Asian Carp on display at the Shedd Aquarium. February 27, 2012 | Brian Jackson~Sun-Times
Updated: March 25, 2013 6:39AM
An interim federal report on Wednesday offered a bit of good news about Asian carp. It looks like we have time to devise comprehensive solutions for these invasive aquatic species instead of rushing into stopgap measures to keep them out of the Great Lakes.
We should take a breath and take advantage of the time we have.
An experimental method of tracking carp called e-DNA, or environmental DNA, indicated the fish might have been on the verge of invading Lake Michigan.
But the news from the U.S. Army Corps of Engineers, the U.S. Fish and Wildlife Service and the U.S. Geological Survey is that e-DNA is not a reliable indicator of where fish actually are. The e-DNA that made it appear carp might have breached electric barriers on the Chicago Sanitary and Ship Canal near Romeoville could have come from storm sewers, fishery sampling gear, barges, dead fish or sediments, the agencies said. The e-DNA also could have come from the feces of birds that feasted on carp elsewhere.
The fear that the carp, which can reach four feet in length and weigh as much as 100 pounds, might get into the lakes and destroy a $7 billion-a-year fishing industry, has led to calls for closing the locks on the Chicago River or building barriers to separate Lake Michigan from the Mississippi watershed. Invasive Asian carp species already have overwhelmed native fish in the Mississippi and Illinois rivers. But closing the locks isn’t practical, and separating the watersheds, even if done properly, would take years.
Most invasive species have come into Lake Michigan from the north, not from the Mississippi River. And the Great Lakes are dotted with possible entry points for carp. Focusing only on waterways in the Chicago won’t keep invasive species at bay.