Are Asian Carp In Lake Michigan?

By JoshMogerman in News on Apr 7, 2013 10:00PM

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The debate about whether Asian carp are swimming through the cloudy waters of Chicago's canals and riverways got even murkier with a study published by respected Notre Dame researchers this month claiming that Asian carp have likely reached the Great Lakes. The findings go head-to-head with a recent Army Corps of Engineers report that suggested tests showing the invasive fishes’ DNA in our area were the result of carp in fish-eating bird crap, restaurant scraps in sewer outfalls, or barge stowaways—all things that the new study authors find unconvincing:

“You’re requiring all kinds of random events to happen simultaneously,” Lindsay Chadderton of The Nature Conservancy, who contributed to the paper [told the Associated Press]. “It’s possible, but highly unlikely.”

Instead, the authors believe that repeated tests showing Asian carp in Chicago’s Lake Calumet and Lake Erie, both places where live carp have been caught, make it far more likely that the fish are indeed present in those bodies of water. Lake Calumet is beyond the electric barrier designed to keep the invasive carp out of Chicago’s waterways. To the researchers, the fact that the Asian carp DNA hits (via environmental DNA or "eDNA" tests) have not been widespread, even though barges and birds move freely around the region, seems to be a smoking gun:

“We know migratory birds go to those other places [where carp eDNA does not exist]. So it’s very unusual that the only places where birds or barges or people throwing fish guts out is the only place where we capture Asian carp,” says Christopher Jerde, a professor in the biological science department at Notre Dame University in South Bend, Ind., and a lead author of the report.
“We’re at the point now where we’ve had captures in the Great Lakes,” he adds. “We can safely conclude there is some evidence of some Asian carp in the Great Lakes.”

“The question is, have we gone past the tipping point,” Professor Jerde says.

There is a ray of sunshine, in that Jerde and the other report authors think the answer to that question is “no.” They believe that if the fish are in the Lakes, there are not enough to set up the breeding populations that many worry would devastate fisheries and the broader ecosystem. But as the debate continues, this publication is another sign that the clock is ticking for strong action to stem the invasion and now is the wrong time to hit the snooze button.

If you haven’t been following the issue, you may be asking what all the hubbub is about. As usual, the amazing animal documentarians at BBC just put out a pretty spectacular view of an infested rivers (let's avoid this in the Lake...please!):