In North America, a few species of carp from Asia have been identified as invasive species. The two species most associated with this invasive action are the bighead or bigheaded carp and the silver carp which are both native to China. Previously, these species were introduced to southern states in the U.S. during the 70s as an inexpensive fish to sell in fresh fish markets and to help maintain aquaculture facilities.
However, by the 1980s, these species of carp were present in the Mississippi River basin and have since moved north. These Asian carp species currently make up about 95% of the biomass in the Mississippi and Illinois Rivers systems. As of now, these species threaten the Great Lakes ecosystem as their current presence in the previously mentioned river systems are connected to the Chicago Sanitary and Ship Canal (CSSC).
Asian carp are primarily filter feeders which eat plankton and blue-green algae. Bighead carp tend to be larger than its silver counterpart at about 30 to 40 pounds. These species can consume up to 20 percent of their body weight per day which can dominate native fish as they too rely on plankton as a food source throughout key development stages. This additional plankton feeding by the Asian carps introduced into a native environment can cause instability within the food web and outcompete native fish species.
The Great Lakes ecosystem is an ideal habitat type for this invasive species as it would be good for reproduction, feeding and maturation. Other than the ability to provide Asian carp with warm, biologically functional waters, it also provides Asian carp with a secondary food source such as detritus or dead organic matter in the bottom of these protected areas. This could greatly impact the wetlands and shoreline vegetation of the Great Lakes that would disturb the native fish reproduction and native waterfowl brooding.
As there are no native Great Lakes fish or other species present in the ecosystem that are large enough to prey on Asian carp, the populations of this invasive species would remain unchecked. If Asian carp becomes established in this area, populations would be almost impossible to eradicate however, it may be minimized through construction of migration barriers that prevent Asian carp from entering these waters.
A series of three electrical barriers through underwater electrodes have been places across the CSSC which should deter Asian carp from entering the canal and further, into Lake Michigan. Species of Asian carp have been recently added to the Federal Lacey Act which makes the transport and possession of this species banned on a federal level.
Asian Carp webpage, This webpage from the New York Invasive Species Information website provides information on the biology, ecological and economic impacts, prevention strategies and origins of this species.
Asian Carp and the Great Lakes Region [PDF], This report from the Congressional Research Service provides background information on the four identified species of Asian Carp and their potential impacts to the Great Lakes Region as well as information on the federal response to Asian Carp and other intervention and prevention strategies for this invasive species.
Asian Carp: Threats to the Lower Great Lakes & St. Lawrence River [PDF], This fact sheet created by New York Sea Grant details the threat of the Asian Carp to the Great Lakes and surrounding regions including the impacts it can potentially have on the New York Region.
Last updated March 22, 2022