CHICAGO (AP) - A federal judge Thursday turned down a plea from five states to order the immediate closure of shipping locks on Chicago-area waterways to prevent Asian carp from entering the Great Lakes, where scientists fear they could disrupt the food chain and starve out other fish.
U.S. District Judge Robert Dow said the states had failed to show that closing the locks immediately was essential to block the huge, voracious carp's path to Lake Michigan. He sided with opponents who argued that the locks are essential to commerce and flood control.
The decision does not end a lawsuit filed by Michigan, Minnesota, Ohio, Pennsylvania and Wisconsin that seeks lock closure and other measures to keep the unwanted invaders out of the lakes. But Dow's refusal to issue a preliminary injunction appears to settle the lock issue for the foreseeable future.
Officials in Michigan and Wisconsin said they were disappointed and would discuss with the other states whether to appeal the ruling or continue the legal battle. A hearing on the status of the suit is scheduled for Jan. 7.
In the meantime, Michigan Attorney General Mike Cox called on President Barack Obama to overrule the Army Corps of Engineers, which operates the lock system and has declined to shut it down.
"Obama's persistent failure to stop Asian carp is a slap in the face to Great Lakes citizens genuinely concerned about preserving their livelihood," Cox said.
A spokesman for the Justice Department said the administration was pleased with the court ruling.
Bighead and silver carp, both Asian species, have migrated up the Mississippi River and its tributaries for decades after escaping from sewage treatment plants and aquaculture ponds in the Deep South. They have advanced to within about 25 miles of Lake
Michigan, and DNA evidence suggests at least some may have evaded an electronic barrier on the Chicago Sanitary and Ship Canal, part of a network of waterways eventually linking the lakes and the Mississippi.
The carp can grow to up to 4 feet long and up to 100 pounds. They eat vast quantities of plankton, a crucial link in the aquatic food chain.
Biologists disagree on what would happen if they established a breeding population in Lake Michigan. But a worst-case scenario envisions them spreading across most or all of the lakes and decimating their fishing industry, valued at more than $7 billion.
The Obama administration in February released a $78.5 million strategy for battling the carp. It calls for strengthening the fish barrier system, netting and poisoning carp in selected areas of the Chicago waterways and developing biological controls such as methods to disrupt their spawning.
Michigan and the other four states say those steps aren't enough and would take too long.
In their July 19 suit, they called for closing the two locks and placing screens, nets and other devices at selected points as temporary measures. They requested an order that the corps speed up a promised study of ways to permanently separate the Great Lakes and Mississippi River watersheds. The suit contends the corps' position on the locks is arbitrary and accuses the agency of operating a nuisance.
Dow acknowledged in his 61-page opinion that a carp invasion might do great harm to the lakes but said the states had not shown it was likely or imminent.
In fact, he said, the evidence suggests that flooding and economic damage to barge operators and businesses that rely on them would "outweigh the more remote harm associated with the possibility that Asian carp will breach the electronic barriers in significant numbers, swim through the sluice gates and locks, and establish a sustainable population in Lake Michigan."
Chicago business groups urged Michigan and the other states to drop the lawsuit, saying there was little chance it would prevail.
"Spending precious time and money on legal action is diverting resources from control and research efforts," said Mark Biel, president of the UnLock Our Jobs Coalition.
Environmental groups acknowledged prospects for closing the locks were slim and called for severing ties between the Great Lakes and Mississippi basins.
"This decision doesn't have any bearing on the main issue, which is that separating the systems is the only way to solve this problem permanently," said Joel Brammeier, president of the Alliance for the Great Lakes.
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