Wisconsin DNR begins Twin Falls walleye stocking
The Wisconsin fisheries team out of the Florence office ran a comprehensive survey of Twin Falls Flowage, a Wisconsin/Michigan border water, in the spring of 2019 to analyze the health of its fishery. Twin Falls is an impoundment of the Menominee River located between Florence and Iron Mountain, Mich.
As a boundary water, Twin Falls may be fished with either state’s fishing license. There are multiple boat landings on the flowage, but the most improved access is in Vagabond Park, just off Hwy. 2 on the Wisconsin side of the flowage.
The Wisconsin DNR’s Florence County fish biologist, Greg Matzke, drafted an initial report from the 2019 survey. That report could change as more information from the survey is reviewed.
The crew set walleye fyke nets April 15, 2019, right after ice was off the main channel. They ran the nets through April 25 to assess walleye and northern pike populations. However, even with tremendous effort put forth, only five walleyes were captured.
“With a relative abundance of one walleye captured for every 24 net-nights, abundance was similar to the last survey where one walleye was captured for every 27 net-nights of effort,” wrote Matzke. “The walleye population is of extremely low abundance, well below what is considered a ‘fishable’ population.”
Those five 2019 walleyes ranged from 13.2 to 24.6 inches. Due to the low abundance, the Wisconsin DNR has begun a stocking initiative and plans to stock about 9,280 large fingerlings (7-8 inches) every other fall in even-numbered years.
That left northern pike as the main target for this fyke net survey. A total of 739 pike (716 considered adults) were captured and marked with an identifiable fin clip from April 15, 2019, to April 23, 2019. A second sample was collected the next two days. The data from these surveys estimate the adult pike population at about 2,229 fish (2.4 per acre).
“The 2019 population estimate suggests a slight decrease in northern pike abundance since 2016 when the adult population was estimated to be 3.1 adults per acre. At nearly 2.5 adults per acre, the northern pike population is of moderate abundance,” wrote Matzke.
The crew captured 831 different pike. The Twin Falls pike size structure has improved slightly from the 2016 survey, but is still below average for the area with 36.1% of the fish longer than 21 inches and 7.9% longer than 28 inches. The largest northern pike went 38.9 inches.
Since largemouth bass and smallmouth bass aren’t easily captured in fyke nets in April because of the cold water temperatures, the crew returned with electrofishing gear for a one-night run in late May and covered 10.8 miles of shoreline in the lower flowage for both bass species.
They netted a total of 269 different largemouth bass, with 266 considered to be adults (longer than 8 inches), at a rate of 24.7 adults per mile shoreline. That was nearly double the average abundance of largemouth bass in the area.
“In all, the Twin Falls largemouth bass population is considered to be abundant. The size structure of the Twin Falls Flowage largemouth bass population is better than the area average with approximately 50.8% of the largemouth bass captured being longer than 14 inches and 23.3% longer than 16 inches,” wrote Matzke.
The biggest fish went a shade longer than 18 inches.
The crew also captured and scienced 72 smallmouth bass on that same run. All of those fish were adults (longer than 8 inches). Abundance of adult smallmouth bass was measured at 6.7 adults per mile, suggesting that smallmouth bass are considerably less abundant than largemouth bass in the lower flowage.
With 30.6% of the smallmouths being longer than 14 inches and 6.9% longer than 17 inches, the size structure of Twin Falls smallmouths is below average for the area.
Yellow perch abundance gauged in 2019 matched closely to the 2016 survey results, which still puts perch at low abundance in Twin Falls. But, perch size structure was just above average for the area with 23% of the fish sampled being longer than 8 inches.
Just like perch, black crappie abundance was assessed during the early spring fyke net survey and was found to be nearly double the abundance from the 2016 survey. That gives Twin Falls one of the more abundant black crappie populations in Florence County. Crappie size structure was slightly below the average, however, with 53% being longer than 8 inches and 20% being longer than 10 inches.
Bluegills are the most abundant panfish in the flowage and is above average when compared to other area lakes. Bluegill size is right at the area average with approximately 67.2% of the fish being longer than 6 inches and 33.0% being more than 7 inches.
Twin Falls Flowage
Nearest town: Florence
Surface area: 928 acres
Max. depth: 50 feet
Water clarity: Stained
Fish species present:
Black crappies, bluegills, pumpkin-seeds, rock bass, yellow perch, white suckers, brook trout (limited), smallmouth bass, largemouth bass, northern pike, walleyes, and muskies (limited).
DNR regional fisheries office (715) 582-5000, the DNR website http://www.dnr.state.wi.us/org/water/fhp/fish, or call Whisler Outdoors at (715) 528-4411.