Maine Contaminants & NRDAR Program
Northeast Region

Ongoing and Recently Completed Investigations

Special Study (Completed): Contaminants in a Crossed bill Bald Eagle

Cross-billed Bald Eagle.  USFWS Photo.  

Bill abnormalities in birds are typically rare. This was the case in Maine until 2011 when the first crossed bill bald eagle was reported in the southern part of the state. The newly fledged bird was observed by residents of Saco and Scarborough foraging for fish. Although a successful hunter, the bird's bill malformation affected its ability to feed on the fish it caught. Growing progressively thinner and weaker, the bird was finally too weak to fly and was recovered by law enforcement officers.

The bird was brought to a raptor rehabilitator in Freedom, ME, but after initial care and after consulting with veterinarians from Tufts University the decision was made to euthanize the bird.

The USFWS assumed custody of the bird and extracted tissue and blood samples for contaminant analyses. Plasma was analyzed for organochlorine pesticides, polychlorinated biphenyl congeners, and polybrominated diphenyl ether (PBDE).  Whole Blood and feathers were analyzed for mercury.  Liver and brain tissue were analyzed for organochlorine compounds, PBDE, metals, and methylmercury. A final report was completed in October 2012. 

Cross-billed bald eagle. USFWS Photo.    

On-Refuge Study (Completed): Contaminant Assessment of Coastal Bald Eagles at Maine Coastal Islands National Wildlife Refuge and Acadia National Park

Productivity of the eagle population within the Maine Coastal Islands National Wildlife Refuge and Acadia National Park has chronically remained below levels achieved in other populations and those considered necessary to maintain strong populations.  Poor production at refuge and park eagle nest sites occurs despite an increasing trend in occupied territories statewide, and remains largely unexplained due to limited investigation.  

In a 1994 study, Maine estuarine eaglets contained six to 12 times the Total PCB levels reported for populations nesting along the shorelines of the Great Lakes - a population impacted by contaminants and considered to be a population sink.  A follow-up study in 1998 found concentrations of PCB and DDE in coastal Maine eagle nestling blood and eggs at levels associated with reproductive impairment in other populations.  Beginning in 2009, we collected plasma from nestlings and non-viable eggs to monitor organochlorine contaminant trends within the midcoast and Downeast regions of Maine.  Potential reproductive impacts from contaminant exposure will be evaluated in particular for the eagles with nest territories on Maine Coastal Islands National Wildlife Refuge and Acadia National Park mainland parcels and islands. The final year of field collections was 2011. Over the last three years, 56 nestling plasma samples and 10 non-viable eggs were collected for the study. A final report was completed in September 2013.   USFWS biologist with an eagle nestling.  Photo Credit: S. Mierzykowski
    USFWS Biologist with an eagle nestling.

On-Refuge Study (Completed): Environmental Contaminants in Brook Trout from Aroostook National Wildlife Refuges

Although the Superfund cleanup of the former Loring Air Force Base in northeast Maine was extensive and involved the removal or remediation of tons of contaminated soil and sediment, residual organochlorine contamination persists in fish tissue. The U.S. Air Force has been collecting and analyzing fish from several areas on the former installation as part of the long-term monitoring program required under the Superfund law. Recently, USFWS analyzed fish from two ponds to verify the contaminant concentrations that have been previously reported.

Sign at Aroostook NWR


In June 2012, brook trout were collected from the Chapman Pond and East Loring Lake on Aroostook NWR.  Skin-on fillets (2 fish from each pond) were analyzed for organochlorine and inorganic contaminants. PCB levels were similar to levels reported by the Air Force and occurred at concentrations that would continue the fish consumption advisory. DDT and mercury levels in the ponds would also trigger reduced consumption advisories.

A final report was completed in March 2013.

Warning sign at Chapman Pond on Aroostook NWR. Photo by S. Mierzykowski, USFWS  

Special Study (Ongoing): Contaminants in Maine Bald Eagle Eggs

Between 2000 and 2012, the Maine Field Office, in collaboration with the Maine Department of Inland Fisheries and Wildlife and other partners, collected and analyzed 79 bald eagle eggs for dioxin, furans, PCBs, DDT metabolites, PBDE, and mercury. Results of these collections will be compared to previous Maine collections in the 1960s through the 1990s. A final report is expected in spring 2014.


Last Updated: March 6, 2014
Maine Field Office
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