In early May, more than 20,000 walleye were tagged in Lake Mille Lacs. The effort will provide a better estimate of the lake’s population of walleye 14 inches or longer and help guide how many fish can safely be harvested in future seasons, according to the Minnesota Department of Natural Resources.
The DNR has conducted similar population estimates six times on Lake Mille Lacs. Those estimates have placed the lake’s walleye population as high as 1.1 million fish in 2002 and as low as 249,000 fish in 2014. A decline in the walleye population has led to restrictive regulations aimed at protecting existing adult fish and a particularly abundant year class of walleye that hatched in 2013. Fish from that 2013 year class are now large enough to be counted in the population estimate.
“We understand the importance of Lake Mille Lacs. Gathering this information will enhance our knowledge of walleye populations and allow us to provide the best walleye angling opportunities possible,” said DNR Commissioner Tom Landwehr.
Tagging concluded on May 10 and was conducted by the DNR, Minnesota Pollution Control Agency, Great Lakes Indian Fish and Wildlife Commission, Fond du Lac Band of Lake Superior Chippewa, and citizen volunteers. Walleye were caught in trap nets and via electrofishing. Each fish 14 inches or longer was outfitted with two yellow tags near the base of its dorsal fin.
Since May 20, DNR fisheries staff have been recapturing tagged walleye using gill nets that are set for less than an hour. As the nets are retrieved, tag data is recorded, and all fish are released.
Based on the number of walleye that were originally tagged and the total number of tagged fish that turn up during the recapture, the DNR can make an accurate estimate of the lake’s walleye population. This type of population estimate is used in addition to the gillnet survey conducted each fall.
“We anticipate the population estimate being conducted will show a stable walleye population dominated by the 2013 year class,” said Don Pereira, DNR fisheries chief. “The population estimate that is underway also will give us valuable information to help evaluate how well our population model is working.”
Recapture work will continue until late June, so anglers should be aware of DNR-netting activity, which may be occurring during the evening. DNR nets are marked with labelled buoys.
Anglers who catch a tagged walleye are asked to leave the tags in the fish and record numbers on both tags by writing down the numbers or by photographing the tags. Consider recording the length of the fish and the location where it was caught. This information can be reported at mndnr.gov/tagged-fish. In return, anglers will receive information collected at the time the fish was tagged and any information submitted by anglers who may have previously reported the fish.
Walleye fishing on Lake Mille Lacs is open to catch-and-release angling only through the summer 2018 season. Handling fish gently and releasing them as quickly as possible will increase chances that released walleye will survive to be caught again.
More information about Lake Mille Lacs can be found at mndnr.gov/millelacslake.