Scientist standing waist-deep in a lake, examining the contents of a dipnet
Scientist looking for dragonfly larvae on Lake Harvey.

© Sean Bailey

Mercury emissions to the atmosphere come from both natural and human sources. Once in the air, mercury can travel great distances and is deposited on land and in water by way of rain, snow, and dust particles. In the environment, mercury undergoes a complex transformation to become methylmercury, which is toxic to all forms of life.

There are also many things we do in the course of a day that contribute to the contamination of lakes and streams. Every-day chemicals such as medications, insect repellent, and personal care products that go down the sink drain are known as contaminants of emerging concern.

Long-term Monitoring

Our contaminants monitoring program has evolved from tracking six different contaminants using tissues of indicator species (bald eagle nestlings and fish), to focusing on mercury in dragonfly larvae. In this, we are part of a nationwide monitoring program coordinated by the NPS Air Resources Division. We are also monitoring contaminants of emerging concern in water samples.

Our partner:

NPS Air Resources Division, Dragonfly Mercury Project

Learn More

Briefs provide a one- or two-page overview of the latest findings and what they mean. Monitoring reports are in-depth technical reports that include data analyses and possibly management recommendations.


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    Source: Data Store Saved Search 387. To search for additional information, visit the Data Store.

    Monitoring Reports

    Source: Data Store Saved Search 420. To search for additional information, visit the Data Store.

    Monitoring Protocol

    Protocol documents detail precisely how monitoring is carried out.

    Route B and Others. 2009. Protocol for Monitoring Environmental Contaminants in Bald Eagles - Version 1.2: Great Lakes Inventory and Monitoring Network. Natural Resource Report. NPS/GLKN/NRR—2009/092. National Park Service. Fort Collins, Colorado

    Wiener J and Others. 2009. Protocol for monitoring and assessing methylmercury and organic contaminants in aquatic food webs. National Park Service