Crews removing thousands of invasive carp from Lake Minnetonka headwaters

The carp landed with a wet slap on the bed of the pickup truck.

"Twenty-four, 25, 26, 27," counted the small crew as they hurled one fish after another from the boat off the shore of Stieger Lake in Victoria.

Friday marked the first day of a multi­week effort to remove common carp from the lakes that drain to Lake Minnetonka. It's the latest chapter in the state's mounting battle to halt the growth of invasive species, which destroy water quality and habitat and can have a significant impact on business and recreation.

"They take in all this energy," said Eric Fieldseth, an aquatic ecologist for the Minnehaha Creek Watershed District. "By removing carp, it's going to allow that energy to go into other organisms."

The watershed district received a $567,000 grant from the state Lessard-Sams Outdoor Heritage Council to get rid of the fish. Crews with Carp Solutions, a Minnesota-based company, will be removing carp from a dozen lakes throughout the fall.

The amount of fish caught in each lake will vary, Fieldseth said. While he hopes to remove about 1,000 from Stieger Lake, there are more than 60,000 carp in Halsted Bay in Lake Minnetonka.

For weeks, crews have used cracked corn to bait the carp above box nets on the lakes. As carp feed in the middle of the night or early morning, crews will release the sides of the nets and capture them, Fieldseth said.

Four workers from Carp Solutions outfitted with waders, white helmets and gloves began removing fish from Stieger Lake early Friday morning. The carp flapped with ferocity as workers lifted the nets onto the boat.

Once removed, the fish are killed using clove oil. Most will be donated to the Wildlife Science Center near Wyoming, Minn., where a wolf pack will feed on them.

The crew, which tossed about a ton of carp out of the lake Friday, will move on to other lakes that have been baited and then return to Stieger Lake later this month.

It's stinky and messy work. The smell of dozens of dead fish emanated from the pickup truck, and the face and arms of Jordan Wein, general manager of Carp Solutions, were splashed with mud.

"Another day at the office, I guess," he said.

Experts talk about species in a lake in terms of biomass. And common carp, which weigh about 8 to 10 pounds on average, have a lot of it.

"They're in pretty much every water body. They're not always damaging," Fieldseth said. "It's really when you get enough carp in the lake [that] it causes damage."

Researchers from the University of Minnesota's Aquatic Invasive Species Research Center studied the Six Mile Creek-Halsted Bay subwatershed for three years and found an unprecedented number of carp, surpassing the biomass threshold of 100 kilograms per hectare.

The fish can uproot aquatic plants and stir up sediment, releasing nutrients that spur algae blooms. The water gets cloudy and usually green, much like in Stieger Lake.

Removing the carp is only one way the watershed district is controlling the population. Crews are installing permanent barriers to stop carp from moving in and out of Wassermann Lake in Victoria and Crown College Pond and Mud Lake, both in St. Bonifacius. They also will be aerating some lakes so that bluegill sunfish, which feed on carp eggs and can help reduce spawning, have enough oxygen to survive the winter.

Smaller habitats could begin to visibly improve within a year, Wein said.

The carp are the first focus of a 10-year strategy to restore the wetlands and uplands of the subwatershed. The Three Rivers Park District, Carver and Hennepin counties, Laketown Township and the cities of Minnetrista, St. Bonifacius, Victoria and Waconia are working with the watershed district.

Not all the carp are being fed to the wolves. Commercial fishermen may take some to the East Coast and overseas, Fieldseth said. Some could even end up as gefilte fish.

One man arrived at Stieger Lake and asked Wein for 10 live carp for a Chabad house in West St. Paul.

"Whoa, they're huge," he said as he looked at the bed of the pickup truck, countless carp gasping in the air.