Invasive Asian carp are poised to enter the Great Lakes from the Mississippi River system through two Chicago-area locks, aquatic experts warned at a U.S. House subcommittee hearing.
But although Great Lakes states such as Michigan and Wisconsin have been pressing for closure of the locks, the Obama administration continues to side with officials from the President’s home state of Illinois, who claim closing the locks would hurt the state’s shipping industry.
Ecosystem Threatened
An Asian carp invasion would devastate the Great Lakes ecosystems, aquatic experts warn. The large, ravenous fish have multiplied rapidly and quickly taken over as the dominant fish in much of the Mississippi River basin. Conservationists fear there would be no reversing the damage once the invasive species entered the Great Lakes.
Asian carp have already advanced to within a few miles of Lake Michigan. Illinois is using electrical barriers in an attempt to keep the carp out of the lake, but environmental DNA tests show at least a few of the fish may have made it through the barriers.
Many scientists have joined with a coalition of Great Lakes states in calling for the federal government to shut down the two locks connecting the Mississippi River and Lake Michigan.
Illinois argues closing the locks will severely impair shipping traffic, cutting off the Mississippi River as an avenue for Great Lakes ships. The state also claims closing the locks will enhance Chicago-area flood risks.
Electrical barriers are sufficient to keep the carp from becoming a menace in the Great Lakes, Illinois argues.
Experts Spar in Hearings
The locks are “a two-way highway for many species,” Professor David Lodge, director of the Center for Aquatic Conservation at the University of Notre Dame, testified at February 9 hearings of the House Transportation and Infrastructure Subcommittee on Water Resources and the Environment.
“We must act swiftly, collaboratively, and wisely,” agreed Michigan Department of Natural Resources and Environment Director Rebecca Humphries.
Del Wilkins, vice president of terminal operations for the Illinois-based Canal Barge Co., countered the carp can be kept out of the Great Lakes through electrical barriers and other measures short of shutting down the locks.
“The question of whether to protect the environment or ensure the continued flow of vital maritime commerce is an unnecessary choice and one our nation cannot afford to make,” Wilkins said.
Carp DNA Not Conclusive
Chicago Metropolitan Water Reclamation District (MWRD) officials question whether environmental DNA upstream from the electrical barrier means carp have broached the barrier.
“Environmental DNA is reflective only of a presence of some kind. It is not an indicator that fish alive or dead have been in that location,” a MWRD official said. “For example, a bird may have eaten carp downstream and eliminated feces with [that] DNA present. Or environmental DNA may have attached in some form to a passing barge, etc.”
E. J. Donovan ([email protected]) writes from Tampa, Florida.
