Report Reveals High Levels of Mercury in Bald Eagles Within New York's Catskill Region

Study Indicated Mercury Occurs at Potentially Harmful Levels


A new study finds high levels of mercury in the blood and feathers of New York's bald eagles.

Mount Kisco, NY | November 25, 2008

Mercury concentrations in adult and juvenile bald eagles are elevated within New York’s Catskill Region and Catskill Park according to a report prepared by the BioDiversity Research Institute (BRI) of Gorham, ME, and the New York State Department of Environmental Conservation (NYSDEC) with support from The Nature Conservancy.

One-in-four bald eagle chicks in the Catskill Region had accumulated mercury from their recent diet (fish), and one-in-three adults had accumulated mercury over their lifetimes, to levels that are known to have negative effects in other birds such as common loons.

Mercury becomes an air pollutant largely through releases from coal-fired power plants, solid waste incinerators, and various smokestack industries. Airborne mercury eventually returns to earth in rain, snow, and fog droplets as well as in dry form. Under the right conditions, mercury is then transformed into methyl-mercury, which becomes magnified toward the top of the food web. Its toxic effects can include both neurological and reproductive harm to wildlife, and to people who consume contaminated wildlife.

“The average mercury level for eagle chicks in the Catskill Region – and especially those near the boundary of the Catskill Park – was comparable to levels found in regions associated with significant mercury pollution histories,” reports Chris DeSorbo, lead investigator of the study and Director of BRI’s Raptor Program.

These findings are consistent with previous research revealing that the Catskill Region in southern New York receives some of the highest rates of atmospheric deposition of mercury in the U.S. Fish and wildlife in this region are regularly exposed to mercury through their diet at levels that are of concern to scientists. The recent study, initiated by a grant from the Conservancy and executed by NYSDEC and BRI, is the first to comprehensively examine mercury exposure in New York’s bald eagles in general and in the Catskill Region in particular.

“The good news” continued DeSorbo, “is that no eagle chicks sampled in New York outside the Catskill Region had mercury levels of concern.” Dr. David Braun, director of conservation science for the Nature Conservancy’s Eastern New York Chapter, explains, “Research over the past few years has documented a tendency for mercury from air pollution to accumulate to harmful levels in wildlife in ‘hotspots,’ where environmental factors combine to move mercury more readily into forest and aquatic food webs. The Catskills appear to be one such hotspot.”

By the early 1970s, breeding bald eagles had nearly vanished from New York State and surrounding regions due to the combined impacts of DDT, habitat loss, and direct killing. Legal protections for eagles, their habitats, and the 1972 ban on DDT eventually led to widespread population recoveries throughout much of the continental U.S. Bald eagle populations have made a strong comeback in New York following intensive restoration efforts led by Peter Nye, leader of the (NYSDEC) Endangered Species Unit.

Initiated by a grant from the Conservancy, BRI and NYSDEC researchers teamed up to determine whether biologists should be concerned about mercury levels in bald eagles from the Catskill Region or elsewhere in New York State. Biologists collected 102 samples from bald eagle chicks and/or adults at 41 nests throughout the state and analyzed them for mercury.

A report released earlier this year by The Nature Conservancy and the Cary Institute of Ecosystem Studies, Threats From Above: Air Pollution Impacts on Ecosystems and Biological Diversity in the Eastern United States, found that no ecosystem in the eastern United States is free of the effects of air pollution. To view the full report, visit

Attention Reporters:

Findings from this study are available in the form of a full report and a two-page fact sheet by clicking here.

Photographs are available upon request.

The following experts are available for interviews:
Dr. David Braun, Director of Conservation Science, The Nature Conservancy
Chris DeSorbo, lead investigator of the study and Director of BRI’s Raptor Program
Dr. David Evers, BioDiversity Research Institute, Wildlife Mercury specialist
Jefferey Loukmas, NY DEC, Fisheries and Mercury Specialist
Peter Nye, NYS Department of Environmental Conservation, Endangered Species Unit Leader
Alan White, Nature Conservancy, Director of the Conservancy’s Catskills conservation project

The Eastern New York Chapter (ENY), the Conservancy’s first chapter, owns and manages 43 nature preserves, encompassing over 15,000 acres. ENY works across six landscape-scale sites from the Catskills to the Berkshires and from the Hudson River to the shores of Lake Champlain. To learn more, visit

BioDiversity Research Institute is a nonprofit organization located in Gorham, Maine. Founded in 1998, BRI is dedicated to progressive environmental research and education that furthers local, regional and global sustainability and conservation policies. BRI’s research efforts emphasize conservation biology issues in New England and across North and Central America.

The Nature Conservancy is a leading conservation organization working around the world to protect ecologically important lands and waters for nature and people. The Conservancy and its more than 1 million members have protected nearly 120 million acres worldwide. Visit The Nature Conservancy on the Web at

Contact information

Ellen Weiss
(914) 244-3271 ext. 21

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