Overview Several species of carp native to Asia have been introduced into the United States. Species of particular concern include the black (Mylopharyngodon piceus), bighead (Hypophthalmichthys nobilis), grass (Ctenopharyngodon idella), and silver (Hypophthalmichthys molitrix) carp, collectively known as "Asian carp."
These nonnative fish species were imported into the United States and can cause significant ecological and economic impacts when introduced into natural water bodies, as demonstrated in the Mississippi River system. While self-sustaining populations of Asian carp have yet to be established in the Great Lakes ecosystem, many consider the threat of their invasion imminent.
Upon introduction, Asian carp populations have thrived in the Mississippi River and connected waterways, causing extensive impacts. Asian carp have migrated toward Lake Michigan through the Illinois River and the Chicago Sanitary and Ship Canal (CSSC). To prevent Asian carp from entering Lake Michigan and the rest of the Great Lakes, an electrical dispersal barrier system has been constructed in the CSSC. Intensive monitoring is being conducted, including screening for the genetic material, or environmental DNA (eDNA), of the bighead and silver carp as well as conventional sampling for actual specimens. The eDNA of bighead and silver carp has been detected in water samples taken throughout the CSSC and from Calumet Harbor in Lake Michigan. In addition, a live, adult bighead carp was collected in Lake Calumet in June 2010. Overall, these results suggest that Asian carp are approaching Lake Michigan.
Environmental impact: Asian carp pose a threat to the Great Lakes given their potential for rapid growth, consumption of vast quantities of food, and prolific reproduction. These fish can weigh up to 100 pounds, and can grow to a length of more than four feet. They have a broad climate tolerance and are particularly well-adapted to that of the Great Lakes region. Asian carp are voracious, nonselective feeders, adapting their diets to their environment, consuming a wide range of zooplankton, phytoplankton, algae, and detritus at a daily rate of two to three times their body weight. Since the Asian carp's diet overlaps with that of certain native species, they may be strong ecological competitors with the potential to displace and/or consume native populations of fishes, plants mollusks, and other invertebrates, causing devastating ecological and economic impacts to the valuable Great Lakes fisheries.
Illustration: Matthew Thomas, Kentucky Department of Fish and Wildlife Resources
Environmental DNA Research University of Notre Dame cutting-edge research on the use of environmental DNA (eDNA) in monitoring for Asian carp. Under contract with the U.S. Army Corps of Engineers in 2009-10, Notre Dame performed eDNA monitoring in the Chicago Area Waterway System and in southern Lake Michigan. This website provides a description of eDNA methods and current research initiatives, along with Asian carp monitoring results.
Risk Assessment for Asian Carp in Canada (2004) Fisheries and Oceans Canada This assessment evaluates the risk of survival, reproduction, and spread of Asian carp, as well as their pathogens, parasites, or fellow travelers if introduction into Canada were to occur.