Chicago Waterway System

Chicago Sanitary and Ship Canal

  • The man-made Chicago Sanitary and Ship Canal connects the Mississippi River to the Great Lakes via the Illinois River and Des Plaines River.
  • The Chicago canal allows invasive species to move between the Great Lakes and the Mississippi River basin.
  • According to the US Fish and Wildlife Service, Asian carp could colonize all of the Great Lakes and sustain high density populations.
  • Currently, the last line of defense is an electric barrier, which, according to lab tests, may not be effective at deterring Asian carp of less than 6 inches.
  • The electric barrier was originally built to prevent the Round Goby, a small fish, from reaching the Mississippi. It failed.

Electric Barriers

  • “After more than a year of environmental DNA testing, electrofishing, netting and rotenone (fish poison) applications, no consensus has emerged among federal and state agencies responsible for control measures as to whether or not the existing electrical barriers have been effective in blocking Asian carp under a variety of river conditions.” (Michigan State study)
  • Tests reveal electric barriers may be ineffective in blocking small fish.
  • Electric barriers must be shut down for periodic maintenance, during which time no electric impulses impede the fish.
  • Electric barriers are also subject to shutdown from flooding, power interruption, debris, and as a result of human safety concerns.
  • The electric barriers cannot block upstream and downstream movement of all kinds of invasive aquatics, including fish, plants, disease organisms and parasites.
  • “An electric field strength low enough to ensure safety of people falling into the water from barges and other watercraft will do little to prevent downstream migration and drifting of invertebrates, fish eggs and larvae, and other potentially harmful plants, parasites and disease organisms,” (from Science paper)
  • Electric barriers are designed only to repel fish that are active swimmers. They do not affect larvae, eggs, seed, bacteria or viruses.
  • The US Army Corps of Engineers has limited the strength of the electric field due to safety concerns.
  • One study reports steel barges in the canals weaken and distort the electric field.