Great Lakes–Mississippi River Separation is Possible, Practical and Preventive

Study shows Canadian waters can be protected from an Asian Carp Invasion

For immediate release
Tuesday, January 31, 2012

A much-anticipated study says separating the Great Lakes and Mississippi River basins to prevent the spread of Asian carp and other invasive species is not only possible, but a natural step toward much-needed action to improve Chicago’s water infrastructure.

Great Lakes environmental groups reacting to the study, released today by the Great Lakes Commission and Great Lakes-St. Lawrence Cities Initiative, commended the authors’ factual analysis concluding that separation is possible and that it must include essential upgrades to sewage, flood control and waterborne transportation while preventing the transfer of invasive species.

“The study is unprecedented in its scope and ambition,” said Jennifer Nalbone, director of Navigation and Invasive Species for Great Lakes United. “It points the way to a solution that not only benefits the Great Lakes states, but also Canadian and Mississippi River stakeholders. Most of North America will ecologically and economically benefit from separating the two basins.”

The study refocuses Canada and the U.S. on a long-term permanent solution and away from stopgap measures that, on their own, will ultimately fail to stop the Asian carp’s march to Lake Michigan, and eventually to the Canadian Great Lakes, tributaries and inland waters.

The bighead and silver carp are the poster fish for the ecological and economic havoc in the offing when invading species travel between the Great Lakes and Mississippi. A 2004 Department of Fisheries and Oceans risk assessment determined that Asian carp species will compete for food with native species, prey on their larvae, as well as potentially cause significant habitat damage and ecological disruption. They may be able to establish in Canadian waters as far north as Hudson Bay. 

Since 2009, multiple hits of Asian carp DNA have been found lakeward of an electric barrier in the Chicago Area Waterway System meant to keep the fish out of Lake Michigan and the Great Lakes. More recently, carp DNA has been reported in waters open to Lake Michigan.  

“Asian carp are a huge threat, which can only be effectively addressed by preventing the fish from entering Lake Michigan where they would be free to enter Canadian waters,” says Elaine MacDonald, Senior Scientist from Ecojustice. “Separating the two basins in the Chicago area is the permanent solution to this tremendous international problem.” 

The authors note that restoring the natural divide between the Great Lakes and Mississippi River basins at Chicago can coordinate with efforts already under way by the city of Chicago, the state of Illinois and the Metropolitan Water Reclamation District to improve water quality and reduce flooding.

Joel Brammeier, president and CEO of the Alliance for the Great Lakes, says the study is the most specific evaluation to date of what it would take to achieve hydrologic separation at the CAWS. “Chicago and Illinois have been under a spotlight as the carp close in on Lake Michigan,” says Brammeier. “This report shines that light in a new direction: toward the transformation of the Chicago waterway into a resource of which everyone in the city, the state and the country can be proud.” 

The GLC-GLSLCI study clearly demonstrates that separation is possible, providing detailed background on three separation options that allow elected officials and community leaders to move the discussion to the next level. As any separation is intrinsically tied to the multiple uses of the waterway system, it is imperative the Chicago region be an engaged partner. 

To that end, the groups stress that the study is a beginning, not an end, and should not be interpreted as a strict set of policy recommendations. Until separation is complete, they say strong interim protections must be implemented to protect against an Asian carp invasion, and note that the study includes such measures within its long-term vision for separation.

The groups say a plodding U.S. Army Corps of Engineers’ study of the problem -- the Great Lakes and Mississippi River Interbasin Study -- could be expedited by incorporating findings from the GLC-GLSLCI study and beginning separation planning now.  

 "Canada’s Department of Fisheries and Oceans completed an Asian Carp Risk Assessment in 2004 and found these voracious Silver and Bighead carp that spawn several times a year will invade nearly all of the Canadian Great Lakes shorelines and then travel up our rivers to get into our lakes. The Great Lakes are bi-national waters and we do not want these invasive carp in our waters, said Mary Muter, Chair of the Great Lakes Section of the Sierra Club-Ontario. "This report shows that we should get construction started soon rather than wait another 5 years for the USACE to study the problem. The time to act is now! " 


Joel Brammeier, Alliance for the Great Lakes,             773-590-6494

Jennifer Nalbone, Great Lakes United,             716-983-3831

Mary Muter, Chair, Great Lakes Section, Sierra Club Ontario,             647-345-7665       or            905-833-2020

Elaine MacDonald, Senior Scientist, Ecojustice             (416) 368-7533       ext. 527, 

The Great Lakes Commission/ Great Lakes-St. Lawrence Cities Initiative report entitled “Restoring the Natural Divide: Separating the Great Lakes and Mississippi River Basins in the Chicago Area Waterway System” and all supporting materials are available at

Find the Department of Fisheries and Oceans Risk Assessment for Asian Carps in Canada” here


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