Dr. Eagles-Smith is a Research Ecologist with the Corvallis Reseach Group in Corvallis, Oregon. His research focuses on the interactions among ecological processes, contaminant bioaccumulation, and effects on wild populations. His 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. Dr. Eagles-Smith's research is broadly applied across taxa (primarily fish and waterbirds) and habitat types (including lakes, freshwater wetlands, agricultural fields, and estuarine habitats).
Education
Ph.D. Ecology. University of California, Davis (2006)
B.S. (Magna Cum Laude) Env. Resource Sciences.
University of California, Davis (2000)
Professional Experience
Supervisory Research Ecologist, USGS, FRESC, Corvallis Research Group (8/07-3/2010).
Wildlife Biologist, USGS, WERC, UC Davis Field Station (8/07-3/2010).
Senior Biologist, US Fish and Wildlife Service, Sacramento (2/07-8/07).
Staff Biologist, US Fish and Wildlife Service, Sacramento (2/03-2/07).
Doctoral Research, Dept. of Wildlife, Fish and Cons. Biology, UC Davis (9/00-11/06).
Staff Research Assistant, Dept. of Wildlife, Fish and Cons. Biology, UC Davis (2/98-9/00).
Research Interests
Stable isotope applications to ecosystem energetics, food web ecology, fish and avian foraging ecology, mercury bioaccumulation in aquatic food webs, mercury effects on waterbirds, mercury bioaccumulation in waterbirds, avian reproductive ecology.
Fish mercury data from State monitoring programs and research studies within the Chesapeake Bay were compiled and summarized to provide a comprehensive overview of the variation in fish mercury concentrations among species and habitats within the watershed. These data are put into context with existing health benchmarks for humans, birds, and fish. Scientists also provide a roadmap for an...
Mercury concentrations were measured in dragonfly larvae across more than 450 sites in 100 national parks and protected places as part of a partnership among Federal agencies, academic researchers, and more than 4,000 citizen scientists. Mercury concentrations in dragonfly larvae were positively correlated with mercury concentrations in fish and amphibians living in the same...
In a comprehensive overview, scientists explain that human and wildlife exposure and toxicological responses to mercury are dependent on factors that operate across global, individual, and molecular scales. They provide a roadmap for unified research to facilitate a better understanding of human and wildlife health risks from mercury exposure.
The Ecologically-Driven Exposure pathways team identifies internal and external pathways and processes that can alter exposure and toxicity of contaminants and pathogens to wildlife the environment. That information is used to distinguish actual health risks to fish and wildlife. If actual risks are identified this project will inform how to economically and effectively minimize risk...
In a study designed to help resource managers when considering mercury exposure risk, scientists determined that sulfur cycling—a process closely related to mercury methylation rates—and ecological conditions that influence exposure are important factors affecting fish mercury concentrations in estuarine wetlands.
Proposed new coal export terminals in Washington and Oregon could increase rail traffic through the Northwest and potentially increase unintended release of coal dust to the environment.
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.
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...
The distribution and occurrence of contaminants and the associated biological exposure in ecological systems are driven by complex interactions between contaminant sources and mobilization pathways that are overlaid upon the habitat requirements of at-risk organisms. Moreover, landscape structure and land uses can strongly influence the driving processes of contaminant cycling, as well as the...
Whereas the other themes of the Contaminant Ecology Research Program focus on where, why, and how contaminants cycle and bioaccumulate in ecological systems, this theme is focused on determining what happens at environmentally relevant concentrations.
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 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.
In order to document potential environmental health risk in Cosumnes River Preserve wetlands due to mercury, we analyzed dragonfly larvae, western mosquitofish, and tree swallow eggs collected from wetlands and rice fields of the Preserve from 2011 to 2013.
The dataset includes the bird species, sex, mercury concentration in breast feathers and whole blood, and the composite measure of fluctuating asymmetry. Statistical models were developed for each species to analyze the relationship between mercury exposure in either breast feathers or whole blood and the composite measure of fluctuating asymmetry, while accounting for the sex of each bird....
The dataset includes specifics on fragments of bullets recovered from shot Belding's ground squirrels from Oregon and California. Ground squirrels were radiographed and then we used ImageJ software to count and measure the area of those bullet fragments.
This dataset contains data on the length, mass, and muscle total mercury concentration of Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss) collected from the Colorado River in Glen Canyon National Recreation Area (GLCA) and Grand Canyon National Park (GRCA), and Bright Angel Creek in GRCA.
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...
Janssen, Sarah E.; Hoffman, Joel C.; Lepak, Ryan F.; Krabbenhoft, David P.; Walters, David; Eagles-Smith, Collin; Peterson, Greg; Ogorek, Jacob M.; DeWild, John F.; Cotter, Anne M; Pearson, Mark; Tate, Michael T.; Yeardley, Roger B.; Mills, Marc A. Montane meadows are areas of high biodiversity and provide many important ecosystem services; however, degradation of 40–60% of these habitats in the Sierra Nevada region of California has left many of these areas impaired. The “pond-and-plug” meadow-restoration technique is 1 type of treatment implemented to restore montane meadows. The...
Tennant, Lora; Eagles-Smith, Collin; Willacker, James; Johnson, Matthew Forest soils are among the world’s largest repositories for long-term accumulation of atmospherically deposited mercury (Hg), and understanding the potential for remobilization through gaseous emissions, aqueous dissolution and runoff, or erosive particulate transport to down-gradient aquatic ecosystems is critically important for...
Eckley, Chris S.; Eagles-Smith, Collin; Tate, Michael T.; Krabbenhoft, David P. Although anthropogenic mercury (Hg) releases to the environment have been substantially lowered in the United States and Canada since 1990, concerns remain for contamination in fish from remote lakes and rivers where atmospheric deposition is the predominant source of mercury. How have aquatic ecosystems responded? We report on one of the longest...
Brigham, Mark E.; VanderMeulen, David D.; Eagles-Smith, Collin; Krabbenhoft, David P.; Maki, Ryan P.; DeWild, John F. Mountain lakes, while seemingly pristine, have been subjected to historical fish stocking practices and exposure to atmospherically deposited contaminants like mercury. Mercury bioaccumulation in these ecosystems varies widely due to strong environmental gradients, and there are complex, hierarchical factors that affect mercury transport and...
Chiapella, Ariana M.; Eagles-Smith, Collin; Strecker, Angela L We conducted a national-scale assessment of mercury (Hg) bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels, by developing a citizen science network to facilitate biological sampling. Implementing a carefully designed sampling methodology for citizen scientists, we developed an effective framework for landscape-level...
Eagles-Smith, Collin; Willacker, James; Nelson, Sarah J.; Flanagan Pritz, Collen M; Krabbenhoft, David P.; Chen, Celia Y.; Ackerman, Joshua T.; Campbell Grant, Evan H.; Pilliod, David Mercury (Hg) is a pervasive environmental pollutant and contaminant of concern for both people and wildlife that has been a focus of environmental remediation efforts for decades. A growing body of literature has motivated calls for revising Hg consumption advisories to co-consider selenium (Se) levels in seafood and implies that remediating...
Gerson, Jacqueline R.; Walters, David; Eagles-Smith, Collin; Bernhardt, Emily S.; Brandt, Jessica E Chemical contaminants are a threat to the Chesapeake Bay watershed, with mercury (Hg) among the most prevalent causes of impairment. Despite this, large-scale patterns of Hg concentrations, and the potential risks to fish, wildlife, and humans across the watershed, are poorly understood. We compiled fish Hg data from state monitoring programs and...
Willacker, James; Eagles-Smith, Collin; Blazer, Vicki S. Supplementary food resources (e.g., subsidies) associated with agriculture can benefit wildlife species, increasing predictability and availability of food. Avian scavengers including raptors often utilize subsidies associated with both recreational hunting and pest shooting on agricultural lands. However, these subsidies can contain lead (Pb)...
Herring, Garth; Eagles-Smith, Collin; Buck, Jeremy A.; Shiel, Alyssa E.; Vennum, Chris R.; Emery, Colleen; Johnson, Branden L.; Leal, David; Heath, Julie A.; Dudek, Benjamin M; Preston, Charles R.; Woodbridge, Brian 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....
Day, Natalie; Schmidt, Travis; Roberts, James J.; Osmundson, Barbara C.; Willacker, James; Eagles-Smith, Collin 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...
Chételat, John; Ackerman, Joshua T.; Eagles-Smith, Collin; Hebert, Craig E. 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...
Low, Katherine E.; Ramsden, Danielle K.; Jackson, Allyson K.; Emery, Colleen; Robinson, W. Douglas; Randolph, Jim; Eagles-Smith, Collin A.
Forest soils can act as repositories for atmospherically deposited mercury, yet forestry practices can influence mercury mobility and fluxes, food web dynamics, and bioaccumulation processes.
The ‘‘pond-and-plug’’ meadow-restoration technique, in which ponds are formed by excavating the floodplain and plugging incised channels with the excavated material, is commonly used in montane meadows in the Sierra Nevada.
Mercury bioaccumulation in mountain lakes varies widely due to strong environmental gradients, and there are complex, hierarchical factors that affect mercury transport and loading, methylmercury production, and food web biomagnification.
Mercury is a pervasive environmental pollutant and contaminant of concern for both people and wildlife.
A team of federal, academic, and NGO researchers conducted a national-scale assessment of mercury bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels.
Bay Journal — By Jeremy Cox — Updated July 2, 2020
Despite the prevalence of mercury contamination in the Chesapeake Bay, large-scale patterns of mercury concentrations, and potential risks to fish, wildlife, and humans across the watershed, are poorly understood.
Avian scavengers, including golden eagles, often eat animals culled though recreational hunting and pest shooting on agricultural lands.
Researchers evaluated tissues from barred owls collected in Washington and Oregon to assess potential exposure of the Northern spotted owl and other old-forest wildlife in the Pacific Northwest to anticoagulant rodenticides (AR). They used ecologically similar barred owls as a surrogate species for the northern spotted owl, as the two species compete for space, habitat, and small mammal prey...
Land use change is an important driver of global mercury cycling. Timber harvest is a common land use that can alter associated aquatic ecosystems, yet little is known about how it affects mercury concentrations and associated food web changes.
Amphibian decline is a global conservation crisis driven by multiple interacting stressors, which often act at a local scale with global implications.
Although feathers are commonly used to monitor mercury in birds, their reliability has not been assessed for many avian species, including most songbirds.