Wyoming Ecological Services
Mountain-Prairie Region

Environmental Contaminants

One of the primary responsibilities of the Environmental Contaminants (EC) program is the identification of environmental contaminant problems affecting National Wildlife Refuge lands, migratory birds, and threatened and endangered species. When problems are identified, appropriate actions are pursued to eliminate the contaminant threat and restore affected resources. Equally important, the program provides technical assistance to other Service programs, to State and Federal agencies, tribes and to the public.

Bird Mortality
Photo Credit: FWS, Ramirez

Bird Mortality Incident Investigations

EC Specialists assist Service Law Enforcement agents with the investigation of bird mortality incidents. Large bird mortality events can be caused by disease, pesticides, oil spills, releases of hazardous materials, or contaminants. EC specialists apply their wildlife toxicology expertise in collecting and analyzing data to assist with determining the probable cause of mortality.

EC Investigations Oiled Grebe

Oiled Bird in Pit
Photo Credit: FWS




Environmental Contaminants Investigations

EC Specialists conduct investigations involving pesticides, lead, selenium, petroleum hydrocarbons, oilfield produced waters, and coalbed methane produced waters. Environmental contaminants and other stressors can impair reproduction, stunt growth, alter behavior, increase sensitivity to disease, and result in direct mortality of fish and wildlife.  Data from EC scientific investigations are used to resolve contaminant threats to fish and wildlife and their habitat.  A rapid turn-around capability ensures that scientifically credible data is readily available for decision-makers.

Migratory Bird Mortality in Oil and Gas Facilities

EC Specialists assist the Service’s Office of Law Enforcement with the assessment of migratory bird mortality in oil and gas facilities (oil production skim pits, reserve pits, oilfield wastewater disposal facilities) in partnership with the U.S. Environmental Protection Agency, Region 8, the Wyoming Department of Environmental Quality, the Wyoming Oil and Gas Conservation Commission, and the U.S. Bureau of Land Management.  The EC staff produces informational materials on best management practices to prevent or minimize bird mortality in oil and gas facilities.

Spill Response

Environmental Contaminants (EC) Specialists respond to oil spills and hazardous materials spills that threaten National Wildlife Refuge lands, migratory birds, and threatened and endangered species. In 2010 and 2011 EC Specialists provided response assistance at the Deepwater Horizon oil spill in the Gulf Coast, the Yellowstone River pipeline spill in Montana, and an oil spill at the Sinclair Refinery in Sinclair, Wyoming.

More information on the EC Program can be found at the Region 6 EC web site:



Additional Information


WYES Environmental Contaminants Reports




Last updated: March 5, 2015