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James J Willacker


Forest and Rangeland Ecosystem Science Center

Office Phone: 541-750-0957
ORCID: 0000-0002-6286-5224

Corvallis Research Group CFSL - IAA
3200 S.W. Jefferson Way
Corvallis , OR 97331

Supervisor: Collin A Eagles-Smith
Western North America is a region defined by extreme gradients in geomorphology and climate, which support a diverse array of ecological communities and natural resources. The region also has extreme gradients in mercury (Hg) contamination due to a broad distribution of inorganic Hg sources. These diverse Hg sources and a varied landscape create a unique and complex mosaic of ecological risk from Hg impairment associated with differential methylmercury (MeHg) production and bioaccumulation. Understanding the landscape-scale variation in the magnitude and relative importance of processes associated with Hg transport, methylation, and MeHg bioaccumulation requires a multidisciplinary synthesis that transcends small-scale...
Categories: Publication; Types: Citation
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 bioaccumulation rates (Table S1), and fish size (Table S2). The data were used in linear mixed effects models to estimate average mercury and selenium concentration in fish species and in fish assemblages, including fish total length (cm), sampling location (Sub basin name and GPS coordinates), and sampling year (Figures 2,3, and 4...
The widespread distribution of mercury (Hg) threatens wildlife health, particularly piscivorous birds. Western North America is a diverse region that provides critical habitat to many piscivorous bird species, and also has a well-documented history of mercury contamination from legacy mining and atmospheric deposition. The diversity of landscapes in the west limits the distribution of avian piscivore species, complicating broad comparisons across the region. Mercury risk to avian piscivores was evaluated across the western United States and Canada using a suite of avian piscivore species representing a variety of foraging strategies that together occur broadly across the region. Prey fish Hg concentrations were...
Categories: Publication; Types: Citation
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). This data release supersedes Eagles-Smith, C.A., Nelson, S.J., Flanagan-Pritz, C.M., Willacker Jr., J.J., and Klemmer, A.J., 2018, Total Mercury Concentrations in Dragonfly Larvae from U.S. National Parks (ver. 7.0, October 2021): U.S. Geological Survey data release, Please contact for access.
Categories: Data, Data Release - Revised; Tags: Acadia National Park, Allegheny Portage Railroad National Historic Site, Amistad National Recreation Area, Apostle Islands National Lakeshore, Appomattox Court House National Historical Park, All tags...
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.
Categories: Data; Tags: Acadia National Park, Allegheny Portage Railroad National Historic Site, Apostle Islands National Lakeshore, Appomattox Court House National Historical Park, Aquatic Biology, All tags...
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