Collin Eagles-Smith
I am a Research Ecologist with the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, Oregon. My research focuses on the interactions among ecological processes, contaminant bioaccumulation, and effects on wild populations.
My work specifically focuses on (1) the ecological factors regulating contaminant bioaccumulation and trophic transfer, with an emphasis on food web processes and contaminant cycling, (2) land use practices and ecosystem restoration effects on contaminant cycling through food webs, and (3) the sublethal effects of contaminants on individuals and contaminant-induced impairment to reproduction in the wild. My research is broadly applied across taxa - primarily fish and waterbirds, and habitat types - including lakes, freshwater wetlands, agricultural fields, and estuarine habitats.
Professional Experience
2010-present: Supervisory Research Ecologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
2007-2010: Wildlife Biologist, USGS Western Ecological Research Center, Davis, CA
2003-2007: Biologist, U.S. Fish and Wildlife Service, Sacramento, CA
Education and Certifications
Ph.D., Ecology, University of California, Davis, CA (2006)
B.S., Environmental Resource Sciences - Magna Cum Laude, University of California, Davis, CA (2000)
Science and Products
Contaminant Ecology Research Team (FRESC)
Contaminant Bioaccumulation through Food Webs
Body Symmetry in Forster's Terns Related to Mercury Exposure
New Method Improves Measurement of Bullet Fragments in Culled Varmints
Synthesis of Mercury Distribution and Bioaccumulation Across Western North America
Mercury in Fish from 21 National Parks in the West
Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Total mercury and methylmercury in biota from Cottage Grove Reservoir, Coast Fork Willamette River, and additional reservoirs in Oregon (ver. 2.0, February 2024)
Survival, growth, behavior and mercury concentrations of mayflies exposed to elevated dietary methylmercury and aqueous selenium
Anticoagulant rodenticide concentrations in blood and tissue of California condors and turkey vultures (ver. 2.0, May 2023)
Biomass and methylmercury concentrations in biweekly biological samples from Brownlee and Oxbow Reservoir outflows, Snake River Hells Canyon Complex (Idaho-Oregon), 2018-2019
Mercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 8.0, December 2022)
Mercury Concentrations and Stable Isotopes in Riparian Songbirds and Invertebrates from the Willamette River, Oregon, 2013
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)
Mercury Bioaccumulation in US National Parks Using Dragonfly Larvae as Biosentinels, 2009-2018
Total Mercury Concentrations in Smallmouth Bass from Chesapeake Bay Tributaries, USA Dataset, 2013-2017
Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
Trask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Collateral damage: Anticoagulant rodenticides pose threats to California condors
Using carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout
What are the toxicological effects of mercury in Arctic biota?
Mercury exposure of tidal marsh songbirds in the northeastern United States and its association with nest survival
Lethal impacts of selenium counterbalance the potential reduction in mercury bioaccumulation for freshwater organisms☆
Small mammal shooting as a conduit for lead exposure in avian scavengers
Metal accumulation varies with life history, size, and development of larval amphibians
Differential reliance on aquatic prey subsidies influences mercury exposure in riparian arachnids and songbirds
Demethylation of methylmercury in bird, fish, and earthworm
Isotope fractionation from In Vivo methylmercury detoxification in waterbirds
Examining historical mercury sources in the Saint Louis River estuary: How legacy contamination influences biological mercury levels in Great Lakes coastal regions
Non-USGS Publications**
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Science and Products
- Science
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.Filter Total Items: 18Contaminant Bioaccumulation through Food Webs
This is a broad theme representing the largest component of the Contaminant Ecology Research Program, acting as a bridge between the “Habitat and Land Use Influences” and “Ecological Effects” themes. “Contaminant Bioaccumulation” focuses on quantifying the transfer or movement of contaminants through food webs, and identifying the primary landscape factors and ecological mechanisms that are...Body Symmetry in Forster's Terns Related to Mercury Exposure
Body symmetry of Forster's terns (Sterna forsteri) in San Francisco Bay was related to blood and feather mercury concentrations. Body asymmetry can affect a bird's fitness by reducing flight efficiency, thus increasing energetic costs (especially during migration) and interrupting normal feeding and breeding behaviors.New Method Improves Measurement of Bullet Fragments in Culled Varmints
A creative combination of radiography and techniques borrowed from meat processing and gold prospecting led to a better method for determining the lead content in ground squirrels shot by hunters to evaluate potential exposure risk to avian scavengers such as golden eagles ( Aquila chrysaetos ).Synthesis of Mercury Distribution and Bioaccumulation Across Western North America
The unique combination of natural processes and human activities present in western North America can strongly affect the exposure of fish and birds to methylmercury, the most toxic form of mercury (Hg).Mercury in Fish from 21 National Parks in the West
U.S. Geological Survey (USGS) and National Park Service (NPS) scientists collaborated in the first study to measure mercury in fish from remote places in 21 National Parks spanning 10 Western States, including Alaska. Mercury levels in fish generally were low, but were elevated in some local areas, including two parks in Utah and Alaska where samples taken from sport fish exceeded the U.S...Mercury cycling, bioaccumulation, and risk across western North America: a landscape scale synthesis linking long-term datasets
Mercury (Hg) is a serious environmental problem that is impacting ecological and human health on a global scale. However, local and regional processes are largely responsible for producing methylmercury, which drives ecological risk. This is particularly true in western North America where the combination of diverse landscapes, habitat types, climates, and Hg sources may disproportionally impact t - Data
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 35Total mercury and methylmercury in biota from Cottage Grove Reservoir, Coast Fork Willamette River, and additional reservoirs in Oregon (ver. 2.0, February 2024)
Comma Separated Value (CSV) file containing data related to total and methyl mercury concentrations in biota from the Willamette Basin in Oregon; specifically, Cottage Grove Reservoir, waters upstream of the reservoir, and additional reservoirs within the Willamette Basin.Survival, growth, behavior and mercury concentrations of mayflies exposed to elevated dietary methylmercury and aqueous selenium
Survival and size of mayflies at each life stage, as well as MeHg concentrations in diatoms and mayflies exposed to low and high MeHg concentrations and a range of selenomethione (SeMet) concentrations.Anticoagulant rodenticide concentrations in blood and tissue of California condors and turkey vultures (ver. 2.0, May 2023)
The dataset includes specifics on liver tissue and blood plasma anticoagulant rodenticide concentrations measured using high-performance liquid chromatography-tandem mass spectrometry.Biomass and methylmercury concentrations in biweekly biological samples from Brownlee and Oxbow Reservoir outflows, Snake River Hells Canyon Complex (Idaho-Oregon), 2018-2019
This dataset describes biomass and methylmercury concentrations in zooplankton, other invertebrates, fish, and coarse and fine detritus samples collected at the outflow locations of Brownlee and Oxbow Reservoirs in the Snake River Hells Canyon Complex. Based on the sampling locations, the sampled materials were presumed to have flowed through the dam turbines or over the spillway, thereby represenMercury in fishes from Clear Lake, California, 2019 and 2020 (ver. 2.0, February 2022)
Comma-separated values (.csv) file containing data related to mercury in fishes collected from Clear Lake, California.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 Stable Isotopes in Riparian Songbirds and Invertebrates from the Willamette River, Oregon, 2013
This dataset includes bird species, invertebrate order and family, sample identification codes, collection date, latitude, longitude, site name, bird age, invertebrate life stage, invertebrate trophic group, carbon and nitrogen stable isotopes in birds and invertebrates, total mercury concentrations in bird blood, and methylmercury concentrations in composite invertebrates.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.Mercury Bioaccumulation in US National Parks Using Dragonfly Larvae as Biosentinels, 2009-2018
Comma-separated values (.csv) files containing data related to a National-scale assessment of mercury bioaccumulation in the US National Parks using dragonfly larvae as biosentinels through a citizen science framework.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.Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
These data were compiled to study mercury and selenium concentrations in fish species and assemblages in lotic waterbodies across the Upper Colorado River Basin. Data were compiled from State and Federal agencies. This data table contains raw concentration data, as well as standardized concentrations corrected for differences based on sample type (i.e., tissue type), species-specific bioaccumulatiTrask River Watershed Study Area Forestry Bioaccumulation Dataset, 2011-2015
This dataset includes timber harvest treatments; mercury concentrations in aquatic macroinvertebrates, salamanders, and riparian songbirds; carbon and nitrogen stable isotopes in aquatic macroinvertebrates and salamanders; and Bayesian estimates of food web length, basal resource diversity, and isotopic niche size for individual feeding guilds. - Multimedia
- Publications
If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.
Filter Total Items: 134In-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 MyersCollateral damage: Anticoagulant rodenticides pose threats to California condors
Anticoagulant rodenticides (ARs) are widespread environmental contaminants that pose risks to scavenging birds because they routinely occur within their prey and can cause secondary poisoning. However, little is known about AR exposure in one of the rarest avian scavengers in the world, the California condor (Gymnogyps californianus). We assessed AR exposure in California condors and surrogate turAuthorsGarth Herring, Collin Eagles-Smith, Rachel Wolstenholme, Alacia Welch, Chris West, Barnett A. RattnerUsing carbon, nitrogen, and mercury isotope values to distinguish mercury sources to Alaskan lake trout
Lake trout (Salvelinus namaycush), collected from 13 remote lakes located in southwestern Alaska, were analyzed for carbon, nitrogen, and mercury (Hg) stable isotope values to assess the importance of migrating oceanic salmon, volcanic activity, and atmospheric deposition to fish Hg burden. Methylmercury (MeHg) bioaccumulation in phytoplankton (5.0–6.9 kg L–1) was also measured to quantify the basAuthorsRyan F. Lepak, Jacob M. Ogorek, Krista K. Bartz, Sarah E. Janssen, Michael T. Tate, Yin Runsheng, James P. Hurley, Daniel B. Young, Collin Eagles-Smith, David P. KrabbenhoftWhat are the toxicological effects of mercury in Arctic biota?
No abstract available.AuthorsRune Dietz, Robert J. Letcher, Josh T. Ackerman, Benjamin D. Barst, Niladri Basu, Olivier Chastel, John Chételat, Sam Dastnai, Jean-Pierre Desforges, Collin A. Eagles-Smith, Igor Eulaers, Jérôme Fort, Jacob Nabe-Nielsen, Feiyue Wang, Simon WilsonMercury 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. OlsenLethal impacts of selenium counterbalance the potential reduction in mercury bioaccumulation for freshwater organisms☆
Mercury (Hg), a potent neurotoxic element, can biomagnify through food webs once converted into methylmercury (MeHg). Some studies have found that selenium (Se) exposure may reduce MeHg bioaccumulation and toxicity, though this pattern is not universal. Se itself can also be toxic at elevated levels. We experimentally manipulated the relative concentrations of dietary MeHg and Se (as selenomethionAuthorsJacqueline R. Gerson, Rebecca A. Consbrock, Collin Eagles-Smith, Emily S. Bernhardt, David WaltersSmall 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 WillackerMetal 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. HossackDifferential 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 PoulinIsotope fractionation from In Vivo methylmercury detoxification in waterbirds
The robust application of stable mercury (Hg) isotopes for mercury source apportionment and risk assessment necessitates the understanding of mass-dependent fractionation (MDF) due to internal transformations within organisms. Here, we used high energy-resolution XANES spectroscopy and isotope ratios of total mercury (δ202THg) and methylmercury (δ202MeHg) to elucidate the chemical speciation of HgAuthorsBrett Poulin, Sarah Elizabeth Janssen, Tylor Rosera, David P. Krabbenhoft, Collin Eagles-Smith, Josh T. Ackerman, Robin Stewart, Eunhee Kim, Zofia Baumann, Jeong-Hoon Kim, Alain ManceauExamining historical mercury sources in the Saint Louis River estuary: How legacy contamination influences biological mercury levels in Great Lakes coastal regions
Industrial chemical contamination within coastal regions of the Great Lakes can pose serious risks to wetland habitat and offshore fisheries, often resulting in fish consumption advisories that directly affect human and wildlife health. Mercury (Hg) is a contaminant of concern in many of these highly urbanized and industrialized coastal regions, one of which is the Saint Louis River estuary (SLRE)AuthorsSarah E. Janssen, Joel C. Hoffman, Ryan F. Lepak, David P. Krabbenhoft, David Walters, Collin Eagles-Smith, Greg Peterson, Jacob M. Ogorek, John F. DeWild, Anne M Cotter, Mark Pearson, Michael T. Tate, Roger B. Yeardley, Marc A. MillsNon-USGS Publications**
Suchanek, T.H., Cooke, J., Keller, K., Richerson, P.J., Eagles-Smith, C.A., Harner, E.J., Adam, D.P., 2009, A mass balance mercury budget for a mine-dominated lake - Clear Lake, California: Water, Air, & Soil Pollution, v. 196, p. 51-73.Richerson, P.J., Suchanek, T.H., Zierenberg, R.A., Osleger, D.A., Heyvaert, A.C., Slotton, D.G., Eagles-Smith, C.A., Vaughn, C.E., 2008, Anthropogenic stressors and changes in the Clear Lake ecosystem as recorded in sediment cores: Ecological Applications, v. 18, no. 8, p. A257-A283.Suchanek, T.H., Eagles-Smith, C.A., Harner, E.J., 2008, Is Clear Lake methylmercury distribution decoupled from bulk mercury loading?: Ecological Applications, v. 18, no. 8, p. A107-A127.Suchanek, T.H., Eagles-Smith, C.A., Slotton, D.G., Harner, E.J., Adam, D.P., 2008, Mercury in abiotic matrices of Clear Lake, California- Human health and ecotoxicological implications: Ecological Applications, v. 18, no. 8, p. A128-A157.Anderson, D.W., Suchanek, T.H., Eagles-Smith, C.A., Cahill, Jr., T.M., 2008, Mercury residues and productivity in osprey and grebes from a mine-dominated ecosystem: Ecological Applications, v. 18, no. 8, p. A227-A238.Suchanek, T.H., Eagles-Smith, C.A., Slotton, D.G., Harner, E.J., Adam, D.P., Colwell, A.E., Anderson, N.L., Woodward, D.L., 2008, Mine-derived mercury- Effects on lower trophic species in Clear Lake, California: Ecological Applications, v. 18, no. 8, p. A158-A176.Suchanek, T.H., Eagles-Smith, C.A., Slotton, D.G., Harner, E.J., Colwell, A.E., Anderson, N.L., Mullen, L.H., Flanders, J.R., Adam, D.P., McElroy, K.J., 2008, Spatiotemporal trends in fish mercury from a mine-dominated ecosystem- Clear Lake, California: Ecological Applications, v. 18, no. 8, p. A177-A195.McEachern, M.B., Eagles-Smith, C.A., Efferson, C.M., Van Vuren, D.H., 2006, Evidence for local specialization in a generalist mammalian herbivore, Neotoma fuscipes: Oikos, v. 113, p. 440-448.**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
- Software
- News
To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.
Filter Total Items: 29