September 2, 2013

Lead poisoning killing loons, necropsies show

A Bay State animal medical examiner is the main voice behind a Maine law banning lead fishing sinkers and jigs.

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Volunteer Julia Graham photographs a loon's wing, as she assists Mark Pokras last month in the necropsy room of the wildlife clinic at Tufts University's veterinary medical school in North Grafton, Mass.

Photos by Joe Phelan/Kennebec Journal

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Mark Pokras holds up a swab that shows that the fishing jig removed from a loon tests positive for lead.

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All of that bird's fat was gone, but its muscles hadn't begun to waste away. A blood test showed the loon was carrying more lead than Pokras could test for.

"This is a bird that didn't starve to death. If it had starved to death, we'd see more muscle loss," Pokras said. "I think the lead killed it before it had a chance to get any further."

LEAD POISONING FROM FISHING GEAR

A 2013 report from the Maine Audubon Society, aggregating the results of 450 Pokras necropsies of Maine loons from 1987 to 2012, found that lead poisoning from fishing gear was the leading cause of death in adult loons, killing 97 out 352 adults examined.

Of those loons, 21 were poisoned to death by lead fishing gear in 11 lakes in Kennebec, Franklin and Somerset counties, including Cobbossee, water bodies in the Belgrade Lakes area and Rangeley Lake, the report says.

Cobbossee and Great Pond, in the Belgrade area, each had four poisoned loons in that time, the most in the state.

Lead, experts say, is a terrible way for a loon to die.

Pokras said the digestive tract contracts irregularly and painfully and birds become dopey and slow to react, making them vulnerable to predators or unrelated illness. They'll often end up beached onshore, eyes half-closed and gasping for air before succumbing.

Poisoning in birds can be treated at clinics like Avian Haven, the bird rehabilitation center in Freedom where the Cobbossee loon was euthanized, according to Diane Winn, the clinic's co-director.

She said two methods of treatment are usually used -- chelation, where agents that bind to lead are given to the bird and excreted -- and gastric lavage, or stomach pumping.

But once loons get to her, they're usually too far gone. Winn said she usually can't save them.

"By the time they're sick enough to beach themselves and be captured, it's usually too late," she said. "It's painful to watch and I'm sure it's painful to experience."

DOUBTING THE SCIENCE

However, Dave Barnes Sr., president of the Bass Federation of Maine and a fishing guide from China, doubts the science used to get the lead ban passed.

He said the loon death count isn't high enough to necessitate the law, which he said would simply discourage fishing by upping the cost for fishing gear.

Testimony from Susan Gallo, who directs the annual Maine loon count for the Audubon Society, before a legislative committee earlier this year, included costs of lead, tungsten and metal jig heads. According to that testimony, 25 of the cheapest lead jigs cost $3.59, or 14 cents apiece. The cheapest alternative, made of tin and bismuth, cost 88 cents apiece.

Barnes also noted that the loon population is healthy. When the loon count started in 1983, it found 1,800 statewide. Last year, it found approximately 3,000.

"You take all these deaths in combination, what's the sense to tax fishermen and anglers doing the sport they love?" Barnes said. "I'm a Vietnam veteran, I fought for this country, and I'll tell you, I never thought I'd have to fight for my right to fish."

But Gallo said lead poisoning is "one of the biggest of the little factors" affecting loons. "If you want to call them little." Others include boat strikes, wakes from boats that upset nesting areas near shorelines, and predators.

In coming years, she said loons will likely see the impact of climate change as lakes warm and rainstorms get bigger, changing shorelines and nesting areas. She said while it's difficult to stop boats from speeding, lead is one of the most easily avoidable threats posed to loons now.

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Additional Photos

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Pokras holds the lead jig he removed in front of an X-ray of it inside the bird.

  


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