The evidence is in: Fishermen’s
lead sinkers are killing loons in the Adirondacks and elsewhere.
Studies in Canada, Michigan, Minnesota, New England and New York
have concluded that lead poisoning from ingestion of sinkers accounts
for 15% to 40% of loon deaths—and the mortality rate on
freshwater lakes where loons breed can run higher.
In one of the most comprehensive studies, a Tufts University researcher
found that lead sinkers were responsible for more than half the
deaths among adult loons on New England lakes. The re-search helped
goad Maine and New Hampshire into passing laws restricting use
of the sinkers.
Other governments also have taken action. This year, the U.S.
Fish and Wildlife Service banned lead sinkers from National Wildlife
Refuges frequented by loons. Canada prohibits lead sinkers in
national parks and wildlife areas. And Great Britain banned the
sinkers in 1987.
 |
|
Photo by Gary Lee |
| Loons need a long running
start in the water to take off. |
New York has not followed suit. In 1995, in fact, the state Department
of Environmental Conservation opposed a bill that would have outlawed
the sale of lead sinkers and jigs (weighted hooks) smaller than
1 ounce. DEC contends that even though lead sinkers kill individual
loons, the state’s loon population is faring well. Nevertheless,
the agency regards the loon as a species of “special concern”—meaning
a species “for which a welfare concern or risk of endangerment
has been documented.”
Wildlife biologists agree that the common loon’s population
appears to be stable, perhaps growing, but they caution that the
state hasn’t surveyed the population since 1985. At that
time, biologists estimated that 800 to 1,000 loons lived in New
York—nearly all in the Adirondacks.
Jeff Wells of the Cornell Laboratory of Ornithology points out
that because loons live so long—up to 30 years—a threat
to the population might not be evident right away. “You
may see a pair of loons on the lake, but they might not be breeding,”
he said. “We need better information before we can say whether
the population is stable or declining or increasing.”
No one is suggesting that lead sinkers threaten to wipe out loons,
but they are only one of several perils. Acid rain kills the fish
that loons eat. Waves from jet-skis and powerboats can swamp their
shoreline nests. Mercury pollution interferes with their breeding
and makes them susceptible to disease.
“There are a lot of factors adding up,” said Nina
Schoch, a loon researcher who works at DEC. “Right now the
population seems to be stable, but there is the potential for
it to go down quickly.”
This summer, Schoch and other scientists took blood samples from
Adirondack loons as part of a three-year study to ascertain their
level of lead and mercury contamination. The study’s sponsors
include DEC, the U.S. Fish and Wildlife Service and the Loon Preservation
Committee of New Hampshire.
Even if the various threats to loons have not reduced the population,
they may be keeping the population from growing at a higher rate
or spreading to its historical range. Many Adirondack lakes regarded
as suitable habitat do not harbor loons—including some that
once did. It’s difficult to say which threat puts loons
most at risk, but many people argue that the lead problem could
be addressed easily through legislation. A loon can ingest a lost
sinker when picking up pebbles and grit that aid its digestion
or when eating a fish that has broken an angler’s line.
One sinker is enough to kill a loon.
Ward Stone, the state’s wildlife pathologist, said the lead,
once dissolved by stomach acids, migrates to organs and nerves,
making the loon unable to swim. “They act like they’re
weak and sick and uncoordinated,” he said. “Sometimes
they will come up to the shallow water and just flounder.”
Since 1972, Stone has examined 81 loons found dead around the
state. He discovered that 15 of them—or 19%—died from
lead poisoning from sinkers, including birds recovered from Long
Lake, Blue Mountain Lake and the Oswegatchie River. It was the
second-leading cause of death, after a fungal infection known
as aspergillosis. Stone doesn’t know why the fungus is killing
so many loons, but he suspects that mercury contamination makes
the birds more vulnerable to infection.
Stone assumes that his mortality statistics reflect the incidence
of lead poisoning in the overall population, although other studies
have found that lead sinkers kill an even greater percentage of
loons. Mark Pokras, a Tufts University veterinarian, has examined
450 dead loons from New England over the past 10 years and determined
that 21% died from ingestion of lead sinkers—the most common
cause of mortality. This statistic, like Stone’s, includes
all loons, whether found in freshwater lakes, where they breed,
or in the ocean, where they often spend the winter. What Pokras
finds especially worrisome is that lead sinkers accounted for
the deaths of 56% of breeding loons whose carcasses were found
on freshwater lakes.
Although most of the research has focused on loons, a bird treasured
by the public as a symbol of the wild, lead sinkers kill numerous
other species, including swans, ducks, geese and herons. Also,
eagles and other birds that feed on fish and fowl can die from
secondary poisoning.
Assemblyman Steven Englebright, a Long Island Democrat, introduced
legislation in 1995 to ban lead sinkers and jigs weighing less
than an ounce—the size most likely to be swallowed by birds.
He later amended the bill to ban only split-shot sinkers, which
usually weigh less than a half-ounce. These sinkers are often
used by freshwater fishermen.
At the time, DEC officials objected to the bill on several grounds,
among them that it would be opposed by fishermen and the fishing-tackle
industry and might hurt tourism, according to an agency memorandum.
DEC spokeswoman Jennifer Post said the department also concluded
that the deaths of individual loons did not put the population
at risk. She pointed out that DEC is encouraging anglers to switch
voluntarily to non-lead sinkers.
In its latest fishing guide, DEC says an-glers who use non-toxic
sinkers “are helping to reduce the risk of lead poisoning
to birds.” But the agency then adds: “The number of
birds poisoned by lead weights is small and does not justify broad
restrictions on routine sinker or jig use.”
This year, Englebright introduced yet another version of his bill
that would require DEC to conduct an education campaign to persuade
anglers to switch to non-toxic sinkers and only later, if the
campaign proved unsuccessful, to adopt mandatory restrictions.
Post said this bill, which is still in committee, has not advanced
far enough for the department to take a position.
The New York State Conservation Coun-cil, which represents 300,000
hunters and anglers, strongly opposes the legislation. Frank Hartmann,
the council’s legislative vice president, contends that
there is no evidence that lead sinkers are hurting the loon population.
He noted that the alternatives to lead such as tin, steel, tungsten
and ceramic–are more costly. “Why should we have to
pay more when there’s no justification for it?” he
asked.
Michael Nussman, a vice president of the American Sportfishing
Association, which represents the tackle industry, said the extra
cost of non-toxic sinkers is slight, but he questions the need
for regulations. “Lead sinkers have in fact killed some
birds,” he said. “We don’t know that they’re
causing any problems at the population level.” If further
research revealed otherwise, he added, the association would support
restrictions on lead sinkers. “Our interests depend on a
healthy aquatic environment.”
Nussman said the association did not oppose the New Hampshire
law, but it has not decided whether to take a stance on the Englebright
bill. He warns, however, that confusion could result if states
adopt different rules. “What we don’t want to see
is 50 different answers to lead sinkers,” he remarked.
Proponents of the bill argue that it’s a good idea to restrict
the use of lead sinkers even if they pose no threat to the overall
loon population–just to reduce environmental pollution.
Lead is highly toxic not only to birds, but also to many other
species, including humans. In a memo accompanying his bill, Englebright
estimates that 100 tons of lead sinkers are lost in New York waters
each year. He obtained his figure by extrapolating from the U.S.
Fish and Wildlife Service’s estimate that 2,700 tons of
lead sinkers are purchased annually in the nation. Since the number
of anglers has remained constant in recent years, Englebright
assumes that newly purchased sinkers replace ones that were lost.
Nussman, however, disagrees. “Clearly, most of this lead
is sitting in someone’s tackle box, not at the bottom of
some lake or stream,” he said.
.............................................................................................
A murky population trend
By Phil Brown
Although the common loon seems to be doing well in New York state,
it probably is not as common as it once was.
The sketchy information from the 19th century suggests that the
loon used to breed in places outside the Adirondacks, its present
nesting ground. John James Audubon saw nesting loons on Cayuga
Lake in 1824. Nest sites were reported along the south shore of
Lake Ontario in the late 1800s.
In the Adirondacks, Theodore Roosevelt reported that the loon
had been thriving in the St. Regis region in 1870 but had become
scarce by 1877. Contemporary observers say loons are no longer
found on some Adirondack lakes where they once bred.
Scientists became concerned about an apparent drop in the loon
population in the 1970s. In 1977, the state embarked on its first
loon survey. Over three years, wildlife biologists visited 420
Adirondack lakes deemed large enough to attract loons. They counted
114 breeding pairs on 91 lakes. They estimated that the Park had
fewer than 200 pairs of breeders.
The survey found that the pairs averaged about one fledgling a
year a high rate compared with loons in Minnesota and New Hampshire.
This good news was tempered by the finding that the density of
the loon population was lower in the Adirondacks than in other
places.
Also, loons were absent from 44 of 79 lakes that were reported
in an informal 1963 survey to have breeding pairs although it’s
possible that the loons simply moved to other lakes.
Biologists conducted a second survey from 1984-85. This time,
they counted 157 breeding pairs on 128 lakes. On the 384 “core
lakes” those inspected in both surveys they found 132 breeding
pairs, as opposed to 113 in the first survey. Also, the number
of core lakes with loons rose from 123 to 184. The researchers
estimated that the state had 216 to 270 breeding pairs.
The second survey affirmed that Adirondack loons have a high fledgling
rate but a low population density. It has been suggested that
the state’s loon population has a high proportion of unmated
birds perhaps because the population is growing or perhaps because
the birds are having trouble nesting or reproducing.
At the moment, the state Department of Environmental Conservation
has no plans to conduct another loon survey.
.........................................................................................
Loon lore
The common loon has long been a favorite with visitors to the
Adirondacks, both for its graceful beauty and its repertoire of
haunting calls.
• Appearance: Black head, black bill, ruby eyes;
white-striped necklace on throat; black- and-white checkered back;
white underneath; webbed feet.
• Sounds: Four basic calls: (1) tremolo, often
described as maniacal laughter; (2) yodel, usually heard at dusk,
at night or in early morning; (3) the wail, a long call; (4) talking
calls, simple notes that mimic conversation.
• Habitat: Breeds on freshwater lakes in Canada
and several northern states. Almost all loons in New York breed
in the Adirondacks. Adirondack loons leave in fall to spend the
winter along the Atlantic coast, returning in April or May. Since
loons take off only from water and need a running start—sometimes
as long as a quarter-mile—they avoid small lakes.
• Food: Eats mostly fish, but also crayfish, crabs,
snails, leeches, frogs, salamanders, aquatic insects. Loons dive
up to 200 feet, sometimes staying under-water for a minute or
more.
• Breeding: Builds nest of matted grass, rushes
and twigs on shore close to water. One to three chicks born in
mid-June to late July. Little chicks sometimes ride on parents’
backs. They become skilled swimmers and divers within two weeks
and fly after about 75 days.
..............................................................................................
For more information about loons in the Adirondacks visit the
Adirondack
Cooperative Loon Program
