There’s concern about the Great Lakes’ ecosystem and researchers are brainstorming to find a solution.

 About 30 invasive fish species are threatening the lakes.

 One researcher, Geoff Peach, based in Goderich, has a radical suggestion.

 Most of us have heard about the Asian carp. It’s a huge fish that's in rivers across the U.S. and is slowly making its way into the Great Lakes.

“If that happens, it’s a pretty serious environmental threat,” says Peach, the coastal resources manager with the Lake Huron Centre for Coastal Conservation.

But there’s another fish that has people talking these days. The Eurasian ruffe is already in the Great Lakes - brought here by the ballast water of international ships. Now the ruffe is threatening to do what the carp is doing, but in reverse.

“Another invasive species, the ruffe is threatening to go south through the Chicago Canal and into the Mississippi. It’s this Chicago Canal - the link between the Mississippi and the Great Lakes - that's the cause of a lot of concern with respect to transference of invasive species,” Peach says.

A multi-million dollar underwater electric fence is slowing the spread of the Asian carp, but isn't designed to stop the ruffe or the 29 other invasive species on the verge of moving either into the Great Lakes or the Mississippi River.

To stop the mass invasion of invasive species, Geoff Peach is recommending something drastic - closing the Chicago Canal.

The man-made waterway, which draws water from Lake Michigan in order to dilute Chicago's waste water as it's carried to the Mississippi River is an important shipping channel and used extensively by recreational boaters and fishermen. Attempts to close it as recently as 2010 have been shot down by the U.S. courts.

“To change the system for Chicago would cost billions of dollars, but it would create a permanent solution to rid the city's wastewater in a more environmentally-friendly manner, and more importantly for us here, create a permanent solution to keep invasive species. And that's the big threat for the Great Lakes," Peach says.