A series of multimillion-dollar electrical barriers have been built along the canal. The barriers are effective at keeping adult carp at bay, but some fear that baby carp may pass through. The United States Army Corps of Engineers has been deployed along with EPA. In 2009 they poisoned the entire canal with rotenone, a chemical that kills fish. The $3 million operation netted over 90 tons of dead fish, and a single carp. Some think that Great Lakes must be cut off from the Mississippi River. The Michigan Attorney General sued to have the canal closed. The Ontario government and some Great Lake states have also taken legal action. But the courts have been persuaded by the value of the canal as a shipping conduit thus far. In the meantime, the barriers continue to hold, but how long can they? The carp have the Great Lakes under siege. Is this a war that we are destined to lose?