Mercury Pollution and

Adirondack Loons


The Adirondack Center for Loon Conservation conducts scientific research to assess the impact of environmental mercury pollution to the Adirondack breeding loon population. This study is now one of the longest-term datasets in the Northeast on the biotic impact of airborne pollutants to aquatic ecosystems, using the Common Loon as an indicator species.

Our goals for this study are to:

  1. Assess trends over time in mercury exposure of Adirondack loons.
  2. Assess the impacts of mercury pollution and lake acidity to Adirondack loon reproductive success.
  3. Evaluate the effectiveness of recently implemented local and regional mercury emission and acid deposition regulations.
  4. Assess the impact of mercury exposure to loon health and immune function.
  5. Integrate our research with other mercury and water quality Adirondack lake studies to provide a more robust assessment of how airborne pollutants affect the aquatic ecosystem as a whole, as well as a broader scientific basis for policymakers to better regulate air-borne pollutants.

How we Collect Data on Loons:

Ten to twenty Common Loons are captured on Adirondack lakes each breeding season using nightlighting and playback techniques. Blood and feather samples are collected from these birds for mercury analysis. The birds are banded with a USGS numbered band and a unique combination of colored bands to enable them to be subsequently identified.

Capture lakes are monitored each summer to determine if the banded loons returned. Returning banded loons are monitored on a weekly basis through the breeding season to determine if they successfully paired with another loon, nested, hatched chicks, and raised the chicks to fledging. Nonviable eggs are opportunistically collected to determine their mercury levels.