Lamprey Infests Lake Champlain

  • 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.

Related Links

Multimillion Dollar Parasite Fight Continues

  • A sea lamprey, the first invasive species in the Great Lakes. (Photo courtesy of the USEPA)

One of the most destructive invasive species in the Great Lakes was also the first one to arrive. The sea lamprey invaded the Lakes more than a hundred years ago, and no one’s been able to get rid of it. As Rebecca Williams reports, it’s the only invader in the Lakes that managers have been able to control… but it takes millions of taxpayers’ dollars every year to keep the blood-sucking parasite in check, and there’s no end in sight:

Transcript

One of the most destructive invasive species in the Great Lakes was also the first one to arrive. The sea lamprey invaded the Lakes more than a hundred years ago, and no one’s been able to get rid of it. As Rebecca Williams reports, it’s the only invader in the Lakes that managers have been able to control… but it takes millions of taxpayers’ dollars every year to keep the blood-sucking parasite in check, and there’s no end in sight:

(Sounds of tank bubbling)


There’s a sea lamprey sucking on Marc Gaden’s hand.


“You can see he’s really got my thumb now, I’ll try and pull him off my thumb – this is a suction cup (popping sound of lamprey being detached).”


Gaden is with the Great Lakes Fishery Commission. It’s a group that was created by the US and Canadian governments with one main purpose: to control the sea lamprey. Gaden isn’t in any actual danger when a lamprey’s hanging on him. They don’t feed on warm-blooded creatures. But fish are another story.


“The mouth is ringed with sharp teeth, row after row of these sharp teeth, and in the middle of the mouth there is a tongue that flicks out and it’s sharp as a razor. What that tongue does is files its way through the side of the fish’s scales and skin and then the sea lamprey has access to blood and body fluids of the fish and that’s what it does, it feeds on them.”


Sea lamprey get fat drinking fish blood and fluids. They leave bloody holes in the side of fish, wounds that often kill the fish. Each lamprey can kill 40 pounds of fish a year.


Lamprey got into the lakes through manmade canals that connected to the Atlantic Ocean. By the 1940’s, the exotic species had invaded every one of the Great Lakes. Marc Gaden says by the 1950’s, lampreys had killed off most of the big predator fish in the Lakes.


“There’s literature around that time period that talked about gaping bloody wounds that commercial fishermen were finding on their catch, the commercial catch was beginning to go down the tubes, also because of overfishing, but sea lamprey was a major cause of that decline.”


Paul Jensen’s family used to fish for the popular lake trout before the lamprey wiped them out. Jensen now fishes for whitefish. He’s one of a small pool of commercial fishers who still pull a living from the Lakes.


“Every port along southern Michigan had commercial fishermen. South Haven, St. Joseph, Ludington, Manistee… There aren’t any, they’re gone. And one of the main reasons they’re gone, I think can be traced back to sea lamprey.”


Jensen says most commercial fishers these days have to do more than catch fish. He also runs a marina and builds research boats. Jensen says commercial fishers either had to adapt to the changes the lampreys brought or get out of the business.


“The whole food chain has just been devastated and turned upside down by exotics, and it’s been kind of a mystery; we have no clue as to where it’s gonna go. We’re glad with what we’re getting but I don’t know if we have much control of where it’s going.”


The people who manage fisheries have been wrestling for control over the sea lamprey. Marc Gaden says the lamprey control program has reduced the parasites’ numbers by 90 percent over the past 50 years. But he says lampreys have recently rebounded above target levels in several areas of the Great Lakes.


“It goes to show you these are crafty beasts. Even though they’re primitive and haven’t evolved much since the time of the dinosaurs, they still will find ways in which to spread and find new stream habitats and we always have to try our best to stay one step ahead of them.”


Gaden says the fishery commission has been aggressively treating the areas where lamprey numbers are too high. The main method is a lampricide that kills lamprey when they spawn in streams. Researchers are also working on chemical attractants to lure lampreys into traps.


But all of this takes money. Since the 1950’s, the US and Canada have spent about $300 million to keep lampreys in check. Marc Gaden says that sounds like a lot of money, until you look at the value of the fishery. It’s valued at about 4 billion dollars a year.


“So the amount of money we spend, upwards of 20 million a year, to keep lampreys under control, is a tiny fraction of the value of that fishery. But nevertheless it’s a cost we’re going to have to endure in perpetuity because the lampreys are not going away.”


But the Bush Administration’s proposed budget cut some of the funding for lamprey control. The fishery commission is hopeful that Congress will restore the funding. Marc Gaden says if we want any sport fishing, any tribal fishing, any commercial fishing… lampreys have to be kept under control, and that takes steady funding from Congress.


For the Environment Report, I’m Rebecca Williams.

Related Links

Multimillion Dollar Parasite Fight Continues (Spot)

The sea lamprey invaded the Great Lakes more than a hundred years ago, and no one’s been able to get rid of it. But Rebecca Williams reports it’s the only invader in the Lakes that managers have been able to control. Experts say it can only be kept in check if Congress continues to provide funding each year:

Transcript

The sea lamprey invaded the Great Lakes more than a hundred years ago, and no one’s been able to get rid of it. But Rebecca Williams reports it’s the only invader in the Lakes that managers have been able to control. Experts say it can only be kept in check if Congress continues to provide funding each year:


The sea lamprey got into the Great Lakes through a manmade canal. The parasite attaches itself to fish and sucks out the blood and body fluids.
By the 1950’s, sea lampreys knocked out the big predator fish in the Lakes.


A few years later, biologists discovered a pesticide that kills lampreys. That pesticide is the major tool managers still use today to keep lamprey numbers down.


Marc Gaden is with the Great Lakes Fishery Commission. The commission’s in charge of controlling the lampreys. He says in order to have healthy fish populations, lampreys have to be kept in check.


“It’s like a coiled spring, as long as you have your thumb on it, everything’s fine but the moment you take it away it’ll just spring out of control, bounce back right to where it was before.”


The Bush Administration’s proposed budget cut some of the funding for the lamprey program. But the fishery commission is hopeful Congress will restore the funding.


For the Environment Report, I’m Rebecca Williams.

Related Links

Ten Threats: Luring the Lamprey

  • The sea lamprey, up close. (Photo courtesy of USFWS)

One of the Ten Threats to the Great Lakes is the decline of many of the native species. The lake trout has been in trouble from over-fishing and because of an invasive species called, the sea lamprey. Conservation agents use a pesticide to keep the lamprey down, but it’s expensive, and sometimes it kills other fish. Now, researchers have discovered a lamprey pheromone that could help the fight against the sea lamprey. Stephanie Hemphill has that story:

Transcript

In our next report in the series Ten Threats to the Great Lakes we hear about how a native
fish has been hurt by an invasive species that swam into the lakes through a canal. Lester
Graham is our guide through the series.


One of the Ten Threats to the Great Lakes is the decline of many of the native species.
The lake trout has been in trouble from over-fishing and because of an invasive species
called, the sea lamprey. Ever since it invaded the Great Lakes, scientists have been trying
to keep the invasive sea lamprey under control.


Conservation agents use a pesticide to keep the lamprey numbers down, but it’s expensive,
and sometimes it kills other fish. Now, researchers have discovered a lamprey
pheromone. They think the chemical attractant could be a big help in their fight against
one of the most destructive invasive species in the Great Lakes. Stephanie Hemphill
has that story:


The sea lamprey came into the Great Lakes through canals more than a hundred years
ago. The slimy parasites attach themselves to big fish and feed on them until they die.
Each lamprey can kill 40 pounds of fish in its lifetime.


Between sea lampreys and over-fishing, the big native fish, the Lake Trout, was wiped out
in the lower Great Lakes. Only a few survived in small pockets in Lake Huron. Lake
Superior is the only place Lake Trout survive in healthy numbers.


There’s an aggressive 15-million dollar a year program to keep sea lamprey numbers
down. Part of the effort is using a chemical called TFM that kills the lamprey.
Wildlife managers spread the lampricide in streams in the spring. It kills some of the
young lamprey as they swim down into the lake.


University of Minnesota biologist Peter Sorensen says he and other scientists noticed that
TFM kills not just the juveniles, but the larvae that live in the streambed too. They also
realized, after a stream is treated, very few adult lamprey come back to the stream to
spawn, or lay new eggs.


“And this led to an observation decades ago, which was key, that adult lamprey must be
selective in how they pick streams. They only pick a few, and if you remove the larvae
they don’t seem to go in there.”


Scientists suspected the larvae might play a role in the spawning migration of adults.
That might mean the larvae are putting out a pheromone that tells the adults it’s a good
place to spawn. Just one larva attracts a lot of adult lamprey, indicating the pheromone
is very potent.


It was up to Jared Fine to determine what the chemical is. Fine is a PhD student working
with Peter Sorensen. For two years he sifted through the water in tanks holding lamprey
larvae.


“Separating the different chemical compounds, testing them biologically, seeing which
ones have activity, coming back to the active ones, further separating them, and just
repeating this until you get down to the one or two or three compounds that have the
activity.”


Fine narrowed it down to three compounds. He purified them and gave them to a colleague in the chemistry department, Thomas Hoye. Hoye created a synthetic version of the most potent pheromone. He says it should be possible to produce it on a large scale, and that means it could be used to treat the
Great Lakes. The question is, how much would he need?


“You know, would it be a tank car load, would it be a football field, would it be a dump
truck? It’s none of those. Would it be a barrel? No. Is it a bucket-full? No. In
fact it’s only about 500 grams, that’s just one pound, would treat all that water for a
month.”


And that’s all it would take, because the lamprey only spawn for a month, but the
treatment would have to happen once a year. Peter Sorensen says when lamprey
approach a stream to spawn, their clock is ticking. They have a powerful urge to lay
eggs, and once they’ve done that, they die.


“They are driven animals. Frankly they’re kind of on autopilot and pheromones are
what’s driving that autopilot to a very large extent, and now that we’ve got it, I think we
can really powerfully use that to our advantage.”


Sorensen says fisheries managers could use the pheromone to attract more lampreys to
streams outfitted with traps.


“You know the key here is the fact that this pheromone is natural, safe, and should be
very inexpensive to add.”


Fisheries managers hope the pheromone will help reduce the cost of controlling the
lamprey and add a new weapon to their arsenal.


The news on lamprey couldn’t have come at a better time for wildlife managers
around Lake Superior. After years of relatively constant numbers, the lamprey
population jumped dramatically this year. Scientists say lamprey may be finding new
spawning grounds in the mouths of streams, where lampricide is less effective. They’re
hoping they can use the pheromone to draw the lamprey to traps further upstream.


For the GLRC, I’m Stephanie Hemphill.

Related Links