BIG KANDIYOHI LAKE, Minn. — Jason George has a simple formula for improving water quality in Minnesota lakes: Take out the carp.
“I know the best thing you can do is get as many out of there as you can,” said George, while netting carp from Big Kandiyohi Lake.
George is hoping to remove 100,000 pounds or more under a special permit that is allowing his firm — Mike’s Rough Fish of Waterville, Minnesota — to harvest the fish.
And he’s right — It’s all about water quality, according to Jerry Brustuen, president of the Big Kandiyohi Lake Association.
Members of the association have made water quality their No. 1 priority, and they are investing in it. The association contracted for separate studies looking at the lake.
The first, a core sediment analysis, found that the lake’s sediment carries a high load of phosphorus. Brustuen said the study found that about two-thirds of the phosphorus load in the lake is internal.
Carp stir up the bottom sediment and uproot the vegetation that would otherwise use the phosphorus. Once suspended in the water, the phosphorus feeds algae blooms that turns the waters of the shallow, 2,682-acre lake the color of pea soup.
The second study funded by the lake association revealed just how big of a role carp are playing in triggering the algae blooms. The study by Wenck Associates, Inc. was conducted on Sept. 28 2018, and included electro-fishing 31 common carp at four different locations.
Based on a model, the study extrapolated that there could be as many as 161,834 carp — with a total mass of roughly 2 million pounds — in the lake.
Even using a more conservative model to do the calculations produced a hypothetical population of 82,567 carp, with a total mass of roughly 1 million pounds.
George doubts there are 2 million pounds of carp in the lake, but he does know the lake is loaded with carp. He’s netted the waters before and ranks Big Kandiyohi’s carp population right up there with Koronis as among the top producers in the lakes he is permitted to commercially fish. He pulled 147,500 pounds of carp from Big Kandiyohi in 2016, along with 49,400 pounds of bigmouth buffalo.
George and his crew worked Lake Minnetaga last winter and netted 168,000 pounds of carp.
Normally, Geroge’s commercial fishing season ends with the start of the Minnesota walleye and northern pike opener. But the Minnesota Department of Natural Resources issued a special permit allowing his after-season netting due to the water quality efforts being undertaken on Big Kandiyohi Lake, as well as this year’s late spring.
As of Wednesday, June 5, George was still waiting for the carp to spawn, which would make them more vulnerable to netting. They’re running a few weeks behind schedule due to the slow warm-up, he said.
His permit allows him to net until June 15, but the lake association is seeking an extension for the permit. It’s also asking the DNR to allow him to net in areas behind the inlet on the east side of the lake. The permit has limited him to that area, which is where he anticipates finding many of the carp coming to spawn.
George and his crew started harvesting on Monday, June 3. Their first day’s net included many bigmouth buffalo. Kandiyohi County’s name is from the Dakota for “where the buffalo fish come,” and this namesake lake still produces.
The netted fish were loaded into oxygenated tanks atop a semi-truck. Once filled, its two drivers take the load to New York City. The red-eye run will assure that the fish are lively when they reach the fish markets there, where live, bigmouth buffalo fish are highly desired.
George is being helped by his father, Mike Sands, who started commercial netting more than 50 years ago. George likened the business to farming.
“One year you have good crops, and the next year you have a hard time paying the bills,” he said, laughing.
Bigmouth buffalo are worth anywhere from 30 to 50 cents a pound, depending on the season, George said.
Carp are worth considerably less, he said, comparing the difference in value as being similar to that of soybeans and corn.
“You’ve got to move a lot of corn to make it work,” he said of carp removal.
The analysis by Wenck recommended removing at least 100,000 pounds of carp to lower the density to the point at which water quality improvements could be achieved in Big Kandiyohi Lake.
Association working for water quality and more
The removal of carp from Big Kandiyohi Lake this month is part of an overall campaign to improve water quality by the Big Kandiyohi County Lake Association.
Association president Jerry Brustuen said it’s hoped that Mike’s Rough Fish can continue to remove carp from the lake in the future. The association is also working to keep carp from getting into the lake by installing fish barriers on its major inlets.
It’s going after them in other ways, too.
The association is asking the Department of Natural Resources to stock bluegills into the lake. The panfish like to feast on carp eggs, and can be an effective means of controlling their population.
The association is also funding ongoing water quality testing. The testing will show a baseline for nutrient and sediment levels. There’s hope that water reaching the lake in the years ahead will carry less of the pollutants, thanks to two upstream projects.
The installation of a structure to drawdown Lake Wakanda will make it possible to winter-kill its carp population and improve water quality in the lake.
Work to complete the restoration of Grass Lake near Willmar means that the shallow water body will capture sediments and nutrients that now flow downstream to Wakanda and Big Kandiyohi.
The Big Kandiyohi Lake Association is targeting invasive curly-leaf pondweed. It will be contracting with lake resident Tim Johnson, who purchased a mechanical harvester, to harvest the invasive aquatic plant before it produces the turions that spread it.
The association is also exploring the idea of seeking special regulations on the lake to reduce the pressure on its jumbo perch population. The association has been working with the DNR to place cedar trees along certain shoreline areas of the lake to serve as habitat for perch spawning.