ST. LOUIS – The troublesome black carp, long a bane to ecosystems in U.S. waterways, is now an officially established species in parts of the Mississippi River basin.

Black carp, which are native to East Asia, were accidentally imported to the United States in the 1970s with shipments of grass carp. Beginning in the 1980s, they were brought in to use to control snails and other mollusks in fish farms and retention ponds. Snails have parasites that can harm channel catfish, hybrid striped bass, and other fish that act as human food sources and thus support local economies.

Unfortunately, the black carp escaped these enclosures due to various floods and other reasons over the years, and, according to a new study co-authored by the U.S. Geological Survey, has become entrenched in our waterways.

As of Tuesday, Dec. 13, 2022, the black carp is known to be an established population in the Mississippi watershed, which is the second-largest drainage system in North America. Meaning, these fish are naturally reproducing and living to adulthood in the ecosystem.

“While prior studies have indicated that wild black carp might be established in parts of the Mississippi River basin, this is the most comprehensive study and the first research to provide strong evidence that they are present and sustaining on their own,” said Patrick Kroboth, a research fish biologist with the USGS and co-author on the study.

“… This suggests that the environment has suitable conditions for black carp’s entire life cycle.”

Once an invasive species becomes established, removing it from that environment can be difficult, according to Gregory Whitledge, a professor with the Center for Fisheries, Aquaculture, and Aquatic Sciences at Southern Illinois University, and the lead author of the study.

The Mississippi River runs 2,320 miles from northern Minnesota to the Gulf of Mexico, and its basin covers 1.15 million square-miles, which includes 32 states and small parts of two Canadian provinces. So, the probability of fishing the black carp to control their population, or even to determine their exact abundance in the river, is low.

However, a person who catches a black carp in the wild can report it to the USGS Nonindigenous Aquatic Species database.

Since 2007, it’s illegal to import black carp into the country. They are listed as an “injurious species” under the Lacey Act.

An infographic highlighting a study finding that black carp, which are an invasive fish species in North America, are now known to be established in the wild in parts of the Mississippi River basin. The infographic was created by the USGS. The USGS was one of the study’s co-authors and the research was led by Southern Illinois University.