Lake Michigan Itself Is the Greatest Asian Carp Deterrent

By Eric Betz | September 22, 2017 3:31 pm
Asian carp jump from the water at the mouth of the Wabash River in Ohio. (Credit: U.S. Army Corps of Engineers/Todd Davis)

Asian carp jump from the water at the mouth of the Wabash River in Ohio. (Credit: U.S. Army Corps of Engineers/Todd Davis)

For years, people have been freaking out that Asian carp are about to invade the Great Lakes.

That concern seemed more real than ever this summer after an Illinois fisherman caught a carp in June less than 10 miles from Lake Michigan — beyond the barriers designed to keep them out.

These voracious fish have already decimated Midwestern rivers. They’re filter feeders who feast on plankton — the tiny plants and critters that prop up foodchains. And they eat lots of them. Adult Asian carp eat pounds of the stuff every day.

Carp are also a little creepy; so they’ve captivated the public’s attention. They spawn in startling numbers, and they’re notorious for all leaping from the water at once, smacking their slimy fish bodies into innocent boaters.

It’s easy to see why conservationists and government agencies are concerned.

“Asian carp are kind of the perfect poster child for invasive species,” says Molly Flanagan, vice president for policy at the Alliance for the Great Lakes. “The silver carp jump and they’re scary — they hurt people. The bighead carp eat a lot.”

And in August, the government finally released its long-awaited $275 million plan to stop carp from reaching the Great Lakes. The Army Corps of Engineers’ so-called “Brandon Road plan” would install electric barriers at a lock and dam near Joliet, Illinois. Underwater speakers would sonically blast the fish as additional deterrent.

Both Republicans and Democrats from neighboring states have supported taking action against carp in hopes of protecting the Great Lakes’ sport fishing industry. But Flanagan says the Trump administration held the study back at the urging of industry groups like shipping companies, who have barges on the waterway.

“What they’re worried about is delays,” she says. “If they have to lock a dam every time they go upriver, how much time is that going to add to their journey?”

A Wet Desert

But surprisingly, when you ask veteran Great Lakes ecologists about the dreaded carp reaching Lake Michigan, you’ll often be met with groans.

Those groans stem from a reality that’s even more horrifying than carp: There’s little left in Lake Michigan to devastate. Other invasives—mostly quagga mussels—have already stripped the lake of its food. Rather than invade Lake Michigan, ravenous carp swimming in the canal might turn back around once they reach the nutrient-poor environment in the lake.


Quagga mussels from fish trawl sample in Lake Michigan. (Credit: NOAA/Greg Marks)

Like carp, the mussels love plankton. And quagga mussels now number in the trillions. Along the lake bottom—stretching more than 100 miles from eastern to western shore—there’s a virtually unbroken bed of filter feeders that has sucked the life from Lake Michigan. Carmen Aguilar of the University of Wisconsin-Milwaukee is an expert on how invasives affect the Great Lakes’ food chain. She says quagga mussels can filter the whole system once roughly once every four days.

Lake Michigan is now an aquatic desert.

“You have desert water from Lake Michigan—water with virtually no food in it—heading toward the Mississippi River,” says fisheries ecologist John Janssen, also of the University of Wisconsin-Milwaukee. “That water will get greener and greener as it heads towards the Mississippi.”

Why is the water better fertilized farther south? Poop. Or, as Janssen puts it “incomplete processing of sewage in Chicago.”

“So, if you imagine yourself as an Asian carp which need the phytoplankton — they need huge amounts of it to survive—what they’re doing swimming up that canal is they’re getting into a desert more and more,” Janssen continues. “And they’re gonna turn around.”

He says he can’t guarantee no carp will make it into Lake Michigan. But, if they do, they’d have a hard time reproducing or even surviving far from city shorelines in the open lakes.

But for Flanagan, the Brandon Road “let’s-electrocute-all-the-carp-plan” is about much more. There are now some 180 invasives in the Great Lakes.

“This isn’t just Asian carp,” Flanagan says. “What we have in the Chicago area waterway system is essentially an invasive species superhighway. It’s a continuous connection between the Great Lakes Basin and the Mississippi River Basin.”

The goal of conservationists is to put a roadblock on that highway.

“Asian carp are the easiest way to get other people interested in potentially doing any of that work,” Flanagan says.

CATEGORIZED UNDER: Environment, Top Posts
  • OWilson

    They are a little late.

    Asian Carp have been the most visible fish in the Great Lakes for 20 years, or more,

    Along the shorelines, and In the upper streams they school in spring and it is a sight to behold, in the rivers and Mill Ponds!

    • Erik Bosma

      Well let’s eat the bastards, OW. You go first. My grampa used to eat anything he caught. He moved here (BC) from Holland. Oma hated it (she couldn’t see past all those mountains) so they moved back. But he loved his fishing. They stayed with us when I was about 10 and God-knows-what would be frying in the pan when we got home from school. Once in awhile there’d be something recognizable. “Mmmmm….” he’d say, “Lekker! Op eeten, kinderen.” And that’s what we’d do but, you know, it was always kind of tasty.

    • Jaycypraea

      You’ve got the wrong Carp my friend. The one they’re talking about is not the one you’re seeing.

  • Uncle Al

    “An average carp is capable of producing hundreds of thousands to sometimes millions of eggs each year” Load up disposable drones with fertilized egg clutches and seed North Korean lakes and rivers. Give the folks something to eat.

    • Jim

      Start an Asian Carp Diplomacy with Kim Jung En.

    • Erik Bosma

      You know Unc, that idea ain’t half bad. But once I think about it, the Asian Carp probably thrived in DKRP’s rivers at one time. However, with all those hungry hungry mouths, they probably didn’t stand a chance and were decimated shortly after the Kims set up their ‘Utopia’. I can just see a million Koreans jumping up out of the water chasing the carp. That’s probably where they leaned to jump like that in the first place. I’m a sick boy…..

      • Scrappysmith

        Polution wiped out the last native Asian Carp

  • Erik Bosma

    Asian carp are eaten by people in Asia. I’ve never tasted one but I doubt they’re that bad. I think the bottom-feeder label freaks people out. It’s just pure protein, folks. And there must be a lot of it in one since they jump so high out of the water.
    Does anyone have any idea what’s in a fish sandwich or in a non-cod or non-halibut order of fish and chips? I didn’t think so. So let’s fish these buggers onto the extinction list and sell the meat to all the people who need or want it. God knows we need more protein in our terrible diets.
    As for those Quagga Mussels, doesn’t something eat them. How about starfish? How about us? And then something to eat the starfish until we reached some sort of equilibrium. Or we could harvest them somehow and, again, pump out the protein.
    Kind of like that story about that old lady who swallowed the fly.

    • lump1

      So I read up on the quagga mussels and got the sense that we don’t want anything to eat them, because their tiny fleshy bits contain all the concentrated pollution of all the water they have filtered. Apparently yellow perch eat them, but that’s not so great, because whatever might prey on the perch gets a very toxic meal, and those toxins shouldn’t pass through the food chain. To me it doesn’t sound like all bad news. I say it’s better for the toxins to be locked up in the mussels instead of being diffuse in the water. Some grad students in a fancy robotics program should 3D print some cheap underwater drones that collect these mussels for safe disposal. If there are enough, maybe we can reach a point where we remove pollutants from the lakes faster than we add them.

      • Erik Bosma

        Those mussels could be used to fertilize certain plants that remove forever the toxins found in the soil. There’s a name for those plants but it escapes me now. Sounds like a bonne idee though.

      • Randall Sharp

        why not use the filtration system of the mussels take filtered out of the lake and replace it with floating fish farm water. The clean water can be used to raise food fish and the waste can be treated by the mussels.

  • Bud Johnson

    So, apparently while we have been so focused on preventing an overpopulation of Carp in Lake Michigan, we already had an overpopulation of Quagga Mussels which left the water without any real nutrition. Does this mean that the fish population in the lake is already dwindling with proper food? Should we be concerned with the overpopulation of mussels? I think I have more questions after reading this than I did before because now if we focus on eliminating the mussels then we need to be refocused with the Carp again.

    • Jaycypraea

      The mussels are also an invasive species which have raised havoc in all the Great Lakes. This fish would further push the lakes to the brink.

  • Leon Li

    Carp is number 1 seafood in southern China for the common people. It is great esp if steamed not too tough – all juicy and tender, using bean paste, green onion and slivers of pork, cilantro, and soy sauce. Use big pan with water and high steam power – trick is to get it done in as short a time as possible. Go online and search for steaming time. If too big, may have to cut it into slices before steaming, about3/4 in tick would be ok. We usually prefer the smaller ones about 2-4 pounds, steamed whole, without filleting. Try it. Takes some practice. Next time you are in Hong Kong, ask for in on the menu. Or deep fry the fillet in any kind of oil. sprinkle a bit of salt and pepper, or garlic salt. i guarantee you, you will be forever hooked.

    • Erik Bosma

      Might as well bleach a patty made of rotting plant and animal matter and their fesces. Which would be the sole diet of most of these fish. Of course crabs aren’t far behind.

      • woad2112

        you have never eaten catfish?

        • Erik Bosma

          By now I have forgotten why I said that…

  • Marshall Gill

    $275M?! Just a quarter of a billion dollars of other people’s money. It might not even work, but who cares? Bilking the taxpayer is what it is all about anyway.

    • Jaycypraea

      The Great Lakes fisheries is a multi billion dollar industry annually. It would become seriously damaged if this fish gets loose in the lakes.

    • rrocklin

      That is 1/28th of the cost of one of the navy’s stealth destroyers.

  • Jaycypraea

    While Lake Michigan may not have much plankton some of the other lakes have plenty. If they get into the lakes, a habitat unique on this planet will take another step towards desecration. As well as economic losses in the billions. Personally, I would poison the entire Mississippi watershed to get rid of these things

    • Erik Bosma

      There’d be a lot of pissed off catfish grabbers (or what are they called?) and connoisseurs at you and that idea. Of course it wouldn’t make a lot of difference in the Gulf dead zone..

  • John Sheakley

    “There are now some 180 invasives in the Great Lakes.”

    At least 25 invasive species of fish have entered the Great Lakes since the 1800s, including:
    • Brachionus leydigii
    • Thermocyclops crassus
    • round goby
    • sea lamprey
    • Eurasian ruffe
    • alewife
    • zebra mussels
    • spiny water flea
    • Asian Carp

    The Great Lakes have also been troubled by fast-growing invasive plants, that displace the native plants that support wildlife habitat and prevent erosion. These include:
    • common reed
    • reed canary grass
    • purple loosestrife
    • curly pondweed
    • Eurasian milfoil
    • frogbit
    • non-native cattail

    I wish we could save a sample of the native plants and animals, kill everything, and then propagate the natives from the sample; call it the Noah’s Arc Plan or the Genesis Plan.

    But like after Noah’s Arc in the Bible, the source problem was not eradicated; human sin. Like after a so called Genesis Plan for the Great Lakes, invasives will return. Thirty percent of invasive species in the Great Lakes have been introduced through ship ballast water.


The Crux

A collection of bright and big ideas about timely and important science from a community of experts.

See More


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Collapse bottom bar