Five states are asking a federal judge in Chicago to take emergency action to close two shipping locks and install barriers to prevent Asian carp from overrunning the Great Lakes via a "carp highway."
At the first hearing in the case Monday, Judge Robert M. Dow Jr. showed no signs of rushing into a decision.
He scheduled Sept. 7 and 8 to hear expert testimony in the case, including from scientists about the environmental DNA testing that has found genetic material from Asian carp in Illinois waterways near Lake Michigan.
The judge's questions reflected awareness of the DNA test's limits.
"Could it have been from something that ate a fish?" the judge asked about carp DNA found in water samples.
Michigan assistant attorney general Robert Reichel acknowledged a bird that ate an Asian carp could excrete carp DNA into the water. The states' experts believe it's more likely that the findings show the recent presence of carp, Reichel told the judge.
The judge also asked about a single 20-pound carp discovered in June, the first to be found in a Chicago waterway above the electric barrier system. The judge asked whether scientists could pinpoint how it got there.
"It's not like litmus paper where it turns blue or red and you know," the judge said.
Asian carp, which can weigh up to 100 pounds, have been migrating up the Mississippi and Illinois rivers toward the Great Lakes for decades. Biologists fear if the ravenous fish get into the lakes, they could decimate a $7 billion-a-year fishing industry by gobbling plankton, a key link in the food chain that supports prized species such as salmon and walleye.
The suit, filed in U.S. District Court in northern Illinois, accuses the U.S. Army Corps of Engineers and the Metropolitan Water Reclamation District of Greater Chicago of creating a public nuisance by operating locks, gates and other infrastructure through which the carp could enter the lakes.
Michigan, Wisconsin, Ohio, Minnesota and Pennsylvania want to temporarily close the O'Brien and Chicago locks and install barriers to stop the fish. The states' request makes allowances for water releases to prevent flooding and other threats to public safety.
The U.S. Supreme Court has twice rejected state pleas to close the locks, but did not rule on the merits of the legal claims.
Reichel argued Monday that the threat to the Great Lakes has reached a "biological tipping point" and the waterways leading into Lake Michigan provide easy access.
"We have here a carp highway," Reichel said.
"Finding one Asian carp in 10 months doesn't make the waterways a highway," Jim Farrell, an executive director with the Illinois Chamber of Commerce, said Monday in a statement. "Far from it, after 10 months of constant testing, electro-fishing, netting and fish kills which resulted in hundreds of thousands of pounds of other fish being caught and/or killed - only one Asian carp was recovered. That one fish was very likely released as were the many Asian carp found in the regions land-locked lagoons."
U.S. Department of Justice attorney Maureen Rudolph said Congress has given the Corps discretion in how to deal with the problem and the court should be reluctant to get involved.
Last week, the judge granted the City of Chicago, the Coalition to Save Our Waterways and Wendella Sightseeing Company permission to participate in the case. Attorneys from the three parties appeared in court Monday.
Lake Michigan is the sole source of Chicago's drinking water. The city is concerned about flood control and access to the locks for police and fire vehicles, according to documents filed in the case.
The coalition, which includes the barge industry and other business groups, filed documents claiming its members' financial existence would be threatened by the lock closures.
Wendella, which operates water taxis and boat tours, also said its business would be threatened by closure of the Chicago lock.
(Copyright 2010 by The Associated Press. All Rights Reserved.)