STATUS OF NON-NATIVE FISH SPECIES IN THE ILLINOIS RIVER.

Kevin S. Irons, T. Matt O'Hara, Michael A. McClelland, and Mark A. Pegg.  
Illinois Natural History Survey, Illinois River Biological Station, Havana, IL 62644.

Since 1990, staff at the Illinois River Biological Station have been monitoring the LaGrange
Reach of the Illinois River as part of the Long Term Resource Monitoring Program (LTRMP). 
Over 700,000 fish have been collected in the past years consisting of 83 species and 7 hybrids. 
Of these, non-native fish species such as common carp Cyprinus carpio, goldfish Carassius
auratus, white perch Morone americana, striped bass Morone saxatilis, grass carp
Ctenopharyngodon idella, bighead carp Hypopthalmichthys nobilis, and silver carp
Hypophthalmichthys molitrix have been found with ever increasing numbers in the LaGrange
Reach of the Illinois River. White catfish Ameiurus catus may also be present as noted by Illinois
Department of Natural Resources biologists.  Several species of trout and salmon, hybrid stripped
bass, and tiger muskies are routinely used in fish management in the Midwest and could affect
both the Illinois River and the Upper Mississippi River System (UMRS) if significant water
quality improvements in the watershed continue. The LTRMP has proved useful in monitoring
and detecting some of these invaders.  Other non-native species are poised for dispersal
throughout the UMRS such as the round goby Neogobius melanostomus (Great Lakes and into
Upper Illinois Waterway), Ruffe Gymnocephalus cernuus, (Lake Superior and Lake Huron),
black carp Mylopharyngodon piceus (Missouri River) and others.  Dynamics of these invaders
should be assessed and plans to slow additional invaders should be investigated.  

Keywords: Illinois River, non-native fish, Long Term Resource Monitoring Program