By Jake Rossen
By Jesse Marx
By Michelle LeBow
By Alleen Brown
By Maggie LaMaack
By CP Staff
By Jesse Marx
Minnesota gave up on carp stocking in the 1890s. But the carp didn't give up on Minnesota. In the book Fishing for Buffalo, authors Rob Buffler and Tom Dickson write, "About this time, people began noticing that as carp numbers were exploding in rivers and lakes, the populations of game fish hadn't rebounded at all, and in fact had continued to deteriorate."
Much of the damage was due to the fish's feeding habits. Carp burrow for food, in the process rooting up phosphorus that long ago seeped into the lake from agricultural run-off. Algae consume the treat, and the lakes go from clear to turbid. Sorenson calls the process a negative cycle.
Popular outrage over the sudden dominance of carp led the state to enact a rough-fish removal program in 1909. Fishermen began to net out carp by the ton. This continued for the next 50 years, but netting alone could not control the prodigious carp.
Scientists took eradication efforts to another level in the 1960s, when the Conservation Department started to treat lakes with high levels of rotenone, a fish poison. The goal was to kill every living thing in the lake, then repopulate it with sport fish.
Like most experiments involving chemicals and mass killings, it didn't turn out well.
"Killing off everything in a lake can create a perfect place for carp to thrive," says Sorenson. "If only a couple find their way into the water system, they'll soon take it over."
The state abolished its rough-fish removal program in 1979. Sorenson estimates that millions of dollars were wasted in the futile efforts to rid the lakes of carp. Yet in that time, there wasn't a single scientific study conducted on the fish they were trying to kill.
Aided by the Australian government (that country is experiencing the same sort of carp problem that Minnesota saw in the early 1900s), Sorenson's team is conducting the first full body of research on the common carp in Minnesota. The hope is to discover better ways to control the fish, possibly with native species. If the carp eggs they found in the bellies of bluegill are any indication, there could be hope.
Walking around the pastoral St. Paul U of M campus, Sorenson discusses another interesting fact about the carp: The fish is a beloved creature in foreign waters. The Brits see carp as a supreme game fish, with anglers paying thousands of pounds each year to go after the biggest carp in England's lakes. As with much of Europe, the English revere carp like Minnesotans appreciate walleye.
"People either love the fish," Sorenson says, "or hate it to death."
Petschl maneuvers the boat near another set of docks. On the shore, a man ignores him as he sets up a sprinkler to snuff the remaining embers of a smoldering brush pile. As Petschl steers toward a deeper section of lake, numerous V-shaped wakes appear and clouds of brown dot the water—a telltale sign of carp.
"Let's go pick up the professor and give this place a chance to calm down," Petschl says.
Back at the docks, Sorenson waves from the shore. Though he's spent years of his life studying carp, he's never seen bowfishing before. After reading headlines about the new regulations, he wanted to check out the sport for himself. He'd heard claims that bowfishing could solve the carp problem, and he wanted to make sure that it didn't get passed off as scientific fact.
Petschl, meanwhile, has no problem showing the professor his sport up close. He welcomes Sorenson into his boat with a sturdy handshake and offers him a seat.
The return trip feels like a first date with the odd couple. The two men sit side by side on the boat, struggling to make small talk. Each seems intimidated by the other.
Sorenson asks about the behavioral pattern of the carp, where they are at each time of day. Petschl says they tend to hang out in deep water during the day and come near shore to feed at night. He thinks they're scared of the motorboats zooming across the lakes.
After each answer, Petschl, who is president of Minnesota's Land of Lakes Bowfishing Association, qualifies that it's just his observation. "I don't have any degrees on it," he says. "It's just what I see."
Sorenson nods and tells him his researchers are finding the exact same patterns. Petschl grins and nods back.
They reach the spot where the carp were thick, but there's no sign of them. With the sunlight fading, visibility reduces to about five yards or less. Chances for a kill are nil.
Petschl calls off the hunt. He cruises back into shore as the sun sets. It's during this lull that talk turns to why both men are attracted to the carp.
"Well, they're really enigmatic," Sorenson says. "The way they use our waterways and interconnected lake systems to thrive is astonishing to anyone curious about ecosystems. And they're really a smart fish. People around here don't give them enough credit."
Petschl listens patiently, then offers a more succinct answer. "My favorite thing about carp? Shooting them."