the data set contains a summary of all measurements that were collected at the cottage grove reservoir over the time period of the study. This dataset is associated with the following publication: Eckley , C., T. Luxton , J. McKernan , J. Goetz , and J. Goulet. Influence of Reservoir Water-Level Fluctuations on Mercury Methylation Downstream of the Historic Black Butte Mercury Mine, OR. Michael Kersten APPLIED GEOCHEMISTRY. Elsevier Science Ltd, New York, NY, USA, 61: 284-293, (2015). NOTE: This dataset has been removed from public access due to revocation. Please refer inquiries regarding this dataset to the listed contact person.

the data set contains a summary of all measurements that were collected at the cottage grove reservoir over the time period of the study. This dataset is associated with the following publication: Eckley , C., T. Luxton , J. McKernan , J. Goetz , and J. Goulet. Influence of Reservoir Water-Level Fluctuations on Mercury Methylation Downstream of the Historic Black Butte Mercury Mine, OR. Michael Kersten APPLIED GEOCHEMISTRY. Elsevier Science Ltd, New York, NY, USA, 61: 284-293, (2015). NOTE: This dataset has been removed from public access due to revocation. Please refer inquiries regarding this dataset to the listed contact person.

The current data entry contains the raw data that was used to create the figures and tables in the publication. This dataset is associated with the following publication: Millard, G., C.S. Eckley, T.P. Luxton, D. Krabbenhoft, J. Goetz, J. McKernan, and J. DeWild. Evaluating the influence of seasonal stratification on mercury methylation rates in the water column and sediment in a contaminated section of a western U.S.A. reservoir. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 316: 120485, (2023).

The current data entry contains the raw data that was used to create the figures and tables in the publication. This dataset is associated with the following publication: Millard, G., C.S. Eckley, T.P. Luxton, D. Krabbenhoft, J. Goetz, J. McKernan, and J. DeWild. Evaluating the influence of seasonal stratification on mercury methylation rates in the water column and sediment in a contaminated section of a western U.S.A. reservoir. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 316: 120485, (2023).

The data set contains a summary of all measurements that were collected at the cottage grove reservoir over the time period of the study. This dataset is associated with the following publication: Eckley, C., T. Luxton, J. Goetz, and J. McKernan. Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.. David Carpenter, and Eddy Zeng ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 222: 32-41, (2017).

Data used to create figures in the manuscript. This dataset is associated with the following publication: Eckley, C.S., T.P. Luxton, B. Stanfield, A. Baldwin, J. Holloway, J. McKernan, and M.G. Johnson. Effect of organic matter concentration and characteristics on mercury mobilization and methylmercury production at an abandoned mine site. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 271: 116369, (2021).

Data used to create figures in the manuscript. This dataset is associated with the following publication: Eckley, C.S., T.P. Luxton, B. Stanfield, A. Baldwin, J. Holloway, J. McKernan, and M.G. Johnson. Effect of organic matter concentration and characteristics on mercury mobilization and methylmercury production at an abandoned mine site. ENVIRONMENTAL POLLUTION. Elsevier Science Ltd, New York, NY, USA, 271: 116369, (2021).

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. Water samples were collected from 3-5 depths at each site and analyzed for: total mercury (filtered and particulate), methylmercury (filtered and particulate), dissolved organic and inorganic carbon with 13C isotopic ratios, nutrients, anions, cations, trace metals, particulate carbon (with 13C isotopic ratios) and particulate nitrogen (with 15N isotopic ratios). Water quality sonde (EXO) field measurements included specific conductivity, temperature, pH, dissolved oxygen, fluorescent dissolved organic matter, chlorophyll, and turbidity. Fish samples were also collected during November 2014 from Good Hope Bay (upper reservoir), Wahweap Bay (lower reservoir), and the San Juan arm and assayed for total mercury for comparison with previous striped bass samples collected by the state of Utah. There are nine files (*.csv) in this dataset: 1) data dictionary ; 2) sediment data; 3) water data; 4) seston data; 5) fish data; 6) EXO main channel profile data ; 7) EXO off channel profile data; 8) quality assurance data; and 9) molecular data.

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. Water samples were collected from 3-5 depths at each site and analyzed for: total mercury (filtered and particulate), methylmercury (filtered and particulate), dissolved organic and inorganic carbon with 13C isotopic ratios, nutrients, anions, cations, trace metals, particulate carbon (with 13C isotopic ratios) and particulate nitrogen (with 15N isotopic ratios). Water quality sonde (EXO) field measurements included specific conductivity, temperature, pH, dissolved oxygen, fluorescent dissolved organic matter, chlorophyll, and turbidity. Fish samples were also collected during November 2014 from Good Hope Bay (upper reservoir), Wahweap Bay (lower reservoir), and the San Juan arm and assayed for total mercury for comparison with previous striped bass samples collected by the state of Utah. There are nine files (*.csv) in this dataset: 1) data dictionary ; 2) sediment data; 3) water data; 4) seston data; 5) fish data; 6) EXO main channel profile data ; 7) EXO off channel profile data; 8) quality assurance data; and 9) molecular data.

Data in this data release were obtained from water samples collected under Yellowstone National Park (YNP) Research Permit YELL-05194 in 2017, 2019, and 2020 through the Integrated Yellowstone Studies Project funded by the Mineral Resources Program. These samples were used to assess mercury cycling within YNP. Water samples were analyzed for total mercury and methylmercury, the bioaccumulated form in food webs. This data informs the biogeochemical processes controlling the broad range of mercury and methylmercury concentrations observed in the park. Natural abundance mercury stable isotopes were also collected to determine if mercury sources or cycling processes varied between different hydrothermal sources. Data produced as part of this study outlines how the different physicochemical processes, including mixing between meteoric and hydrothermal waters, boiling, and sorption, affect mercury isotope values in YNP.