This data release includes laboratory analyses for fish tissue samples collected from Lake Koocanusa and the Kootenai River Basin in Montana during 2022. Samples were collected by the U.S. Geological Survey (USGS) Wyoming-Montana Water Science Center (WY-MT WSC) in cooperation with Montana Fish, Wildlife and Parks (MT FWP) and Montana Department of Environmental Quality (MT DEQ). Analyses include histology, percent moisture, and 30 elements, including selenium, mercury, and methylmercury. This data release also compiles laboratory quality-assurance and quality-control data associated with the samples.

Montana Fish, Wildlife, and Parks (MT FWP), in collaboration with the United States Geological Survey (USGS) Wyoming-Montana Water Science Center (WY-MT WSC), Montana Department of Environmental Quality (MDEQ), and the United States Environmental Protection Agency (USEPA) collected fish from the Koocanusa Reservoir in 2021 for tissue analysis. Fish tissue collected included muscle, eggs, liver, and whole body. Analysis of tissues included characterization of the concentration of selenium, mercury and methyl mercury, nitrogen and carbon stable isotopes, and vitamins A and E. The purpose of these analyses was to inform state and federal management agencies on transboundary coal mining impacts to downstream fish health.

Montana Fish, Wildlife, and Parks (MT FWP), in collaboration with the United States Geological Survey (USGS) Wyoming-Montana Water Science Center (WY-MT WSC), Montana Department of Environmental Quality (MDEQ), and the United States Environmental Protection Agency (USEPA) collected fish from the Koocanusa Reservoir in 2021 for tissue analysis. Fish tissue collected included muscle, eggs, liver, and whole body. Analysis of tissues included characterization of the concentration of selenium, mercury and methyl mercury, nitrogen and carbon stable isotopes, and vitamins A and E. The purpose of these analyses was to inform state and federal management agencies on transboundary coal mining impacts to downstream fish health.

Working in cooperation with EPA, the USGS coordinated the collection of fish tissue for processing and analyses by the EPA Region 10 Manchester Environmental Laboratory located in Port Orchard, WA. This effort was being tied to existing operations work performed by state wildlife agencies in Idaho and Montana (Ross et al. 2018). Annually, in late August and September, the Idaho Department of Fish and Game (IDFG), the Montana Department of Fish, Wildlife and Parks (MTFWP), and the Kootenai Tribe of Idaho conduct population surveys on the Kootenai River. During the 2018 electrofishing population surveys, state wildlife agency personnel also retained collected fish for this effort. The following were key design components of fish collection in the Kootenai River: (1) Fish were caught and analyzed for selenium and mercury in multiple tissues (filet, whole body, and/or egg/ovaries) as available to assess baseline contamination/bioaccumulation in fish species between Libby Dam and downstream of Bonners Ferry, ID. (2) Fish were caught from the mainstem Kootenai River in early September 2018 and analyzed for selenium and mercury from immediately downstream of Libby Dam (tailwater), downstream of Troy, MT, downstream of the ID/MT border, and in the proximity of Shorty’s Island downstream of Bonner’s Ferry. (3) The EPA Region 10 laboratory provided in-kind support for selenium and mercury analyses for the 142 fish samples collected. EPA Region 10 also provided data and sample management support via the Scribe Project Manager (RSCC). More details of the study design are given by USEPA and USGS (2018). Results: A total of 142 fish representing 13 species were retained for tissue analysis. Eggs were obtained from two species, kokanee salmon and mountain whitefish. In kokanee salmon, eggs were found in two fish from only site KR13 (Kootenai River below Libby Dam) and ranged from 4.17 to 5.01 mg/kg selenium as dry weight (dw). Eggs were found in mountain whitefish from all sites except the most downstream site sampled, KR4 (Kootenai River near Shorty’s Island). Selenium concentrations in mountain whitefish eggs ranged from 11.6 to 24.8 mg/kg (dw). An objective of the study was to compare selenium concentrations in fish and water to USEPA nationally recommended water quality criteria for selenium. The national criteria recommend that concentrations in fish eggs not exceed 15.1 mg/kg (dw), concentrations in whole-body of fish not exceed 8.5 mg/kg dry weight, or (b) concentrations in muscle tissue not exceed 11.3 mg/kg dry weight (USEPA 2016). For eggs, 6 of the 8 mountain whitefish egg samples exceeded EPA’s recommended value. No samples exceeded the whole-body criterion component of 8.5 mg/kg dry weight and no samples exceeded the muscle criterion component of 11.3 mg/kg dry weight. References: Ross, T.J., K. McDonnell, R. Hardy, and S. Stephenson. 2018. Kootenai River resident fish mitigation: white sturgeon, burbot, native salmonid monitoring and evaluation (Annual Progress Report May 1, 2016 — April 31, 2017). BPA Project # 1988-065-00, Idaho Department of Fish and Game. Report to the Bonneville Power Administration, Environment, Fish and Wildlife, Portland, OR. 118 pp. https://www.cbfish.org. USEPA. 2016. Aquatic Life Ambient Water Quality Criterion for Selenium – Freshwater 2016. 822-R-16-006, U.S. Environmental Protection Agency. 807 pp. https://www.epa.gov/wqc/aquatic-life-criterion-selenium [Accessed February 21, 2018]. USEPA and USGS. 2018. Kootenai River Fish Tissue Study Quality Assurance Project Plan. Prepared by U.S. Environmental Protection Agency, Regions 8 and 10, and U.S. Geological Survey, Idaho Water Science Center. 28 August 2018 (Revised 01 October 2018). 41 pp.

Working in cooperation with EPA, the USGS coordinated the collection of fish tissue for processing and analyses by the EPA Region 10 Manchester Environmental Laboratory located in Port Orchard, WA. This effort was being tied to existing operations work performed by state wildlife agencies in Idaho and Montana (Ross et al. 2018). Annually, in late August and September, the Idaho Department of Fish and Game (IDFG), the Montana Department of Fish, Wildlife and Parks (MTFWP), and the Kootenai Tribe of Idaho conduct population surveys on the Kootenai River. During the 2018 electrofishing population surveys, state wildlife agency personnel also retained collected fish for this effort. The following were key design components of fish collection in the Kootenai River: (1) Fish were caught and analyzed for selenium and mercury in multiple tissues (filet, whole body, and/or egg/ovaries) as available to assess baseline contamination/bioaccumulation in fish species between Libby Dam and downstream of Bonners Ferry, ID. (2) Fish were caught from the mainstem Kootenai River in early September 2018 and analyzed for selenium and mercury from immediately downstream of Libby Dam (tailwater), downstream of Troy, MT, downstream of the ID/MT border, and in the proximity of Shorty’s Island downstream of Bonner’s Ferry. (3) The EPA Region 10 laboratory provided in-kind support for selenium and mercury analyses for the 142 fish samples collected. EPA Region 10 also provided data and sample management support via the Scribe Project Manager (RSCC). More details of the study design are given by USEPA and USGS (2018). Results: A total of 142 fish representing 13 species were retained for tissue analysis. Eggs were obtained from two species, kokanee salmon and mountain whitefish. In kokanee salmon, eggs were found in two fish from only site KR13 (Kootenai River below Libby Dam) and ranged from 4.17 to 5.01 mg/kg selenium as dry weight (dw). Eggs were found in mountain whitefish from all sites except the most downstream site sampled, KR4 (Kootenai River near Shorty’s Island). Selenium concentrations in mountain whitefish eggs ranged from 11.6 to 24.8 mg/kg (dw). An objective of the study was to compare selenium concentrations in fish and water to USEPA nationally recommended water quality criteria for selenium. The national criteria recommend that concentrations in fish eggs not exceed 15.1 mg/kg (dw), concentrations in whole-body of fish not exceed 8.5 mg/kg dry weight, or (b) concentrations in muscle tissue not exceed 11.3 mg/kg dry weight (USEPA 2016). For eggs, 6 of the 8 mountain whitefish egg samples exceeded EPA’s recommended value. No samples exceeded the whole-body criterion component of 8.5 mg/kg dry weight and no samples exceeded the muscle criterion component of 11.3 mg/kg dry weight. References: Ross, T.J., K. McDonnell, R. Hardy, and S. Stephenson. 2018. Kootenai River resident fish mitigation: white sturgeon, burbot, native salmonid monitoring and evaluation (Annual Progress Report May 1, 2016 — April 31, 2017). BPA Project # 1988-065-00, Idaho Department of Fish and Game. Report to the Bonneville Power Administration, Environment, Fish and Wildlife, Portland, OR. 118 pp. https://www.cbfish.org. USEPA. 2016. Aquatic Life Ambient Water Quality Criterion for Selenium – Freshwater 2016. 822-R-16-006, U.S. Environmental Protection Agency. 807 pp. https://www.epa.gov/wqc/aquatic-life-criterion-selenium [Accessed February 21, 2018]. USEPA and USGS. 2018. Kootenai River Fish Tissue Study Quality Assurance Project Plan. Prepared by U.S. Environmental Protection Agency, Regions 8 and 10, and U.S. Geological Survey, Idaho Water Science Center. 28 August 2018 (Revised 01 October 2018). 41 pp.

This Data Release presents multi-agency data for selenium concentrations in ecosystem media that includes water column, suspended particulate material, zooplankton, invertebrates, and fish. Because the data are compiled from multiple sources, the significant figures used to report contaminant concentrations and other metrics may not be internally consistent. These data will serve as the basis for ecosystem-scale modeling of Lake Koocanusa, a bi-national reservoir in Montana and British Columbia. Spreadsheets are ordered in a food-web format to facilitate modeling that emphasizes spatially and temporally paired data. Selenium concentrations are species-specific for fish and taxa-specific for invertebrates to address required specificity for biodynamic dietary modeling. Phytoplankton, zooplankton, and invertebrate densities or biomass are compiled, in addition to fish catches, to help elucidate productivity and identify which groups, taxa, or species are abundant on a seasonal basis. For water quality context, the historical record of selenium concentrations is given, with emphasis on the primary selenium loading site near where the Elk River enters Lake Koocanusa. Spreadsheets with the term "annex" in their file name address a competing toxin, mercury, for fish. Recent high frequency monitoring of selenium concentrations at the international border and at a gaging station below Libby Dam provide a perspective on future selenium data availability. Methodologies are described as federal, provincial, and state agencies transition to a consistent set of protocols to ensure consistency in monitoring for locations on both sides of the border.

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 2019, February 2020, and June 2020 following the removal operation. Zooplankton samples were collected at four of the six sites during the sampling period. Fish were collected from within two regions of the lake: in the Wooley Creek arm of the lower reservoir, and in the upper reservoir near the targeted area for sediment removal operations. Vertical profiles of water quality were measured with a multi-parameter sonde during water collection events and during one zooplankton event. Thirty-six surface water and thirty-six bottom water samples were collected at each site and analyzed for total mercury (filtered and particulate), methylmercury (filtered and particulate), total suspended solids, sulfate, chloride, selected dissolved nutrients, particulate 13-C/12-C and 15-N/14-N isotopic ratios, total particulate carbon and nitrogen, particulate carbon to nitrogen molar ratio, dissolved organic carbon, and dissolved organic-matter properties (absorption and fluorescence). Thirty-six bed-sediment samples were analyzed for total mercury, methylmercury, total reduced sulfur, and organic content. Pore water extracted from bed sediment was analyzed for filtered total mercury, filtered methylmercury, sulfate, chloride, selected dissolved nutrients, and dissolved organic carbon. Surface water, bottom water, and sediment collections included an additional four field replicates each for analysis - pore water had six replicates. One hundred six zooplankton samples and twenty-three replicates were analyzed for total mercury, methylmercury, 13-C/12-C isotopic ratio, and 15-N/14-N isotopic ratio. Two hundred ninety fish samples were analyzed for total mercury, methylmercury, 13-C/12-C isotopic ratio, 15-N/14-N isotopic ratio, and total mass carbon and nitrogen. Water-quality field measurements made with a multi-parameter sonde included water temperature, barometric pressure, specific conductance, dissolved oxygen, pH, and turbidity. The within-reservoir data includes seven data tables given as both machine readable tab-delimited text (*.txt) and Excel formats (*.xlsx): 1) DataDictionary_LCR17-21, the data dictionary, which provides definitions and details related to the six other data tables, and includes citations of analytical methods; 2) SurfWater_Field-Lab_LCR17-20, the surface water and bottom water data table; 3) Sediment_LCR17-20; 4) PoreWater_LCR17-20; 5) Zooplankton_LCR17-20; 6) Fish_LCR18-21; and 7) SurfWater_Profiles_LCR17-20.

Between 2011 and 2018, numerous restoration treatments were constructed on the Straight and Braided Reaches of the Kootenai River in northern Idaho as part of the Kootenai River Habitat Restoration Project. This child item of the larger data release contains two .csv file with the data used to investigate the potential impacts of restoration treatments on suspended sediment transport within the study reach. One .csv file contains data collected between 2006 and 2023 at the upstream end of the study reach at U.S. Geological Survey (USGS) streamgage Kootenai River Below Moyie River (streamgage 12308000) and USGS site 4842231161104. The other file contains data collected between 2006 and 2023 at the downstream end of the study reach at USGS streamgage Kootenai River Tribal Hatchery near Bonners Ferry, ID (streamgage 12310100). Each .csv files contains measured suspended sediment concentrations (SSC, in mg/L), the percent fines (< 0.0625 mm) in each sample, and the estimated total discharge for tributaries between Libby Dam and the study reach. Estimated tributary discharge was used in the analysis rather than Kootenai River discharge because Libby Dam upstream of the study reach has a high sediment trapping efficiency and SSC in the study reach is driven primarily by tributary inputs between Libby Dam and the study reach.

Between 2011 and 2018, numerous restoration treatments were constructed on the Straight and Braided Reaches of the Kootenai River in northern Idaho as part of the Kootenai River Habitat Restoration Project. This child item of the larger data release contains two .csv file with the data used to investigate the potential impacts of restoration treatments on suspended sediment transport within the study reach. One .csv file contains data collected between 2006 and 2023 at the upstream end of the study reach at U.S. Geological Survey (USGS) streamgage Kootenai River Below Moyie River (streamgage 12308000) and USGS site 4842231161104. The other file contains data collected between 2006 and 2023 at the downstream end of the study reach at USGS streamgage Kootenai River Tribal Hatchery near Bonners Ferry, ID (streamgage 12310100). Each .csv files contains measured suspended sediment concentrations (SSC, in mg/L), the percent fines (< 0.0625 mm) in each sample, and the estimated total discharge for tributaries between Libby Dam and the study reach. Estimated tributary discharge was used in the analysis rather than Kootenai River discharge because Libby Dam upstream of the study reach has a high sediment trapping efficiency and SSC in the study reach is driven primarily by tributary inputs between Libby Dam and the study reach.

These data were compiled to examine analyte concentrations, including mercury and selenium, and stable isotopes in native and non-native fish across rivers in the Upper Colorado River Basin. Data were collected in 2016 and 2017. Tissue samples were collected as whole-body or muscle plugs (biopsies). Tissue samples were analyzed for stable isotopes in 772 samples, for selenium and 54 other analytes in 646 samples, for total mercury in 379 samples, and for methylmercury in 337 samples. The data tables contain raw concentration data, as well as standardized conversions for differences based on tissue type (whole-body or muscle) and dry or wet weight.