, and Lead-210) were quantified to describe land-based sediment sources and runoff to Olowalu Reef in February 2022. Charcoal counts, total organic carbon contents, and 76 urban- and wildfire-associated contaminants called polycyclic aromatic hydrocarbons (PAHs) were quantified to explore urban and wildfire effects in watersheds above Olowalu Reef and in reef sediment. Sampling occurred approximately two months after winter flooding and one month after tsunamigenic waves impinged on the Maui shore from the eruption of Hunga-Tonga volcano in the South Pacific. The USGS Coastal and Marine Hazards and Resources Program...
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As part of the Triangle Area Water Supply Monitoring Program, the U.S. Geological Survey conducted a study to evaluate the occurrence and distribution of mercury in 14 streams and 15 reservoirs in the Triangle area of North Carolina. This Data Release contains the associated data described in the Scientific Investigations Report, "Occurrence and Distribution of Mercury in Streams and Reservoirs in the Triangle Area of North Carolina, July 2007 – June 2009". Water samples were collected seasonally between July 2007 and June 2009 for laboratory analysis of mercury, organic carbon, chlorophyll a, sulfate, and suspended sediment. Field measurements of dissolved oxygen, pH, water temperature, and specific conductance...
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Laboratory experiments were performed between 2019 and 2020 to examine how dissolved organic matter (DOM) and phytoplankton (Raphidocelis subcapitata) cells alter mercury (Hg) uptake and isotope fractionation. Experiments were performed at ambient Hg to thiol ratios using natural organic matter isolates received from collaborators at the University of California-Davis. Two types of experiments were performed: (1) one set with SRFA isolates at two concentrations and Hg, termed uptake experiment, and (2) one set with DOM isolates, Hg, and cultured Raphidocelis subcapitata cells, termed sunlight exposure experiment. For additional experimental details, including culturing conditions, experimental set-up, and analysis,...
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An ecological study on mercury contamination in the wetland of West Dongting Lake in China. This study measured the total mercury concentration in the soil and compared it to the measured total concentration of mercury in the above and below ground tissue of different plant species on the floodplain of West Dongting Lake. Bioconcentration, bioaccumulation, and translocation factors were determined for each plant species at the nine study sites. Soil data on mercury concentration as well as moisture and bulk density was collected. Measurements of species richness, evenness and biodiversity were also calculated.
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Elemental compositions are reported for the fine fraction of surface sediments from Bellingham Bay (June 2017 and March 2019) and in the fine fraction of streambank sediment from the Nooksack River (September 2017, March 2019, September 2019), Squalicum Creek (March and September 2019), Whatcom Creek (March and September 2019), and Padden Creek (March and September 2019). Major oxide percentages are reported in Nooksack River fine sediment collected in September 2017. Ancillary data for sediment collected during 2017 and 2019 from Bellingham Bay, Nooksack River, and small creeks include: percent weights of gravel, sand, and fines; total organic carbon content (TOC); carbonate content (CaCO3); ratios of stable carbon...
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Sediment samples were collected from mercury-contaminated streams and lakes in Texas, Virginia, and Tennessee and were analyzed for total carbon (TC) and total nitrogen (TN). A portion of the sample was combusted at 550 degrees C for 2 hours prior to analysis to remove the organic carbon and nitrogen, thus giving total inorganic carbon (TIC) and total inorganic nitrogen (TIN). Total organic carbon (TOC) and total organic nitrogen (TON) were calculated from these values.
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This dataset includes field measurements and laboratory analyses of surface water, bottom water (sediment-water interface), surficial (0-2 cm) sediment, pore water (0-2 cm), and biota collected in Lake Combie, California, from September 2017 through August 2021. The study area includes six sites within the reservoir where discrete samples of surface water, bottom water, sediment, and pore water were taken along the length of the reservoir at the following distances from the spillway: 0.07 miles, 0.5 miles, 0.9 miles, 1.2 miles, 1.3 miles, and 1.4 miles. The within-reservoir sites were sampled during September 2017, February 2018, and May 2018, prior to a large sediment removal operation, and again during September...
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In 2021, the U.S. Geological Survey (USGS) Mercury Research Laboratory (MRL) conducted a large-scale assessment of mercury (Hg) concentrations and Hg stable isotope values in tributaries of Lake Superior in order to define the sources and amounts of Hg entering the lake. Water samples were collected monthly from 18 tributaries in the United States from April through October in 2021 and during 2022 spring melt (May 2022). As a complement, 10 tributaries on the Lake Superior Northshore were sampled three times a year (spring, summer, and fall) by Lakehead University and Lakehead Region Conservation Authority. Nine tributaries were also sampled twice per year (spring and summer) in Pukaskwa National Park by Parks Canada....
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Mercury (Hg) is a well-known toxic element and environmental contaminant. The central valley of California has long been identified as a hotspot for Hg contamination due to the historic mining of Hg in the California coast range, and its use in the mining of gold in the Sierra Nevada, with these mountainous regions bordering the east and the west of the valley, respectively. While the whole central valley is world renowned as a major agricultural area, the northern portion, known as the Sacramento valley region, is dominated by commercial rice production. Since rice is grown in flooded fields, and since wetland soils are known to be particularly effective habitats for converting inorganic mercury into the more toxic...


    map background search result map search result map Geochemistry of fine-grained sediment in Bellingham Bay, Nooksack River, and small creeks from June 2017 to September 2019 Water and Bed Sediment Data Associated with the Occurrence and Distribution of Mercury in Streams and Reservoirs in the Triangle Area of North Carolina, July 2007 - June 2009 High resolution and discrete temporal and spatial water-quality measurements in support of modeling mercury and methylmercury concentrations in surface waters of the Sacramento-San Joaquin River Delta Discrete sample surface-water data for the Sacramento-San Joaquin River Delta Geochemical data for water, sediment, and biota in Lake Combie, California, 2017-2021 Mercury Concentrations and Loads in United States and Canadian Tributaries of Lake Superior Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury Carbon and Nitrogen in Sediments from Hg-Contaminated Streams and Lakes in Texas, Virginia, and Tennessee Geochemistry of surface sediment and sediment cores in Bellingham Bay, Whatcom County, Washington, in February 2020 Data Release: Mercury accumulation potential of aquatic plant species in West Dongting Lake, China Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay Mercury concentration data for soil, surface water and rice grain from six commercial rice growing fields in the Sacramento Valley of California (USA) Anthropogenic metals and other elements from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay Metals and PAHs in watershed soil and reef sediment at Olowalu and leeward Maui, February 2022 Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) in watershed soil and reef sediment at Olowalu, Maui, 2022 Elemental chemistry, radionuclides, and charcoal in watershed soil and reef sediment at Olowalu, Maui, 2022 Measurements of mercury stable isotopes during planktonic uptake and photochemical demethylation of methylmercury Geochemical data for water, sediment, and biota in Lake Combie, California, 2017-2021 Geochemistry of surface sediment and sediment cores in Bellingham Bay, Whatcom County, Washington, in February 2020 Metals and PAHs in watershed soil and reef sediment at Olowalu and leeward Maui, February 2022 Parent and alkylated polycyclic aromatic hydrocarbons (PAHs) in watershed soil and reef sediment at Olowalu, Maui, 2022 Elemental chemistry, radionuclides, and charcoal in watershed soil and reef sediment at Olowalu, Maui, 2022 Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay Data Release: Mercury accumulation potential of aquatic plant species in West Dongting Lake, China High resolution and discrete temporal and spatial water-quality measurements in support of modeling mercury and methylmercury concentrations in surface waters of the Sacramento-San Joaquin River Delta Discrete sample surface-water data for the Sacramento-San Joaquin River Delta Water and Bed Sediment Data Associated with the Occurrence and Distribution of Mercury in Streams and Reservoirs in the Triangle Area of North Carolina, July 2007 - June 2009 Mercury Concentrations and Loads in United States and Canadian Tributaries of Lake Superior Carbon and Nitrogen in Sediments from Hg-Contaminated Streams and Lakes in Texas, Virginia, and Tennessee