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
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.
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 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
Mercury in smallmouth bass from the Snake River, USA, 2013-2022
Mercury and biogeochemical parameters in surface water and sediment from U.S. National Parks, 2014-2015 (ver. 2.0, December 2023)
Total mercury and methylmercury in biota from Cottage Grove Reservoir, Coast Fork Willamette River, and additional reservoirs in Oregon (ver. 2.0, February 2024)
Biomass and methylmercury concentrations in biweekly biological samples from Brownlee and Oxbow Reservoir outflows, Snake River Hells Canyon Complex (Idaho-Oregon), 2018-2019
Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 8.0, December 2022)
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
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.
Riparian methylmercury production increases riverine mercury flux and food web concentrations
Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest
Geographic drivers of mercury entry into aquatic food webs revealed by mercury stable isotopes in dragonfly larvae
Wildfire burn severity and stream chemistry influence aquatic invertebrate and riparian avian mercury exposure in forested ecosystems
Habitat and dissolved organic carbon modulate variation in the biogeochemical drivers of mercury bioaccumulation in dragonfly larvae at the national scale
Reservoir stratification modulates the influence of impoundments on fish mercury concentrations along an arid land river system
A multi-level assessment of biological effects associated with mercury concentrations in smallmouth bass, Micropterus dolomieu
The influence of short-term temporal variability on the efficacy of dragonfly larvae as mercury biosentinels
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Small mammal shooting as a conduit for lead exposure in avian scavengers
Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California
A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework
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.
Mercury Condition Index Tool
Science and Products
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.
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 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
Mercury in smallmouth bass from the Snake River, USA, 2013-2022
Mercury and biogeochemical parameters in surface water and sediment from U.S. National Parks, 2014-2015 (ver. 2.0, December 2023)
Total mercury and methylmercury in biota from Cottage Grove Reservoir, Coast Fork Willamette River, and additional reservoirs in Oregon (ver. 2.0, February 2024)
Biomass and methylmercury concentrations in biweekly biological samples from Brownlee and Oxbow Reservoir outflows, Snake River Hells Canyon Complex (Idaho-Oregon), 2018-2019
Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 8.0, December 2022)
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
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.
Riparian methylmercury production increases riverine mercury flux and food web concentrations
Wildfires influence mercury transport, methylation, and bioaccumulation in headwater streams of the Pacific Northwest
Geographic drivers of mercury entry into aquatic food webs revealed by mercury stable isotopes in dragonfly larvae
Wildfire burn severity and stream chemistry influence aquatic invertebrate and riparian avian mercury exposure in forested ecosystems
Habitat and dissolved organic carbon modulate variation in the biogeochemical drivers of mercury bioaccumulation in dragonfly larvae at the national scale
Reservoir stratification modulates the influence of impoundments on fish mercury concentrations along an arid land river system
A multi-level assessment of biological effects associated with mercury concentrations in smallmouth bass, Micropterus dolomieu
The influence of short-term temporal variability on the efficacy of dragonfly larvae as mercury biosentinels
In-reservoir physical processes modulate aqueous and biological methylmercury export from a seasonally anoxic reservoir
Small mammal shooting as a conduit for lead exposure in avian scavengers
Fish habitat use and food web structure following pond and plug restoration of a Montane Meadow in the Sierra Nevada, California
A national-scale assessment of mercury bioaccumulation in United States National Parks using dragonfly larvae as biosentinels through a citizen-science framework
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.