The Glenwood Area Fisheries Department released its annual newsletter this winter, and in it is information on what the local staff saw during their work on area lakes in 2019.
Below are some of the details from this year’s newsletter.
Minnewaska sees good young-of-the-year walleye numbers
Work during the mid-summer is largely dedicated to completing standard lake surveys on select bodies of water, and a total of 15 area lakes were studied last year.
Full reports from those lakes are not available until this spring as DNR staff ages fish and analyzes data, but some numbers from Lake Minnewaska might have anglers excited about the future. Minnewaska was one of eight lakes in the area where fish sampling continued into the fall through the use of electrofishing to look at young-of-the-year walleye numbers. Young-of-the-year refers to fish that are sampled in the same year they are hatched.
After four years of poor numbers on Minnewaska, the lake produced a near record catch rate of 75.5 fish-per-hour in 2019.
Low catch rates of young-of-the-year walleyes has been a concern of the Glenwood Area fisheries staff on many lakes in recent years.
Research in Minnesota has suggested that young-of-the-year walleye grow slower and are more at risk in lakes infested with zebra mussels, the invasive species that filter water through their system and strain out available food particles such as plankton that fish species rely on at their youngest stage.
Smaller fish are more vulnerable to predation, have less food reserves going into winter and are more limited in the prey they can consume, all of which can limit early survival.
Muskie survey on Miltona
The Glenwood DNR started a muskie survey on Lake Miltona in the spring of 2019 that will help the staff better understand how the big game-fish species is performing in the lake.
DNR staff implanted Passive Integrated Transponder (PIT) tags under the skin in all the muskies they captured. These tags are similar to microchips used by veterinarians in pets. When scanned, the PIT tags have an individual identification number that allows the staff to track the age and growth of fish, and estimate the number of muskies in Lake Miltona. The two-year study will be completed in 2020.
Walleye hatchery numbers
Walleye hatchery production resulted in nearly 55 million walleye fry produced in 2019.
Most of the fry, which are fish right after hatching, were stocked into area lakes. The remaining fry were stocked into holding ponds for walleye fingerling production.
The walleye fry stay in the ponds until the fall when they typically reach about 4-7 inches in length. They are then harvested and stocked into lakes. More than 13,000 pounds of walleye fingerlings were stocked into area lakes in the fall of 2019.
Lake survey information
The Glenwood Area DNR uses lake surveys as its primary tool for guiding fish management.
Standard lake survey consists of trap nets, gill nets and electrofishing.
Electrofishing is conducted in the spring to target bass, while gill nets sample offshore fish such as walleye, northern pike and yellow perch, and trap nets sample near shore panfish like bluegill and black crappie.
Nets are checked and moved daily on each lake for about a week in the summer. Nets are placed in the same locations within a lake each year, with the idea being that surveying over many years allows the DNR to track trends in fish populations.
Survey information can be accessed by going to https://www.dnr.state.mn.us/lakefind/index.html and typing in the lake of interest.
Area lakes that had standard surveys in 2019 were Burgen, Little Chippewa, Maple, Round, Goose, Cowdry, Long (Douglas County), Miltona, Stowe, Leven, Ida, Long (Stevens County), Red Rock, Amelia and Villard.
Area lakes that will be sampled in 2020 are Andrew, Darling, Grant, Mina, L’ Homme Dieu, Blackwell, Freeborn, Irene, Vermont, Carlos, Geneva, Jessie and Victoria.