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)
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: 17
Contaminant 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...
Ecological Effects of Contaminants
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.
Habitat and Land-Use Influences on Contaminant Bioaccumulation
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...
Mercury Cycling and Effects on Ecological Communities
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...
Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
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.
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
Ecosystem Effects of Increased Coal Transport Across the Pacific Northwest
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.
Roadmap to Understanding Factors Influencing Mercury Exposure and Adverse Health Effects
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.
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...
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: 17Contaminant 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...Ecological Effects of Contaminants
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.Habitat and Land-Use Influences on Contaminant Bioaccumulation
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...Mercury Cycling and Effects on Ecological Communities
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...Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
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.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 tEcosystem Effects of Increased Coal Transport Across the Pacific Northwest
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.Roadmap to Understanding Factors Influencing Mercury Exposure and Adverse Health Effects
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.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... - Data
- Publications
- News