This data release includes results of raw water, soil, seston, and fish tissue samples collected from 14 lakes within Lake Clark National Park and Katmai National Park between 2007 and 2017. Specifically, these data include total mercury and methylmercury concentrations in water, size-sieved seston, and particulate matter. Additionally, these data include soil and volcanic ash measurements from the surrounding watersheds. Finally, these data include energetic profiling of seston, lake trout (Salvelinus namaycush), and sockeye salmon (Oncorhynchus nerka) as well as mercury isotope measurements of the fishes. These data, except for Lake Clark data, were use in interpreting mercury mass balance flows and bioavailability to the food web and are a part of an associated journal article published in Environmental Science and Technology Letters (https://doi.org/10.1021/acs.estlett.2c00096). Lake Clark data include mercury and methylmercury concentrations in water, seston, and fish tissue from 2011 and 2012. Mercury isotope measurements were not collected as part of this assessment. These data were used to understand drivers of bioaccumulation within predator fish from southwest Alaska and are part of an associated journal article published in Environmental Pollution (https://doi.org/10.1016/j.envpol.2023.121678).

This data release includes results of raw water, soil, seston, and fish tissue samples collected from 14 lakes within Lake Clark National Park and Katmai National Park between 2007 and 2017. Specifically, these data include total mercury and methylmercury concentrations in water, size-sieved seston, and particulate matter. Additionally, these data include soil and volcanic ash measurements from the surrounding watersheds. Finally, these data include energetic profiling of seston, lake trout (Salvelinus namaycush), and sockeye salmon (Oncorhynchus nerka) as well as mercury isotope measurements of the fishes. These data, except for Lake Clark data, were use in interpreting mercury mass balance flows and bioavailability to the food web and are a part of an associated journal article published in Environmental Science and Technology Letters (https://doi.org/10.1021/acs.estlett.2c00096). Lake Clark data include mercury and methylmercury concentrations in water, seston, and fish tissue from 2011 and 2012. Mercury isotope measurements were not collected as part of this assessment. These data were used to understand drivers of bioaccumulation within predator fish from southwest Alaska and are part of an associated journal article published in Environmental Pollution (https://doi.org/10.1016/j.envpol.2023.121678).

These data were collected as part of the Southwest Alaska Inventory and Monitoring Network (SWAN) freshwater contaminants protocol. The protocol outlines a framework for monitoring mercury (Hg) concentrations in resident lake fish within SWAN parks. The primary goal of this monitoring is to understand the spatial differences, temporal trends, and health ramifications of Hg contamination in resident lake fish. Monitoring relies on total Hg in fish axial muscle as an indicator of methyl Hg exposure. It targets four high-priority lakes which vary in size, depth, wetland cover, glacial influence, and Hg concentration. These lakes are in Katmai National Park and Preserve (KATM). The focal species is lake trout (Salvelinus namaycush), a widespread, long lived, top predator in SWAN lakes. However, if other species are sampled as bycatch, they may be retained and analyzed if they represent species-specific data gaps in Hg concentration. Two broad types of data are generated from this protocol. The first type includes observations and measurements that are recorded while sampling and processing fish (e.g., length, weight, sex). The second type includes results of analyses performed by contract laboratories (e.g., age, total Hg). This particular dataset includes those two broad types of data for 40 fish sampled in 2021. Of those fish, all 40 were lake trout.

These data were collected as part of the Southwest Alaska Inventory and Monitoring Network (SWAN) freshwater contaminants protocol. The protocol outlines a framework for monitoring mercury (Hg) concentrations in resident lake fish within SWAN parks. The primary goal of this monitoring is to understand the spatial differences, temporal trends, and health ramifications of Hg contamination in resident lake fish. Monitoring relies on total Hg in fish axial muscle as an indicator of methyl Hg exposure. It targets four high-priority lakes which vary in size, depth, wetland cover, glacial influence, and Hg concentration. These lakes are in Katmai National Park and Preserve (KATM). The focal species is lake trout (Salvelinus namaycush), a widespread, long lived, top predator in SWAN lakes. However, if other species are sampled as bycatch, they may be retained and analyzed if they represent species-specific data gaps in Hg concentration. Two broad types of data are generated from this protocol. The first type includes observations and measurements that are recorded while sampling and processing fish (e.g., length, weight, sex). The second type includes results of analyses performed by contract laboratories (e.g., age, total Hg). This particular dataset includes those two broad types of data for 40 fish sampled in 2021. Of those fish, all 40 were lake trout.

This dataset describes mercury (Hg) stable isotope values in fish dorsal muscle from different freshwater environments across the globe. Fish were collected at numerous field sites in North America, South and Central America, Africa, and Asia from 2006-2020. Sub-samples were provided by cooperators to the U.S. Geological Survey Mercury Research Laboratory and the University of Wisconsin for mercury stable isotope analysis. Samples were analyzed for mercury stable isotopes from 2017-2021. These specimens represent multiple trophic levels and body sizes from different food webs and when adequate mass was available, multiple species from the same food web were examined. Cooperators include, but are not limited to: Anton de Kom University of Suriname, Kenya Marine and Fisheries Research Institute, Tanzania Fisheries Research Institute, University of Dar es Salaam, Centre National de la Recherche Scientifique et Technologique of Gabon, Direction de la Faune et des Aires Protegees and la Delegation a la Recherche Scientifique et Technologique of Republic of Congo, Central African Forest Ecosystems Programme (now NaturAfrica) -Congo, Kingdom of Thailand’s Department of Fisheries, ASMA Guatemala, Southern African Scientific Service Centre for Climate Change and Adaptive Land Management, Hawaii Division of Aquatic Resources.

This dataset describes mercury (Hg) stable isotope values in fish dorsal muscle from different freshwater environments across the globe. Fish were collected at numerous field sites in North America, South and Central America, Africa, and Asia from 2006-2020. Sub-samples were provided by cooperators to the U.S. Geological Survey Mercury Research Laboratory and the University of Wisconsin for mercury stable isotope analysis. Samples were analyzed for mercury stable isotopes from 2017-2021. These specimens represent multiple trophic levels and body sizes from different food webs and when adequate mass was available, multiple species from the same food web were examined. Cooperators include, but are not limited to: Anton de Kom University of Suriname, Kenya Marine and Fisheries Research Institute, Tanzania Fisheries Research Institute, University of Dar es Salaam, Centre National de la Recherche Scientifique et Technologique of Gabon, Direction de la Faune et des Aires Protegees and la Delegation a la Recherche Scientifique et Technologique of Republic of Congo, Central African Forest Ecosystems Programme (now NaturAfrica) -Congo, Kingdom of Thailand’s Department of Fisheries, ASMA Guatemala, Southern African Scientific Service Centre for Climate Change and Adaptive Land Management, Hawaii Division of Aquatic Resources.

These data were collected as part of the Southwest Alaska Inventory and Monitoring Network (SWAN) freshwater contaminants protocol. The protocol outlines a framework for monitoring mercury (Hg) concentrations in resident lake fish within SWAN parks. The primary goal of this monitoring is to understand the spatial differences, temporal trends, and health ramifications of Hg contamination in resident lake fish. Monitoring relies on total Hg in fish axial muscle as an indicator of methyl Hg exposure. It targets four high-priority lakes which vary in size, depth, wetland cover, glacial influence, and Hg concentration. These lakes are located in two parks: Lake Clark National Park and Preserve (LACL) and Katmai National Park and Preserve (KATM). The focal species is lake trout (Salvelinus namaycush), a widespread, long lived, top predator in SWAN lakes. However, if other species are sampled as bycatch, they may be retained and analyzed if they represent species-specific data gaps in Hg concentration. Two broad types of data are generated from this protocol. The first type includes observations and measurements that are recorded while sampling and processing fish (e.g., length, weight, gender). The second type includes results of analyses performed by contract laboratories (e.g., age, total Hg). This particular dataset includes those two broad types of data for 49 fish sampled in 2019 and 2020 from 2 lakes in LACL: Lake Clark and Kijik Lake. Of those 49 fish, 40 were lake trout, 6 were burbot (Lota lota), 2 were Arctic grayling (Thymallus arcticus), and 1 was Arctic char (Salvelinus alpinus).

Under the Great Lakes Restoration Initiative, the U.S. Geological Survey Mercury Research Lab (USGS MRL) conducted a multiyear assessment of mercury across the Laurentian Great Lakes. Biannual sampling was conducted across all five lakes onboard the U.S. Environmental Protection Agency (US EPA) research vessel Lake Guardian (in years 2010–2014, 2018) at pelagic sampling locations established by the long-term US EPA Great Lakes monitoring program. In addition to the regularly scheduled biannual sampling, in September 2013 and 2014 Lake Michigan and Lake Erie (respectively) were sampled with increased focus on shallow nearshore locations. Throughout these sampling efforts, sediments, mussels, surface water, and plankton were collected from open-water locations within all five of the Great Lakes. Additionally, surface water from Great Lake tributaries were sampled by the USGS MRL and preceded (2005 or 2006) or overlapped (2010-2015) with the open lake sampling efforts. All surface water samples were analyzed for methylmercury, total mercury, and dissolved organic carbon. Plankton and mussel tissue were analyzed for methylmercury, total mercury, and carbon/nitrogen stable isotopes and concentrations (plankton only). Sediments were analyzed for methylmercury, total mercury, and carbon content.

Under the Great Lakes Restoration Initiative, the U.S. Geological Survey Mercury Research Lab (USGS MRL) conducted a multiyear assessment of mercury across the Laurentian Great Lakes. Biannual sampling was conducted across all five lakes onboard the U.S. Environmental Protection Agency (US EPA) research vessel Lake Guardian (in years 2010–2014, 2018) at pelagic sampling locations established by the long-term US EPA Great Lakes monitoring program. In addition to the regularly scheduled biannual sampling, in September 2013 and 2014 Lake Michigan and Lake Erie (respectively) were sampled with increased focus on shallow nearshore locations. Throughout these sampling efforts, sediments, mussels, surface water, and plankton were collected from open-water locations within all five of the Great Lakes. Additionally, surface water from Great Lake tributaries were sampled by the USGS MRL and preceded (2005 or 2006) or overlapped (2010-2015) with the open lake sampling efforts. All surface water samples were analyzed for methylmercury, total mercury, and dissolved organic carbon. Plankton and mussel tissue were analyzed for methylmercury, total mercury, and carbon/nitrogen stable isotopes and concentrations (plankton only). Sediments were analyzed for methylmercury, total mercury, and carbon content.

Comma-separated values (.csv) file containing data related to mercury in fishes collected from Clear Lake, California.