DNR completes spring stocking of Loon Lake in Waseca

Fish stocking of Loon Lake in Waseca has been completed as part of a plan to reclaim the lake, according to the Minnesota Department of Natural Resources (DNR).

Scott Mackenthun, DNR fisheries, said bluegills, largemouth bass and channel catfish have been stocked into the lake with good results.

“We introduced adult bluegills and bass so that we could get a good spawn right away this year,” Mackenthun said. “The channel catfish we put into the lake were in the 8- to 10-inch range and could be eating size as early as next year.” Northern pike may be introduced into lake later this year.

Mackenthun explained that stocking the lake is part of a reclamation plan that began last fall.

Loon Lake became dominated by black bullheads after a winterkill in 2009-2010 claimed the majority of northern pike, bass, bluegills and black crappies in the lake. Once a shallow lake becomes dominated by black bullheads, the ecosystem goes out of balance. Black bullheads feed on the bottom, putting sediments in suspension and fueling algae blooms. Algae blocks sunlight to rooted plants and limits habitat for insects and fish that use plants for shelter and food. Soon the lake can only support the most tolerant of fish species, namely other black bullheads.

A return to a healthy and diverse fishery is impossible without a complete reclamation.

DNR fisheries staff worked in cooperation with the Waseca Lakes Association to develop a three-point plan to reclaim Loon Lake. Last fall, an oxygen inhibitor was put into the lake to eliminate the black bullheads. This spring, the lake was stocked with more desirable fish. Next fall, new aeration equipment will be installed to deliver better dissolved oxygen to fish in the winter. The Waseca City Council has signed an aeration agreement with DNR to operate new aerators on the lake starting in the winter of 2013-2014.

“Observations from the lake so far are really super,” Mackenthun said. “We’re seeing clear water and a variety of vegetation.” He added that DNR staff were not surprised to find a few bullheads in trap nets this spring, but expects the channel catfish will provide biological control of spawning bullheads.

The DNR will continue to monitor the lake and is planning a population assessment in the summer of 2014 or 2015.

“The best fishing is yet to come,” Mackenthun said. “Next year will be better and the year after should be great.”