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Western North America Mercury Connections
Western North America Mercury Connections

Mercury Cycling, Bioaccumulation, and Risk across Western North America: A Landscape Scale Synthesis Linking Long-Term Datasets

BRI collaborated with researchers across North America to assess environmental mercury deposition throughout the western region of the continent. With insight and experience gained from the two previous synthesis efforts, researchers collected state, provincial, and federal measurements of mercury in biota, air, water, and soil to better understand spatial and temporal trends in mercury accumulation and deposition in western regions of the United States and Canada. 

The capstone of this project is a Virtual Special Issue published by Science of the Total Environment, containing a collection of 17 journal articles examining the sources, storage, and transport of mercury throughout western North America, the risk posed to wildlife and humans, and associated management implications.

Special Issue!


Findings for the Western North America Mercury Synthesis have been published in a Virtual Special Issue of Science of The Total Environment: Mercury in Western North America—Spatiotemporal Patterns, Biogeochemistry, Bioaccumulation, and Risks

This special issue includes 17 papers - five of which are co-authored by BRI researchers - that will also be published in the October 2016 issue of the journal.

Project Summary

Project Summary

As part of the Western North America Mercury Synthesis team led by the U.S. Geological Survey (USGS), BRI contributed towards the documentation of widespread mercury contamination in air, soil, sediment, plants, fish, and wildlife at various levels across western North America. The team evaluated potential risk from mercury to human, fish, and wildlife heath, and examined resource management activities that influence this risk.

The research team gathered decades of mercury data to examine patterns of mercury and methylmercury in numerous components of the western landscape. The results show where mercury occurs in western North America, how it moves through the environment, and the processes that influence its movement and transfer to aquatic food chains. 

Complete findings for the Western North America Mercury Synthesis have been published in a 2016 special issue of Science of The Total Environment: Mercury in Western North America—Spatiotemporal Patterns, Biogeochemistry, Bioaccumulation, and Risks.

Additionally, a complete summary of results can be found in the USGS Environmental Health Science Feature, Comprehensive Study finds Widespread Mercury Contamination Across Western North America.

Geographic Focus

Geographic Focus

The bi-national project, including the United States and Canada, will encompass the largest mercury synthesis undertaken to date by BRI.

  • United States — Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, Wyoming, and an independent special focus on the Prairie Pothole region including North and South Dakota
  • Canada — Alberta, British Columbia, Saskatchewan, and the Yukon Territory
Key Findings and Implications

Key Findings and Implications

Below are some of the key findings from studies with a focus on fish and wildlife. A complete summary of findings can be found in the USGS Envirironmental Health Science Feature.

  • Methylmercury contamination in fish and birds is common in many areas throughout western North America, and large-scale ecological attributes, such as climate and land cover, are important factors influencing mercury contamination and availability to animals.
  • Fish and birds in many areas were found to have mercury concentrations above levels associated with toxicity.
  • Patterns of methylmercury, the most toxic form of mercury, exposure in fish and wildlife across western North America do not overlap with patterns of inorganic mercury on the landscape, indicating a disconnect between inorganic mercury distribution and exposure in fish and wildlife
  • Land and water management activities can strongly influence how methylmercury is created and transferred to fish, wildlife, and humans.

Effective management of environmental health risks associated with mercury goes beyond controlling sources of inorganic mercury, and would be improved with tools for controlling the production of methylmercury and its introduction to animal and human food sources.


Principle Investigators

  • James Wiener, Ph.D.
    University of Wisconsin — La Crosse (Retired)
Photo Credits: Header photo: © BRI-Allison Byrd; Project Summary © Ken Archer; Geographic Focus © Ken Archer; Key Findings © BRI Staff; Publications © Ken Archer
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