Great Lakes Article:

The newest threat to the Great Lakes is a fish that can grow up to 4 feet long, weigh up to 100 pounds and leap 6 to 10 feet out of the water.

With its voracious appetite, it has the potential to eat all available food in the lakes and starve other fish species, significantly altering the natural ecosystem.

This invader, now the target of a high-stakes environmental battle, is the Asian carp.

Since the early 1980s, the fish -- actually four different species -- have been moving up the Mississippi River after escaping from farms in the South. Asian carp are now believed to be less than 50 miles from Lake Michigan.

``It's scary, very scary,'' said Lake Erie expert Roger Thoma of the Ohio Environmental Protection Agency.

Once invaders like the Asian carp get into the Great Lakes, Thoma said, getting rid of them is impossible.

The fear is that the invasive carp could become the dominant fish species in the lakes and hurt commercial and sport fishing for salmon, walleye and yellow perch.

Ohio Gov. Bob Taft has called for ``increased attention, action and funding'' to fight the carp.

They pose ``a threat that will ultimately lead to potentially overwhelming economic and ecological losses,'' Taft said. ``Changes occurring within the Great Lakes often have significant and lasting effects, so action on this issue must be done quickly.''

For the past eight months, the U.S. Army Corps of Engineers has been operating an underwater electric barrier on the Chicago Ship and Sanitary Canal, which connects Lake Michigan to the Mississippi via the Illinois River.

The barrier is designed to keep the Asian carp from getting into Lake Michigan and eventually the other Great Lakes.

Joel Brammeier of the Lake Michigan Federation, a Chicago-based eco-group, said the carp are believed to be within 15 miles of the electric barrier at Romeoville, Ill., and perhaps 45 miles from Lake Michigan.

``The potential damage is so great that it's not worth taking the risk of doing nothing,'' Brammeier said. ``That's not an option.''

The fish-shocking barrier, which began operating last spring, cost $2.2 million to construct, said Beldon McPheron, a spokesman for the Corps of Engineers. Annual operating costs are about $150,000, in addition to $84,000 for electricity and $100,000 for fish monitoring.

McPheron said the barrier was designed as a demonstration project to last three years and a more permanent solution is needed.

Preliminary work has begun on a second barrier designed to last 20 to 30 years, he said. It will likely cost $6.5 million, McPheron said.

This barrier would remove oxygen from the water and use sound and bubble walls to deter the fish, in addition to the electric shock.

The University of Illinois and the Illinois Department of Natural Resources currently are conducting tests to determine how successful the electric barrier is.

It provides a graduated electric shock to fish. The closer they get to the underwater barrier, the stronger the shock.

Some wildlife experts, however, feel that electrical barriers are little more than a delaying action and that the best remedy is to permanently cut off the connection from the Chicago Ship and Sanitary Canal to Lake Michigan.

But that proposal is generally considered a long-shot solution because the canal is used for sewage disposal and by boaters.

The canal was built in 1900 to reverse the flow of the South Branch of the Chicago River away from Lake Michigan. That enabled Chicago to send its sewage to the Illinois River.

The species of invading carp are the bighead, silver, grass and black. But most of the concern surrounds the bighead and silver carp.

These carp, from eastern China, were added to catfish farms in the early 1970s to control algae and snails. During floods in the early 1980s, the fish escaped into streams in Arkansas and other Southern states.

They have been heading north up the Mississippi at a rate of about 50 miles a year. They also are found in the Ohio, Missouri and Illinois rivers.

On those rivers, Asian carp have taken over some pools, crowding out other species.

Bighead and silver carp are voracious filter feeders and eat algae and small animals that are the basis of the Great Lakes food chain. They eat up to 40 percent of their body weight every day.

There is little market for the invading carp. Asians eat them, but they want the fish kept alive until just before it is cooked.

Two bighead carp already have been caught in Lake Erie. One was a 50-pounder netted in 2000 by researchers from Ontario's Guelph University. One was found in a fountain next to Lake Ontario in Toronto. Most experts think that people released those fish into the lake.

Lake Erie is still reeling from the effects of another invasive species -- the zebra mussel, a fingernail-sized mollusk from Eastern Europe. Found in the lake in 1988, the zebra mussel likely hitched a ride in the ballast water of ocean-going freighters that sailed into the Great Lakes.

``We don't know what the impacts would be of the Asian carp,'' said the Ohio EPA's Thoma. ``We can only speculate. But there is a lot of concern, a lot of concern.''