Fight
against sea lampreys going well
Biologists
say measures to wipe out devastating predators are working By
Associated Press
08/16/2002 CHEBOYGAN --
The tide may be turning in favor of native species in the
battle against predatory sea lampreys.
A U.S. Fish and Wildlife Service biologist
says there is an "encouraging" sign that measures to eradicate
lampreys -- which kill Great Lakes trout and whitefish --
are working.
Native to the North Atlantic, the lampreys
have worked their way down the man-made canals in the St.
Lawrence River over the last 50 years. They feed by hooking
their toothy, disc-shaped mouth onto the sides of fish and
essentially eating them from the inside out. The U.S. and
Canadian governments first teamed up to fight the infestation
in the 1960s.
The invertebrates have been blamed for
declining populations of trout and whitefish.
U.S. Fish and Wildlife Service biologist
Mike Toohey, who heads the lamprey control program from
his Marquette office, said a trap his office set in the
Cheboygan River netted fewer lampreys this year than in
previous years.
"Either we didn't do as well trapping,
or there weren't as many to trap," he told the Traverse
City Record-Eagle for a recent story.
Another nearby trap also reported lower
than average numbers, he said.
Lampreys are harmless to humans, but will
feed on fish of any weight. Recently, Toohey's program has
instituted a toxin he calls "Lamprecide." His crew treats
rivers that flow in and out of the Great Lakes every three
or four years with the chemical.
Bill Swink, a U.S. Geological Service
biologist at the Hammond Bay Biological Station, said the
program has raised public concern about dumping chemicals
into rivers.
The state just spent $12 million re-registering
two chemicals in use since the 1960s when standards were
different with the Environmental Protection Agency.
"The only reason we have fishing in the
Great Lakes is because of the lamprey control program, and
that's primarily the lamprecide," Swink said.
Other methods used by the program are
catch and release sterilization of male lampreys and low
dams called "roadblocks." The dams prevent lampreys from
swimming past, but fish such as steelhead and salmon have
no problem hopping over. The drawback is that high water
levels sometimes allow lampreys access anyway. Electric
barriers also are being tested.
Pheromone research is another facet of
the program. Toohey said there is a possibility of using
synthetic lamprey pheromones to confuse mating lampreys
and augment the sterilization program.
Toohey doesn't think anyone would mind
if the unsavory looking creatures were gone for good, though
total eradication is unlikely.
"If they were cute we'd have a very hard
time with this program," he said.
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