From the Summer 2018 issue of Living Bird magazine. Subscribe now.

When Len Fleischer and Erika Radich moved near Spofford Lake in southwestern New Hampshire a decade ago, they enjoyed kayaking the many coves and swimming with their twin granddaughters. This past summer, however, something magical happened.

“For the first time we saw a nesting pair of loons, gliding around in the water, with two babies on their backs, calling and yodeling,” said Fleischer. “What a thrill.”

There is something about the northern-woods lake diver with a haunting call that stirs people. The Common Loon has been the subject of legend and lore and musical scores, so beloved that it adorns license plates in five states as well as the Canadian dollar coin, known as the “loonie.”

In the quiet hours at dawn and dusk, many North Woods lakes reverberate with the echoes of loon wails and yodels and tremolos, which writer John McPhee described as “the laugh of the deeply insane.” Photo by Roberta Olenick.

An Indicator of Environmental Health

Ecologically speaking, the loon’s presence is an important sign of overall lake health. Loons are at the top of a lake’s food chain, so keeping tabs on contaminants in loons helps scientists monitor the health of lake ecosystems. “As a top-level fish predator in aquatic systems, loons contribute to the ecological integrity of the systems they occur in,” says Jim Farquhar, a biologist with the New York Department of Environmental Conservation. “More importantly, they are an indicator of a healthy system.”

Common Loons nest in quiet, protected, hidden spots of lakeshore, typically in the lee of islands or in a sheltered bay. The male selects the nest site. Male and female build the nest together and take turns incubating eggs. Photo by Roberta Olenick.

Loons require clear, clean lakes and they are harmed by pollution, development, and disturbances—all of which caused loon populations to crash in the southern portion of their range in the early to mid-20th century. Breeding loons disappeared from California and Oregon in the West, across a Midwestern swath from Iowa to Ohio, and from eastern Massachusetts and Connecticut in the East. But starting in the 1970s, around the time of the Clean Water Act, loons started a comeback. In 1975, a pair of loons recolonized the Quabbin Reservoir in central Massachusetts. As of 2015 there were 45 breeding pairs found on 20 lakes across the state.

A study of loon mortalities over two decades in New Hampshire documented the high death toll from lead poisoning via fishing tackle. The study concluded that New Hampshire’s loon population would be 43 percent larger if not for lead poisoning. Graphic by Jillian Ditner, source: Loon Preservation Committee; photo by Roberta Olenick. See larger image.

Elsewhere across the Great Lakes and the Northeast, Common Loons are now nesting in lakes where they haven’t been seen in decades. In Wisconsin, the population increased from just over 3,000 pairs in 1995 to an estimated 4,000 in 2010. In New York—where the loon population was down to the last 200 breeding pairs in the Adirondacks— there are between 600 and 850 nesting pairs today from the Adirondacks to the Finger Lakes. In New Hampshire, where breeding pairs dropped to fewer than 50, there are 300 breeding pairs of loons today. The total North American Common Loon population is estimated at around 250,000 breeding pairs.\

Yet those seemingly robust numbers hide a sobering fact: The loon’s recovery would be even better were it not for deadly lead poisoning. In the contiguous United States, loon populations remain well below historical levels.

“Once they are gone, it’s hard to get them back,” says Harry Vogel, wildlife biologist and director of the Loon Preservation Committee, a nonprofit conservation group in New Hampshire. “We have been working for 40 years and are still only halfway to a recovered population.”

Loons still face many threats today, including the lead commonly used in fishing tackle. Decades after the U.S. government began regulating lead out of our environment through lead bans in gasoline, household paint, and the shotgun ammunition used for hunting waterfowl, the poisonous soft metal is still being directly introduced into lakes and waters via fishing tackle. In the contiguous U.S., lead is a leading cause of death in the Common Loon. And now for the first time, researchers in New Hampshire have discovered a much worse population-level impact than previously suspected.

The Great Northern Diver Sunk By Lead

With heavy webbed feet set back on its body and a compact frame, the torpedo-shaped loon is an exceptionally adept diver, plunging up to 75 feet deep and maneuvering with speed and accuracy. Underwater, they execute hairpin turns at astonishing speeds. At strategic moments when chasing prey, loons achieve top speed by blowing air out of their respiratory system and flattening their feathers to squeeze out any air bubbles within their plumage—all the better to catch perch and other small, fast-moving fish.

When loons dive, they sometimes retrieve something other than tasty fish–pebbles, which end up in the gizzard, a pouch-like organ that they fill with small rocks. The gizzard aids in the digestion of fish by churning the pebbles to grind the fish up, bones and all.

It’s in a loon’s search for pebbles that a case of mistaken identity can turn deadly. The sinkers and jigs used by anglers end up on the bottom of the lake, where they are indistinguishable from pebbles.

Lures with hooks called “jigs” and weights called “sinkers” are the most common kinds of fishing tackle that cause lead poisoning in loons, though nonleaded tackle is available for sale. Above, the top row of jigs and sinkers are lead, while the bottom row are tin. Photo by Joanne Avila.

When a loon scoops up a leaded sinker or jig among the small rocks, the lead ends up in the gizzard, where it sends poison swimming through the loon’s veins. Within days, the loon becomes lethargic and can’t eat. Then paralysis sets in. Death eventually comes from a nasty combination of exposure, suffocation, and starvation.

“A small amount of lead will cause massive fatal lead poisoning in a loon,” says Vogel. “It’s a terrible death for these birds. And it is so easily avoidable.”

Vogel and other members of the committee have been at the forefront of studying lead effects on loons. In the mid-1970s a team from the Loon Preservation Committee recovered and brought for testing the first-ever loon confirmed to have been killed by lead poisoning. Over the past four decades, the committee has built a citizen-science network of more than 1,500 volunteers throughout New Hampshire capable of monitoring nearly every breeding loon pair in the state.

This makes New Hampshire an unparalleled laboratory for studying loon populations.

“There are no other locations where loons have been studied as intensely or as long,” says Tufts University wildlife veterinarian Mark Pokras. “In this one relatively small state, people have been monitoring just about every nest and territory for 40 years. There is no other data set like that.”

A small amount of lead will cause massive fatal lead poisoning in a loon. It’s a terrible death for these birds. And it is so easily avoidable.

~Harry Vogel

Pokras, Vogel, and a team of researchers used the committee’s loon-monitoring data from 1989 to 2012 to investigate causes of loon mortality in New Hampshire. Their research paper Population‐level effects of lead fishing tackle on common loons—published in the Journal of Wildlife Management—quantified the population-level impact of lead on loons. The study found that 49 percent of 253 necropsied loons were victims of lead poisoning—and fatalities were the highest during peak fishing season. Jigs accounted for more than half of the lead fishing tackle objects found in loons.

According to the report, lead-related deaths reduced New Hampshire’s loon population growth rate by 1.4 percent annually over the two decades of the study. In other words, the loon population would have been 43 percent higher in the state if so many loons hadn’t been poisoned.

Other states have documented loon death rates affiliated with lead poisoning as well. In New York, the Department of Environmental Conservation’s necropsies over several decades show that lead responsible is for 15 to 21 percent of loon deaths. Necropsies in Minnesota suggest a similar death toll.

Documentation of loon deaths caused by lead has led to some regulatory policy. In 2000 New Hampshire became the first state in the U.S. to restrict the use of lead sinkers. Since then the Granite State has twice passed additional legislation, so that it is now illegal to sell or use lead sinkers or jigs of an ounce or less—essentially a ban on all lead commonly used for fishing tackle.

Four other Northeastern states have restrictions on lead fishing tackle (Massachusetts and Maine have restrictions on both sinkers and jigs, whereas Vermont and New York have bans only on sinkers). In the Pacific Northwest, Washington has implemented fishing regulation restrictions on lead sinkers and jigs in 13 lakes where loons breed.

But these restrictions were implemented in the face of strong protests from angling and sporting groups; regulations on lead in the tackle box have drawn fierce opposition whenever they have been proposed. In Connecticut, legislation to ban lead sinkers and jigs has failed twice. Back in 1994, a nationwide ban on lead sinkers proposed by the federal Environmental Protection Agency was derailed. More recently, the Obama administration in its final days proposed a lead ban on federal lands, but that was quickly overturned by the Trump administration during its first days in office.

Veterinarians at Cornell University perform surgery on a sickened Common Loon to remove ingested fishing tackle. Photo by Melissa Groo.

Loons, Lead, and Anglers

Lead is a problem everywhere loons and anglers share the water, says Nina Schoch, executive director of the Adirondack Center for Loon Conservation.

“Sometimes we free a loon that’s tangled in fishing line only to have it succumb a few days later to lead poisoning because it also swallowed a lead sinker or jig,” says Schoch.

Because New York’s loon numbers are more than twice what they were in the mid-1980s, there are greater opportunities for loon territory to overlap with anglers, she says: “As our loon and angler populations have grown, we’ve seen more and more loon–human interactions.”

An X-ray of a loon shows a lead jig head lodged in the gizzard. Source: Mark Pokras, Tufts University.

Despite the current regulations, lead tackle is still an issue. Last year’s Journal of Wildlife Management study concluded that the “current use” of lead in fishing tackle is a bigger problem than residual lead at the bottom of lakes.

Pro angler John Gaulke is a fishing guide in New York who leads up to 150 fishing trips a year. He says a more comprehensive ban on lead fishing tackle (the state currently bans half-ounce lead sinkers, but not lead jigs or larger tackle) would hurt his business.

“A total ban would be a huge hardship,” says Gaulke. “Many anglers make their own jigs and sinkers, and lead is a cheap way to weight something. Reducing lead use makes sense, but a total ban doesn’t, especially now that we see more loons on our lakes than in the 30 years I’ve been in business.”

That’s a common refrain from sporting groups: Loon populations are growing, so there isn’t a need to ban all the lead out of fishing tackle. Cost is another commonly cited concern. Hunting and fishing groups in New Hampshire fought against the lead ban because they thought it would prompt recreational anglers to fish in other states to avoid the cost and hassle of obtaining nonlead tackle. For anglers, a #5-sized split-shot lead sinker that weighs less than 1/10 of an ounce costs less than 5 cents, while a tin sinker of the same size costs about 15 cents.

Anglers also complain that nonleaded fishing tackle is harder to find, and that the quality of non-lead jigs is inferior, according to New Hampshire Fish and Game spokesman Mark Beauchesne. So far the lead restrictions in New Hampshire do not seem to have dampened fishing license sales. Going back to 2003, the state’s fishing license sales increased by more than 10 percent through 2016—the last year for which sales numbers are available.

In Minnesota, home to roughly 12,000 loons, the legislature voted down a ban on lead sinkers in 2003. Instead, that state’s wildlife conservationists rely on public education campaigns and general recommendations for anglers about using nonleaded fishing tackle.

But even in Minnesota, where the loon is the state bird, generations of anglers are set in their ways, and it’s an uphill battle to get them to switch their fishing tackle.

“Fishing here is a huge industry and trying to sensitize that many people about an issue like this, especially for people using lead sinkers their whole life, it’s a reeducation process,” says Carrol Henderson, the nongame wildlife program supervisor for the Minnesota Department of Natural Resources.

Hope for the Next Generation

Henderson is pinning his hopes on the next generation, and on a possible multi-million-dollar grant. Some loons that breed in Minnesota spend winter in the Gulf of Mexico region that was affected by the 2009 Deep Water Horizon disaster. That makes Minnesota loons eligible for BP oil spill remediation funds. Henderson is leading a grant proposal for a loon-friendly lake initiative that would, among other things, include a large-scale education campaign to raise awareness about the dangers of lead.

He’s particularly excited about reaching young anglers.

A Common Loon towers over its newly hatched chick. Photo by Roberta Olenick.

“Kids get it right away,” he says. “They’ve grown up understanding the consequences of lead. It’s not good for humans, or waterfowl.”

Back in New Hampshire, conservationists say education is an important part of the legal ban on lead-tackle sales, because many anglers don’t fully understand the deadly impact of lead on loons.

“We are in this for the long haul,” says Vogel of the Loon Preservation Committee. “It’s one thing to have [a ban on] the sale of lead tackle on the books, and another to make people aware. Many fisherman come across state lines or are using the lead in Grandpa’s old tackle box.”

Vogel expects it will take many more years before loon populations in New Hampshire no longer exhibit the effects of lead poisoning.

“These aren’t turkeys or ducks,” says Vogel. “Loons are long-lived, they reproduce slowly, they don’t breed until they are 6 to 7 years old, and pairs are lucky to fledge half a chick per year. To maintain a viable population, we must keep adults alive.

“Lead is the largest known cause of mortality in adult loons in New Hampshire, and that’s within our power to change.”

Lauren Chambliss is a senior lecturer with Cornell University’s Department of Communication. A former economics corre­spondent for the London Evening Standard, she now teaches communication and writes about the environment and sustainability.