Researchers are finding flame retardants and stain repellent chemicals in herring gull eggs in the Great Lakes region.
These chemicals are used in a lot of consumer products, but they can last a long time in the environment and some of them can build up in the food web.
Lisa Williams is a contaminants specialist with the U.S. Fish and Wildlife Service. She’s an author on both of these studies.
“We believe that most of these chemicals are taken up by the birds when they’re feeding on fish in the Great Lakes,” she says.
She says the chemicals move through the mother's body into the eggs.
“These compounds tend to be more fat-soluble than water-soluble, so they’re released into the Great Lakes in a variety of ways, but then they’re accumulated into organisms in the Great Lakes,” Williams says. “And so the fish are also obtaining them through their diet.”
She says these findings could be cause for concern.
“By finding these compounds in herring gull eggs, we’re showing that they’re persistent enough in the environment to be bio-accumulated through the food web,” she says. “And so they are then in the egg, exposing the embryo of the bird to these compounds. And that is a life stage that’s very often very sensitive to contaminants.”
For this reason, she says it’s crucial to understand more about the toxicity of these chemicals.
The research team measured the chemicals in the herring gull eggs in very small concentrations, Williams says, mostly in the parts per billion range.
“Very few of the compounds were found at the parts per million level,” she says.
But she says low concentrations do not necessarily reduce the risk of trouble for birds.
“Some of these compounds that we do know about have effects at levels in the parts per billion range,” she says. “So it’s possible that some of the ones that we don’t know also have effects at levels down in that range, and we could be nearing a point where these compounds could be causing problems for the birds.”
A drop in levels of some chemicals
In one of these studies, Williams and her team compared measurements of certain kinds of flame retardants in the gull eggs that have been phased out of consumer products with measurements of newer flame retardants in the eggs.
“We saw that some of the compounds that have been phased out are indeed decreasing in concentrations, and that’s good news,” she says.
But she says the levels of the replacement flame retardants are increasing in the gull eggs, she says.
“They might be accumulating to a level that might cause problems for the birds,” she says. “And we don’t have good information from laboratory studies about how sensitive some of these species that are being exposed might be.”
Williams says there are just a handful of researchers who are doing these kinds of studies in the field.
“Very few people are doing toxicity studies,” she says. “And that’s the kind of information that we need in order to interpret these results.”
Here's more about the research from the USFWS Field Notes site:
As part of the Great Lakes Herring Gull Monitoring Program, the Canadian Wildlife Service has collected herring gull eggs for over 30 years to track the status and trends of legacy contaminants across the Great Lakes basin. More recent collections by the U.S. Fish and Wildlife Service in partnership with Canada, the Michigan Department of Environmental Quality and partners at Michigan State University, Clemson University and the University of Maryland have added to this monitoring program. Recent research regarding contaminants of emerging concern, which include pharmaceuticals, personal care products, agricultural chemicals and wastewater treatment plant byproducts, have prompted the Canadian Wildlife Service to analyze archived samples to evaluate levels and trends within the Canadian Great Lakes. In an effort to characterize the contaminants of emerging concern within the United States Great Lakes, the East Lansing Field Office obtained funding from Great Lakes Restoration Initiative to work with partners in University of Maryland, Carleton University, Canadian Wildlife Service and Environment Canada to analyze eggs from sites within the United States.