Frederica Freyberg:
We continue coverage of a story from last week, the invasion of Asian carp in the Chicago canal and their threat to Lake Michigan. Wisconsin officials this week called for the sealing of locks separating Lake Michigan from a series of canals which connect the Great Lakes system to the Mississippi River and its tributaries. Last week one of those canals was the scene of a massive dispersal of poison to kill any possible invasive fish, poison intended to provide a temporary fix for what many fear is the pending invasion of the Asian carp. "Here & Now" producer Art Hackett has been following this story. He reports now on the reaction of those who make their living fishing on Lake Michigan.

Art Hackett:
Three thousand pounds of white fish hit the dock in Gill's Rock in Door County. Jeff Weborg and his family will be on the water until ice makes it impossible.

Jeff Weborg:
We can break ice with that boat, but it's not an icebreaker.

Art Hackett:
The ice was already encroaching around the dock, but ice wasn't the only hazard sneaking up on Great Lakes fishermen.

John Rogner:
It's time to man the barricading. For nearly 10 years, we have watched as two species of introduced Asian carp, those are the big-head carp and the silver carp, have moved up the Mississippi River and up the Illinois rivers, and now they're here. They're now at the gates to the Great Lakes.

Art Hackett:
Asian carp have been in the Mississippi River for a decade after they escaped from southern catfish farms. They are known for jumping from the water in response to the sound from motor boats. Biologists like Marc Gaden knows them for something else.
Marc Gaden:
These are fish that reproduce very quickly and in large numbers. They eat enormous quantities of plankton. We've seen the utter destruction that they've laid on the ecosystems that they've invaded.

Art Hackett:
Asian carp have been found just below an electrified barrier in Illinois which was set up to keep them from advancing into the lakes. When it became time to take that barrier down for maintenance, environmental agencies responded by poisoning a six-mile stretch of the river, killing hundreds of thousands of fish, including one Asian carp. But the greater concern is that DNA from Asian carp was recently found several miles above the barrier.

Marc Gaden:
Because that's the first time that any DNA or any other hint of this fish being above this barrier has been detected. What's important about that is right now it's just the DNA. It doesn't mean that necessarily that the fish are there, but it doesn't mean that they're not there. So they're going to have to go out and look and try and find an actual specimen of this to confirm whether there are Asian carp above the barrier.

John Rogner:
If in fact one or two fish get through, it is not the end of the world. It is not game over, by any means. They become your proverbial little fish in a big pond.

Charlie Henricksen:
We don't know what game over is. We've had all sorts of things happen, you know, from VHS to the zebra mussel to the quagga mussels. Where is the tipping point where it’s game over?

Art Hackett:
Fishermen like Charlie Henricksen of Sister Bay are tired of battling one invasive species after another. He used to catch chop, but those fish were decimated by mussels.

Charlie Henricksen:
We've got so many problems with invasives that are here now that there's nothing you can do to stop them, that you hate to see another one of this magnitude come in.

Jeff Weborg:
From everything I’ve read, they will devastate the Great Lakes.

Art Hackett:
These men both fish on the Lake Michigan side of the Door Peninsula. They fear it's worse on the Green Bay side, like Mark Maricque.

Mark Maricque:
From what I understand, they are a warm water species. Green Bay naturally gets very warm in the summertime. Whether or not they'd be able to inhabit Green Bay over winter months is still unknown. I heard that maybe probably not. But, again, whenever we have an exotic come in, they seem to be able to adapt. One is still too many.

Charlie Henricksen:
We wish we would have closed the whole Great Lakes off about 15 years ago because that's when it really went to heck. 

Art Hackett:
As the poisoning project took place, there were calls from Michigan and Wisconsin state officials to create a permanent seal between the canals and Lake Michigan by closing locks such as this one near Calumet City, Illinois. The Illinois DNR's John Rogner says that's been considered before.

John Rogner:
Over the years we've looked at all options, and there is one option that we've called ecological separation, trying to create some kind of a separation to truly prevent movement of fish between the Great Lakes and Mississippi drainages. It is feasible under any number of possible scenarios, but it's not easy. It's a complicated fix.

Jeff Weborg:
Some already slipped through. They don't know if their electronic barrier is 100 percent. They think it is. They don't know. What they're doing is they're gambling with a billion dollar fish industry in the Great Lakes.

Frederica Freyberg:
That was Art Hackett reporting.