Toxic gulls: Quebec's contaminated bird colony offers clues about flame retardants
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Environmental Health News
Part 6 of Winged Warnings
September 2, 2014
DESLAURIERS ISLAND, Quebec – There are no homes, few trees and no real reason for any human to visit this 45-acre hunk of clay and dirt. Gulls run this island, their screaming audible for miles, their guano covering every square foot.
“There are about 100,000 of them,” says Jonathan Verreault. “And they’re pretty loud.”
An avian toxicologist, Verreault has ventured to this island in the St. Lawrence River about two miles off the tip of Montreal dozens of times over the past four years.
From afar it seems inconsequential, a barren landscape crumbling around its edges after decades of battering from high water and giant ships. Yet it is a focal point of research exploring the health effects of widely used chemicals that have contaminated animals, people and the environment around the globe.
The gulls that inhabit Deslauriers Island every summer are the most contaminated colony in Canada when it comes to flame retardants, including one compound that has accumulated in their eggs at concentrations up to 44 times higher than elsewhere.
Although several of these flame retardants were banned a decade ago, they are still showing up in gulls, kestrels and other winged creatures from the Great Lakes to China, prompting scientists to examine where they are lingering, what hidden health effects they are having on birds and what this all might mean for humans.
Research on Deslauriers and in Canadian laboratories indicates that flame retardants are altering birds’ thyroid hormones, reducing their clutch sizes, damaging their eggs, changing their behavior, shifting their gender ratio toward males and weakening their bones.
“Unfortunately for birds they’re the sentinels,” said U.S. National Institute of Environmental Health Sciences Director Linda Birnbaum, a toxicologist who specializes in the health effects of environmental contaminants.
“If we ignore what we see in birds we ignore real risk.”
Shrieking chemical monitors
The Jacques-Cartier Bridge is packed with honking cars and aggressive bicyclists trying to squeeze into Montreal. But on this late-spring morning, Verreault, an associate professor at the Université du Québec à Montréal, is headed west, toward a different kind of chaos.
About 5 percent of the world’s ring-billed gulls – about 48,000 pairs – inhabit Deslauriers Island. Their namesake comes from the black ring around the tip of their yellow bill. Orange rings circle their intense yellow eyes, a sharp contrast against their white body and drab gray wings.
The gulls, which winter mostly in the Great Lakes region and the Southeastern United States, arrive on the island around March to have babies and, like the tourists in nearby Old Montreal, enjoy the local urban dining options.
Verreault is greeted at a makeshift boat launch by Francis St-Pierre, a wildlife technician in charge of getting people to the island and back in one piece.
“You should’ve been here yesterday. Yesterday it was like summer,” St-Pierre says, tossing out winter coat-sized life preservers. “It’s rough out there today … Wind out of the north.”
The St. Lawrence River bounces the boat around as St-Pierre zigzags through the choppy current. Deslauriers takes shape in the distance. They hear the island before they reach it – a piercing cacophony of gulls swirling over the island and water.
Some gulls sit on crumbling nests of green and brown speckled eggs about the size of a chicken’s, biting each other whenever one gets too close. Others scurry around, occasionally taking flight. They all shriek maniacally, seemingly annoyed by the humans prying around their business.
“They don’t really attack or anything,” Verreault says, as he greets his team of graduate students and steps carefully so as not to step on any eggs. Chloé Desjardins, a graduate student of Verreault’s, smiles and pulls up a poncho sleeve to expose a fresh purple bruise from a snapping gull.
Using the gulls as chemical monitors for the region, Verreault and his team have been coming here during the late spring and early summer since 2010. A human presence in Montreal helps this colony – where there are people, there’s food. Flame retardants from furniture and electronics have permeated a landfill on the mainland where the gulls feed, the small fish they pluck out of the St. Lawrence River and a Montreal sewage treatment plant where they congregate.
“If something’s not in ring-billed gulls, it’s likely not in other species,” Verreault says.
Verreault has put in his time doing the dirty work and is now mostly an observer at Deslauriers. Four graduate students speak in clipped French to one another and weave around masses of gulls. They carry a remote control from a toy car and a metal case with wires protruding. Anthony Francois and his bird poop-covered colleagues set the trap – thin fishing line circling a bird nest connected to a battery and a trigger – and walk away with their remote to wait for a gull to plop back down on its eggs.
“We have about an 80 percent success rate in catching them,” Verreault says, proud of the homemade contraption. The numbers are on the scientists’ side today. The gull ambles back to its nest and is soon caught up in the line.
They capture, draw blood and then kill some gulls from the island every spring before the babies hatch. In a makeshift laboratory sheltered from the gulls by tall reeds, the students kill the bird using a horse castrator then use miniature razor blades to slice up the thyroid glands, liver and brains, storing all of the organs in nitrogen to bring back to the lab later that evening to test for contaminants.
All the gulls they test contain traces of flame retardants. Since the 1970s companies have added these chemicals, called polybrominated diphenyl ethers or PBDEs, to furniture cushions, electronics and clothing in an effort to slow the spread of flames if they catch fire.
The chemicals quickly built up in people and the environment. The world took notice in 2000 when Swedish researchers found that PBDEs were doubling in women’s breast milk every five years.
Over the next decade, regulations aimed at curbing PBDE use culminated in 2009 when two common mixtures, penta and octa, were added to a United Nations treaty, the Stockholm Convention, as persistent pollutants to be phased out by 152 countries.
Flame retardants stay in the environment for a long time and accumulate in wildlife tissues by moving up food chains. For birds, the original worry was for species that ate a lot of contaminated fish, such as the Great Lakes’ herring gulls.
However, researchers a decade ago found flame retardants in Sweden’s peregrine falcons, a land-based bird of prey. It was quite a shock because most experts thought PBDEs would act like the infamous industrial chemicals called PCBs, and accumulate mostly in fish, not in land creatures, said Cynthia de Wit, a Stockholm University professor who studied the falcons.
“We found them in cow tissues and such and I started thinking, what other animals in the terrestrial environment could end up with high levels?” de Wit said. “Everyone thinks of eagles and falcons because of DDT. And then wow, we found it.”
Dosing captive kestrels
Examining wild birds, however, wasn’t enough to figure out whether the chemicals were harming them.
By dosing captive kestrels – North America’s fierce little falcon – with levels found in wild birds, Kim Fernie and her colleagues have spent more than a decade pumping out evidence that flame retardants could be damaging kestrels' health and reducing their populations.
“We can’t do cause and effect studies with wild birds,” said Fernie, a research scientist with Environment Canada. “Birds are exposed to so many different types of stressors and to a whole slew of chemicals.”
Most of their findings have shown changes to kestrels’ reproduction. Exposure to PBDEs as an embryo caused enlarged testicles and decreased testosterone for male birds. When male kestrels ate a diet containing a newer flame retardant, called TBECH, before mating, 47 percent of the nests had at least one failed egg, compared with 23 percent of the non-exposed males. The exposed kestrels had about half as many male offspring.
During egg hatching in the laboratory, exposed kestrels had lower nest temperatures, which are critical for baby birds to develop properly. And when the birds were fed PBDE amounts found in wild birds, higher levels of the chemicals meant smaller eggs with thinner shells and delayed egg laying.
It seemed to span generations, as male kestrels that were exposed to PBDEs through their mothers grew up and couldn’t reproduce as well – 43 percent of their female pairs failed to lay eggs, and the males made fewer mating calls. Work with other birds corroborated such generational impacts, as zebra finches exposed to PBDEs while still in their eggs grew up to have smaller clutch sizes. Their baby birds also were born smaller than those of unexposed birds.
Then there’s the weird behavior.
When male kestrels dosed with PBDEs had their nestlings “they entered the nestbox less often and retrieved food less often” than non-exposed birds, Fernie said. The females made fewer mating calls and ate less. In unpublished research, male kestrels’ aggression levels were two times higher during courtship and incubation if they had been exposed to TBECH, Fernie reported at a toxicology conference.
“Anytime you see interference with reproduction or development, especially in captive populations like this, it should be a big red flag,” said Michael Fry, an environmental contaminant specialist with the U.S. Fish and Wildlife Service.
American kestrels declined about 1.5 percent a year between 1966 and 2010, according to the Cornell Lab of Ornithology. But it’s complicated when trying to pin a population decline on a specific contaminant, Fry said. Kestrels also struggle with habitat loss and other chemicals.
affect thyroid hormones in glaucous and herring gulls.Just because chemicals harm one bird species doesn’t mean it harms others, said Rob Letcher, a research scientist with Environment Canada. Nevertheless, PBDEs seem to
And some initial evidence at Deslauriers suggests the flame retardants might mess with ring-billed gulls’ hormones, too. Gulls with high levels of flame retardants, especially the PBDE mixture called deca, are more likely to have altered thyroid hormones and lower bone mineral density, Verreault said. Thyroid hormones have been varied – both high and low – in Deslauriers’ ring-billed gulls with a lot of flame retardants, especially deca, in their blood.
While moseying around the island, Verreault picks up a handful of gull eggs from a scrappy little nest of sticks, grass and moss. Unlike other birds, gulls won’t abandon eggs if humans touch them. The colony’s population is strong but it has declined over the past few years. Verreault worries that if chemicals are messing with different hormones, bones and proteins it could mean trouble for the gulls.
“It’s all very subtle,” he said. “But all of this can add up to lower the health of the bird.”
What’s happening in captive kestrels and observed in wild gulls should be a warning, said Birnbaum of the National Institute of Environmental Health Sciences. She said there is “clear evidence” from studies of birds and other animals that PBDEs interfere with the endocrine system.
“Nature’s inherently conservative – the endocrine system was basically conserved throughout the vertebrate kingdom. When we see impacts on behavior in birds, nesting, impacts on survival, and behavior … the question becomes, why would we expect this would not be relevant to us?” Birnbaum said.
In human observations and rodent studies, PBDEs have been linked to reproductive problems, hampered brain development and reduced attention, motor skills, coordination and IQ.
“Whether it’s a bird or a person, thyroid hormones are critical to brain development, and some of these flame retardants impact the conversion of testosterone to estrogen,” Birnbaum said. “The developing brain needs this estrogen.”
“They don’t eat furniture”
While Francois draws blood from a hooded gull, Verreault pokes at the ground nearby. He picks up a small pile of puke-splattered plastic – the same type of stuff he found in the gastrointestinal tracts of some gulls in his lab last year. He holds up part of a plastic bag and points out small plastic pellets on the ground.
“Ring billed gulls regurgitate non-digestibles like plastic bags, pellets,” Verreault says. “However, the birds can still absorb some of the contaminants from them before their system throws it up.”
The Deslauriers gulls are essentially a terrestrial bird and what Verreault calls an “opportunistic eater,” which leaves them with a plethora of contaminants. “We do not have access to a non-contaminated ring-billed gull,” Verreault says. “This is the real problem. We just don’t have a reference.”
One compound stands out in the colony: a PBDE called deca that’s most often used in televisions and computers.
North American manufacturers of deca stopped making the chemical last year, and it is banned in Europe. It is currently under evaluation for international phaseout under the Stockholm Convention.
The penta and octa mixtures are declining for the most part across the globe since they were banned, de Wit said. “Penta going down is proof, if you do stop using something, it will improve the situation,” she said.
For deca, however, the trends are still upward. Part of the problem is that “these compounds were not used in transient products,” said Robert Hale, a chemist and professor at the William & Mary Virginia Institute of Marine Science. “With deca we’re talking furniture, electronics. We keep these things a long time, and then, when we’re done with them, there will still be releases.”
Birds’ chemical loads are largely dependent on where they sit in the food chain, Letcher said. Traditionally scientists have assumed most of birds’ exposure comes from fish. But “all of these species eat from different parts of the ecosystem,” Fernie said.
Verreault does find some fish in the Deslauriers’ gulls – the processed kind found in supermarket fish sticks. When he checked out the insides of some gulls last year he found French fries, meat, rice, corn, soybeans, worms, bugs and plastic.
They have a human-like signature of pollutants in their tissues. “Essentially it’s a human with feathers,” he said.
He suspects it’s not what they’re dining on that’s leaving them with loads of flame retardants but where – at the landfills and wastewater treatment plants. “They don’t eat furniture,” he says.
Flame retardants end up in landfills when people trash furniture, TVs, carpet padding and electronics, said Heather Stapleton, a Duke University associate professor of environmental sciences and policy who specializes in flame retardants. Deslauriers Island is about 18 miles from Lachenaie dump, North America’s third largest landfill, which handles about one-third percent of Montreal-area garbage, with hills of trash up to 130 feet high.
“When these things sit in the landfills they start breaking down and leaching into the landfill,” Stapleton said. “Wildlife, birds feeding in the areas can pick them up through food.”
Flame retardants also latch onto dust particles in the air, she said. The birds can inhale them or they can get stuck on their feathers so when they preen, they gulp down chemicals.
Sewage is another concern as Deslauriers Island is right in the path of the treated wastewater released in the St. Lawrence River by the Jean-R. Marcotte treatment plant, the largest in North America. PBDE concentrations doubled over the past two decades in nearby Lake St. Pierre, most likely due to Montreal’s wastewater.
The loads in landfills and sewage treatment plants “are coming from our homes,” Stapleton said.
Deca, in particular, is a different beast from PCBs and other contaminants that end up in fish, Hale said. “It’s in computers and fabric coatings, we have much more intimate exposure potential, it’s in our homes and offices,” he said.
Finding the deca mixture in the ring-billed gulls has international significance because it proves that the chemical can build up in animals and people, said Joe DiGangi, senior science and technical advisor for the International POPs Elimination Network, which advocates for safe chemical policies.
“During recent Stockholm discussions at the screening phase, industry kept pushing back and saying [deca] is too big of a molecule to bioaccumulate, which is what they’ve said for years,” DiGangi said.
“And everyone would hold up scientific papers of birds.”
Verreault will probably only take one more trip to Deslauriers this summer. He will bring his children, including his 5-year-old son, who will have to be closely monitored because he tries to “add to the genetic diversity” by moving eggs from nests.
But now the hard part begins. Francois, Desjardins and others will run tests on the body parts and blood to check for PBDEs and their replacement chemicals, which also are starting to show up in the ring-billed gulls as well as in people and creatures around the world.
It’s a cat-and-mouse game: Just as researchers start to understand what a chemical might do to people or wildlife, a bunch more hit the market.
“The flame retardant story is especially illustrative of regrettable chemical substitutions,” DiGangi said. “Industry has been playing this game since the 1970s, substituting one bad chemical for another.”
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