Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=157488
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Courtesy of Great Lakes Fishery Commission

Silver carp, of the Asian carp species, jump out of the water when perturbed by boat engines. This is one of the hazards of carp reaching the Great Lakes.


Elusive carp hunt continues with new threats to the economy

by Leslie Streicherand Julia Edwards
Feb 18, 2010


CARPNET_Lake

Leslie Streicher/MEDILL

Asian carp could out-compete native fish and threaten the Great Lakes ecosystem and fishing if they reach Lake Michigan.

Despite using nets and electric currents, a team of state and federal “fishermen” has yet to catch an Asian carp this week.

A live fish has not been found anywhere beyond the electric barriers near the Lockport Lock and Dam. But that hasn’t lulled the fears that the voracious fish will invade Lake Michigan and calls to close the locks continue as more economic threats surface.  

About 15 tour boat operators from Chicago’s Wendella Boats who attended a public forum in Ypsilanti, Mich., Wednesday said the closure would undoubtedly shut down their business.

According to Wendella spokesman Greg Pupecki, the boats have no other access point to Lake Michigan except through the Chicago Lock. He said that the lock is being used as a “political football” because even a water tight lock is not guaranteed to keep carp out.

“It would stop business is what it would stop,” Pupecki said.

The water tourism industry and overall job loss were left out of a recent report by expert witnesses from the Michigan Attorney General’s office, which said lock closure would have only a “modest impact” on Chicago’s economy.

The report counters Illinois’ claim to the U.S. Supreme Court that “even a temporary closure of the locks will devastate the local economy and Illinois’ role in the regional, national and global economy.”

The report predicted that redirecting the 7 million tons of cargo that currently pass through the O’Brien Lock each year would cost $70 million.

“That 7 million tons might seem like a large volume but in the context of the region it really isn’t,” said Jim Roach, a Michigan transportation expert who presented his report on a conference call Thursday. “On a daily basis about the same amount of cargo moves on two rail-unit trains, such as a coal train or a grain-unit train. And the Chicago region has about 500 trains each day.”

As the economic debate heats up, members of the Illinois Department of Natural Resources and the U.S. Fish and Wildlife Service launched a fishing expedition in the area between Lockport's electric fish barriers and Lake Michigan in hopes of confirming the presence of carp.      

Officials are using nets and electrofishing, a method of herding fish by stunning them with electric currents, and will concentrate their efforts in warm-water outflows where fish like to congregate during winter. The netting operation Wednesday once again came up empty handed, but fishing will continue for the next two to three weeks.

“The carp are a big threat,” said Chris McCloud, a natural resources department official. “We have a responsibility to try to keep them from establishing a population in the Great Lakes.”

If carp get into the lake, officials predict the species will out-compete other fish and destroy the lake’s ecosystem. As a consequence, a $7 billion-a-year fishing industry could be damaged, according to Michigan officials.

Carp DNA has been detected in several area waterways, including the Calumet River and Harbor and the Wilmette Pumping Station. Tests are sponsored by the U.S. Army Corps of Engineers and use a system developed at the University of Notre Dame called eDNA, or environmental DNA.         

But McCloud said eDNA testing does not officially confirm a carp presence, since the DNA could be found in scales or wastes washed into these areas.

“eDNA doesn’t tell us how many carp there are, where they are, or if there is a sustainable population,” he said. “We will try to find out with fishing.”    

And what if a carp is caught?

“The fish will be removed and disposed of,” McCloud said.

President Obama announced last week that $78.5 million of federal money will go toward carp management initiatives. The plan calls for shipping locks and gates in the Chicago waterways to be opened less frequently in hopes of diminishing the chance of carp slipping into the lake. However, some experts think even locks won’t stop them.

Michigan Attorney General Mike Cox renewed his request to completely close Chicago locks a couple of weeks ago, even though the U.S. Supreme Court declined Michigan’s previous request to do so.

Although Michigan wants to close the locks, it does not oppose opening them to prevent flooding in an emergency.

And though the locks are only opened about once a year for flood control, the chance of such an event prompts officials to search for a safety net.

“People are working on developing an aggressive management plan if the locks need to be opened for flood water,” said Jennifer Nalbone, an official with Great Lakes United. “Some of the tools being explored are chemical control, netting and electrofishing to knock back fish if they are too close to the locks.”

The locks are a short-term solution and are not 100 percent effective in keeping the fish out of the lake, according to Nalbone.  

“The locks are not watertight,” she said. “But it’s safe to say it would be easier for a fish to swim through an open lock than it would be to swim through a closed lock.  We still need to develop a long-term solution.”