Invasive Carp

Overview

Invasive carp are a tremendous threat to the Great Lakes and could devastate the lakes if they enter our Great Lakes ecosystem. The invasive carp includes four species: black carp, grass carp, bighead carp, and silver carp. 

Originally, invasive carp were introduced to the United States as a management tool for aqua culture farms and sewage treatment facilities. The carp have made their way north to the Illinois River after escaping from fish farms during massive flooding along the Mississippi River. 

Due to their large size, ravenous appetite, and rapid rate of reproduction, invasive carp pose a significant threat to the Great Lakes ecosystem by consuming large quantities of phytoplankton and competing with native fish for habitat. Steadily, the carp have become the most abundant species in some areas of the Mississippi, out-competing native fish. Invasive carp can grow to an average of four feet and 100 pounds, and can consume up to 20 percent of their body weight in plankton per day. Carp have shown an affinity for becoming the dominant large fish species over more desirable native species or established fish that are recreationally and economically important. Invasive carp aggressively out-compete and eventually displace native fish altogether. With no natural predators and the ability to produce 2.2 million eggs, the invasive carp could devastate the Great Lakes’ multibillion dollar fishing industry. In addition to the threat invasive carp pose to Great Lakes fisheries, carp also pose an actual physical threat to boaters. The silver species of invasive carp can leap out of the water creating a hazard for boaters and water-skiers as the fish crash into boats, hitting people and damaging equipment.

The Chicago Ship and Sanitary Canal connects the Mississippi River to the Great Lakes. In attempt to prevent the invasive carp from entering the Great Lakes, the United States Army Corps of Engineers (USACE) erected a dispersal barrier system on the Chicago Sanitary and Ship Canal. The electric barrier on the canal is designed to repel the carp back from entering Lake Michigan. 

Ultimately, the permanent solution is to restore the ecological barrier between the Great Lakes and Mississippi River Basins to prevent invasive species from moving back and forth between the two bodies of water. Studies are underway to evaluate separating the Great Lakes and Mississippi River Basins.