Examination of Silver and Bighead Carp Distribution in the Illinois River with QGIS

Abstract

Silver carp (Hypophthalmichthys molitrix) and Bighead carp (H. nobilis) were initially introduced to control algal blooms in private ponds. Use of them for this purpose was successful; however, they escaped captivity and invaded the Mississippi River and its tributaries. Garvey (2007) found large populations in the Mississippi and Illinois rivers. These two species are highly invasive. They overcome native populations by outcompeting them for food, they grow rapidly, and they are very prolific spawners. Using QGIS software, images were constructed showing the distribution of both species. Populations have increased within the lower Illinois River and Des Plaines River. Using K cluster analysis, silver carp were seen to have more population clusters than bighead carp while bighead carp were found in a greater number of areas. Overall, silver carp have increased significantly in population size. Management efforts should be focused on the areas with the highest number of clusters to prevent further invasion in the waterways of Illinois. Management suggestions include using the locks and dams in the Illinois River coupled with nonphysical barriers such as sound to deter Asian carp from entering vulnerable areas.