Decades Spent Battling the Sea Lamprey

  • John Stegmeier electro-shocking for lamprey in Sand Creek. Stegmeier is one of the many people who go out every year to find where lamprey are spawning. (Photo by Dustin Dwyer)

What has rows and rows of sharp teeth…. sucks blood and rings up a 20 million dollar tab?

This is the Environment Report. I’m Rebecca Williams.

If you were thinking shark… or maybe blockbuster vampire movie… nope! It’s actually the sea lamprey.

HOW DID THE SUCKER GET IN?

LAMPREY INFO

Transcript

It’s an invasive parasite found in every one of the Great Lakes.  It invaded the Lakes in the early 20th century, and no one’s been able to get rid of it.  It’s a fish with a round mouth like a suction cup.  It latches onto big fish like lake trout and salmon…. and gets fat drinking their blood.

Fishery managers in the U-S and Canada work to keep this parasite in check.  It costs them 20 million dollars a year.  Those are your tax dollars, by the way.

Marc Gaden is with the Great Lakes Fishery Commission.  It’s the commission’s job to protect the multi-billion dollar fishery.

Gaden says the lamprey control program has beaten back the lamprey’s population by 90 percent.  And he says for now, humans are winning.

“The threat from lampreys at the moment is like a coiled spring.  As long as you have your thumb on it you’re going to be okay.  But the moment you let up on that control they’re going to spring back pretty quickly out of control.”

Gaden says they’re using a combination of weapons against the parasite.  They include a targeted poison to kill lamprey larvae, traps and barriers and sterilizing male lampreys. 

He says we are probably stuck with the lamprey forever.  That means we’ll be continuing to spend millions of dollars… every single year.

 
(music sting)

This is the Environment Report. 

 
So we’ve been wrestling with the sea lamprey for decades… maybe you’re wondering who’s actually out there in the trenches?  Dustin Dwyer caught up with one of the lamprey hunters:

 
John Stegmeier stands in a shady stretch of Sand Creek near Grand Rapids, looking like a Ghostbuster. He’s wearing waterproof waders, and has a metal box strapped to his back, with wires and knobs sticking out.

I meet him in the middle of the stream, where he’s prowling for sea lamprey larvae. But he tells me to stay up on a log out of the water, because he’s packing a charge.

“That’s giving little pulses of electricity into the water. And then if one comes up, then we give them a fast pulse, and that would keep them from being able to swim and we’re able to scoop them up with our paddles here.”

 They go into a bucket alive, then they’re counted for a survey. These surveys help determine where the U.S. Fish and Wildlife service decides to dump a poison targeted specifically for sea lamprey.

Stegmeijer is one of just a dozen people on a survey team that’s responsible for testing every stream and river in the entire Lower Peninsula, plus the southern shores of Lake Erie.
On days like this one in the gentle stream of Sand Creek, he says, it’s a fun job.

“But there are days on little trout streams in beautiful woods and there are days in agricultural ditches next to dairy farms that might smell a little, and there’s some industrial ditches.”

In short, he has to go wherever the sea lamprey larvae go, and sometimes they go to some inconvenient places.

It’s all part of the battle to keep the sea lamprey in check, and Steigmeyer says it’s not exactly a losing battle.

“We’re kind of winning it, but it’s only a kind of win because we can’t get rid of them.”

What they can do is control them – keep the population low.
Stegmeier says if they weren’t doing this, sea lampreys could devastate the multibillion dollar fishing industry in the Great Lakes, but even with the treatments, every year, sea lampreys make it farther up Michigan’s rivers to spawn. And every year, there’s more area for his small team to cover, and more places that need chemical treatment – treatment that can get extremely expensive.
Still the battle must be fought.

For the Environment Report, I’m Dustin Dwyer in Grand Rapids.

  
You can take a look at a sea lamprey’s ugly little face… and see photos of what the lamprey does to fish at environment report dot org. 

I’m Rebecca Williams.

Lake Huron’s Invasive Species

  • Filmmaker John Schmit says he wanted to make this film to show how even the smallest invader could mess up the delicate balance of life in the lake. (Photo courtesy of the NOAA GLERL)

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

Transcript

You might call Lake Huron the forgotten Great Lake. There are no major cities on its shores. It doesn’t get the media attention the other four Great Lakes do. But its problems are just as bad or worse. Rebecca Williams reports a new documentary tells the story of Lake Huron’s struggle with dozens of alien invaders… and the biologists and fishermen who are trying to reclaim their lake:

The documentary Lake Invaders is a cautionary tale about opening the door to strangers. It tells how Lake Huron was opened up to alien invasive species. The film paints fish biologists as the heroes rushing in.

“Seems like it always has to wait until it’s at a disaster level before you know, we can start fixing it… we’re constantly putting out these biological fires, running from fire to fire, to try to keep them under control. We have to find another way to approach this.”

More than 180 non-native species have gotten into the Lakes… and some of them have turned everything upside down. Long, slithering, blood-sucking parasites called sea lamprey were the first to get in. They slipped through a canal that connects the Atlantic Ocean and the Great Lakes. Lamprey killed off most of the big predator fish in the Lakes.

Then… came the alewife. Since the lamprey had taken out the top predators… there was nothing to eat the invading alewives. In the film… biologist Jeff Schaeffer explains how the small fish took over the lakes.

“At that time over 90% of the fish biomass of Lake Michigan and Lake Huron was probably dominated by the exotic alewife. One of my colleagues refers to the Great Lakes at that time as alewife soup.”

Suddenly… there was a major stinking mess. Each spring, hundreds of millions of dead alewives washed up on shore and rotted. Not the best thing for tourism.

Filmmaker John Schmit says he was surprised to learn what happened to the lakes next.

“The funny thing about the Great Lakes is there’s Pacific salmon in them.”

Schmit says biologists brought in millions of salmon from the Northwest to control the alewives. The crazy thing is… it worked. In the film we see how a 4 billion dollar sport fishing industry was born. And the native fish of Lake Huron were pretty much forgotten about.

The salmon fishery boomed for decades. Until the alewives crashed in 2003.

Fisher Doug Niergarth says then… the salmon started starving.

“Two years ago we saw some monster salmon heads that were sitting on little dwarfed bodies. And it was the ugliest thing and rather nasty. Just skinny and withered away. It was the nastiest thing you ever done seen.”

The fishing industry started slipping away. Marinas just scraped by. Tackle shops and motels closed. People finally realized there was something wrong with the lakes.

John Schmit says he wanted to make this film to show how even the smallest invader could mess up everything… both the delicate balance of life in the lake and the people who fish it and depend on money from tourism.

“Lake Huron has been the most impacted by the newest invaders. My personal concern, my investment in the Great Lakes and making this documentary is for people to be aware of the kind of damage invasive species can do to these huge lake systems.”

He says his film Lake Invaders is an example of what invasive creatures can do… not just to Lake Huron… but any ecosystem.

For The Environment Report, I’m Rebecca Williams.

Related Links

Invasive Die-Off Stirs Fishery Debate

  • A naturally reproduced wild lake trout fingerling. (Photo courtesy of MI DNR.)

The fisheries in the Great Lakes are seeing dramatic changes. In one lake, an invasive species that has become part of the food chain has collapsed. But some native fish are doing better because of that collapse. Lester Graham reports some fishery managers are debating what to do next:

Transcript

The fisheries in the Great Lakes are seeing dramatic changes. In one lake, an invasive species that has become part of the food chain has collapsed. But, some native fish are doing better because of that collapse. Lester Graham reports some fishery managers are debating what to do next:


When we started digging canals, connecting the lakes to the Atlantic Ocean, things changed a lot for the fish in the Great Lakes.


First, the sea lamprey got into the lakes through the Welland canal that bypasses Niagara Falls.


The lamprey is an eel-like parasite that nearly wiped out the big fish in the Great Lakes by attaching to them and sucking the life out of them.

Also slipping through the canals was a smaller fish, the alewife. Since the lamprey wiped out most of the predator fish in the lakes, the alewife population exploded. They out-competed native fish for food. It got so bad, that by the mid 1960s, if you weighed all the fish in Lake Michigan, more than 80% of the weight would have been alewives.


So, once wildlife managers got the sea lamprey under control, they had to figure out what they could do to get alewives under control. The fish biologists decided to introduce new predators, trout and salmon, to prey on the alewives. These fish were not native to the Great Lakes. Expensive nurseries were built by federal and state game agencies to keep supplying new trout and salmon every year to prey on alewives.


Forty years later, in Lake Huron, the alewife population collapsed, and in Lake Michigan alewives are declining rapidly. Mission accomplished, right?


Well, in that 40 years, a whole recreational fishing industry has grown up around fishing for those introduced trout and salmon. Some fishery managers now say we have to find a balance of the right amount of alewives to sustain the introduced trout and salmon fishery. So, recently states have cut their trout and salmon stocking programs to give alewives a chance to recover.


Tom Trudeau [who] operates a fish nursery for the state of Illinois says it would cause trouble to try to take the Great Lakes back to native fish only.


“We do have this industry that we have pressure to keep. You know, you’re putting a lot of people out of business if you get rid of it.”


And Trudeau says because of ecological damage, many of the smaller native fish on which big predators used to feed have been wiped out.


“So, I mean, of the six or seven species in that category, we only have one. And a couple of them are extinct. So, I mean, we could talk about going back to the ideal situation of pure native species, but we’ve disrupted the habitat so much.”


So, the argument goes, the invasive alewives are now needed. But something unexpected happened when the alewives disappeared from Lake Huron. The native fish, walleye, yellow perch, and lake trout started doing better.


Dave Fielder is a fisheries research biologist with the Michigan Department of Natural Resources.


“We’ve long known that adult alewives were a predator and a competitor on newly hatched perch and walleye fry. We just didn’t realize how substantial that effect was until finally the adult alewives were removed from the system and now we’re enjoying some greatly increased reproductive success. Walleye, particularly in Saginaw bay, are at some of the highest levels that we’ve seen in a long time.”


But, after 40 years, people are used to fishing for those introduced trout and salmon. And some fisheries managers are wondering what will happen to all those expensive nurseries that provide their jobs.


What happens to all of those charter boat fishing operations, fishing tourism, if the government were to stop stocking those trout and salmon? Would they switch to fishing for native fish? And, can the native fish even survive in the long-run since so many of the smaller native prey-fish are no longer around?


Dave Fielder says it’s hard to say.


“So, we’re kind of in the middle of a change – it’s really a paradigm shift in many ways – and that’s always scary because nobody really knows how we’re going to end up, but I prefer to be optimistic. I think there are a lot of reasons to be hopeful in regards to the benefits that we’re seeing for our native species.”


But some fisheries managers say the debate of whether to go all native or to try to find the right mix of native and non-native fish is not over. Since invasive species, pollution, and habitat destruction have changed the Great Lakes so much, wildlife managers think they’ll still have to keep stocking one kind of fish or another to keep the recreational fishing industry going. If that’s the case, does it matter whether it’s native fish, or the introduced fish that anglers have grown to like so much?


For the Environment Report, this is Lester Graham.

Related Links

Pheromone to Help Control Lamprey?

  • The sea lamprey drastically changed the Great Lakes ecosystem. (Photo courtesy of the Great Lakes Fishery Commission)

Researchers say they’ve discovered a migration pheromone
in sea lamprey. It’s a natural attractant that could boost efforts to
control the invasive parasite. The Great Lakes Radio Consortium’s
Stephanie Hemphill reports:

Transcript

Researchers say they’ve discovered a migration pheromone in sea lamprey. It’s a natural attractant that could boost efforts to control the invasive parasite. The Great Lakes Radio Consortium’s Stephanie Hemphill reports:


Each lamprey can kill forty pounds of fish in its lifetime. Managers use a pesticide to keep the lamprey numbers down, but it’s expensive, and sometimes it kills other fish.


University of Minnesota biologist Peter Sorensen says he’s isolated a chemical signal put out by lamprey larvae. The larvae live in streams, and the signal apparently tells adult lamprey that the stream is a good place to lay eggs.


“We’ve got a cue that’s very powerful, very safe, we don’t need very much of it, and it can control the distribution of the lamprey in a way that other things can’t.”


Sorensen says the pheromone can be used to corral lamprey into areas where they can be trapped or treated with pesticide. The pheromone is being tested in a river in Michigan.


For the GLRC, I’m Stephanie Hemphill.

Related Links

Luring an Invasive Fish With Pheromones

A scientist has discovered a chemical compound that attracts
an invasive fish. The Great Lakes Radio Consortium’s Mike Simonson
reports that this could be a breakthrough in controlling harmful fish
populations:

Transcript

A scientist has discovered a chemical compound that attracts an invasive fish. The
Great Lakes
Radio Consortium’s Mike Simonson reports that this could be a break through in
controlling
harmful fish populations:


Eurasian ruffe were introduced in the Duluth-Superior harbor from ballast water of
ocean-going
ships in the 1990’s. Ruffe reproduced so quickly, they now make up 80 to
90-percent of the fish
population, squeezing out native fish. Now, they’re spreading eastward across Lake
Superior
toward the lower Great Lakes.


University of Minnesota Fisheries Professor Peter Sorenson says he’s isolated a
pheromone that
will cause the fish to cluster in great numbers of male ruffe who are tricked into
thinking it’s time
to mate.


“It causes a great deal of sexual arousal and excitement. So to help detect this
thing, I suppose
like a dog they get a little crazy and just start swimming around like crazy and
nudging and
inspecting the fish in the tank.”


Once they’re clustered, Sorenson says it may be possible to find a way to cut their
population.
Sorenson hopes to find a similar pheromone in carp and sea lamprey, other invasive
species
which threaten native fish in the Great Lakes.


For the Great Lakes Radio Consortium, I’m Mike Simonson.

Related Links

Native Lake Species Fighting Back

  • Alewives washed up on Lake Michigan shores after the invaders' populations exploded, then crashed. Researchers have a difficult time predicting how invasive species will affect the balance of nature in the Great Lakes.

Ever since the Great Lakes were opened to shipping, exotic species of aquatic animals have invaded the lakes. Nearly always it’s been bad news for the region’s native fish and wildlife. The Great Lakes Radio Consortium’s Lester Graham reports on the latest effects of the invaders:

Transcript

Ever since the Great Lakes were opened to shipping, exotic species of aquatic animals have invaded the lakes. Nearly always it’s been bad news for the region’s native fish and wildlife. The Great Lakes Radio Consortium’s Lester Graham reports on the latest effects of the invaders.


Some of the exotic species that have caused major problems in the Great
Lakes have been around since the 1940’s and ’50s. For example, the sea lamprey found its way into the lakes through manmade channels. It’s a parasite that attacks lake trout and other large game fish. It devastated the lake trout fisheries. Only recently have efforts gotten the lamprey under control. It’s still out there, but it’s not decimating the lake trout population as it once was.


More recently, a big concern has been the zebra mussel. It hitchhiked its way to the Great Lakes in the ballast water of cargo ships. In the last couple of decades the zebra mussel has caused major changes in all the lakes except for Superior where it seems limited to the shallow and warmer bays.


David Jude is a researcher with the University of Michigan’s Center for
Great Lakes and Aquatic Sciences. He says the huge numbers of zebra mussels siphon through lake water like a giant network of filters. There are so many of them that water in the lakes is actually clearer.


“I think people tend to hear about the water clarity increases. ‘Ah, the water’s clearer,’ you know, ‘That’s great!’ But it’s not great, because there’s a lot of things going on in the water column.”


Things such as, algae converting the sun’s energy into more phytoplankton.
Small fish and tiny invertebrate animals called zooplankton eat the phytoplankton and then they become food for fish. But, the zebra mussels filter out a lot of the phytoplankton, stealing food from the native zooplankton.


David Jude says a couple of other invaders are also causing havoc at the base of the food chain in the Great Lakes. Instead of eating just the green phytoplankton, zooplankton invaders from the Black and Caspian Seas also eat their North American cousins.


“These are predators. And they feed on the zooplankton, our native zooplankton that is out there already. So, not only do we have the impact of zebra mussels removing algae which is a food for these zooplankton, now we’ve got two predators that have been introduced and both of those will eat zooplankton which would have been food for fish to eat.”


Besides the zooplankton floating around in the water column, a major food source for fish is in the sediment at the bottom of the lakes, and it’s disappearing. James Kitchell is with the University of Wisconsin – Madison. He says many different kinds of fish depend on a little creature called diaporeia, which have become scarce in many areas.


“It appears to correlate in general with an increases in zebra mussels. So, there’s the prospect that diaporeia is literally starving to death as a consequence of zebra mussels eating the available food, but when you look at the diaporeia, they appear to be healthy. They’re not skinny and look to be starving. So that doesn’t explain it.”


It’s a big concern because a lot of fish that anglers like, such as yellow perch, depend on diaporeia for food.


Besides the zebra mussels and the two zooplankton predators, a fourth invader is causing problems. Populations of the round goby, an ugly, aggressive feeding little fish from Eastern Europe, have exploded in the Great Lakes. The round goby scours the bottom, eating the eggs and larvae of native fish. The University of Michigan’s David Jude says as big of a problem as the invasive fish has been over the last several years. The round goby’s future might soon be curtailed a bit.


“We did SCUBA dives in Lake Erie, for example, we’d turn over rocks. Round gobys would tear out from under the rocks and we’d have small mouth bass following us around and they would ignore the round gobys. They didn’t know how to catch a round goby. But, because there’s so many round gobys now, they had to learn how to eat them or die. So, the predators are definitely learning how to eat round gobys.”


Other native fish are beginning to eat the exotics. The silver chub, which once nearly disappeared from the Great Lakes, is making a bit of a comeback feasting on zebra mussels. With each invader, the lakes ecosystems go through upheaval, and then find a new balance. But make no mistake. It’s a different balance. Nicholas Mandrak is a researcher at Youngstown State University. He says exotic species invading the Great Lakes will mean continued changes, and for people who fish the lakes, not many of the changes will be good.


“You’re not going to be able to catch as many species that you’re used to catching. You know, the native species are going to decline. The walleye are going to decline. So, I think the bottom line is the recreational and commercial fisheries are going to change in a manner that is negative to most people.”


Researchers, though, have learned to be careful about predicting how invasive species will affect the lakes. They’re often surprised by the intricacies of the food web and the ecosystems that support it. Throwing an exotic invader into the mix makes it that much more unpredictable, and it will likely get worse. Mandrak says they’ve been studying how global warming might affect the lakes. One scenario suggests 30 to 40 new exotic species from the South will make their way through manmade canals as temperatures rise. For the biologists, it’s a worrisome concept. For the Great Lakes Radio Consortium, this is Lester Graham.

NATIVE LAKE SPECIES FIGHTING BACK (Short Version)

It appears that fish native to the Great Lakes are beginning to prey on some of the alien species that have invaded the lakes. The Great Lakes Radio Consortium’s Lester Graham reports:

Transcript

It appears that fish native to the Great Lakes are beginning to prey on some of the alien species that have invaded the lakes. The Great Lakes Radio Consortium’s Lester Graham reports.


Aquatic Species from Europe and elsewhere have hitchhiked to the Great Lakes in the ballasts of cargo ships for many years. A lot of them have upset the natural ecosystems of the lakes. Lately, though, some native fish are taking advantage of the invaders. Nicholas Mandrak is a researcher at Youngstown State University. He says a Great Lakes minnow that was once thought to have died out has recently re-emerged.


“And they’re eating zebra mussels. So, it looks like the increase
in silver chub is related to zebra mussels, so we finally found a native
fish that is benefiting from the zebra mussel.”


Other researchers say small mouth bass are beginning to prey on another invasive species, the round goby, which eats the eggs and larvae of fish native to the Great Lakes. The researchers say the benefits don’t outweigh the negative affects on native species. But it evens the score a little. For the Great Lakes Radio Consortium, this is Lester Graham.

Commercial Lamprey Harvest May Soon End

A program to control the invasion of exotic species has got the lamprey eel under control throughout the Great Lakes…everywhere except the St. Mary’s River. But now, the lamprey are the target of a new time-release chemical that should reduce the lamprey population by 85-percent. But as the Great Lakes Radio Consortium’s Mike Simonson reports, bringing the species under control will mean the end to a recent money-making experiment: