LITCHFIELD — The Minnesota Department of Natural Resources in New Ulm is considering its first application for a lake aeration system in more than 20 years.
The application by the Round Lake Improvement Association in Meeker County is anything but a sure bet.
“It’s not crystal clear to any of us,” said Jack Lauer, the New Ulm Regional Fisheries Manager, at the conclusion of a virtual public meeting held on the application on Nov. 17. “It’s kind of a hard decision for all of us.”
The DNR makes a decision on the permit application Dec. 21 and is taking public comments through Dec. 1.
The shallow lake south of Litchfield has been a popular fishing destination in recent years. There were 40 boats bouncing on the waves of the 263-acre lake for the fishing opener this year. “It was crazy, never seen anything like that before,” said John Grabow, representing the lake association. The lake has public access, and “there is a lot of the public using it.”
Although the lake is no more than eight feet deep, it is connected downstream to Lake Ripley in Litchfield and upstream to Hoosier Lake, a small lake that has been used as a walleye rearing pond. Fish migrate among the lakes, and anglers have been enjoying the benefits in Round Lake. Grabow has a phone filled with photographs of anglers holding nice-sized catches of walleye, sunfish, crappies, largemouth bass, and northern pike.
The lake is vulnerable to winterkill. Lake association members know that all of the good fishing could end with one harsh winter. Grabow said that is why they want to install the aeration system. It would protect the game fish. Otherwise, it can take years after a winter kill for a diversity of fish to return to the lake.
“It has been a boom and bust, northern pike fishery,” said Scott Mackenthun, fisheries supervisor with the DNR in Hutchinson. The lake is popular with waterfowl hunters and northern pike anglers and dark house spearers, Mackenthun said during the virtual hearing on the aeration application. The lake is kind of unique for the southern region in that it is primarily managed for its northern pike population, he added.
“We use winter kill to manage this fishery,” said the fisheries supervisor.
There are currently 110 permits for lake aeration systems in the southern portion of the state overseen by the New Ulm DNR office, according to Lauer, the regional fisheries supervisor. About 50 to 70 are actually operated in any given year, he said.
Overall, the DNR is seeing a trend towards fewer aeration systems in operation. They can be costly and difficult to operate, said Lauer.
They also create a drowning risk by creating areas of thin ice and open water. He pointed to two drownings on Lake Benton.
Aeration systems can be beneficial to game fish in some lakes, according to Mackenthun and Lauer. Lakes that offer an area of 15 feet in depth or more, such as Lake Sleepy Eye, tend to benefit the most, they explained.
Aeration systems prevent winter kills by providing refuge areas where some game fish can survive when oxygen levels are depleted during a hard winter, according to the two.
The fisheries supervisor pointed out that when those gill nets were pulled up in August, each net held about 95 to 96 fish. Of the catch in a net, over half or 55 were bullheads, along with 18 northern pike, three walleye, 1.3 yellow perch, one crappie and a “spare” largemouth bass.
Bullheads are very abundant in the lake, and were commercially harvested from it during the 1950’s to 1970. Mackenthun said that an aeration system could inadvertently “tip the scales” in favor of bullheads during a harsh winter by allowing them to survive in large numbers. The lake could become a “bullhead pump,” allowing the bottom feeders to expand and migrate to Ripley and Hoosier lakes.
Grabow said it’s also possible the reverse could happen. By helping game fish in Round Lake survive a harsh winter, they could benefit the connecting lakes.
“We are not asking for anything from the DNR besides the permit to run the aerator,” Grabow told the Tribune “We just want to give it a chance. We are all about helping the lake and creating an awesome fishery.”
If it turns out that the aerator benefits bullheads to the detriment of game fish, “we’d shut the aerator off,” he said.
Comments on the aeration application should be sent via email to the Hutchinson fisheries office: firstname.lastname@example.org.