Invasive Round Goby. - FWS photo

A Bighead carp (top) and Silver Carp. - FWS photo

Gary Czypinski, Ashland  Fishery Resources Office, Wisconsin, and Terry Hubert from the USGS Upper Midwest Environmental Sciences Center, La Crosse, Wisconsin, crewed one of 14 survey vessels that comprised the 12^th annual Carp Corral/Goby Round Up in the Illinois Waterway.  

The purpose of this survey is to assess relative abundance and monitor the range expansion of the invasive round goby and other aquatic invasive species as they migrate and expand their range from Lake Michigan down the Illinois River toward the Mississippi River. 

This survey also verifies the effectiveness of the experimental electrical fish barrier located near Romeoville, Illinois, in preventing range expansion of Asian carp upstream of Romeoville toward Lake Michigan and range expansion of Lake Michigan invasive residents downstream of Romeoville toward the Mississippi River.  

In this way, the experimental electrical fish barrier and the Carp Corral/Goby Round-Up support one of eight elements comprising the Ruffe Control Plan, to prevent the movement of ruffe from the Great Lakes to the Mississippi watershed via the Chicago, Des Plaines, and Illinois Rivers.

Targeting the round goby, the Ashland /La Crosse crew sampled a 7-mile reach (RM 150-143) of the Illinois River downstream of the Peoria Lock and Dam, the leading edge of the goby range in the Illinois River. 

Sampling with minnow traps and bottom trawls, the crew collected no gobies or other AIS during the 3-day effort, but numerous silver (Asian) carp were observed jumping around the sampling vessel.  A few carp managed to jump into the vessel.  

A mud substrate maintained by dredging within this reach assists in deterring occupation and migration of round goby, which prefer rock substrate.  Although not preferred by round goby, the mud substrate in the dredged channel together with the high turbidity of the water is preferred habitat for invasive ruffe    With exception to silver carp, no goby or other AIS were captured, and the leading edge of the goby range in the Illinois River remains at the Peoria Lock and Dam.