Chicago — Was it a bird, was it a plane – or was it a real life Asian carp?
After scientists discovered DNA from one of the invasive fish in a water sample taken from Lake Michigan’s Sturgeon Bay, sportsmen and fisheries biologists were still unsure if the genetic material came from a live fish or some other source.
What is known is that the sample was the second positive DNA result for Asian carp in Lake Michigan. A sample taken in 2010 from the lake’s Calumet Harbor also was positive.
The most recent red flag comes as DNR, the U.S. Fish and Wildlife Service and a host of others with an interest in protecting the Great Lakes work to figure out how close Asian carp have come to Lake Michigan. Or, how far the fish have advanced toward the lake.
Asian carp are feared for many reasons. Two of the four species of Asian carp – bighead and silver carp – are known to consume large amounts of plankton. Scientists fear if they reach the Great Lakes, they could beat out native species for plankton and other foods and threaten the lakes’ fishing industry, which some value at nearly $7 billion. The effects would trickle across the states that border the Great Lakes, including Illinois.
Plenty of money and effort has been spent defending the lake over the past five years. An electric barrier places in a shipping canal 37 miles from Chicago was installed to prevent the carp from progressing north. One live Asian carp has been found past the barrier.
While DNA from fish commonly comes from their body waste, some biologists and fisheries experts have been quick to point out that droppings of birds that have eaten an Asian carp could also have crated the positive DNA test. Because the DNA sample was taken in Wisconsin waters, that state’s DNR is also looking for answers to the questions “how?” and “when?” and “where?”
“It’s hard to know what to make of it,” Mike Staggs, director of fisheries management for Wisconsin DNR, said.
The samples were collected and analyzed by researchers with the University of Notre Dame, Central Michigan University and The Nature Conservancy as part of a broader Great Lakes fish survey.
The USFWS indicated that additional samples will be taken from the same area where the positive DNA was discovered. The hope is that the sample was a fluke – a one-time wonder.
“One sample is a smoke detector,” said Chris Jerde, a Notre Dame biologist. “A couple of more samples is a fire.”
And the positive test caused a flurry of activity among lawmakers from the Great Lakes states. Sen. Debbie Stabenow, a Michigan Democrat, said the result underscores “the need for the U.S. Army Corps of
Engineers to expedite proposals for permanently shielding the Great Lakes from Asian carp.”
“These fish could destroy the Great Lakes ecosystem, as well as boating and fishing industries and hundreds of thousands of jobs,” Stabenow said.
Confusing to may anglers and sportsmen not familiar with the Asian carp is the face that there are four species of the fish.
Grass carp live in slow moving rivers standing ponds and lakes. The grass carp was legally introduced into at least 35 states. Silver carp grow to weigh as much as 60 pounds and jump from the river. Bighead carp are filter feeders and can grow to 100 pounds, but typically weigh about 40 pounds.
The least-known of the species is the black carp, which are legal in the U.S., but can’t be intentionally released into waterways. In Illinois, the bighead carp is the one that most concerns DNR. DNRs in Wisconsin and Michigan are also concerned about the bighead.
Staggs, who is skeptical of a live carp being in the lake, said the federal testing that resulted in the positive DNA sample was part of a fish survey of more than 800 various ports across the U.S.
“They ran two tests on the sample, a standard test and then a more sensitive test that did not find it,” he said. “I’m really skeptical there’s an Asian carp out there. We’ve asked Fish and Wildlife to take another series of tests. If there really are some fish, it will be in repeated samples. It’s not likely to appear again. We should get those results in January.
The Associated Press contributed to this report.