The Minnesota Department of Natural Resources (DNR), having recently conducted an assessment of Lake Mille Lacs, has identified a smaller than anticipated walleye population.
The lake's walleye index has reportedly dropped from 10.8 fish per net in 2010 to 9.7 fish per net in 2011. This is a drop from 22.9 pounds per net to 16 pounds per net. This is the second lowest walleye abundance that has been reported since the DNR large lake monitoring program began in 1983.
The long-term trend of walleye population assessments on Mille Lacs since the mid-1980s has been declining overall, but the trend for female walleyes has been stable. This may reflect the fact that the walleye harvest strategies employed by both the state and the Chippewa Bands are more selective for smaller, male walleyes.
The implications of the decline in males to the overall fishery are not clear. Fisheries biologists are evaluating the new data to better understand these implications and how they might influence future management options.
The new fish population information comes at a time when walleye fishing is good at Mille Lacs. DNR Fisheries managers believe good fishing may continue this winter and spring, even in the face of a decreasing walleye population. This may be due to relatively low numbers of young-of-the-year perch, the primary food sources for young walleye. The perch are also small in size, according to the new assessment data.
Fisheries managers understand that a smaller perch population typically results in hungry walleyes, especially of the sizes anglers prefer to keep. Looking to 2012, a resulting high harvest would be a concern if it is projected to reach or exceed the state’s allocation, which will be set in February in cooperation with Chippewa Band managers.
Northern pike abundance also went down, according to the recent assessment. This was expected given a regulation change in 2011. The former regulation was a 24- to 36-inch protected slot that allowed the keeping of one northern pike longer than 36 inches. In 2011, a new regulation protected northern from 27- to 40-inches and allowed the taking of one fish longer than 40 inches.
Tullibee (cisco) abundance also dropped in 2011 from relatively high abundance levels in 2009 (34 fish per net) and 2010 (11 fish per net) to catches of less than two per net in 2011. The relatively warm late summer may have resulted in higher than usual mortality for this cold-water species.
Smallmouth bass have been increasing in abundance for many years, and although not at an all-time high as observed in 2009 (1.9 fish per net), they were above average in abundance at 1.1 fish per net.
Prior to setting the 2012 regulations, DNR managers will meet with the Mille Lacs Fisheries Input Group, an advisory group of anglers and local business interests, to discuss the status of the lake’s fish populations.
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