It was a marvel of civil engineering, but today there's growing support for undoing some of the damage caused by the Chicago Sanitary and Ship Canal, now from the Governor of Illinois, himself. Four particularly damaging species of invasive carp dubbed "Asian Carp" are poised to cross over from the Mississippi waterways into the Great Lakes via the canal, threatening a $7 billion Great Lakes fishing industry, as well as tourism and ecosystems, by crowding out existing fish populations and filtering out organisms at the base of the food chain.

In a meeting with Great Lakes governors on Saturday, Illinois Governor Pat Quinn referred to the separation of the Great Lakes and Illinois and Mississippi watersheds as the "ultimate solution" for the Great Lakes. This development could be a huge turning point for groups trying to keep the invasive carp species out of the Great Lakes.

How did this threat to the Great Lakes get started?

In 1900, the first portion of the Chicago Sanitary and Ship Canal connected the Great Lakes and Mississippi watersheds for the first time ever. The canal reversed the flow of the Chicago river so the growing city's waste could be flushed down the Mississippi rather than into Lake Michigan where the drinking water came from.

Fast forward to the 21st century, and we're starting to notice all sorts of invasive species from international trade using the Mississippi/Great Lakes connection as a highway to invade aquatic ecosystems in huge portions of the Continental U.S.'s waterways. The canal enables invasive species to hop easily from the enormous Great Lakes watershed on over to the sprawling Mississippi watershed, and vice versa.

In the 1970s, aquaculture operations in the South used several voracious species of carp to keep ponds clean:

Big Head Carp

Silver Carp

Grass Carp

Black Carp

Flooding in the 1990s caused Southern aquaculture ponds to overflow, allowing their carp helpers to escape into the Mississippi watershed in breeding populations where they've ravaged and devastated the ecosystems all along the Mississippi and its tributaries. Bighead carp have voracious appetites and grow fast, out competing other species for food. Silver carp, when disturbed by passing boats, leap from the water with enough force to break a boater's arm. Grass carp wipe out aquatic vegetation, eating up to 100 percent of their body weight in vegetation per day.

The Army Corps of Engineers installed electric barriers near the Sanitary and Ship Canal to keep the fish from crossing into Lake Michigan, but in 2009, Asian carp DNA was found beyond the barriers. In December 2009, the Army Corps of Engineers poisoned a six mile stretch of the canal with rotenone in an attempt to kill fish beyond the barrier before a breeding population of the fish could reach the Great Lakes. Another poisoning was conducted a few months later in 2010. Only one Asian carp was found, total, from the poisonings. However, calls for separating the two watersheds grew louder.

Michigan's then-governor, Jennifer Granholm, called on President Obama to close the Chicago shipping canals in early 2010, and in mid-2010 Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin filed a lawsuit against the Army Corps of Engineers to permanently separate the connection between the Great Lakes and Mississippi watershed. Note the absence of two important Great Lakes states: Illinois and Indiana. Both objected to the closure of the shipping canal, citing the economic importance of shipping for their states. The Sanitary and Shipping Canal offers a navigable shipping route from the East Coast of the U.S. via the St. Lawrence Seaway, through the Great Lakes, into the Mississippi on down to the Gulf of Mexico, right through the center of the Continental U.S.

The Army Corps of Engineers began a study in 2007 called the Great Lakes and Mississippi River Interbasin Study which included research into the feasibility of separating the water basins. "As part of this study, USACE will conduct a detailed analysis of various ANS controls, including hydrologic separation." Environmental, political, and business leaders throughout the Great Lakes region have been calling on the Army Corps to present its findings early in the belief that the conclusions of the study would come too late to keep the Asian carp out of the lakes.

The potential for economic and ecological devastation from Asian carp entering the Great Lakes has lead to rising alarm and urgency among Great Lakes states with State and National representatives holding presentations and panel discussions about the impacts of an Asian carp invasion.

On Saturday, when Illinois Governor Quinn suggested that separating the watersheds was the "ultimate solution" in the conference with Great Lakes governors, it drew applause from lawmakers and others. For regions and groups concerned with keeping Asian carp out of the Great Lakes, this is an important new development, with Illinois on the side of closing the Mississippi and Great Lakes watershed in the state where it's connected.

[Photo Credit: Asian Carp Regional Coordinating Committee Source]