Chicago Sanitary and Ship Canal

Sarah Droher

Feb/13/2012

The Chicago Sanitary and Ship Canal is the only shipping connection between the Great Lakes and the Mississippi River. The canal was constructed from fear of Chicago’s sewage infiltrating into the drinking water supply and to serve as the primary connection between the Great Lakes and the Mississippi in the early 1900’s. The completion of the canal actually switched the watershed from the Great Lakes basin to the Mississippi River basin, puncturing a Continental Divide.

This man-made connection has introduced the Great Lakes to invasive species particularly the Asian carp. They were brought into the US to control the algal blooms in catfish ponds, but in the 1990’s flooding released these fish into the natural system (Perea).  Now, the carp have made it up River and are established in the Mississippi, Ohio and Illinois rivers.  Asian carp are serious threats to the native species; they specialize in feeding on zooplankton and phytoplankton (which is the food base for all fish) and reside in the backwaters of the River (critical spawning locations for native species).  There is serious concern that if the fish were to enter the Great Lakes system they could seriously alter the food web and the entire ecosystem.

Currently, there is one thing blocking the carp from entering the Great Lakes, an experimental electrical barrier constructed within the Chicago Sanitary and Ship Canal. It was built in 2002 by the US Army Corps of Engineers (USACE) and consists of cables that run across the bottom of the canal. A low-voltage, pulsing DC current is sent through the cables, creating an electric field in the water (USACE).This doesn’t hurt the fish; it makes fish uncomfortable, turning them around. In 2004, construction began for a new permanent barrier, at the costs of nearly $10 million for completion and operation.

The concerns: What about the maintenance costs of the barrier? What about the barges? – The powerful wakes could pull fish right through the barrier. What about a black-out in Chicago? Or how about Asian larvae being dumped out from the ballast tanks of ships? According the USACE, the closest verified capture of an Asian carp has been approximately 15 miles downstream of the barriers. Can anyone say too close for comfort? It has been said that the only way to make sure is to ecologically disconnect the two waterways. Although shutting down the canal would upset movement of vital shipments of cargo, totaling more than $1.5 billion a year, and contribute to the loss of hundreds, perhaps thousands of jobs (Merrion). But, the Great Lakes states argue that sport and commercial fisheries alone is $4 billion annually (great-lakes.net).

So, where do we go from here? Do we alter our ways of shipping- increase costs but ultimately save the Great Lakes? Or would we only be pushing off the inevitable?

Perea, P.J. "Asian Carp Invasion." Illinois Periodicals Online at Northern Illinois University - (Main Page).  May 2002. Web. 13 Feb. 2012. <http://www.lib.niu.edu/2002/oi020508.html>.

US Army Corps of Engineers. “Chicago Sanitary & Ship Canal Fish Barrier System” uscgnews. Dec. 2008. Web. 13 Feb.  2012. <http://www.d9.uscgnews.com/external/content/document/443/246093/1/Army%20Corps%20Barrier%20Fact%20Sheet%202%20Dec%2008.pdf>.

Merrion, Paul. “Illinois fights back as states seek carp-blocking canal closures.” Crain’s Chicago Business. Jan. 2010. Web. 13 Feb 2012 . <http://www.chiagobsiness.com/cgi-bin/news.pl?id=36611&ba=1>.

"Tourism in the Great Lakes Region." Great Lakes Information Network. Feb. 2012. Web. 13 Feb. 2012. <http://www.great-lakes.net/tourism/>.