Ecologically-Driven Exposure Pathways Science Team Active
The Team Determines Factors That Influence Fish and Wildlife Exposure
to toxicants such as mercury in the environment
Scientists Can Sample Tissues and Blood in Small Birds Without Harm
to understand factors such as maternal transfer of contaminants to offspring
The Team Studies Factors that Influence Exposure Risk in Mammals
such as foraging and fasting behavior in elephant seals
Factors that Influence Pathogen Transmission are Identified
Advanced Techniques are used to Understand Contaminant Sources
The Ecologically-Driven Exposure Pathways Integrated Science Team identifies how ecological pathways and physiological processes within a single organism can alter exposure and toxicity of contaminants and pathogens and seek to understand outcomes at different scales from individuals to populations and ecosystems.
Contaminant and pathogen exposure alone does not necessarily result in adverse health outcomes in fish, wildlife, or humans. There are numerous pathways and processes that can alter the toxicity of naturally occurring and human-made contaminants in the environment.
The team uses their broad scientific expertise in hydrology, geochemistry, biology, and ecotoxicology to understand the complexities associated with the movement of toxicants and pathogens through the environment and within individual organisms. That information is used to determine how, where, and when exposure occurs and if exposure results in health risks to wildlife and humans.
Current Science Questions and Activities
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What are the various ecological factors, such as habitats and foraging strategies, that influence the pathways of contaminant exposure, health risks to fish and wildlife?
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What are the pathways of antimicrobial resistance in the environment?
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What are the major intrinsic and extrinsic drivers of mercury exposure and risk to humans, fish, and wildlife at a global scale?
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What are the internal physiological determinants such as metababolism, transfer of mercury to offspring, changes in body mass, and molting that influence exposure and health risks in fish and wildlife?
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How do the internal factors differ among species and life stages?
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What are the Influences of landscape alterations, perturbations, and restoration on pathways and movement of contaminants through ecosystems and bioaccumulation into the food web of aquatic biota?
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Do multiple types and chemical mixtures have additive, synergistic, or antagonistic effects that influence the health of fish and wildlife?
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What are the internal and external drivers and regulators of human exposure to mercury?
- What is the risk of pathogen exposure and transmission among wildlife, livestock, and humans?
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What are the key environmental factors that control the viability of avian influenza virus shed by wild birds and what are the key environmental pathways of exposure and transmission of the virus?
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What is the role of soil, water, and vegetation in disease transmission such as Chronic Wasting Disease?
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How do invasive species influence the timing of contaminant uptake and bioaccumulation in fish and wildlife?
USGS science related to this science team’s activities.
Satellite Tracking of Birds in Alaska Points to Distant Sources of Lead and Mercury Exposure
The following are the data releases from this science team’s research activities.
Mercury concentrations in songbird feathers and tissues
Total Mercury and Methylmercury in Riparian Songbirds and Aquatic Invertebrates from the Willamette Valley, Oregon, 2013-2014
Feather mercury concentrations in North American raptors sampled at migration monitoring stations
Variability of mercury concentrations among whole bird feathers, feather homogenates, and feather components quantified in California in 2017-2018
Polychlorinated biphenyl concentrations in adult walleye from the Fox River (Wisconsin) population, 2014
Fox River walleye mercury isotope data
Annual winter elk movements in the Greater Yellowstone Ecosystem 2001-2015
Geochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
Pacific Northwest Avian Scavenger Lead and Mercury Dataset, 2012-2016
Wetland water-management may influence mercury bioaccumulation in songbirds and ducks at a mercury hotspot data release
Mercury speciation and other constituent data from deep sediment cores in Alviso Slough, South San Francisco Bay, California, 2006-16
Polychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA
Below are publications associated with this science team.
Host correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Mercury exposure of tidal marsh songbirds in the northeastern United States and its association with nest survival
Sustaining transmission in different host species: The emblematic case of Sarcoptes scabiei
Antimicrobial resistance: Wildlife as indicators of anthropogenic environmental contamination across space and through time
Small mammal shooting as a conduit for lead exposure in avian scavengers
Insect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies?
Metal accumulation varies with life history, size, and development of larval amphibians
Using tree swallows to assess reductions in PCB exposure as a result of dredging at Great Lakes Restoration Initiative (GLRI) sites in the Upper Midwest, USA
Cross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Differential reliance on aquatic prey subsidies influences mercury exposure in riparian arachnids and songbirds
Demethylation of methylmercury in bird, fish, and earthworm
Foraging in marine habitats increases mercury concentrations in a generalist seabird
- Overview
The Ecologically-Driven Exposure Pathways Integrated Science Team identifies how ecological pathways and physiological processes within a single organism can alter exposure and toxicity of contaminants and pathogens and seek to understand outcomes at different scales from individuals to populations and ecosystems.
Contaminant and pathogen exposure alone does not necessarily result in adverse health outcomes in fish, wildlife, or humans. There are numerous pathways and processes that can alter the toxicity of naturally occurring and human-made contaminants in the environment.
The team uses their broad scientific expertise in hydrology, geochemistry, biology, and ecotoxicology to understand the complexities associated with the movement of toxicants and pathogens through the environment and within individual organisms. That information is used to determine how, where, and when exposure occurs and if exposure results in health risks to wildlife and humans.
Current Science Questions and Activities
-
What are the various ecological factors, such as habitats and foraging strategies, that influence the pathways of contaminant exposure, health risks to fish and wildlife?
-
What are the pathways of antimicrobial resistance in the environment?
-
What are the major intrinsic and extrinsic drivers of mercury exposure and risk to humans, fish, and wildlife at a global scale?
-
What are the internal physiological determinants such as metababolism, transfer of mercury to offspring, changes in body mass, and molting that influence exposure and health risks in fish and wildlife?
-
How do the internal factors differ among species and life stages?
-
What are the Influences of landscape alterations, perturbations, and restoration on pathways and movement of contaminants through ecosystems and bioaccumulation into the food web of aquatic biota?
-
Do multiple types and chemical mixtures have additive, synergistic, or antagonistic effects that influence the health of fish and wildlife?
-
What are the internal and external drivers and regulators of human exposure to mercury?
- What is the risk of pathogen exposure and transmission among wildlife, livestock, and humans?
-
What are the key environmental factors that control the viability of avian influenza virus shed by wild birds and what are the key environmental pathways of exposure and transmission of the virus?
-
What is the role of soil, water, and vegetation in disease transmission such as Chronic Wasting Disease?
-
How do invasive species influence the timing of contaminant uptake and bioaccumulation in fish and wildlife?
-
- Science
USGS science related to this science team’s activities.
Filter Total Items: 25Satellite Tracking of Birds in Alaska Points to Distant Sources of Lead and Mercury Exposure
U.S. Geological Survey (USGS) scientists measured lead in blood from tundra swans that nest in Alaska and then followed the migration of these birds using satellite telemetry. Levels of lead in blood were higher in adults than young swans,suggesting exposure to lead occurs on wintering areas and/or during migration, rather than on the summer breeding grounds in Alaska. The lowest blood levels were... - Data
The following are the data releases from this science team’s research activities.
Filter Total Items: 38Mercury 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.Total Mercury and Methylmercury in Riparian Songbirds and Aquatic Invertebrates from the Willamette Valley, Oregon, 2013-2014
This dataset includes bird species, invertebrate order and family, sample identification codes, capture date, latitude, longitude, habitat, site name, bird age, total mercury concentrations in bird blood, and methylmercury concentrations in whole body aquatic invertebrates.Feather mercury concentrations in North American raptors sampled at migration monitoring stations
We assessed total mercury concentrations in breast feathers of diurnal North American raptors collected at migration monitoring stations. We sampled raptor feathers from 9 species in the Pacific Flyway and compared species, sex, date, and flyway effects on mercury concentrations. We also explored year effects on 3 species of raptors in the Pacific Flyway during 13-years (2002-2014). Finally, we coVariability of mercury concentrations among whole bird feathers, feather homogenates, and feather components quantified in California in 2017-2018
These data are the raw total mercury (THg) concentrations in whole feathers, feather homogenates, and feather components (i.e., rachis, vane, calamus) that are presented in the Journal Article "Mercury concentrations vary within and among individual bird feathers: A critical evaluation and guidelines for feather use in mercury monitoring programs" in Environmental Toxicology and Chemistry by PeterPolychlorinated biphenyl concentrations in adult walleye from the Fox River (Wisconsin) population, 2014
Adult walleye (10 females and 10 males) were caught in Fox River (Wisconsin) during April 2014. Total length, weight, and age were determined for each of the walleye. Whole-fish homogenates were prepared during 2017. Lipid concentration and polychlorinated biphenyl (PCB) congener concentrations were determined in each of the homogenates during 2017-2018. For each sample, PCB congener concentrationFox River walleye mercury isotope data
Adult walleye were caught in Fox River (Wisconsin) during April 2014. Age-0 walleye were caught in Fox River during October 2014. Total length, weight, age, and proportion of weight represented by water were determined for each of the walleye. Whole-fish homogenates were prepared during 2014-2015 and during 2017. Total mercury (HgT) concentration, methylmercury (MeHg) concentration, and mercury (HAnnual winter elk movements in the Greater Yellowstone Ecosystem 2001-2015
521 unique elk with GPS collars were tracked using telemetry from 2001 to 2015 in the Greater Yellowstone Ecosystem to determine winter-to-winter annual dispersal distance of each individual. All elk were identified and located using telemetry during the months of January and February for two successive years. An individual elk was included at most three times in the data and each year was consideGeochemistry of shallow sediment including mercury, methylmercury and other constituents in the Cache Creek Settling Basin, Yolo County, California, 2010-16
The Cache Creek Settling Basin (CCSB) is a 13.3 km2 leveed basin located at the terminal drainage of the Cache Creek watershed, immediately NE of the town of Woodland (Yolo County), California and approximately 18 km NW of Sacramento, California. The basin was constructed by the U.S. Army Corps of Engineers (completed in 1937 and modified in 1993) for the purpose of trapping suspended sediment traPacific Northwest Avian Scavenger Lead and Mercury Dataset, 2012-2016
The dataset includes the bird species, region where sampled, sampling site, capture location, mercury concentration in whole blood, lead concentration in whole blood, sulfur stable isotope concentration in blood plasma, carbon isotope concentration in blood plasma, whole blood ALAD activity, and fecal corticosterone concentrations.Wetland water-management may influence mercury bioaccumulation in songbirds and ducks at a mercury hotspot data release
We examined the role of wetland water-management on mercury bioaccumulation in songbirds and ducks. This database contains records of mercury concentrations in blood of wetland-foraging songbirds (80 common yellowthroats [Geothlypis trichas] and 14 Nelson's sparrows [Ammospiza nelsoni]) and eggs of upland-nesting ducks (28 gadwall [Mareca strepera], 19 blue-winged teal [Spatula discors], and 13 noMercury speciation and other constituent data from deep sediment cores in Alviso Slough, South San Francisco Bay, California, 2006-16
This dataset includes mercury and other constituent concentration and physical properties data for seven deep sediment profiles (ranging from 79 cm to 214 cm in length) collected from the thalwag of Alviso Slough, a major tributary to South San Francisco Bay (California, USA). Field sampling occurred during May 2012 (4 sites) and January 2016 (3 sites). Each profile was comprised of 1-4 core sub-sPolychlorinated biphenyl concentrations and lipid content in riparian spiders at the Ashtabula River Area of Concern, USA
We measured polychlorinated biphenyl (PCB) concentrations in two taxa of riparian spiders from nine sites in 2011 at the Ashtabula River Area of Concern. We analyzed the extracts for 122 congeners following EPA method SW846 Method 8270D using gas chromatography mass spectrometry in the selective ion monitoring (SIM) mode. All target compounds were quantified using the method of internal standards, - Publications
Below are publications associated with this science team.
Filter Total Items: 135Host correlates of avian influenza virus infection in wild waterfowl of the Sacramento Valley, California
Avian influenza viruses (AIVs) are distributed globally in members of the family Anatidae (waterfowl), and significant disease may occur when these viruses infect commercial poultry or humans. Early detection of AIV through surveillance of wild waterfowl is one measure to prevent future disease outbreaks. Surveillance efforts that are designed to account for host and environmental determinants ofAuthorsElizabeth A. Bianchini, Raymond J. Bogiatto, Robin A. Donatello, Michael L. Casazza, Josh T. Ackerman, Susan E. W. De La Cruz, Troy D. ClineMercury exposure of tidal marsh songbirds in the northeastern United States and its association with nest survival
The biogeochemistry of tidal marsh sediments facilitates the transformation of mercury (Hg) into the biologically available form methylmercury (MeHg), resulting in elevated Hg exposures to tidal marsh wildlife. Saltmarsh and Acadian Nelson’s sparrows (Ammospiza caudacutua and A. nelsoni subvirgatus, respectively) exclusively inhabit tidal marshes, potentially experiencing elevated risk to Hg exposAuthorsKatherine J Ruskin, Garth Herring, Collin Eagles-Smith, Alyssa B. Eiklor, Chris S Elphick, Matthew A. Etterson, Chrisopher B. Field, Rebecca A. Longnecker, Adrienne I. Kovach, W Greg Shriver, James F. Walsh, Brian J. OlsenSustaining transmission in different host species: The emblematic case of Sarcoptes scabiei
Some pathogens sustain transmission in multiple different host species, but how this epidemiologically important feat is achieved remains enigmatic. Sarcoptes scabiei is among the most host generalist and successful of mammalian parasites. We synthesize pathogen and host traits that mediate sustained transmission and present cases illustrating three transmission mechanisms (direct, indirect, and cAuthorsE Browne, MM Driessen, Paul C. Cross, L. E. Escobar, Janet E. Foley, JR López-Olvera, KD Niedringhaus, Liza Rossi, Scott CarverAntimicrobial resistance: Wildlife as indicators of anthropogenic environmental contamination across space and through time
Prior assessments support wildlife as indicators of anthropogenically influenced antimicrobial resistance across the landscape. A ground-breaking new study suggests that wildlife may also provide information on antimicrobial resistance in the environment through time.AuthorsAndrew M. RameySmall mammal shooting as a conduit for lead exposure in avian scavengers
Lead (Pb) exposure is a widespread wildlife conservation threat. Although commonly associated with Pb-based ammunition from big-game hunting, small mammals (e.g., ground squirrels) shot for recreational or pest-management purposes represent a potentially important Pb vector in agricultural regions. We measured the responses of avian scavengers to pest-shooting events and examined their Pb exposureAuthorsGarth Herring, Collin Eagles-Smith, John Goodell, Jeremy A. Buck, James WillackerInsect-mediated contaminant flux at the land–water interface: Are ecological subsidies driving exposure or is exposure driving subsidies?
Chemical contamination of freshwaters is a global problem. In the United States alone, millions of kilometers of rivers and hectares of lakes and wetlands are impaired from contamination by chemicals including mercury, pesticides, polychlorinated biphenyls (PCBs), and trace metals (US Environmental Protection Agency, 2017). Efforts to mitigate the risks of contamination have largely focused on aquAuthorsJohanna M. Kraus, Jeff S. Wesner, David WaltersMetal accumulation varies with life history, size, and development of larval amphibians
Amphibian larvae are commonly used as indicators of aquatic ecosystem health because they are susceptible to contaminants. However, there is limited information on how species characteristics and trophic position influence contaminant loads in larval amphibians. Importantly, there remains a need to understand whether grazers (frogs and toads [anurans]) and predators (salamanders) provide comparablAuthorsKelly L. Smalling, Emily Bea Oja, Danielle M. Cleveland, Jon D Davenport, Collin Eagles-Smith, Evan H. Campbell Grant, Patrick M. Kleeman, Brian J. Halstead, Kenzi M Stemp, Brian J. Tornabene, Zachary J Bunnell, Blake R. HossackUsing tree swallows to assess reductions in PCB exposure as a result of dredging at Great Lakes Restoration Initiative (GLRI) sites in the Upper Midwest, USA
Tree swallows (Tachycineta bicolor) were used to assess the effectiveness of reducing polychlorinated biphenyl (PCB) exposure to wildlife as a result of contaminated sediment removal at locations across the Great Lakes under two dredging scenarios, full or spot dredging. For comparative purposes, other locations where no dredging occurred were also assessed. Calculating accumulation rate, from theAuthorsChristine M. Custer, Thomas W. Custer, Paul DummerCross-ecosystem fluxes of pesticides from prairie wetlands mediated by aquatic insect emergence: Implications for terrestrial insectivores
Contaminants alter the quantity and quality of insect prey available to terrestrial insectivores. In agricultural regions, the quantity of aquatic insects emerging from freshwaters can be impacted by insecticides originating from surrounding croplands. We hypothesized that, in such regions, adult aquatic insects could also act as vectors of pesticide transfer to terrestrial food webs. To estimateAuthorsJohanna M. Kraus, Kathryn Kuivila, Michelle Hladik, Neil Shook, David M. Mushet, Kelen Dowdy, Rachel HarringtonDifferential reliance on aquatic prey subsidies influences mercury exposure in riparian arachnids and songbirds
Cross-ecosystem subsidies move substantial amounts of nutrients between ecosystems. Emergent aquatic insects are a particularly important prey source for riparian songbirds but may also move aquatic contaminants, such as mercury (Hg), to riparian food webs. While many studies focus on species that eat primarily emergent aquatic insects, we instead study riparian songbirds with flexible foraging stAuthorsAllyson K. Jackson, Collin Eagles-Smith, W Douglas RobinsonDemethylation of methylmercury in bird, fish, and earthworm
Toxicity of methylmercury (MeHg) to wildlife and humans results from its binding to cysteine residues of proteins, forming MeHg-cysteinate (MeHgCys) complexes that hinder biological functions. MeHgCys complexes can be detoxified in vivo, yet how this occurs is unknown. We report that MeHgCys complexes are transformed into selenocysteinate (Hg(Sec)4) complexes in multiple animals from two phyla (aAuthorsAlain Manceau, Jean-Paul Bourdineaud, Ricardo B. Oliveira, Sandra LF Sarrazin, David P. Krabbenhoft, Collin Eagles-Smith, Josh T. Ackerman, Robin Stewart, Christian Ward-Deitrich, M Estela del Castillo Busto, Heidi Goenaga-Infante, Aude Wack, Marius Retegan, Blanka Detlefs, Pieter Glatzel, Paco Bustamante, Kathryn L. Nagy, Brett PoulinForaging in marine habitats increases mercury concentrations in a generalist seabird
Methylmercury concentrations vary widely across geographic space and among habitat types, with marine and aquatic-feeding organisms typically exhibiting higher mercury concentrations than terrestrial-feeding organisms. However, there are few model organisms to directly compare mercury concentrations as a result of foraging in marine, estuarine, or terrestrial food webs. The ecological impacts of dAuthorsCorey A. Clatterbuck, Rebecca L. Lewison, Rachael A Orben, Josh T. Ackerman, Leigh G Torres, Robert M. Suryan, Peter Warzybok, Jaime Jahncke, Scott A. Shaffer - Web Tools
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