A judge on Thursday denied a request by five U.S. states to close off man-made waterways that connect the Great Lakes to inland rivers, ruling there was no imminent threat of Asian carp entering the lakes.
Five states bordering the lakes, led by Michigan, had sought a preliminary injunction that would have required the U.S. Army Corps of Engineers to immediately shut off the waterways, arguing action was necessary to head off a disaster for the lakes' $7 billion fishery.
But U.S. District Court Judge Robert Dow disagreed, saying the states were unlikely to win their lawsuit against the Army Corps and had not proved the threat of a carp invasion was imminent.
Earlier this year, the Obama administration named a "carp czar" to oversee the government's response to the issue and diverted more than $75 million from a Great Lakes restoration fund to pay for additional carp control measures and studies.
Bighead and silver carp, which reproduce rapidly and devour the bottom of the freshwater food chain, have proliferated in the Mississippi River basin and moved up the Illinois River to within dozens of miles of Lake Michigan.
The city of Chicago, commercial shippers, and recreational boaters had joined the Army Corps in opposing the move to separate the lakes from the Mississippi River basin, arguing a multimillion-dollar effort that included electrical barriers at a bottleneck was sufficient to keep the carp at bay.
There were questions raised in the court hearings about scientific evidence that the carp had breached the barriers, including environmental DNA detected in water samples taken close to the lakes.
Once the fish are established, the officials from the plaintiff states and environmental groups feared the carp would decimate the lakes' $7 billion commercial and recreational fishery. The lakes are already far from their pristine state, harboring dozens of invasive species.
The lakes also provide drinking water for tens of millions of people.
Judge Dow said there were other factors to consider such as the potential for residential flooding and sewage backups during storms in the Chicago area if locks on the century-old waterways are permanently shut.
In addition, Dow said the defendants showed that more than $1.2 billion is spent annually on commercial shipping, recreational boating, and commercial cruises reliant on two key locks. The two sides each produced experts who differed on the economic impact of closing off the lakes, he said.
"Indeed, based on the evidence of record, the harms associated with the potential for increased flooding and sanitary issues and the economic hardships associated with the requested relief (by the states) 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," Dow concluded.
Reuters, "Judge denies request to close Great Lakes to carp", accessed December 2, 2010