The Center Square
Carbondale, Ill. — Southern Illinois University-led research has found an established population of black carp in parts of the Mississippi River basin, according to a recent U.S. Geological Survey announcement.
This means Illinois waterways are being invaded by another invasive species that could threaten the ecosystem. Black carp, which are native to east Asia, were first
imported into the U.S. to control snails in fish farms where fish are
bred. How they escaped is unknown.
Some states ban possession of black carp, and importation of black carp into
the U.S. has been prohibited since their 2007 listing as an injurious
species under the Lacey Act.
In the SIU study, researchers examined black carp captured between May
2011 and September 2018 for size, age, their environments and whether
they were reproduced in controlled settings or the wild.
“When an invasive species becomes established, eradication can be difficult,
but it can also be challenging to collect robust information during the
onset and early stages when abundance is typically low,” said Gregory Whitledge, a professor with the Center for Fisheries, Aquaculture, and Aquatic Sciences at SIU, and
the lead author of the study. “This research includes the largest sample
size and is the most robust analysis of wild black carp in the
Mississippi River basin, helping inform those making decisions to
curtail further expansion.”
DNR thinks black carp have moved up the Illinois River as far as central Illinois.
A silver carp was removed from Lake Calumet in August, triggering a
closer search for the species in the area. Lake Calumet is only seven
miles from Lake Michigan. If the invasive carp enter the Great Lakes,
they have the ability to dominate the food chain and cause major
disruptions to the ecosystem.
Black carp can grow quickly and reach more than three feet long. They prey on
species such as snails and mussels and pose a risk to many already
imperiled native mussels in this region. Mussels support ecosystem
health by improving water quality – they filter out bacteria, algae and
pollutants as they breathe and feed – and provide food and nutrition for
Knowledge on the extent of invasion can help inform federal, state, and local
agencies as they develop control strategies, mitigate effects and
consider plans and limitations on the use or transportation of live
Native to east Asia, black carp were first imported to control snails in fish
farms where fish are bred. Snails are hosts of parasites that can harm
channel catfish, hybrid striped bass and other fish that are important
human food sources and support the regional economy.
The use of black carp in these types of aquatic environments is regulated
and requires permits, and there isn’t a clear understanding on how black
carp escaped those settings.
“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 study
finds that in the area examined, wild black carp have naturally
reproduced, there are multiple ages present, carp are living to
adulthood and the population primarily consists of fertile fish that are
capable of reproducing. This suggests that the environment has suitable
conditions for black carp’s entire life cycle.”
A map of black carp observations in the Mississippi River basin reported
to the USGS as of Nov. 30, 2022, is available on the agency’s website.
The data on the USGS map includes incidental captures by the public and reports from federal and state agencies.
There are limited sampling efforts targeting black carp and the probability
of individuals catching them in the large rivers they inhabit is
currently low, USGS officials point out.
The Mississippi River basin covers more than 1,150,000 square miles and
includes 32 states and small parts of two Canadian provinces. The river
originates in northern Minnesota and flows south to Louisiana. Black carp have been observed in
several locations, but exact species abundance and distribution isn’t
currently known because there are limited sampling efforts targeting
black carp and the probability of catching them in the large rivers they
inhabit is low.
The study was authored by SIU, the USGS, the U.S. Fish and Wildlife Service,
Missouri State University, and the Missouri Department of Conservation.
Black carp have been collected in Horseshoe Lake in Alexander County as well as the Ohio and Mississippi rivers.
DNR and other agencies have worked to slow the fish’s spread. Their presence is the result of good intentions gone bad.
“It’s the same story as the grass, silver and bighead. It was looked at as a
solution to an environmental issue and turned out to be its own
environmental issue,” Brian Schoenung, Aquatic Nuisance Species Program
Manager for DNR, said earlier this year. “The Arkansas fish farmers take
the hit on a lot of this things, but the reality is the Fish and
Wildlife Service and the Environmental Protection Agency were at the
forefront of bringing these things in. They were trying to reverse an
environmental problem without using chemicals. It seemed like a viable
option at the time.”