Asian Carp Invasion

by Hannah Ettema
MNA Intern
asian carp fish

Asian Carp

One of the biggest threats to the Great Lakes is a 100-pound fish.

Swimming up the Mississippi River, Asian carp have the potential to destroy the Great Lakes ecosystems if they are not stopped.

Earlier this month it was announced that the U.S. Army Corps of Engineers will be spending an estimated $25 million dollars to study and prevent the Asian carp from coming any closer to the Great Lakes than they already are.

Blocking the Way
Currently an electrical barrier is in place at an entry point to the Chicago Area waterways to prevent the Asian carp from continuing into Lake Michigan.

chicago water map

Chicago Area waterways map showing location of carp barrier (Illustration courtesy of Phil Moy, University of Wisconsin Sea Grant Institute)

Underwater electrodes create a barrier so that as a fish swims towards it, they have an uncomfortable feeling and swim back the other way.

The electrical barrier is the best large-scale method for prevention, but like any machine, it has the potential of temporary malfunctions. Scientists agree that other measures in addition to the barrier will need to be taken.

Disruptive Species
Asian carp are ravenous eaters. They eat plankton, stealing the main food source for fish. Asian carp share the diet of native fish, which now have to compete for food. Averaging 30-40 pounds, Asian carp can grow up to 100-150 pounds and can eat 5-20 percent of its body weight each day.

In the Mississippi River system, Asian carp are already problematic and showing signs of destruction.

In addition to disrupting the food web in rivers, Asian carp are cutting into the fishing industry. The commercial value of Asian carp is much lower than the native species they are replacing.

You wouldn’t think a fish could physically harm people, but Asian carp do. Because they are easily skittish, Asian carp will jump out of the water, potentially ten feet, when they hear a boat motor.

asian carp jumping

Asian carp jumping at the sound of a boat motor.

Having a 20 pound fish fly at you is not anyone’s idea of fun. One woman in Peoria suffered a broken nose and arm when on Asian carp hit her.

In their native China, Asian carp have predators which can keep them in check. In the Mississippi River and Great Lakes, there are no predators to challenge an adult Asian Carp.

More than the Great Lakes
Asian carp are not naturally big water fish. However they will still find home in the Great Lakes basin in the streams, vegetated shorelines and wide bays around Michigan. They will most likely stick to the coast for feeding and eventually inland to rivers in order to spawn.

MNA has more than fifteen sanctuaries on the west side of the state that could potentially be at risk in the near future. If the Asian carp were to penetrate the entire Great Lakes system, any and all sanctuaries that have a water system could have damage from the carp.

Getting Closer
Originally imported in the 1970s by catfish farmers, Asian Carp overflowed out of their ponds in the 1990s due to flooding and were accidently released into the Mississippi River. Since then, they have steadily progressed north.

Using a new method of detection, eDNA or environmental DNA, scientists have been able to detect Asian carp in the Chicago Area waterways, coming dangerously close to Lake Michigan.

eDNA, developed at the University of Notre Dame, is a method of detecting DNA from a water sample. Species, like Asian carp, release genetic material into the environment through slime, feces and urine—all of which can be detected in the water if caught soon enough.

For information on what to do if you find an Asian carp, click here.