Two sea lampreys attached to a large fish. This predatory parasite is wiping out freshwater salmon and trout in Lake Champlain. (Photo courtesy of U.S. Fish & Wildlife Service)
Government biologists working on Lake
Champlain, between New York and Vermont, say
they’re losing the fight against the sea
lamprey, a parasite that targets freshwater
salmon and trout. The lamprey population has
surged in recent years. Brian Mann reports
scientists say the best solution might be to
turn the fight over to federal biologists
who have had greater success fighting
lamprey on the Great Lakes:
Transcript
Government biologists working on Lake
Champlain, between New York and Vermont, say
they’re losing the fight against the sea
lamprey, a parasite that targets freshwater
salmon and trout. The lamprey population has
surged in recent years. Brian Mann reports
scientists say the best solution might be to
turn the fight over to federal biologists
who have had greater success fighting
lamprey on the Great Lakes:
On a gorgeous April morning, charter boat captain Richard
Greenough went fishing. He didn’t like what he found on his line:
“I went out this morning, I got one fish. Looked like it had been
sitting in front of a machine gun. It was skinny. It looked sick.
And that was a good one, because it’s alive.”
Lake Champlain’s freshwater salmon and trout are being wiped out by a
predator called the sea lamprey. The parasites are awful creatures – long and slimy
with circular suckers used to clamp onto the side of fish.
Back in the early 90s, New York and Vermont partnered with the US Fish
and Wildlife Service on an experimental project to kill lamprey, but
since 1998, the parasites have come roaring back. Speaking at a sea lamprey summit
in Burlington, Vermont, Captain Greenough says his customers regularly catch fish
that are half-eaten and scarred:
“It’s almost an embarrassment right now. Two years ago, I thought it
was bad with a 13-inch lake trout with three lampreys on it. Well, it’s
got so good we got a 12-inch with five on it last year.”
State biologists in Vermont and New York concede that the lamprey
response here simply isn’t working. Doug Stang is chief of fisheries
for New York’s Department of Environmental Conservation:
“You see in our current effort, even though substantial and
significant, just isn’t cutting it. We need to put forth more effort. Or
we need to pick up our toys so to speak and go home.”
Government biologists say abandoning an intensive lamprey program
would mean a complete crash of lake salmon and trout populations.
The fish are in danger of being wiped out by the lamprey. Biologists also say the parasites would likely begin feeding on other
species. One possible solution, Stang says, is turning the lamprey battle over
to the federal government, modeling the effort here after a much larger
lamprey program on the Great Lakes:
“This would provide us with a more centralized approach and this would provide us with a more a coordination for funding
and sea lamprey control efforts.”
The sea lamprey program on the Great Lakes isn’t a complete success.
The program is struggling with proposed funding cuts… and some
critics say the lamprey population in the Great Lakes is still too high.
Despite those concerns, Dale Burkett says the feds are ready to do more on Lake Champlain.
He heads sea lamprey control operations for the Great Lakes Fishery
Commission and works for the US Fish and Wildlife Service:
“The expansion in dollar amount would be somewhere around $310,000 more than is
currently being spent by the collective. I think the Fish and Wildlife
Service has indicated that they are willing, if tasked with that
responsibility, to step up to the plate.”
Federal scientists say that new investment would help to save a $250 million sport fishery.
Even so, the Federal takeover would be controversial. The main weapon
in this fight is a kind of poison called TFM that’s used to kill sea
lamprey larva in rivers.
On the Great Lakes, the use of TFM has a long track record, dating back
to the 1950s, but in New York and Vermont the practice is still
controversial. Joanne Calvi is with a group called the Poultney River
Committee. She says the toxins could affect other native species, including
several varieties of freshwater mussels that are considered endangered or threatened by state biologists:
“I’m opposed to chemical treatment with TFM to control native sea
lamprey in the Poultney River. I feel it should be prohibited.”
A new wrinkle here is the growing scientific consensus that the lamprey are a native species
and might not be invasive at all. Green groups say the parasite’s growing numbers reflect a larger problem with Lake Champlain’s eco-system.
Rose Paul is with the Vermont Chapter of the Nature Conservancy:
“We need to manage the lake’s species and habitats in a more holistic
way, that would help us identify root causes of problems.”
Scientists are experimenting with other methods of controlling lamprey including nest destruction, the release of
sterilized males, and trapping. But in the short term, government resdearchers say lampricide poison is
the only cost-efficient way to prevent the parasite from destroying Lake Champlain’s fishery.
For the Environment Report, I’m Brian Mann in Burlington.
