Asian carp invasion threatens Great Lakes fishery

With fisheries on the line, Canada hopes high-tech measures can stop Asian carp

Attack of the alien carp

Benjamin Lowy/Getty Images

Asian carp, imported into the southern U.S. decades ago, have been pushing north up the Mississippi ever since flooding gave the invasive species a chance to make a break for it in the 1970s. Now the voracious eaters are poised to slip into the Great Lakes, which could mean both environmental disaster and the ruin of a multi-billion-dollar fishery. So this week the Canadian government announced it will pour $17.5 million into high-tech measures designed to keep the scaly pests out of our waters. Might as well call Canada’s new program of forensic early-detection what it is—CSI: Carp.

The two species in question—silver carp, known for leaping high up from the waters when disturbed, and bighead carp—have already appeared in Lake Michigan, gaining access mainly through the Chicago Sanitary and Ship Canal, where a series of electrically charged fences can occasionally malfunction. In the past, detecting unwanted aquatic critters has required a series of strategically placed nets, a less-than-perfect gambit. But experts believe the new federal dollars will go in part toward just-developed DNA probing techniques.

“This is all done using advanced molecular methods,” says Hugh MacIsaac, an invasive species biologist at the University of Windsor. “You don’t catch the carp, you just get the water it’s been swimming in and process it for DNA.”

The method depends on the specific genetic fingerprint for Asian carp uncovered by a team of Univesity of Notre Dame scientists in 2010. Once detected, the carp can be rooted out or poisoned. Speed is key.

“They’re very likely to invade if given sufficient opportunity,” says Tony Ricciardi, an invasive species biologist at McGill University. “It’s not an experiment I’d like to try.”


Asian carp invasion threatens Great Lakes fishery

  1. I have no faith in barriers, biotic resistance (high native predator population) control recruitment control the fish. The Feds admit we have native predators for Juvenile Asian carp.

    • The presence of a predator rarely guarantees that the population of an introduced species will be controlled. Native predators have not controlled the round goby; numerous species of fish can consume it, but its recruitment rate is too high to be suppressed.

      • Spot on Chuck. Additionally, a problem with bighead & silver carp are their rapid growth rates. I’ve heard that native predators in the Illinois and MississippI Rivers will really mow down on the juveniles. Iin that first year of life, though, the juveniles grow so fast that they become too big for all but the largest predators in the system. Native fish can eat a ton of them, but they only have a few months to do it before the carp are too big to be preyed upon. That doesn’t allow for much top down control of Asian carp populations.

        • The Alligator Gar grows to ten feet and over 300 Lbs Tim are native to the Mississippi, Red, Arkansas, Missouri and Illinous Rivers! The U.S. Fish & Game are restocking the fish in the lower tributary’s of the Mississippi and the Mississippi itself.

  2. Maybe we should look closer at there Predators Native to North America. There historical, current and future (expanding it to meet the threat) distribution.
    The fish I’d consider as potential predators are the Northern Pike, Muskellunge, types of Catfish and the Alligator Gar. I hope there’s more though I’d include the Alligator itself.
    World Famous River Monsters Jeremy Wade’s commented on the destruction of the predator fish populations of North America, the Alligator Gar Specifically, as having been a potential contributing factor in the Asian Carps massive population growth. I know from my local knowledge in the Muskellunge’s prototected in some Southern Ontario waters because its close to being exterpitated and has been for decades.
    Should we consider restocking Indigineous Predatorial Fish at the farthest extent’s of there historical range and cutting back on or curtailing Sport Fishings take of them for a time till the populations expanded suficiently.
    There’s no doubt the answer for Carp eradication will involve Heavy Industrial Harvesting but they’ll never be wiped out by this method alone! Once the profit margin of the Industry, currently in it’s infancy, fails it will cease to exist and the populations will boom just as fast as before.
    Some of the most arcane fish species are grown in Private Fishing Preserves around the world to attract the International Sport Fishing Tourist. Surely we can harvest and stock the major river systems with Native Predator Species to contibute to the destruction of the Asian Carp!

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