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.




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.