Great Lakes barrier may be too weak to stop carp

Voltage coursing through electrical barriers designed to keep invasive Asian carp (left) out of the Great Lakes may need to be raised to keep out juvenile fish, U.S. officials said on Friday.

The Army Corps of Engineers has mounted a multi million-dollar effort to keep voracious Bighead and Silver Carp that now infest the Mississippi River Basin out of the Great Lakes, where scientists predict they could decimate the lakes' $7 billion fishery.

"The current barrier operating parameters are effective for fish as small as 5.4 inches in length," the U.S. Army Corps of Engineers said in a news release.

"The research published in this report suggests that slightly higher operating parameters than those currently in use may be necessary to immobilize all very small Asian carp, as small as 1.7 to 3.2 inches in length."

Juvenile carp can swim 37 miles by the time they reach 6 inches in length.

Environmentalists and several state governments have fought to create a permanent ecological separation between the Mississippi River basin and the Great Lakes.

The U.S. Army Corps of Engineers, other federal agencies and Chicago-area governments have joined commercial shippers, sightseeing operators and recreational boaters in an bid to keep the waterways open.

For now, officials say smaller, juvenile carp are well downstream from the three electrical barriers (right: how electric barriers work) on the canal that links the river system to the Great Lakes, so the two-volt current laid down by the barriers will be maintained.

The best estimate of a potentially reproducible population of Bighead carp is 25 miles downstream from the barriers, Charles Wooley of the U.S. Fish and Wildlife Service said.

Lock and dam structures have impeded the carp's progress, Wooley said, and agency crews will be vigilant during the summer spawning season to kill carp in the pools between dams.

A U.S. study to be completed this spring will determine the impact on barges and barge operators if the voltage in the barriers is raised to 2.3 volts, which laboratory tests show is sufficient to repel the juvenile carp.

Army Corps Major General John Peabody stressed that the voltage impact on the juvenile carp was measured in a laboratory, and "needs to be validated" in the field.

Source:
Reuters,"Great Lakes barrier may be too weak to stop carp", by Andrew Stern , accessed March 25, 2011

Judge denies request to close Great Lakes to carp

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.

Source:
Reuters, "Judge denies request to close Great Lakes to carp", accessed December 2, 2010

From the Inbox: Monstrous Fish Invade our Treasured Lakes

Dear Friend, There are ravenous monsters at the gates of the Great Lakes. They’re called Asian carp — an invasive species that can grow up to four feet long, weigh up to 100 pounds and eat up to 40% of their body weight every single day. Their massive size, rapid reproduction rates and greedy appetites make it easy for them to deplete the food supply of native fish. This makes them a deadly threat to much of the Great Lakes ecosystem. Your help is urgently needed to protect the Great Lakes! Right now, Asian carp are making their way through the Chicago waterway system, looking for a way to infiltrate the lakes. Even the electrical barriers erected to keep them out can’t contain these beasts! Without immediate action, Asian carp will find a way into the Great Lakes. The ecological and economic impacts would be devastating. Native fish like lake trout, walleye, small mouth bass and other species won’t stand a chance competing for food. And the region’s $23 billion fishing and recreational boating industries will severely suffer if this happens. National Wildlife Federation has a four-pronged solution to keep the Asian carp at bay: Impede Asian carp movement through the Chicago waterway system, so that they cannot establish breeding populations in Lake Michigan. Pressure government agents to stop the flooding of rivers that seed the Chicago waterway system with invasive fish. Prevent flooding in the Wabash River, which contains Asian carp, from washing into tributaries that lead into Lake Erie. Create a permanent barrier to prevent invasive species from infiltrating the Great Lakes. These strategies make up the only real solution to the Asian carp crisis. But we must act now, before our treasured Great Lakes turn into nothing more than giant carp ponds. We’ve put together a vast team of experts whose number one priority is to stop the Asian carp invasion. But our success hinges on your support. We simply can’t do it without you. Please donate today to protect the Great Lakes and other wildlife and wild places across the nation. Sincerely, Andy Buchsbaum Regional Executive Director NWF Great Lakes Regional Center

Monstrous Asian carp threaten wildlife and people alike. Boaters have been injured when carp leap from the water and collide with boats. Some have even hit people directly! Please help stop the carp onslaught.

First Asian carp found in waterway near Great Lakes

A 20-pound (9-kg) Asian carp was fished out of a waterway close to the Great Lakes and beyond twin electric barriers designed to keep them out, authorities said on Wednesday.

It was the first time the voracious invader has been found beyond the electric barriers in the waterways that connect Lake Michigan, one of the five Great Lakes, with the Mississippi River basin, where the carp have proliferated.

"It's important evidence, and the more information we know about where the carp are, the better ... that's the reason we're intensifying the effort" to find any Asian carp beyond the barriers, said Chris McCloud, a spokesman for the Illinois Department of Natural Resources.

The live Bighead carp was fished out on Tuesday by a fisherman contracted by the government in Lake Calumet, 6 miles from Lake Michigan. It could have been dumped there or could have found its way past the electric barriers meant to block all fish species, McCloud said.

Michigan and several other U.S. states bordering the Great Lakes have filed suit demanding a separation of the two basins, fearing Asian carp will ruin the Great Lakes' $7 billion fishery. Several environmental groups support the separation of the basins, which were connected by man-made waterways a century ago.

Commercial interests including tour boat operators, barge companies, and the recreational boating industry oppose the closing of the connecting waterways.

Federal and local authorities have embarked on a long-term project to build more barriers, search for invasive carp, and use fish poisons and other measures to kill the carp before they become established.

Source:
Reuters, "First Asian carp found in waterway near Great Lakes", accessed June 24, 2010