12
Mar
Bird Eggs Found to Contain Chemical Contaminants
(Beyond Pesticides, March 12, 2008) BioDiversity Research Institute, a nonprofit ecological research group, released a new report that was presented March 12, 2008 to Maine’s Joint Standing Committee on Natural Resources. Entitled “Contaminant Screening in Maine Birds,” it documents over 100 harmful contaminants that were found in Maine bird eggs.
Scientists collected 60 eggs, representing 23 species of birds, all of which test positive for chemical contaminants, some at levels believed to be harmful to the birds. Flame retardants (PBDEs), industrial stain and water repellants (PFCs), transformer coolants (PCBs), pesticides (OCs), and mercury are found in all 23 species of birds tested. The bird species studied live in a variety of habitats: on Maine’s ocean, salt marshes, rivers, lakes and uplands.
“This is the most extensive study of its kind to date and the first time industrial stain and water repellants were discovered in Maine birds,” says report author, senior research biologist Wing Goodale with the Institute.
The Common loon, Atlantic puffin, piping plover, belted kingfisher, great black-backed gull, peregrine falcon and bald eagle have the highest contaminant levels. The flame retardant deca-BDE, banned last year in Maine, is found in eight species. Overall, eagles carry the greatest contaminant load, and for many contaminants have levels multiple times higher than other species. Many of the contaminants levels recorded are above those documented to have adverse effects.
“These results are significant because many of these contaminants can interact to create effects more harmful than one toxic pollutant alone,” said Mr. Goodale, “and the pervasiveness of the pollutants strongly suggests that birds and wildlife in other states are also accumulating these contaminants.”
“Since we found that birds with high levels of one contaminant tended to have high levels of other contaminants, these compounds may cause top predators, such as bald eagles and peregrine falcons, to have greater difficulty hunting and caring for young,” Mr. Goodale added.
The report also shows the contaminants are coming from both global and local sources. All the types of contaminants were found in all species””including birds that feed hundreds of miles offshore. This indicates that the pollutants are most likely in rain and snow. Birds in mid-coast and southern Maine tended to have higher levels, suggesting the compounds may also come from local sources such as incinerators and water treatment facilities.
“There is good news,” Mr. Goodale said. “We found that banned chemicals like PCBs and DDT were significantly lower in Maine today than in the past, showing that by banning chemicals we can decrease levels of harmful contaminants in the environment.”
Organochlorine (OC) pesticides, such as DDT, endosulfan, chlordane, and dieldrin have been especially problematic due to their persistent nature. OCs are moderately toxic to bird species and are stored in the fat of birds. Residues find their way into egg yolks at measurable concentrations. Recent studies have found that these pesticides are also responsible for reducing the hatching rate of alligator eggs (See Daily News of July 9, 2007). The National Park Service (NPS) has also documented chemical contamination across parks throughout the western United States and Alaska, exceeding consumption levels for humans and wildlife in some areas. (Daily News of February 29, 2008). Other wildlife species such as sharks, frogs and salmon are also at risk from chemical contamination.
Source: BioDiversity Research Institute
