Spring Estimate Shows Lake Mille Lacs Walleye Population is Healthy
“After last fall’s gill net survey, there was some uncertainty about the amount of walleye that could be safely harvested from Mille Lacs,” said Ron Payer, DNR fisheries section chief. “But our spring population estimate confirms that the safe harvest level established in January is consistent with Mille Lacs’ walleye population.”
Safe harvest levels are established by biologists each year for walleye and other species in Lake Mille Lacs, which is managed differently than other lakes in the state because the fishery is shared between state-licensed anglers and tribal harvests taken under treaty fishing rights. Walleye counts during the fall 2007 gill net survey suggested an unexpected decline in the walleye population. After taking a number of factors into account, including the uncertainty of the gill net estimate, biologists established the 2008 safe harvest level at 430,000 pounds in January.
“This spring’s population estimate was conducted to address the uncertainty caused by last fall’s low counts,” Payer said. “The preliminary results of the 2008 spring survey indicate a safe harvest level of approximately 400,000 pounds, consistent with the level that was set in January.”
He said a variety of data sources are used in the models to determine the safe harvest level each year to avoid the estimate being overly influenced by one information source. The spring population estimate is currently being subjected to critical scientific review and will be finalized later this year.
Field aspects of the spring population estimate went well, though late ice out during tagging operations and wind and storms during the recapture sampling were challenging for field crews. In total, nearly 19,000 walleyes were tagged with small, yellow, uniquely numbered tags during late April and early May. Nearly 5,000 walleyes were captured during mid-May through mid-June and examined for tags. Approximately 130 tagged walleyes were recaptured in that effort.
The DNR is still interested in getting information on tagged fish. Anglers who catch a tagged fish are asked to report the tag information to the DNR. If the fish is harvested, the tag should be removed and returned to the DNR in Aitkin. Tags should be left in released fish and tag numbers should be written down and reported to the DNR in one of several ways. Tag cards are available at public access sites and businesses around Mille Lacs. Information can also be sent to MN-DNR Fisheries 1200, Minnesota Avenue, Aitkin, MN 56431. E-mails can be sent to fishtags [at] dnr [dot] state [dot] mn [dot] us or information can be entered at http://mndnr.gov/fishing/tagged_fish_reporting.
The walleye regulation for Mille Lacs is that all walleye 18-to 28-inches must be immediately released and the possession limit is four. One fish may be longer than 28 inches.