During the first week of December, the U.S. Army Corps of Engineers is planning on performing maintenance on one of the two electric barriers in operation on the Chicago Sanitary and Ship Canal. During this period the Canal will be shut down to all traffic for a period of four to five days. The electric barriers in the canal were put in place to stop the movement of Asian carp into Lake Michigan and the Great Lakes. Asian Carp pose a significant threat to the Great Lakes ecosystem because of their ravenous feeding and spawning habits. If introduced to the lake, the Asian carp would be very difficult to control and would quickly out-compete native species by disrupting their food chain and consequently become the dominant species in the lake. This would not only devastate the Great Lakes ecosystem but have a significant economic impact on the $7 billion fishery. Asian carp have been detected using environmental DNA testing in the canal below the barrier. Therefore, when the electric barrier is shut down for maintenance there is a fear that the Asian carp could travel down the canal to Lake Michigan. The Illinois Department of Natural Resources who is working with other environmental agencies such as the MWRDGC as part of the Asian Carp Rapid Response Group will be applying Rotenone, a fish poison, in the canal during the electric barrier shut-down. According to IDNR, the Rotenone will provide the highest level of certainty that Asian carp will not advance past the electric barrier when shut down. Rotenone will kill the Asian carp as well as other fish in the canal but when used properly does not present a risk to people or other wildlife.
For more information read the IDNR press release and Asian carp FAQ.