James J Willacker, Jr.
I am an Ecologist specializing in aquatic and trophic ecology at the USGS Forest and Rangeland Ecosystem Science Center in Corvallis, OR
I am broadly interested in aquatic ecology and in particular the application of trophic ecology to questions of ecotoxicology, evolution, physiology, and conservation biology. My current research focuses on understanding the interplay among ecological, biogeochemical, and physiological processes that govern contaminant accumulation in biota, particularly fishes and other aquatic taxa. My work is also aimed at quantifying ecological risk and toxicological impacts associated with contaminants, particularly mercury.
Professional Experience
2013 - Present: Ecologist, USGS Forest and Rangeland Ecosystem Science Center, Corvallis, OR
2009 - 2013: Doctoral Researcher, University of Alaska Fairbanks, Fairbanks, AK
2009 - 2012: Instructor, Alaska Community Action on Toxics, Anchorage, AK
2007 - 2009: Aquatic Ecologist, Environmental and Natural Resource Institute, Anchorage, AK
Education and Certifications
Ph.D., Biological Sciences, University of Alaska, Fairbanks, AK (2013)
M.S., Biological Sciences, University of Alaska, Anchorage, AK (2009)
B.S., Environmental and Forest Biology- Summa cum laude, State University of New York College of Environmental Science and Forestry (2006)
Honors and Awards
Outstanding Graduate Researcher Award, Environment and Natural Resources Institute, University of Alaska, Anchorage, AK. (2011)
Valedictorian, SUNY ESF (2007)
University Scholar, SUNY (2007)
Faculty Honors, Department of Environmental and Forest Biology, SUNY ESF (2007)
Robin Hood Oak Award, SUNY ESF (2006)
Science and Products
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.
Sampling dragonflies for mercury analysis in Grand Canyon National Park, 2018–2024: A contribution of the Dragonfly Mercury Project Sampling dragonflies for mercury analysis in Grand Canyon National Park, 2018–2024: A contribution of the Dragonfly Mercury Project
Contrasting magnitude and timing of pulsed aqueous methylmercury bioaccumulation across a reservoir food web Contrasting magnitude and timing of pulsed aqueous methylmercury bioaccumulation across a reservoir food web
Ecosystem drivers of freshwater mercury bioaccumulation are context-dependent: Insights from continental-scale modeling Ecosystem drivers of freshwater mercury bioaccumulation are context-dependent: Insights from continental-scale modeling
Riparian methylmercury production increases riverine mercury flux and food web concentrations Riparian methylmercury production increases riverine mercury flux and food web concentrations
Forest cover influences fish mercury concentrations in national parks of the western U.S. Forest cover influences fish mercury concentrations in national parks of the western U.S.
Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest
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.
Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring
Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
Contaminant Ecology Research Team (FRESC)
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 concentrations in biota from the Hells Canyon Reservoir Complex on the Snake River, Idaho and Oregon, USA Total mercury and methylmercury concentrations in biota from the Hells Canyon Reservoir Complex on the Snake River, Idaho and Oregon, USA
Mercury in soil, water, sediment, and biota in headwater streams associated with wildfires in the northwestern U.S., 2021-2022 Mercury in soil, water, sediment, and biota in headwater streams associated with wildfires in the northwestern U.S., 2021-2022
Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks Mercury Stable Isotope Assessment of Dragonflies and Fish Tissues across United States National Parks
Mercury in bird blood and benthic aquatic invertebrates in Plumas National Forest, 2015-2016 Mercury in bird blood and benthic aquatic invertebrates in Plumas National Forest, 2015-2016
Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022 Hydrological, Chemical, and Biological Characterization of the Snake River and Associated Tributaries and Irrigation Drains from River Mile 448 to 346, 2022
Mercury in smallmouth bass from the Snake River, USA (ver. 2.0, January 2025) Mercury in smallmouth bass from the Snake River, USA (ver. 2.0, January 2025)
Mercury Condition Index Tool Mercury Condition Index Tool
Science and Products
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.
Sampling dragonflies for mercury analysis in Grand Canyon National Park, 2018–2024: A contribution of the Dragonfly Mercury Project Sampling dragonflies for mercury analysis in Grand Canyon National Park, 2018–2024: A contribution of the Dragonfly Mercury Project
Contrasting magnitude and timing of pulsed aqueous methylmercury bioaccumulation across a reservoir food web Contrasting magnitude and timing of pulsed aqueous methylmercury bioaccumulation across a reservoir food web
Ecosystem drivers of freshwater mercury bioaccumulation are context-dependent: Insights from continental-scale modeling Ecosystem drivers of freshwater mercury bioaccumulation are context-dependent: Insights from continental-scale modeling
Riparian methylmercury production increases riverine mercury flux and food web concentrations Riparian methylmercury production increases riverine mercury flux and food web concentrations
Forest cover influences fish mercury concentrations in national parks of the western U.S. Forest cover influences fish mercury concentrations in national parks of the western U.S.
Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest
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.
Bioaccumulation of Mercury in Fish Varied by Species and Location in the Chesapeake Bay Watershed—Summary of Existing Data and a Roadmap for Integrated Monitoring
Scientists Identify Processes that Affect Fish Mercury Concentrations in Estuarine Wetlands
Contaminant Ecology Research Team (FRESC)
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.