Getting the Lead Out of Fishing Getting the Lead Out of
Fishing

Virginia R. Gumm and
Daniel Poleschook, Jr.
Loon Lake, Washington

Lead poisoning is a problem for wildlife (Lee,
2003) and waterfowl as well as for people. Lead is
a naturally occurring metal that is toxic to both
humans and wildlife. In humans it can result in
irreversible brain and kidney damage, muscle
weakness, reproductive dysfunction, gastrointestinal
disorders, headache, anemia and other problems.
Fetuses and young children are most at risk.

Symptoms of lead poisoning in waterfowl (Lee,
2003) include neurological and gastrointestinal
problems, limb paralysis, staggering and difficulty
walking on land, inability to fly and escape
predators, wings can be mal-positioned or drag on
the water or ground, vocal changes, swelling of the
face or esophagus and bright green feces. Anemia,
muscle wasting and overall emaciation ensue. Lead
toxicosis also produces a constant and chronic
weight loss and often a bird will expire after
ingesting one or two lead pellets or sinkers.

Common loons expire quickly (within two weeks)
after ingesting lead, mostly from fishing lines,
hooks, lead sinkers and jigs. They can also ingest
lead when they collect small pebbles from lake
bottoms and inadvertently swallow lead sinkers.

Ingestion of lead fishing gear is the single largest
cause of mortality for adult common loons in New
England (Mass. Wildlife, 2004). Veterinarians at
Tufts University-School of Veterinary Medicine
examined over 180 dead adult loons from fresh
water over the past 10 years and determined that
more than half of those birds died as the result of
lead poisoning from the ingestion of lead fishing
gear. Their ongoing research has documented that
ingestion of lead sinkers (including split shot)
accounted for approximately 70% of the dead adult
loons from fresh water. Just a single lead sinker can
poison a loon (Pokras and Chafel, 1992).

Every year, loons, swans, and other waterbirds die
needlessly of lead poisoning after swallowing lead
sinkers and jigs. Dabbling ducks, loons and grebes,
sea ducks, cranes, herons, swans, geese, birds of
prey and scavengers die of lead toxicosis because of
the food they eat or the way they get their food.
Duck species, swans and geese that use aquatic
plants as a primary food source, will also eat large
amounts of marshland sediment and are exposed to
both lead shot and lead sinkers in the process. They
also search the lake bottom to ingest gravel that is
used in the gizzard to help grind food for digestion
and can mistakenly ingest lead at that time. The
species that are most commonly documented
(Canadian Wildlife Service, 2005) to be poisoned by
lead shot and sinkers are mallards, black ducks,
northern pintails, canvasbacks, Canada geese, snow
geese, tundra and trumpeter swans, and the common
loon.


Species that are known to have ingested lead sinkers
and jigs in the United States are:
common loon, great egret, American white pelican,
trumpeter swan, tundra swan, Canada goose,
American black duck, laughing gull, red-breasted
merganser, snowy egret, double-crested cormorant,
mute swan, wood duck, redhead, herring gull,
canvasback, great blue heron, brown pelican, royal
tern, whistling swan, mallard, sandhill crane, and
white ibis, common merganser, greater scaup, lesser
scaup, white-winged scoter, white-fronted goose,
and bald eagle (Environment Canada, 2005).


Lead in the environment can create a serious
problem as lead shot and sinkers can break down
transferring lead to the soil and water. Lead breaks
down most quickly where the soil and water are
acidic and oxygenated. When lead is in soil, it can
be moved to new places by erosion. Lead that is
dissolved in water can run off into nearby water or
move down through the soil into the groundwater.
It can also be taken up from the water or soil by
plants (Canadian Wildlife Services, 2005).

Lead, once dispersed into lakes, may persist for up
to 300 years, though degradation can be more rapid
depending upon soil conditions and other factors.
The U.S. banned the use of lead shot for hunting
migratory waterfowl in l991. Non-toxic shot is the
standard. Great Britain in 1987 has banned lead
sinkers after a voluntary effort there did not produce
results. New Zealand has recognized the problem
also (Educational Brochure for Michigans
Fishermen, 2005).
Water birds can be poisoned long after the shot or
sinkers first fall to the ground or into the water.
This is because lead shot and sinkers generally take
decades to break down into the environment. Lead
poisoning of wildlife can happen at any time of the
year, but is usually greatest during and after the fall
hunting season. Waterfowl hunters often hunt along
migratory paths, where large flocks of ducks and
geese gather in the fall. As a result, lead shot often
builds up in the very areas that water birds use for
resting and feeding locations during their migration.

Lead sinkers can be found in areas that are fished,
like along shorelines, rocky places and piers of
lakes, ponds, and streams. These areas often overlap
with the breeding and feeding grounds of waterbirds
including the common loon. Waterbirds can
swallow lead sinkers or jigs any time that the water
is open (not frozen.) Depending on the location,
poisoning from swallowed lead sinkers or jigs
accounts for up to half or more of all common loons
found dead in eastern Canada and the United States
(Canadian Wildlife Services, 2005).
Lead sinker ingestion with lead toxicosis is the
leading cause of death of the common loon and it
may be an important factor limiting loon
populations in some areas by increasing the
mortality of breeding adults. With nearly 700 loons
studied, the research suggested that about 54% of
adult loons are dying from lead poisoning from
ingesting fishing gear, and in areas of heavy fishing,
84% (Pokras and Chafel, 1992).

In Washington State, there have been several known
common loon

deaths and suspected deaths of lead
toxicosis due to fishing tackle ingestion during
migration and nesting (Poleschook and Gumm,
2005). Most of the lakes that the common loon uses
for migration and nesting are highly utilized by
fishermen. With only a small population of
territorial/breeding loons, Washington State has
already been stated as being The State that is the
closest to having its common loon population
extirpated, states David Evers (pers. comm.), at
BioDiversity Research Institute in Gorham, Maine.
Lead in fishing is placing Washingtons
population of common loons at risk.

There were 8-10 territorial/breeding pairs of
common loons in Washington State in 2004. From
this low population, four established
territorial/breeding loons were involved in life-
threatening situations involving fishing tackle and
lead. They had either swallowed jigs, fish with
broken and trailing fishing line with lead sinkers
attached, or ingested lead sinkers from lake bottoms.
The three lakes (Ferry, Swan, and Lost) that these
loons use for their breeding territories are highly
used by fishermen; and there is much discarded
fishing tackle and line, including lead sinkers, seen
along the shoreline and in the water (Poleschook
and Gumm, 2004).

The territorial male loon from Lost Lake expired
from suspected lead toxicosis, although his carcass
was most likely taken by predators and no autopsy
was performed. His behavior, described by an
individual during the last stages of his life, indicates
symptoms of lead toxicosis. The bird had beached
itself on the shoreline, was unable to hold up its
head which had flopped over onto its back, and had
great difficulty with balance and movement. Since
this was the male and the defender of the territory,
the newly hatched chick was easily taken after the
males death by a bald eagle. The chicks death
could be considered a secondary

death contributed
to lead toxicosis and demise of the adult male.

A second healthy-appearing adult common loon was
found beached and expired at Omak Lake during the
spring migration of 2004. It was autopsied by

Darwin Long, IV, assistant biologist, BRI, and
found to have one triangular-shaped lead sinker in
its gizzard. Lead toxicosis was the diagnosis
(Poleschook and Gumm, 2005).


In the spring of 2003, two common loons were
found beached and one had expired at Chelan Lake
near a popular fishing area.

The other was retrieved
and expired shortly afterwards. It was autopsied by

BRI, (see figure #1 below) and it was found to have
two large lead sinkers and two smaller-sized
rounded and eroded sinkers in the gizzard. The
diagnosis was due to lead toxicosis (Long, 2003).

In 2005, another Common Loon was found beached
and expired in the Puget Sound area of La Conner,
WA. The loon appeared to be healthy and have
adequate stores of fat over the keel, although it
showed some predation in areas of the neck and
legs. Lead toxicosis is suspect due to the position of
the head and posturing of the expired loon. An
autopsy is currently being done

on this loon, who
was co