Mercury contamination is a serious issue that impacts both ecosystem and human health on a global scale. In its organic (methylmercury) form, mercury is highly bioaccumulative and is among the most toxic compounds commonly found in the environment. Mercury is a relatively distinctive contaminant in the sense that the risk of deleterious environmental effects is more strongly related to ecological factors that control its cycling than to its inputs and sources.
Thus, even with limited inorganic mercury loading, an ecosystem can suffer serious harmful impacts. The ecological risk of mercury toxicity is directly related to the production of the bioaccumulative and toxic form, methylmercury, which is driven by specific biogeochemical parameters. Importantly, those parameters are directly linked to landscape scale factors such as land use, landscape disturbance, habitat type, water inundation and wetting and drying cycles, organic carbon and nutrient cycling, and inputs from upland terrestrial habitats. Bioaccumulation is driven by population dynamics, habitat use, and food-web structure.
The Contaminant Ecology Research Program (CERP) at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, Oregon is actively engaged in a broad suite of ongoing mercury studies across the western United States, with a strong focus on habitats and locations within the Pacific Northwest. Our research focuses on two primary themes: (1) landscape and food web factors that influence mercury bioaccumulation and (2) the effects of mercury exposure on vertebrate physiology, behavior, and reproduction. Within those themes some of our active research includes studies about mercury bioaccumulation in wetland habitats and the influence of different wetland management practices on controlling mercury risk; mercury bioaccumulation in food webs of high-elevation lakes on public (National Park Service and U.S. Forest Service) lands; the impacts of non-native fish introductions to food-web energetics and mercury exposure in native amphibians; the role and impact of timber harvest on mercury cycling and bioavailability in the Pacific Northwest; the role of seabirds as vectors of marine-derived mercury to freshwater lakes in oceanic islands; the spatial extent of legacy mining impacts on downstream mercury bioaccumulation, and mercury exposure and associated physiological responses in songbirds, shorebirds, and piscivorous birds across a gradient of habitat types.
Additionally, USGS FRESC is currently leading a new collaborative initiative to synthesize the landscape and climate influences on mercury distribution, cycling, and bioaccumulation across western North America. This initiative involves dozens of scientists from federal and state agencies, academic institutions, and non-profit organizations.
Active Projects
- Western North America Mercury Synthesis: A Landscape-Scale Analysis of Mercury Cycling, Bioaccumulation, and Risk Linking Long-term Datasets
- Effects of Non-native Fishes on Mercury Bioaccumulation and Risk to Pond-breeding Salamanders in Olympic National Park
- Experimental Control of Methylmercury in Rice Wetlands Using Alternative Rice Harvest Practices
- Forestry Effects on Mercury Cycling and Bioaccumulation at a Watershed Scale
- Incorporating Wildlife Mercury Exposure and Risk Estimates Using Biomagnification Factors into BOG California Lake Monitoring
- Mercury Bioaccumulation in Fish from High-Elevation Lakes in National Parks across the Western United States
- Mercury Bioaccumulation in Terrestrial Songbirds and the Influence of Aquatic Energy Subsidies
- Mercury Bioaccumulation in Waterbodies of the Wallowa-Whitman National Forest
- Mercury Contamination in Waterbird Eggs and Risk to Avian Reproduction at Bear River Migratory Bird Refuge and Great Salt Lake
- Mercury Cycling and Bioaccumulation across the Aleutian Archipelago: Landscape Patterns of Wildlife Risk within the North Pacific Ocean
- Mercury Cycling and Ecological Risk across Habitats in Mount Rainier National Park
- Mercury Effects on Avian Reproduction in San Francisco Bay
- Mercury Exposure and Risk to Purple Martins Breeding in the Willamette Valley, Oregon
- Off-channel Habitats in the Willamette River: Implications for Methylmercury Cycling, Bioaccumulation, and Risk
- The Effects of Wetland Restoration on Mercury Bioaccumulation in the South Bay Salt Pond Restoration Project: Using the Biosentinel Toolbox to Monitor Changes across Multiple Habitats and Spatial Scales
Below are other science projects associated with this project.
Contaminant Ecology Research Team (FRESC)
Below are data or web applications associated with this project.
Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 8.0, December 2022)
Mercury Concentrations and Mercury Isotopes in Salmonid fishes from the Snake River and tributaries in Idaho and Oregon, 2015 and 2019 (ver. 2.0, February 2021)
Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
Mercury concentrations in songbird feathers and tissues
Below are publications associated with this project.
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Synthesis of maternal transfer of mercury in birds: Implications for altered toxicity risk
Methylmercury exposure in wildlife: A review of the ecological and physiological processes affecting contaminant concentrations and their interpretation
Songbird feathers as indicators of mercury exposure: High variability and low predictive power suggest limitations
Spatial variation in aquatic invertebrate and riparian songbird mercury exposure across a river-reservoir system with a legacy of mercury contamination
Mercury and lead exposure in avian scavengers from the Pacific Northwest suggest risks to California condors: Implications for reintroduction and recovery
A critical time for mercury science to inform global policy
Mercury on a landscape scale—Balancing regional export with wildlife health
Mercury concentrations in multiple tissues of Kittlitz's murrelets (Brachyramphus brevirostris)
Modulators of mercury risk to wildlife and humans in the context of rapid global change
Stream mercury export in response to contemporary timber harvesting methods (Pacific Coastal Mountains, Oregon, USA)
- Overview
Mercury contamination is a serious issue that impacts both ecosystem and human health on a global scale. In its organic (methylmercury) form, mercury is highly bioaccumulative and is among the most toxic compounds commonly found in the environment. Mercury is a relatively distinctive contaminant in the sense that the risk of deleterious environmental effects is more strongly related to ecological factors that control its cycling than to its inputs and sources.
Thus, even with limited inorganic mercury loading, an ecosystem can suffer serious harmful impacts. The ecological risk of mercury toxicity is directly related to the production of the bioaccumulative and toxic form, methylmercury, which is driven by specific biogeochemical parameters. Importantly, those parameters are directly linked to landscape scale factors such as land use, landscape disturbance, habitat type, water inundation and wetting and drying cycles, organic carbon and nutrient cycling, and inputs from upland terrestrial habitats. Bioaccumulation is driven by population dynamics, habitat use, and food-web structure.
The Contaminant Ecology Research Program (CERP) at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, Oregon is actively engaged in a broad suite of ongoing mercury studies across the western United States, with a strong focus on habitats and locations within the Pacific Northwest. Our research focuses on two primary themes: (1) landscape and food web factors that influence mercury bioaccumulation and (2) the effects of mercury exposure on vertebrate physiology, behavior, and reproduction. Within those themes some of our active research includes studies about mercury bioaccumulation in wetland habitats and the influence of different wetland management practices on controlling mercury risk; mercury bioaccumulation in food webs of high-elevation lakes on public (National Park Service and U.S. Forest Service) lands; the impacts of non-native fish introductions to food-web energetics and mercury exposure in native amphibians; the role and impact of timber harvest on mercury cycling and bioavailability in the Pacific Northwest; the role of seabirds as vectors of marine-derived mercury to freshwater lakes in oceanic islands; the spatial extent of legacy mining impacts on downstream mercury bioaccumulation, and mercury exposure and associated physiological responses in songbirds, shorebirds, and piscivorous birds across a gradient of habitat types.
Additionally, USGS FRESC is currently leading a new collaborative initiative to synthesize the landscape and climate influences on mercury distribution, cycling, and bioaccumulation across western North America. This initiative involves dozens of scientists from federal and state agencies, academic institutions, and non-profit organizations.
Active Projects
- Western North America Mercury Synthesis: A Landscape-Scale Analysis of Mercury Cycling, Bioaccumulation, and Risk Linking Long-term Datasets
- Effects of Non-native Fishes on Mercury Bioaccumulation and Risk to Pond-breeding Salamanders in Olympic National Park
- Experimental Control of Methylmercury in Rice Wetlands Using Alternative Rice Harvest Practices
- Forestry Effects on Mercury Cycling and Bioaccumulation at a Watershed Scale
- Incorporating Wildlife Mercury Exposure and Risk Estimates Using Biomagnification Factors into BOG California Lake Monitoring
- Mercury Bioaccumulation in Fish from High-Elevation Lakes in National Parks across the Western United States
- Mercury Bioaccumulation in Terrestrial Songbirds and the Influence of Aquatic Energy Subsidies
- Mercury Bioaccumulation in Waterbodies of the Wallowa-Whitman National Forest
- Mercury Contamination in Waterbird Eggs and Risk to Avian Reproduction at Bear River Migratory Bird Refuge and Great Salt Lake
- Mercury Cycling and Bioaccumulation across the Aleutian Archipelago: Landscape Patterns of Wildlife Risk within the North Pacific Ocean
- Mercury Cycling and Ecological Risk across Habitats in Mount Rainier National Park
- Mercury Effects on Avian Reproduction in San Francisco Bay
- Mercury Exposure and Risk to Purple Martins Breeding in the Willamette Valley, Oregon
- Off-channel Habitats in the Willamette River: Implications for Methylmercury Cycling, Bioaccumulation, and Risk
- The Effects of Wetland Restoration on Mercury Bioaccumulation in the South Bay Salt Pond Restoration Project: Using the Biosentinel Toolbox to Monitor Changes across Multiple Habitats and Spatial Scales
- Science
Below are other science projects associated with this project.
Contaminant Ecology Research Team (FRESC)
The FRESC Contaminant Ecology research program evaluates the distribution, movement, and ecological effects of environmental contaminants across the landscape and strives to provide relevant science in support of natural resource conservation, management, and decision making. - Data
Below are data or web applications associated with this project.
Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 8.0, December 2022)
Comma-separated values (.csv) file containing data related to mercury concentrations in dragonfly samples from U.S. National Parks collected as part of the Dragonfly Mercury Project (DMP)Mercury Concentrations and Mercury Isotopes in Salmonid fishes from the Snake River and tributaries in Idaho and Oregon, 2015 and 2019 (ver. 2.0, February 2021)
Comma-separated values (.csv) file containing data related to mercury in Salmonid fishes collected from the Snake River and tributaries, Idaho and Oregon.Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
This dataset includes fish scientific name, fish common name, site identification codes, latitude, longitude, site name, sample identification codes, collection date, tissue type, percent moisture content in fish samples, and wet and dry total mercury concentrations in fish tissues.Mercury concentrations in songbird feathers and tissues
This dataset includes the bird species, sex, age, and total mercury concentrations in feathers, muscle, liver, and nail tissues. - Publications
Below are publications associated with this project.
Filter Total Items: 28In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Anoxic conditions within reservoirs related to thermal stratification and oxygen depletion lead to methylmercury (MeHg) production, a key process governing the uptake of mercury in aquatic food webs. Once formed within a reservoir, the timing and magnitude of the biological uptake of MeHg and the relative importance of MeHg export in water versus biological compartments remain poorly understood. WAuthorsAustin K. Baldwin, Collin Eagles-Smith, James Willacker, Brett Poulin, David P. Krabbenhoft, Jesse Naymik, Michael T. Tate, Dain Bates, Nick Gastelecutto, Charles Hoovestol, Christopher F. Larsen, Alysa Muir Yoder, James A. Chandler, Ralph MyersMercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Mercury (Hg) and selenium (Se) are contaminants of concern for fish in the Upper Colorado River Basin (UCRB). We explored Hg and Se in fish tissues (2,324 individuals) collected over 50 years (1962–2011) from the UCRB. Samples include native and non-native fish collected from lotic waterbodies spanning 7 major tributaries to the Colorado River. There was little variation of total mercury (THg) inAuthorsNatalie K. Day, Travis Schmidt, James Roberts, Barbara C. Osmundson, James Willacker, Collin Eagles-SmithSynthesis of maternal transfer of mercury in birds: Implications for altered toxicity risk
Maternal transfer is the predominant route of methylmercury (MeHg) exposure to offspring. We reviewed and synthesized published and unpublished data on maternal transfer of MeHg in birds. Using paired samples of females’ blood (n=564) and their eggs (n=1814) from 26 bird species in 6 taxonomic orders, we conducted a meta-analysis to evaluate whether maternal transfer of MeHg to eggs differed amoAuthorsJoshua T. Ackerman, Mark P. Herzog, David C. Evers, Daniel A. Cristol, Kevin P. Kenow, Gary Heinz, Raphael A Lavoie, Rebecka Brasso, Mark L. Mallory, Jennifer F Provencher, Birgit M Braune, Angela Matz, Joel A. Schmutz, Collin A. Eagles-Smith, Lucas J Savoy, Michael W. Meyer, C. Alex HartmanMethylmercury exposure in wildlife: A review of the ecological and physiological processes affecting contaminant concentrations and their interpretation
Exposure to methylmercury (MeHg) can result in detrimental health effects in wildlife. With advances in ecological indicators and analytical techniques for measurement of MeHg in a variety of tissues, numerous processes have been identified that can influence MeHg concentrations in wildlife. This review presents a synthesis of theoretical principals and applied information for measuring MeHg exposAuthorsJohn Chételat, Joshua T. Ackerman, Collin Eagles-Smith, Craig E. HebertSongbird feathers as indicators of mercury exposure: High variability and low predictive power suggest limitations
Although feathers are commonly used to monitor mercury (Hg) in avian populations, their reliability as a sampling matrix has not been thoroughly assessed for many avian species, including most songbirds (Order Passeriformes). To better understand relationships between total Hg (THg) concentrations in feathers and other tissues for birds in the thrush and sparrow families, we (1) examined variationAuthorsKatherine E. Low, Danielle K. Ramsden, Allyson K. Jackson, Colleen Emery, W. Douglas Robinson, Jim Randolph, Collin A. Eagles-SmithSpatial variation in aquatic invertebrate and riparian songbird mercury exposure across a river-reservoir system with a legacy of mercury contamination
Mercury (Hg) loading and methylation in aquatic systems causes a variety of deleterious effects for fish and wildlife populations. Relatively little research has focused on Hg movement into riparian food webs and how this is modulated by habitat characteristics. This study characterized differences in Hg exposure in aquatic invertebrates and riparian songbirds across a large portion of the WillameAuthorsAllyson K. Jackson, Collin A. Eagles-Smith, Colleen EmeryMercury and lead exposure in avian scavengers from the Pacific Northwest suggest risks to California condors: Implications for reintroduction and recovery
Mercury (Hg) and lead (Pb) are widespread contaminants that pose risks to avian scavengers. In fact, Pb exposure is the primary factor limiting population recovery in the endangered California condor (Gymnogyps californianus) and Hg can impair avian reproduction at environmentally relevant exposures. The Pacific Northwest region of the US was historically part of the condor's native range, and effAuthorsGarth Herring, Collin A. Eagles-Smith, Daniel E. VarlandA critical time for mercury science to inform global policy
Mercury is a global pollutant released into the biosphere by varied human activities including coal combustion, mining, artisanal gold mining, cement production, and chemical production. Once released to air, land and water, the addition of carbon atoms to mercury by bacteria results in the production of methylmercury, the toxic form that bioaccumulates in aquatic and terrestrial food chains resulAuthorsCelia Y. Chen, Charles T. Driscoll, Collin A. Eagles-Smith, Chris S. Eckley, David A. Gay, Heileen Hsu-Kim, S. E. Keane, Jane L. Kirk, Robert Mason, Daniel Obrist, Henrik Selin, Noelle Selin, Marcella R. ThompsonMercury on a landscape scale—Balancing regional export with wildlife health
The Cosumnes River watershed requires a 57–64 percent reduction in loads to meet the new Delta methylmercury (MeHg) total maximum daily load allocation, established by the Central Valley Regional Water Quality Control Board. Because there are no large point sources of MeHg in the watershed, the focus of MeHg load reductions will fall upon non-point sources, particularly the expansive wetlands consAuthorsMark C. Marvin-DiPasquale, Lisamarie Windham-Myers, Jacob A. Fleck, Joshua T. Ackerman, Collin A. Eagles-Smith, Harry McQuillenMercury concentrations in multiple tissues of Kittlitz's murrelets (Brachyramphus brevirostris)
Mercury (Hg) is a non-essential, toxic metal that is distributed worldwide. Mercury biomagnifies in food webs and can threaten the health of top predators such as seabirds. The Kittlitz's murrelet (Brachyramphus brevirostris) is a seabird endemic to Alaska and the Russian Far East and is a species of conservation concern in the region. We determined Hg concentrations in eggshells, guano, blood, anAuthorsLeah A. Kenney, Robb S. Kaler, Michelle L. Kissling, Alexander L. Bond, Collin A. Eagles-SmithModulators of mercury risk to wildlife and humans in the context of rapid global change
Environmental mercury (Hg) contamination is an urgent global health threat. The complexity of Hg in the environment can hinder accurate determination of ecological and human health risks, particularly within the context of the rapid global changes that are altering many ecological processes, socioeconomic patterns, and other factors like infectious disease incidence, which can affect Hg exposuresAuthorsCollin A. Eagles-Smith, Ellen K. Silbergeld, Niladri Basu, Paco Bustamante, Fernando Diaz-Barriga, William A. Hopkins, Karen A. Kidd, Jennifer F. NylandStream mercury export in response to contemporary timber harvesting methods (Pacific Coastal Mountains, Oregon, USA)
Land-use activities can alter hydrological and biogeochemical processes that can affect the fate, transformation, and transport of mercury (Hg). Previous studies in boreal forests have shown that forestry operations can have profound, but variable effects on Hg export and methylmercury (MeHg) formation. The Pacific Northwest is an important timber producing region that receives large atmosphericAuthorsChris S. Eckley, Collin A. Eagles-Smith, Michael T. Tate, Brandon M Kowalski, Robert Danehy, Sherri L Johnson, David P. Krabbenhoft