The electric fish barrier was constructed by the Corps of Engineers under the authority of the Aquatic Nuisance Species Act to prevent Asian Carp from entering Lake Michigan through the Illinois River system. The barrier works by generating a low-voltage electric field across the canal that prevents Asian Carp from migrating further upstream. Field testing conducted by the Coast Guard and Army Corps of Engineers indicated that the fish barrier posed a significant risk to commercial and recreational navigation. To mitigate this risk, navigational and operational restrictions have been placed on all vessels transiting through the barrier. For more information go to http://www.uscg.mil/d9/msuChicago/docs/FishBarrierHandout.pdf.