AQUATIC NUISANCE SPECIES: AN EVALUATION OF BARRIERS FOR 
PREVENTING THE SPREAD OF BIGHEAD CARP TO THE GREAT LAKES. 

Ronald M. Taylor1, Mark A. Pegg1 and John H. Chick2 
1Illinois River Biological Station,  Illinois Natural History Survey, 704 North 
Schrader Avenue, Havana, Illinois 62644. 2Great Rivers Field Station, Illinois 
Natural History Survey, 8450 Montclair Avenue, Brighton, Illinois 62012		
					

Reproducing populations of bighead carp (Hypophthalmichthys nobilis) and silver 
carp (Hypophthalmichthys molitrix), large filter-feeding fishes native to Asia, 
are moving upstream in both the Mississippi and Illinois Rivers. These fishes 
will enter the Great Lakes in large numbers if nothing is done to stop their 
upstream spread. Such an introduction poses a very serious threat to the ecology 
of these systems as both species are planktivorous. Consequently, these aquatic 
invaders could affect every species of fish in the Great Lakes as all fishes 
forage on plankton at some point during their lives. Therefore, identifying 
mechanisms to control their range expansion is imperative. We evaluated the 
effectiveness of three behavioral fish guidance systems (bio-acoustic, 
integrated electric / bio-acoustic and electric) in restricting the movements of 
bighead carp in outdoor experimental raceways. Each barrier experiment consisted 
of three trials with each trial being three days in duration. A total of 3219 
observed attempts to cross the bio - acoustic array were made by Bighead carp. 
Of those attempts, 57% were successful repels. The integrated electric / bio – 
acoustic barrier was found to be more effective in restricting the movements of 
bighead carp. In total, only 54 attempts were made to cross this barrier type. 
Of those attempts, 87% were successful repels. Finally, the electric barrier was 
found to be the most effective of the three barrier types. A total of 59 
attempts were made by bighead carp to cross this barrier type. Of those attempts 
100 % were successful repels. Large - scale applications related to these 
finding will be addressed.

Keywords:  Asian carp, Illinois River, planktivore, barrier, behavior