By Colin Nickerson, Globe staff
Eggs from an array of Maine birds – from lordly bald eagles to timorous piping plovers; from swallows snarfing insects in suburban backyards to storm-petrels feeding hundreds of miles at sea – contain 100 industrial and household contaminants, scientists will report today.
According to research to be presented to the Maine Legislature, all 60 eggs tested by biologists and chemists – taken from 23 wild species, inhabiting every major ecosystem in the state, from Kittery to Calais – carried at least trace amounts of the 100 chemicals, occasionally at levels believed to be harmful to the birds.
“We found mercury, flame-retardants, industrial repellents, transformer coolants, and pesticides in [the eggs of] birds that live on Maine’s oceans, salt marshes, rivers, lakes, and uplands,” said Wing Goodale, senior biologist with the BioDiversity Research Institute in Gorham, the center for environmental science that carried out the research.
Contaminants in eggs are an indicator of pollutants carried by the mother birds, but are all but certain to be passed on to their offspring, although not necessarily at full strength, scientists said. Since the chemicals are mostly acquired through food, levels will increase as the squawking chicks are fed in the nest and will intensify in later generations of birds if the contaminants are not removed from the food chain, biologists say.
The study did not show any obvious damage to birds at current contaminant levels. But in the long run, Goodale said, these chemicals could have harmful effects on bird brains and organs, ability to raise young, and immunity to diseases.
The study, the largest ever documenting historical and emerging contaminants in Maine birds, points to the pervasiveness of a new breed of pollutants: chemicals integral to products that barely existed a few decades ago, whether personal computers or stain-resistant clothing.
The research marked the first time that such relatively unscrutinized pollutants as industrial stains and water repellents showed up in Maine birds.
“What’s surprising is, a lot of this stuff doesn’t come from big production plants; it’s just everyday material that’s become a part of our lives,” said Barry Mower, a contaminant specialist with the Maine Department of Environmental Protection, which was not involved in the research. “It’s also surprising – and worrisome – that these contaminants were found in such a wide variety of species.”>/p>
It is unclear how the toxic chemicals reached the environment, say scientists. Generally speaking, wildlife is in better shape in Maine and other parts of the United States than it was 30 or 40 years ago, thanks to cleaner air and water.
DDT, once the scourge of eagles and other raptors but banned for decades, appears to be fading from the ecosystem, although some levels of the pesticide were detected in all of the tested eggs. So, too, were PCBs, another long-outlawed environmental villain. But new decades and new technologies bring new pollutants.
more stories like this”Obviously, birds aren’t falling dead all over the wild,” said Goodale. “But things are showing up that just shouldn’t be in the wild. And they are showing up all over, in seabirds, shorebirds, waterfowl, perching birds, and raptors.”>/p>
Their presence in Maine birds partly points to the long reach of atmospherically borne emissions from distant power plants, industrial smokestacks, and the other usual sources of ecological grime. But the chemicals also appear to be coming, somehow, from such mundane objects as furniture treated with flame retardants or made with stain-resistant fabric.
Far-off industry may be partly to blame, but locals are not off the hook, either.
The study pointed out that bird eggs collected from midcoastal and southern Maine, the most urbanized section of the state, bore the heaviest burden of pollutants.
“There’s no single smoking gun,” said Goodale. “But this suggests contaminants are not just coming from a global pool, but may have local sources, such as release from consumer products, incinerators, and water treatment facilities.”>/p>
For example, a worn-out office sofa gets tossed in a local incinerator. The flame retardants and stain repellants impregnating its artificial fibers, along with the chemical components of the fibers themselves, rise into the air and return to the surface with rain or snow. They land on the surface of a bay and make their way into the systems of microbial creatures. These are eaten by crustaceans, which, in turn, are eaten by larger fish. Along comes an osprey and gobbles the fattest of the swimmers.
“Lo and behold, you’ve got PBDEs and PFCs [flame retardants and stain repellents] in the bird,” Goodale said. “These go into her eggs. The chick is hatched with . . . these contaminants. Then it grows up eating the same fish.”>/p>
Disturbing to some scientists is the rise of new pollutants in the eggs of birds that live in some of the most remote and presumably pristine regions of the state.
“If it’s in our wildlife, it’s in our kids,” said Susan Gallo, a wildlife biologist with the Maine Audubon Society.
Bald eagles, which occupy a high perch on the food chain, were the species whose eggs were found to possess the highest levels of contaminants. But researchers were shocked to find that Leach’s storm-petrel, which feeds on fish caught hundreds of miles out to sea, bore high levels of contaminants, as did piping plovers, a tiny, endangered shorebird.