There’s bad news from the front lines in the battle to keep Asian carp out of the Great Lakes. Agencies which have been monitoring the area around the so-called “carp barrier” in the Chicago Sanitary and Ship Canal say environmental DNA samples indicate that the invasive Silver and Bighead carp have breached the barrier. But Cameron Davis with the federal Environmental Protection Agency insists that does not mean the carp will enter Lake Michigan. “This is not a foregone conclusion,” Davis said during a media conference call on Friday. Davis called the eDNA sampling is “the best we have . . . we believe it’s very accurate.”
While Davis said no actual fish have been found beyond the barrier yet, Dr. David Lodge, the University of Notre Dame scientist who’s conducting the testing, said it’s likely the invasive carp have in fact bypassed the barrier. “There is no reason to think that their aren’t carp present when the DNA is detected,” said Lodge.
How did the carp breach the electric barrier which was supposed to stop their advance? “My response to that is, we don’t know,” said Major General John Peabody with the U.S. Army Corps of Engineers, which operates the barrier. “We just don’t know and I’m not in a position to speculate.”
So what’s next? John Rogner with the Illinois Department of Natural Resources. “If we actually collect Asian Carp and confirm their presence, then we would have to think about broader measures to keep them out of the Great Lakes,” said Rogner. “We are committed to do everything possible to keep them out of the Great Lakes, but it’s just too soon to say exactly what the response would be at this point.”
The Big Head and Silver carp have already devastated native species in the Mississippi River system. The fish can grow up to fifty pounds and pose a boating hazard, because of their tendency to jump out of the water at the sound of engines. They were apparently imported in the 1960s for experimental use in sewage treatment plants on the southern U.S., and escaped to begin working their way up the Mississippi. “Asian Carp are like cancer cells,” said EPA’s Davis. “They can grow and spread very, very quickly, and overtake other healthy living organisms in ecosystems where they don’t exist.”