Lake Invaders

As fish go, silver carp — one of several species that fall under the general term Asian carp — have a lot going for them. They eat like crazy, they can grow to more than 40 lb. (18 kg), and their bony bodies mean few Americans want to eat them, so they can escape the overfished fate of their more filletable cousins. But they do have one slight evolutionary drawback: silver carp respond to the sound of a motorboat’s engine by leaping out of the water. And that puts them at the mercy of hunters like Zach Nayden, who has come with his crew to the small town of Bath, Ill., to capture some carp. As we join the flotilla roaring down the Bath Chute, an 8-mile-long (13 km) channel next to the Illinois River, the carp start jumping, sometimes in high-arced pop flies, sometimes with the trajectory and velocity of a hard line drive. Nayden’s boatmates lean out with nets and grab the shimmering fish as they somersault in the air.

(Watch TIME’s video “Holy Carp! Fly Fishing in Illinois.”)

See pictures of the Redneck Fishing Tournament.

Nayden is here for the annual Redneck Fishing Tournament (yes, that’s the official name), where the boat that catches the most carp can take home hundreds of dollars. It’s an intense competition, with a frisson of danger. A flying adult silver carp is like a sea-to-air missile. “One of these nails you, it’s like getting hit with a brick,” Nayden says as he steers the boat with one hand and wields a net with the other. As if on cue, one of his crew gets whacked by a carp. “Right in the face!” Nayden exults. “That was awesome!”

O.K., so the sixth annual Redneck Fishing Tournament may not be the most humane, safe or sane sporting event. But the two-day competition, held in early August, has its roots in a real problem. Asian carp have invaded the Mississippi and Illinois rivers, where they’ve crowded out more valuable native species and injured many an unsuspecting boater. Now they’re poised to infiltrate the Great Lakes, where they could ravage the native ecosystem and disrupt a commercial and sports fishery worth billions of dollars.

The situation is so serious that the Supreme Court has weighed in. There was a carp summit at the White House earlier this year, and Washington may soon name a carp czar. Last month, several Great Lakes states filed a federal lawsuit to force the Army Corps of Engineers to step up its anticarp measures. “Asian carp will kill jobs and ruin our way of life,” Michigan attorney general Mike Cox said after filing the latest lawsuit. “We cannot afford more bureaucratic delays — every action needs to be taken to protect the Great Lakes.”

So how did these illegal immigrants get here? Like many invasive species, the Asian carp are an object lesson in unintended consequences. There are two main Asian carp species in the U.S.: the silver carp and the apparently smarter bighead carp, which can grow as large as 110 lb. (50 kg) but thankfully don’t jump out of the water. They were imported in the 1970s from Asia — where they’ve been raised in aquaculture for thousands of years — for fish farms in the southern Midwest. At some point, most likely due to flooding, they escaped into the Mississippi River and have steadily moved upstream since.

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The carp have thrived in their new environment. In parts of the Illinois River, which branches off the Mississippi, 9 of every 10 fish are now Asian carp. Voracious filter feeders, Asian carp can eat as much as 20% of their body weight in plankton per day, and females can lay a million eggs at a time. Though they’re not predators, the fear is that if Asian carp establish themselves in the Great Lakes and their tributary rivers, the invasive species will wipe out the bottom of the aquatic food chain, wreaking havoc on an already stressed ecosystem. “From everything we’ve seen in other water bodies, [the carp] basically take over,” says David Ullrich, executive director of the Great Lakes and St. Lawrence Cities Initiative. “There’s tremendous fear of what they could do.”

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If the Asian carp do take over, it would most likely be through the Chicago Sanitary and Ship Canal, the only connection between the Mississippi River system and the Great Lakes. The canal is the Thermopylae in the war against the carp, and the Army Corps of Engineers has done its best to close off the pass, installing underwater electrical barriers about 30 miles (48 km) downstream from Chicago. The barriers send a small jolt of juice across the water, enough to repel any approaching carp while allowing free passage to ships and sewage. (The canal carries Chicago’s treated waste.) The corps is also looking into backup measures, like an additional barrier that uses acoustics and bubbles to dissuade incoming carp, as well as longer-term strategies, so officials believe they can defend the Great Lakes. “I feel confident that working together with other agencies, we can do this,” says Colonel Vincent Quarles, the commander of the Chicago district of the corps.

But some environmentalists and politicians worry that the corps’s barrier system is far from impregnable. Researchers from the University of Notre Dame have found carp DNA in Lake Michigan, and earlier this summer a fisherman caught a 3-ft.-long (1 m) bighead carp in Lake Calumet, which is upstream of the electrical barriers. That doesn’t mean the barriers aren’t working — some scientists think the fish that was caught might have been introduced directly into Lake Calumet by a person, and the same possibility could account for the presence of any other carp in Lake Michigan. Then again, the barriers were shut down for a short time in 2008, which might have allowed carp to pass through. Plus, flooding can link the canal and the nearby Des Plaines River, giving Asian carp a chance to bypass the barriers altogether.

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Critics of the all-out anticarp offensive argue that the fact that so few live carp have been found past the barriers indicates that they’re working. But carp are hard to catch, especially if their numbers are still small. “If there were a thousand fish in Lake Michigan, we might have no idea for sure for a long time,” says Duane Chapman, a biologist with the U.S. Geological Survey. “We can’t rule out that possibility.”

For those who really fear the fish, the mere possibility of their presence is enough to call for more drastic measures, including closing the locks on the Chicago canal to seal off a water route from the Mississippi to the Great Lakes. Business interests in Illinois have fought hard against that course, arguing that the economic damage inflicted by closing the shipping lanes would far exceed the damage carp could cause if they slip past the barriers. The shipping advocates are also pushing an environmental angle. “A single barge on the canal carries 80 truckloads of material that would instead have to be on our roads,” says Jim Farrell, executive director of infrastructure at the Illinois Chamber of Commerce. “It’s irresponsible.”

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The lawsuit filed by Michigan’s Cox and other state attorneys general isn’t likely to succeed — the Supreme Court denied similar attempts earlier this year. But even with the Obama Administration spending nearly $80 million on Asian-carp control, more may need to be done. The fish is hardly the only invasive species threatening the Great Lakes. There are more than 180 alien species in the system, including zebra mussels, round gobies and sea lampreys, that can go back and forth between the Mississippi and the lakes. Beyond beefing up surveillance of international shipping — many invaders hitch a ride inside the ballast water of container ships — blocking off the waterway is the only sure way to prevent the carp and other species from making a home in the Great Lakes. Or, to borrow the words of Nicholas Schroeck, executive director of the Great Lakes Environmental Law Center, “How much longer will we battle this stupid thing when we could get a much better solution by instituting a physical barrier?”

As I’m zipping around the river during the fishing tournament, I have to admit that for a brief, sunny moment, having a lot of Asian carp around seems less an ecological disaster than a totally excellent sporting adventure. But then Nayden hits a school of carp, and suddenly the sky is filled with fish, like shrapnel from a grenade burst. They’re coming at us from all directions. I flinch as one hits me square in the stomach, leaving behind blood, scales, slime and one ruined shirt. O.K., carp — now it’s war.

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