|
Not Toxic Shot Makes A Difference
by: Steve McCadams
A new study suggests that the U.S. Fish and Wildlife Service's
1991
nationwide ban on the use of lead shot for waterfowl hunting has had
remarkable success, preventing the premature deaths of millions of
waterfowl from lead poisoning.
The study, "Ingestion of Lead and Nontoxic Shotgun Pellets by Ducks
in the Mississippi Flyway," was funded in part by the Service's
Great Lakes and Southeast Regional offices and published this summer in
the Journal of Wildlife Management.
In order to gauge the effect of the ban on lead shot, researchers
examined thousands of ducks harvested in the Mississippi Flyway during
the 1996 and 1997 waterfowl seasons, the fifth and sixth seasons
after the 1991 ban on lead shot.
Based on the survey's findings, the ban on lead shot reduced lead
poisoning deaths of Mississippi Flyway mallards by 64 percent, while
overall ingestion of toxic pellets declined by 78 percent over previous
levels.
The report concludes that by significantly reducing lead shot
ingestion
in waterfowl, the ban prevented the lead poisoning deaths of
approximately 1.4 million ducks in the 1997 fall flight of 90 million
ducks. In addition, the researchers state that approximately 462,000 to
615,000 acres of breeding habitat would have been required to produce
the same number of birds that potentially were saved by nontoxic shot
regulations that year.
With the ban now entering its ninth year, ingestion of lead shot
has probably continued to decline from the levels documented in the
study, preventing an increasing number of lead poisoning deaths.
"The results of this important report suggest that the ban on lead
shot has been a resounding success for the health of waterfowl
populations, and has almost certainly contributed to the record numbers
of waterfowl we have seen in recent years.
I'm proud that the Service took the initiative in
phasing out lead shot for waterfowl hunting, and continues to expedite
the approval of nontoxic alternatives to lead shot for hunters,"
said Service Director Jamie Rappaport Clark.
In addition to steel and tungsten-matrix shot, hunters can also
use
tungsten-iron, tungsten-polymer and bismuth-tin shot.
Tungsten-matrix shot, manufactured by the Kent Cartridge
Manufacturing Co., was given temporary approval for the previous two
seasons while testing was completed. If temporary approval is extended
to tin shot for the upcoming season, hunters will have a choice of six
nontoxic shots.
Clark pointed out that the ban on lead shot has probably also
benefited
more than 27 other bird species in which lead poisoning has been
documented, including bald eagles. Bald eagles have been found to be
particularly vulnerable to lead poisoning because they often feed on the
carcasses of hunter-crippled and lead-poisoned waterfowl.
"In addition, the study demonstrates what we've known for
some time - that the vast majority of hunters have acted responsibly and
ethically to reduce lead poisoning in waterfowl by complying with the
law," said Clark, noting that only 1.1 percent of examined ducks
showed evidence of being shot with lead.
The majority of birds examined by the researchers showed no
evidence of ingesting shot pellets, with ingestion rates ranging from
4.3 percent for scaup to 12.7 percent for ring-necked ducks. Shot
pellets were found in the gizzards of 8.9 percent of mallards.
Researchers found that of birds with shot pellets in their
gizzards, 68 percent of mallards, 71 percent of canvasbacks, 44
percent of scaup and 45 percent of ring-necked ducks contained no
evidence of toxic lead shot pellets. The gizzards of the remaining birds
contained one or more lead shot pellets, sometimes mixed with non-toxic
shot pellets.
Studies have suggested for decades that lead poisoning is a
serious problem for waterfowl. Ducks regularly grub for food on the
bottoms of lakes, streams and wetland habitat, and also ingest gravel
that is used in the gizzard to help grind up food for digestion. They
are therefore vulnerable to ingesting spent lead pellets that settle on
the bottom of waterways and wetlands.
A 1959 study, also by the Illinois Natural History
Survey, estimated that 2 to 3 percent of the North American waterfowl
population was killed annually by lead poisoning between 1938 and 1954.
Efforts to phase out lead shot began in the 1970s, but a
nationwide ban on lead shot for all waterfowl hunting was not
implemented until 1991. Canada instituted a complete ban on the use of
lead shot in 1999, after banning its use near bodies of water and on
national wildlife areas earlier.
The information above is
compiled by outdoor writer
Steve McCadams
Steve is a professional hunting and fishing guide
here in the Paris
Landing area and host of the The Outdoor Channel's television series
IN-PURSUIT.
|
|
