(The Center Square) – 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.
Black carp can grow quickly and reach more than 3 feet long. A fisherman once caught a 115-pound black carp near East Cape Girardeau, Illinois, near the Illinois-Missouri border. The fish was then sent to Southern Illinois University in Carbondale for study.
“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.”
Black carp have been observed in several locations, but exact species abundance and distribution isn’t currently known because the probability of catching them in the large rivers they inhabit is low.
“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 United States Geological Survey and co-author on the study.
The Illinois Department of Natural Resources 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.
