A 20-pound Asian carp has been caught just 6 miles from Lake Michigan - beyond an electric barrier designed to keep the huge, invasive fish out of the Great Lakes. Now some groups are calling for dire action, saying government efforts at containment have failed.
Commercial fishermen working on behalf of state and federal agencies netted the 35-inch-long Bighead in Chicago's Lake Calumet on Tuesday. It's too soon to know whether the finding means an Asian carp invasion of nearby Lake Michigan is imminent, officials said.
Scientists say if Asian carp -- with their large size, voracious appetite and ability to reproduce prolifically -- become established in the Great Lakes, they could starve and crowd out native species and decimate the region's $7 billion fishing industry.
"We feel that we have to start to get some additional information about the significance of this population," said John Rogner, assistant director of the Illinois Department of Natural Resources, in a conference call with reporters announcing the Asian carp finding Wednesday. "What we're trying to determine now is, does this represent an individual fish in the lake or is it part of a larger population?"
Rogner says officials have no way of knowing yet how this particular fish got into Lake Calumet, whether it was dumped there by someone or swam upstream to the lake on its own.
But environmental groups say the finding shows that downstream barriers haven't worked, and more urgent action is needed to keep the invasive species from establishing in the Great Lakes.
"We have a significant problem with the Chicago waterway system being a highway for invasive species," says Henry Henderson, Midwest program manager for the Natural Resources Defense Council. "Debate over that is fundamentally over, and I think it's time to focus on real solutions."
The primary solution he and others advocate is "disconnecting the Great Lakes from the Mississippi."
The Great Lakes and Mississippi River watersheds are not naturally connected. In the late 1800s, the city of Chicago dug a series of canals and reversed the flow of the Chicago River, so instead of naturally flowing into Lake Michigan, it now flows down toward the Illinois and Mississippi rivers, taking waste and sewage from the city away from the Chicago area's drinking water intakes in Lake Michigan.
It was an engineering marvel for its time and also created shipping channels for numerous commodities that are still vital for many Midwest businesses and industries today.
With Asian carp in recent years moving rapidly up the Illinois River toward the manmade waterways that could carry the fish into Lake Michigan, the Army Corps of Engineers has established a series of electric barriers on the Chicago Sanitary and Ship canal, about 40 miles southwest of Chicago, to try to keep the invasive species out.
The barriers shock the water with pulsating electricity in hopes of jolting approaching fish into turning back. A third electric barrier is expected to be completed later this year.
Ever since Asian carp DNA was detected in November, crews have also been electro-fishing and netting in the Chicago-area waterways that connect Lake Michigan with the Illinois River, in hopes of detecting the fish early. And that's how the single Bighead Asian carp was netted Tuesday.
Originally imported to help control algae in fish farms and water treatment plants in the South, Asian carp made their way into Louisiana rivers, possibly during floods in the early 1990s, and spread quickly up the Mississippi River and its tributaries.
They're a huge and voracious fish, with no natural predators. Bigheads, known to grow up to 100 pounds, consume up to 40 percent of their body weight each day in plankton. Silvers, which regularly grow to 20 to 40 pounds, are known to jump high out of the water when startled by boat motors. Boaters and water-skiers have been seriously injured in run-ins with massive Silvers, which have almost completely taken over parts of the Illinois River.
In recent years, Illinois officials have tried to encourage commercial fishing of Asian carp, and while there are some markets for the fish, it's been a tough sell.
Some Chicago chefs have tried to come up with tasty Asian carp recipes, but they say that while the fish is tasty, its unusual bone structure makes it costly and difficult to prepare. Copyright 2010 National Public Radio. To see more, visit http://www.npr.org/.