鈥淢ercury is widespread in the environment, and under certain conditions poses a substantial threat to environmental health and natural resource conservation,鈥� says Collin Eagles-Smith, Ph.D., USGS ecologist and team lead.
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.
鈥淭his integrated effort provides critical information on mercury pathways to humans and wildlife that government regulators, lawmakers, and the public can use to make decisions,鈥� says David Evers, Ph.D., executive director and chief scientist of Biodiversity Research Institute and co-organizer of the project. 鈥淭he Western mercury synthesis builds upon our Northeastern and Great Lakes regional efforts through which we collected and analyzed environmental mercury data that were often separated by sample type.鈥� The initiative for the western region of the continent continues BRI鈥檚 efforts to assess environmental mercury deposition across North America in the Institute鈥檚 series of studies called Mercury Connections.
Complete findings for the Western North America Mercury Synthesis (the Western Synthesis) have been published in a 2016 special issue of Science of The Total Environment: Mercury in Western North America鈥擲patiotemporal Patterns, Biogeochemistry, Bioaccumulation, and Risks. Dr. Evers is co-author on five out of the 17 papers published in this Virtual Special Issue (available only online). All of the papers will also be published in the October issue of the journal.鈥働apers co-authored by Dr. Evers include:1. Mercury in western North America: A synthesis of environmental contamination, fluxes, bioaccumulation, and risk to fish and wildlife2. Mercury risk to avian piscivores across western United States and Canada3. Assessing potential health risks to fish and humans using mercury concentrations in inland fish from across western Canada and the United States4. Avian mercury exposure and toxicological risk across western North America: A synthesis5. Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada
Summary of Key Findings and Implications (related to fish and wildlife) include:鈼� 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.鈼� Fish and birds in many areas were found to have mercury concentrations above levels associated with toxicity.鈼� 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 鈼� Land and water management activities can strongly influence how methylmercury is created and transferred to fish, wildlife, and humans.鈼� 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
The Western Synthesis results suggest that effective management of environmental health risks associated with mercury goes beyond controlling sources of inorganic mercury, and could be improved by development of tools to control the production of methylmercury and its bioaccumulation through the food web, ultimately affecting animals and humans.
For a complete summary of the Western Synthesis results, visit: USGS Environmental Health Science Feature
This body of work was conducted as part of the Western North America Mercury Synthesis Working Group and supported by the USGS John Wesley Powell Center for Analysis and Synthesis. The Working Group is comprised of partners from other U.S. and Canadian federal, state, and provincial agencies, as well as academic institutions and non-governmental organizations. Primary funding support was provided by the U.S. Geological Survey, National Park Service, and U.S. Environmental Protection Agency, with additional support from the individual authors鈥� organizations.
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Biodiversity Research Institute, headquartered in Portland, Maine, is a nonprofit ecological research group whose mission is to assess emerging threats to wildlife and ecosystems through collaborative research, and to use scientific findings to advance environmental awareness and inform decision makers. BRI supports ten research programs within three research centers including the Center for Mercury Studies, which was initiated in 2011.
BRI is assisting in multiple ways with the ratification and implementation of the Minamata Convention on Mercury鈥攁 globally binding agreement facilitated by the United Nations Environment Programme (UNEP). BRI is a co-lead of UNEP鈥檚 Mercury Air Transport and Fate Research Partnership Area and a member of the Artisanal and Small-scale Gold Mining (ASGM) Partnership Area. BRI is also an Executing Agency of the United Nations Industrial Development Organization and serves as an international advisor for the United Nations Development Program and United Nations Environment Programme to help coordinate and facilitate enabling activities to conduct Minamata Initial Assessments for more than 30 countries. Visit for more information.
The U.S. Geological Survey provides science about the natural hazards that threaten lives and livelihoods; the water, energy, minerals, and other natural resources we rely on; the health of our ecosystems and environment; and the impacts of climate and land-use change. Our scientists develop new methods and tools to supply timely, relevant, and useful information about the Earth and its processes.
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