Frequently Asked Questions

The term invasive carp refers to several species of related fish that originated from Asia. As many as ten types of carp are considered invasive around the world, but in the United States and Canada we use invasive carp to refer to four of these species – black carp, grass carp, bighead carp, and silver carp. Though all are fast growing and prolific feeders that out-compete native fish and can leave a trail of environmental destruction in their wake, the four species of invasive carp do not impact the underwater environment in the exact same ways. Grass carp present significantly different risks to the ecosystem compared to highly invasive bighead carp and silver carp. For more information on the differences between the four species, please refer back to our species pages.

We are concerned that if a self-sustaining population of invasive carp becomes established in the Great Lakes it will hurt native fish populations. The four species of invasive carp found in the United States are all fast growing and prolific feeders that are able to out-compete native fish for food, as well as alter the underwater environment so that it is uninhabitable for other native plants and animals. Silver carp also jump out of the water when agitated by the sound of a boat motor, which poses a safety hazard to recreational boaters.

Eradication of an invasive species like invasive carp is expensive, time intensive and not always successful. Prevention is the most cost effective solution, which is why the partnership is targeting control and management resources around the leading edges of invasive carp populations, especially in the Illinois River.

A manmade connection, known as the Chicago Sanitary and Ship Canal, connects the Great Lakes to the Illinois River, which in turn connects to the Mississippi River. This canal system provides the most direct pathway for invasive carp to enter the Great Lakes.

Invasive carp were originally imported from Southeast Asia to the southern United States to help aquaculture and wastewater treatment facilities keep retention ponds clean. Flooding and accidental releases allowed these fish to escape into the Mississippi River system and migrate into the Missouri and Illinois rivers. The Mississippi, Missouri, and Illinois rivers are all connected and therefore fish swim freely between them. The Illinois River is also connected to the Great Lakes by a manmade connection, known as the Chicago Sanitary and Ship Canal.

No, there is currently no evidence to suggest that Lake Michigan is home to a self-sustaining population of invasive carp. The best indication of a sustainable population would be repeated capture of both young and adult invasive carp, but intensive annual monitoring and fish sampling efforts have not found this to be the case above the electric dispersal barriers in the Chicago Sanitary and Ship Canal or Lake Michigan.

Yes, the U.S. Army Corps of Engineers is working with state natural resource agencies to identify and close off other potential aquatic pathways where invasive carp could enter the Great Lakes basin. This effort is part of the Great Lakes and Mississippi River Interbasin Study (GLMRIS) and is referred to as the "Other Pathways Study."

U.S. Geological Survey’s Nonindigenous Aquatic Species Database tracks where black carp, grass carp, silver carp, and bighead carp are found in North America.

Do not release the fish back into the water. If you catch or find an invasive carp in the Great Lakes or any of its tributaries, freeze the fish in a sealed plastic bag, note the date and location, and call your state or provincial natural resource agency. Note: if you are in Illinois on the Chicago Sanitary and Ship Canal, the above instructions pertain to any invasive carp found above the electric barrier.

Since bighead, silver, black and grass carp are invasive species they have no natural predators in North American waters. Invasive carp are only susceptible to predation when they are very young and still small. White pelicans and eagles have been observed feeding on small adult invasive carp, and largemouth bass have also been observed feeding on young invasive carp. Unfortunately, invasive carp are able to produce many offspring that in turn grow quickly. In the absence of natural predation, invasive carp are therefore capable of overwhelming native fisheries when conditions are favorable.

Yes, everyone has a role to play in preventing the spread of invasive animals like bighead, silver, black and grass carp. Learn about the steps you can take to combat the spread of invasive carp.

While members of the Invasive Carp Regional Coordinating Committee are always available to respond to inquiries, we are not structured or funded to support start-up businesses or subsidize commercial fishing operations focused on invasive carp. If you are a member of the public looking to earn income from an idea related to invasive carp, we encourage you to reach out to groups better equipped to help small businesses, as well as agencies at the state level who can answer questions about appropriate research and fishing permits and licenses.

Environmental DNA, or eDNA, refers to genetic material that an animal leaves behind in the water. Environmental DNA can be left in the environment in the form of scales, cells, feces or mucus. At present, eDNA evidence cannot verify whether live invasive carp are present, whether the DNA may have come from a dead fish, or whether water containing invasive carp DNA may have been transported from other sources such as bilge water, storm sewers or fish-eating birds. Please visit our eDNA page to learn more about this monitoring technique.