February 7, 2006

Group Tests Toxin Levels of Bald Eagles

OLD TOWN, Maine -- A research group is conducting studies of bald eagles to determine the levels of environmental toxins in their systems and gain a better understanding of the overall health of the bird population.

As part of the project, U.S. Fish and Wildlife Service biologist Steve Mierzykowski used a scalpel and medical scissors on Sunday to part a dead eagle's feathers and slice through its skin and flesh. A few well-placed snips and Mierzykowski removed the liver, placing it in a specimen jar.

The rest of the carcass will be shipped to a national repository for deceased eagles, but the liver is headed to a laboratory for scientific analysis.

"The liver is the organ that filters out a lot of the contaminants in the bird's body, and the idea is to take the liver out of the bird ... to gather information," he said.

Bald eagle populations have rebounded in Maine and across the United States over the past 30 years to the point where the bird likely will be removed from the federal endangered species list later this year.

Maine now has 385 nesting pairs of eagles, up from less than two dozen three decades ago when DDT and other chemicals nearly drove the species to extinction.

Mierzykowski's research group is in the first year of a three-year project to test the livers of 15 eagles a year. A lab will measure levels of polychlorinated biphenyls, or PCBs, dioxins, pesticides such as DDT, as well as mercury and other heavy metals.

The results will be compared with earlier contamination studies and analyses of Maine eagle eggs that never hatched to gain a better glimpse of eagle health.

Other participants in the study include one of the Maine Department of Inland Fisheries and Wildlife's eagle specialists, Charles Todd, as well as representatives of the Penobscot tribe, the nonprofit Gorham-based BioDiversity Research Institute, and FPL Energy-Maine Hydro.

Federal law prohibits individuals from possessing an eagle carcass or parts of the birds, including feathers or talons, without a permit.

The Maine Department of Inland Fisheries and Wildlife annually receives five to 10 eagle carcasses, which are kept in special freezers. Of the four eagles dissected Sunday, one was found beneath a power line while another likely came from a wildlife rehabilitation center.

On Sunday, Mierzykowski and his 17-year-old son, Jake Smith, took measurements of the largest specimen on the table - a 13-pounder with a wingspan of more than 6 feet.

"Isn't that something? Isn't that amazing?" Mierzykowski said as he extended the wings of the bird, which was struck by a car in Freedom in January 2005.

The pair worked carefully as they extracted the two lobes of the liver, one of which will go to a lab for analysis, at a cost of about $750 per test.

If high levels of toxins are found, the second lobe will be sent for more detailed, and expensive, testing by the lab.

The research also should help with contaminant monitoring that will be required after the bald eagle is delisted, Mierzykowski said.


Information from: Bangor Daily News, http://www.bangornews.com