Potential environmental contaminant risks to avian species at important bird areas in the northeastern United States

Environmental contaminants can have profound effects on birds, acting from the molecular through population levels of biological organization. An analysis of potential contaminant threats was undertaken at 52 Important Bird Areas (IBAs) within the northeastern Atlantic coast drainage. Using geographic information system methodology, data layers describing or integrating contamination (impaired waters, fish or wildlife consumption advisories, toxic release inventory sites, and estimates of pesticide use) were overlaid on buffered IBA boundaries, and the relative threat at each site was ranked. The most threatened sites include Jefferson National Forest (NF), Stewart B. McKinney National Wildlife Refuge (NWR), Great Dismal Swamp NWR, Blue Ridge Parkway, Shenandoah National Park (NP), Adirondack Park, Edwin B. Forsythe NWR, George Washington NF, Green Mountain NF, Long Island Piping Plover Beaches, and Merrymeeting Bay. These sites exhibited moderate to high percentages of impaired waters and had fish consumption advisories related to mercury and polychlorinated biphenyls, and were located in counties with substantial pesticide use. Endangered, threatened and Watch List bird species are present at these sites. The Contaminant Exposure and Effects--Terrestrial Vertebrates database was searched within buffered IBA boundaries, and for a moderate number of sites there was concordance between the perceived risk and contaminant exposure. Several of the IBAs with apparently substantial contaminant threats had no avian ecotoxicological data (e.g., George Washington NF, Shenandoah NP). Based upon this screening level risk assessment, contaminant biomonitoring is warranted at such sites, and data generated from these efforts should foster natural resource management activities.