Illinois environmental officials hoped to kill off any carp in the canal while the electrical barrier designed to keep them from the Great Lakes is turned off for maintenance.
Biologists from the Illinois Department of Natural Resources are monitoring the fish kill. Department spokesman Chris McCloud says more than a dozen boats will be used Thursday to begin cleanup operations.
Environmentalists fear the carp could starve out other fish and cause the collapse of the $7 billion-a-year Great Lakes fishing industry.
Biologists agree this is just about the last stand against the Asian carp because if the species gets into the Great Lakes, it will be a catastrophe for the lake system. Teams from the Illinois Department of Natural Resources sent electricity along booms attached to the electric fish fence near the Lockport powerhouse to stun fish and then relocate species of value, the preliminary step to stopping the march of the invasive Asian carp.
"We have no choice now but to move forward with treatment of the canal near the barrier. We believe it is the sensible thing to do as the Corps shuts down the barrier for necessary maintenance," said John Rogner, Illinois Dept. of Natural Resources.
It is a massive operation involving government agencies from the state to the international level and everything in between
"We need to constantly consider what the impacts would be, so the Corps of Engineers is working with the other agencies, and we will from our expertise make sure that we're doing due diligence into any future decisions," said Commander Vincent Quarles, Army Corps.
The plan involves first poisoning a chunk of the CSSC from above the electric fence and then introducing 2,200 gallons of poison sequentially at five stations downriver every two hours -- the path the Asian carp have used to come up from the Mississippi River.
Scientists have already found Asian carp DNA in water residue beyond the electric fence, but they are not worried that the effort is too little too late
"You do get reports from time to time, but we have not been able to verify any of those, so we're operating as if there are no carp in Lake Michigan now," Rogner said.
But that threat has the governor of Michigan asking her attorney general to see if the courts can get the sanitary canal's connections to Lake Michigan closed, a potentially mammoth undertaking that would affect shipping and the management of Lake Michigan water levels.
"We are looking at everything we can and doing everything we can within the laws and regularities we need to work with. Our top priority is keeping those carp out of the Great Lakes while balancing other considerations that we have as well," said Cameron Davis, US EPA senior advisor.
The rotenone is safe for humans and animals, and an antidote to it will be mixed into the river at 11:30 Thursday morning. Officials concede their engineering prowess needs a dose of luck for their plans to work
Three hundred organizations are involved with in the effort. On Thursday morning, dead fish started floating; officials expect 200,000 pounds of fish to eventually rise to the surface.
The Associated Press contributed to this report.