Tag: gaden

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.

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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: Break in the Food Chain?

  • Diporeia are disappearing from Lakes Michigan, Huron, Erie, and Ontario. The actual size of a diporeia is ½ an inch. (Courtesy of the EPA)

Some of the life in the Great Lakes has been hit hard by industry and trade. Pollution and
invasive species have hurt some of the native plants and animals important to the food
chain. While popular game fish might be the first to come to mind, it’s a little organism
at the bottom of the food chain that has biologists and fishing experts most concerned.
The Great Lakes Radio Consortium’s Lester Graham reports:

Transcript

In a survey, experts said one of the Ten Threats to the Great Lakes is a disappearing
species. Some native fish populations and organisms are declining. Our guide through
the Ten Threats series is Lester Graham.


Some of the life in the Great Lakes has been hit hard by industry and trade. Pollution and
invasive species have hurt some of the native plants and animals important to the food
chain. While popular game fish might be the first to come to mind, it’s a little organism
at the bottom of the food chain that has biologists and fishing experts most concerned.
The Great Lakes Radio Consortium’s Lester Graham reports:


(Sound of swinging doors)


Jack Donlan is taking me behind the fish counter at Donlan’s Fish House. In the
backroom he’s scaling and filleting some whitefish.


“Of the fishes caught in the Great Lakes, whitefish is one of the big volume fishes. Lake
perch, walleye bring more money per pound, but I would think from a tonnage-wise,
whitefish, it’s an extremely popular fish.”


This is a popular place to get Great Lakes fish, but Donlan’s suppliers, the commercial
fishers, are worried about the catch. At some places in the Great Lakes whitefish aren’t
doing too well.


(Sound of Lake Guardian motors)


Tom Nalepa is trying to figure out why whitefish are struggling. He’s onboard the U.S.
Environmental Protection Agency research ship, the Lake Guardian. Nalepa is a
biologist with the National Oceanic and Atmospheric Administration’s Great Lakes
Environmental Research Lab. He’s been studying Lakes Michigan and Huron, and on
this day he’s getting ready to study the bottom of Lake Erie.


He’s not studying whitefish. He’s actually looking for a tiny shrimp-like crustacean, only an
eighth to a quarter inch long, called diporeia. Eighty-percent of the whitefish diet is
made up of diporeia.


“And what we’re seeing is a dramatic drop in populations, and not only drops, but there are
large areas now in all the lakes, except Lake Superior, that no longer have diporeia. This
is real concern because diporeia is a very important fish food.”


Researchers used to find eight to 10-thousand diporeia or more in a square meter of sediment just
a few years ago. Now, there are only a dozen or so, or none at all. Diporeia is one of the
mainstays of the bottom of the food chain, and Nalepa says whitefish aren’t the only ones
that eat the tiny critters in the sediment at the bottom of the lakes.


“Just about every type of species found in the Great Lakes will feed on diporeia at some
stage in its life-cycle. Diporeia is high in calories and has a high-energy content. It’s a
very good food, nutritious food source for fish.”


Without it, fish are not getting enough to eat. Marc Gaden is with the Great Lakes
Fishery Commission. He says when diporeia disappears, commercial fishers can’t help
but notice.


“Right now we’re seeing skinnier whitefish. Whitefish that are somewhat emaciated in
some areas because they just don’t have as much of these low-end of the food web organisms
to eat, and we think it’s related to an invasive species that came in.”


That invasive species is the zebra mussel, and more recently another invader that was
likely carried to the lakes in the ballasts of ocean-going cargo ships, the quagga mussels.


Back on the Lake Guardian, Tom Nalepa says he’s seen the connection again and again.


“There’s no question that it’s related to zebra mussels and quagga mussels. In every area
that we’ve studied, regardless of the lake area, declines were happening a couple of years
after the quagga mussel or zebra mussel were first found, but that connection remains
elusive.”


Biologists thought the invasive mussels might have been filtering out all of the food the
diporeia eat, but when they find diporeia, they don’t appear to be starving. They appear
healthy. Now, scientists are wondering if there’s some kind of disease or toxin spread
by the mussels that’s wiping out the diporeia.


Even if researchers learn why the diporeia are disappearing, there might be nothing that
can be done to help. Some scientists worry that the decline of diporeia and other
organisms at the base of the food chain might ultimately lead to a massive collapse of fish
stocks in the Great Lakes.


For the GLRC, this is Lester Graham.

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Ten Threats: The American Eel

  • Researchers measuring an American Eel. (Courtesy of United States Department of Agriculture)

Pollution and invasive species are killing off or crowding out native plants and animals,
but for some species, it’s not just one problem, but many problems that are hurting them.
Few species illustrate the dangers of the multiple threats to the Great Lakes as the American
eel. Only fifty years ago, the snake-like fish accounted for half of the biomass in Lake
Ontario. Today, it has all but disappeared. David Sommerstein has that story:

Transcript

In our next report in the series Ten Threats to the Great Lakes we hear about native
species that are in trouble. Our guide in the series is Lester Graham. He says some fish
and organisms are disappearing.


Pollution and invasive species are killing off or crowding out native plants and animals,
but for some species, it’s not just one problem, but many problems that are hurting them.
Few species illustrate the dangers of the multiple threats to the Great Lakes as the American
eel. Only fifty years ago, the snake-like fish accounted for half of the biomass in Lake
Ontario. Today, it has all but disappeared. David Sommerstein has that story:


Before you say, who cares about a slimy critter like an eel, eels are amazing. They spawn
in the Sargasso Sea, the Bermuda Triangle, but no one’s ever caught them in the act.


After they’re born, they’re like tiny glassy leaves. They float thousands of miles north
and west on ocean currents. Then, they wiggle up the St. Lawrence River and into the
Great Lakes. They live up to 20 years in fresh water before they start the long journey to
the Sargasso to spawn.


The problem is their offspring are not coming back. People are worried about the eel, and
those who relied on it for a living feel like they’re disappearing too.


(Sound of waves)


Just ask fisherman John Rorabeck. He grew up here by the lighthouse on Point Traverse,
a peninsula that juts out into northeastern Lake Ontario.


Rorabeck’s been fishing these waters for more than 30 years. Eels were his prime catch.
He points past the lighthouse.


“I remember when I started fishing there were nights on that south shore, the most fish
that would be eels at certain times and there was literally tons of them on that south
shore. Now, you could go back there and you’ll find nothing.”


Rorabeck stopped fishing eels several years ago because it just wasn’t worth it. Now he
dedicates his fishing time to science. He catches specimens for leading eel expert John
Casselman, who examines them in his lab.


“It is truly a crisis. A crisis of concern.”


Casselman’s a scientist at Queens University in Kingston, Ontario. In 1980, at a point on
the St. Lawrence River in mid-summer, he counted more than 25,000 eels a day. Now
there are as few as 20 a day.


Casselman ticks off a list of causes. It sounds like a who’s who of environmental threats
to the Great Lakes – over fishing, dammed up rivers, erosion, pollution, invasive species,
climate change. If scientists could sift out how all the factors relate, they could take a big
step in better understanding the Great Lakes delicate ecosystem.


The problem is, Casselman says, there’s no time to wait. In 2003, eel experts from 18
countries made an unusual statement. In what they called the Quebec Declaration of
Concern, they urged more action, not more science.


“I’m a research scientist, and of course I love data. At this point, you don’t want me.
Don’t ask me to explain what’s going on here because by the time I get it figured out, it
may be too late.”


People are starting to do something about it, Casselman says. Several U.S. agencies are
considering giving the eel “rare and endangered” status. More money is going toward
research for fish ladders over dams.


Marc Gaden is spokesman for the Great Lakes Fishery Commission.


“We’re committing ourselves, our resources to working to make the recovery of the
species a reality.”


The province of Ontario has closed the eel fishery in its waters for the foreseeable future.


(Sound up at beach)


Fisherman John Rorabeck supports that plan. He stares out across the waters he’s
trawled for decades. He says he’s behind anything to bring the eel back for future
generations.


“And hopefully we can, but I don’t expect to see it in my time. When I…[crying]…when I
think of all the times that we’ve had out in the lake and my forefathers and see what’s
happening here, it breaks you down.”


Rorabeck says when he thinks of the eel nearing extinction, he feels like he and his way
of life are becoming extinct too.


For the GLRC, I’m David Sommerstein.

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Congress Rejects Carp Barrier Funding

The Asian Carp is a big eater… and it’s moving closer to
the Great Lakes. Great Lakes states are hoping to stop the carp with electric barriers on the Chicago Ship and Sanitary Canal. But as the Great Lakes Radio Consortium’s Rebecca Williams reports… a Congressional committee voted against operating money for the barriers:

Transcript

The Asian Carp is a big eater, and it’s moving closer to the Great Lakes.
Great Lakes states are hoping to stop the carp with electric barriers on the
Chicago Ship and Sanitary Canal, but as the Great Lakes Radio Consortium’s
Rebecca Williams reports a Congressional committee voted against operating
money for the barriers:


It’s estimated the Asian Carp is about 20 miles away from Lake Michigan.
Right now there’s a temporary electric barrier standing in its way, and the
Army Corps of Engineers is building a second, stronger barrier. Great Lakes
states are looking to Congress for money to operate the carp barriers, but a House-Senate
conference committee recently voted against any funding for them. Without federal funding the
state of Illinois will have to come up with the hundreds of thousands of dollars to operate and
maintain the barriers.


Marc Gaden is with the Great Lakes Fishery Commission.


“We think that this is actually a national problem. The carp escaped from the
southern United States and have been making their way northward and have been causing
destruction on their whole path, so this is something that’s more than just
a Great Lakes or even a state of Illinois issue.”


Gaden says two additional bills before Congress could provide money to
operate the barriers, but he says the carp might move faster than either of
those bills.


For the GLRC, I’m Rebecca Williams.

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