When fish strike back

If you've been boating on the lower Missouri River lately, you've probably seen your share of high-flying fish--silver or bighead carp--that unexpectedly leap around, over and even into boats, sometime with grave consequences for the occupants.

These days, the experts say, it's not enough to carry only the standard boating safety equipment on the Missouri, you need personal protection gear, as well.

"When you're running a small boat on the Missouri River today, be sure to use a tethered kill switch on the engine, wear your PFD and by all means, carry a CDD," warns Duane Chapman, a fish biologist who often works on the river around Columbia, MO.

A CDD? What's that?

"That stands for Carp Deflection Device," he explains, only slightly tongue-in-cheek as he holds up a metal trashcan lid. It's now standard issue on Chapman's U.S. Geological Survey research boats for protection against this new breed of alien invaders.

Native to China and recently escaped from U.S. fish farms, Asian carp have put new meaning into the term "flying fish." They can grow to four feet of more and weigh-in at 70 lbs.-plus.

"The silver carp is the real jumper of the four Asian carp species now found in the Mississippi-Missouri River basin," Chapman says. "These fish seem to hate boats and they'll jump completely out of the water when a boat is going by, apparently in response to the engine noise," he reports. "If you crank up a big two-stroke outboard, that really makes 'em mad."

They're called "crazy fish" locally and probably a lot of unprintable other names, especially when they launch a surprise attack into the side of a boat or, worse yet, slam into a passenger. This seems to be happening with increasing frequency. Other CDDs boaters use on the lower Missouri River and on the Mississippi around St. Louis include boat cushions, plywood, even lawn chairs.

"There have been numerous reports of boaters injured by flying carp and we've even had some of our own guys hurt," Chapman says of river survey teams. "It's getting dangerous to be out on the water around here."

Despite its angry attitude and aerial antics, the carp is a fragile fish that will bleed profusely and even, quite literally, lose its head on impact, Chapman reports.

"If you've got a pretty boat and one lands inside, it can be a real mess," he says. "I had one over 10 lbs. that hit a stanchion on my boat so hard the head went one way, the body went the other and the blood went everywhere else."

Not only are boaters physically at risk, the entire freshwater ecosystem of the Missouri, Mississippi and Illinois river basins are suffering irreparable harm, Chapman says as these alien invaders continue to spread, by leaps and bounds, as it were.

Enemy at the Gates

Flying just under the freshwater biologists' radar for a decade of more, three species of Asian carp seem to be gathering steam now and they are headed upstream--in the Missouri and Illinois Rivers as well as in the Mississippi where the fish are now well-established downstream into Louisiana.

Yes, this is another one of those foreign fish that can out-eat, out-swim and out-spawn the locals, one that has biologists, boaters and anglers worried, particularly on the Great Lakes.

Scientists caution that failure to stop the Asian carp's march up the Illinois River and though the Chicago Ship and Sanitary Canal to Lake Michigan could wreak more havoc on Great Lakes ecosystems than the previous invasions of the sea lamprey and the zebra mussel combined. Indeed, the International Joint Commission has appealed to the U.S. and Canadian governments to do everything in their power to halt the spread, calling for a permanent electrical barrier on the canal.

An invisible electronic fence that repulses fish began operation on the canal in mid-2002 to contain the nuisance round goby fish as well as zebra mussels upstream and it seems to be working. Headed in the opposite direction, though, the creeping--and leaping--Asian carp threat may now be within 25 miles of Lake Michigan so officials want a back-up electro-fence installed as well as funding assurances so the juice won't ever be turned off.

If that happens and silver carp take up residence in those sweetwater seas, hard has could become de rigeur boating wear on the Great Lakes. Meanwhile, back on the Big Muddy, where it's almost come to that, Chapman says Asian carp now are the most abundant large fish, making up 66.4% of the catch in his research surveys. So now it looks like the only defense will be a strong offense, he says.

Carpe Carp

"We'll never eliminate this fish from the Missouri River; there's no way to get rid of them," Chapman concedes. "We just have to deal with them now that they're here."

The Missouri Conservation Department's plan to deal with Asian carp is to dish them up as seafood. The agency is encouraging commercial carp fishing on the river, publishing recipes for carp cookery and generally promoting the fish as desirable table fare--which they are, Chapman says, but only if prepared properly.