Getting The LEAD Out - Lead fishing tackle kills loons; with no national policy to fight the problem, conservationists are convincing anglers to switch to nontoxic alternatives

National Wildlife, August-Sept, 2001 by Steve Nadis

KATE TAYLOR got the call on the Fourth of July: A dead body near Lovell Lake. She drove from her office in Moultonborough, New Hampshire, to Wakefield near the Maine border, where she found the plastic body bag just where it was supposed to be. A note fastened to the bag directed her to a suspicious character down at the town beach.

A senior biologist with the Loon Preservation Committee, Taylor identified the suspect on the beach instantly. The bird, a common loon, was skinny and lethargic, with droopy eyes, a gaping mouth and head tremors-all classic signs of lead poisoning. She approached the bird and picked it up-something a healthy wild animal would never allow-and took it to a local veterinarian. An X ray revealed a dense lump of metal in the loon's stomach, most likely a piece of lead fishing tackle. The humane choice, the two scientists agreed, was to euthanize the bird.

Taylor then froze both birds she'd found, packed each in a separate labeled bag and sent them to Tufts University School of Veterinary Medicine in Massachusetts for more detailed analysis. Research biologist Rose Miconi, who conducted necropsies of the specimens at the university's Wildlife Clinic, confirmed the original diagnosis of lead poisoning. Both loons were emaciated, with no visible fat beneath the skin and high levels of lead permeating their livers and tissues. From each of the birds' stomachs, Miconi removed a lead sinker-a round weight anglers attach to a fishing line to keep it below the surface.

Unfortunately, such incidents are all too common. According to Wildlife Clinic Director Mark Pokras, he and his colleagues have conducted post- mortem exams of more than 500 loons since 1988. About half the adult birds collected in New England had died from accidentally ingesting lead sinkers or weighted lead fishing hooks known as jigs. Though lead fishing tackle kills plenty of other bird species too, loons-and particularly New England's loons-are the hardest hit of all. With no federal laws or regulations on the books to combat this long- documented-and easily solved-problem, conservationists are now launching programs to convince anglers to voluntarily switch from lead to nontoxic alternatives.

About 20 percent of all loon deaths in the United States are blamed on lead fishing tackle. One reason the problem is most acute in New England, biologists believe, is that shallower waters here than, say, the Great Lakes mean loons have easier access to gear that sinks to the bottom. While the region's precise death toll is unknown (many lead- poisoning victims are never recovered), Pokras estimates that it adds up to at least a couple of hundred loons a year. In New England, says Miconi, "lead sinkers are the single greatest cause of adult loon mortality."

Nationwide, birds of more than 30 species from at least ten states have died as a result of ingesting lead fishing tackle. In addition to loons, the victims include swans, pelicans, geese, ducks, cranes, herons and eagles. "I don't think anyone fully appreciates the magnitude of this problem," says Pokras.

Still, loons seem to be the most affected species of all. That suspicion was confirmed in 1999 by a report from Chris Franson and colleagues at the U.S. Geological Survey in Madison, Wisconsin. Their study-which examined the frequency of lead-sinker ingestion by 30 bird species-put loons at the top of the list, with brown pelicans second.

Loons ingest lead fishing gear in two ways: They may eat a fish that has a hook and sinker already attached to it, or the birds may pick up sinkers from the bottom of a lake along with the small stones they use to aid digestion (the stones help loons grind up the food in their stomachs). In either case, the effects are devastating, usually leading to the bird's death within a week.

A severely lead-poisoned loon cannot fly and is also impaired in the water, making it more likely to be struck by a boat or to drift into another bird's territory (where it may be attacked). More importantly, the bird loses its ability to dive underwater for fish, resulting in starvation. Because lead targets the central nervous system, victims also become so weak and uncoordinated that they may beach themselves. On land, the sick loon is an easy target both for predators and infectious agents like bacteria. And if the bird miraculously survives all this, nerve damage eventually shuts down its digestive system, meaning that the loon can die of starvation even with a full stomach.

According to Taylor, the death of the two loons she found near Lovell Lake was a particularly significant loss. They comprised a male and female breeding pair-one of only about 200 in New Hampshire. Some loons may spend a lifetime trying, unsuccessfully, to secure a mate and a territory to call their own in order to produce offspring. "Only the fittest animals manage to do this year after year," says Taylor, "so we lost the cream of the crop."

Nor is lead the only problem loons face. Near the top of the hazards list stands another heavy metal-mercury. Because most mercury in places like New England comes from the atmosphere-as a pollutant discharged by power plants, incinerators and other sources, either local or global-it is dispersed widely throughout the environment and has the potential to affect the health of the species as a whole.