Series of weak year-classes drives dip in Lake of the Woods walleye abundance, survey shows

Nov. 25—BAUDETTE, Minn. — Walleye abundance in Lake of the Woods lingers slightly below management goals, and while sauger numbers remain strong, they're slightly below the 20-year average, according to data from the Minnesota Department of Natural Resources' fall gillnet survey.

Crews from the DNR's area fisheries office in Baudette sampled 12.8 walleyes per net during the annual assessment, down from the historical average of 15.2 but up from 11.5 in 2021. Combined with results from 2020, when crews sampled 12.8 walleyes per net, the 2020-2022 average of 12.3 lags below the DNR's three-year management goal of 13.9 walleyes per net for walleye populations in Lake of the Woods.

Saugers, meanwhile, averaged 16 fish per net during the September survey, the DNR said, down slightly from the 2002-2021 average of 19 per net, but still above the management goal of 15.7. Survey crews sampled 23 saugers per net in 2021 and 25.7 per net in 2020, putting the three-year average at slightly more than 21.5.

Sauger numbers peaked between 2008 and 2010, primarily driven by a boomer year-class in 2006, the DNR said. A year-class represents the number of fish from a particular year's hatch that is recruited to the population.

According to the DNR, the decline in walleye abundance results from weak year-classes in 2012, 2017 and 2019. The 2011, 2013 and 2014 year-classes were strong, the DNR said, while hatches in 2015, 2016, 2018 and 2020 were average, at best.

"Ideally, we'd like to see walleye abundance stay above the management goal of 13.9 fish per net, but it's not surprising, due to the below average year-classes produced in 2017, 2019 and 2020," said Brett Nelson, large lake specialist for the DNR in Baudette. "The strength of recent year-classes ultimately drives abundance, and the table is set to have a couple of strong year-classes to come through.

"Ebbs and flows in walleye abundance are common in naturally reproducing populations, and Lake of the Woods is no exception."

The DNR conducts the fall population survey over 17 days, beginning the Tuesday after Labor Day, setting 64 nets at sites across the Minnesota side of the lake from the south shore to the Northwest Angle and leaving them in the water overnight.

Fisheries crews then tally the number of fish from a given species, measure the fish and determine their gender and state of maturity.

Small walleyes from 8 inches to 10 inches long were abundant in the fall survey, the DNR said, suggesting the 2021 year-class may be strong. Walleyes aren't effectively sampled in the survey gear until they're 2 years old and about 10 inches long, the DNR said. In general, a 3-year-old walleye in Lake of the Woods is about 12 inches long.

"The lower end of harvestable-size fish (about 12 inches to 14 inches) is well below the 20-year average," Nelson said. "Walleye 14 to 19 inches are just below average."

The abundance of walleyes 20 inches and larger has remained relatively stable over the past decade, at about 1.5 per net, Nelson says. This year, 10% of the fall walleye catch was within the 19 1/2 - to 28-inch protected slot. Meanwhile, 0.7% of the walleyes sampled during the survey were greater than 28 inches, up slightly from the average of 0.5%.

Based on results from this year's fall survey, saugers from 11 inches through 16 inches were above historic averages. Smaller saugers were less abundant, however, suggesting weaker year-classes in 2020 and 2021.

What the findings mean for winter fishing prospects is difficult to predict, Nelson says.

"Based on data from our recent fall surveys, it could be reasonable to expect lower-than-average numbers of harvestable-sized walleyes in the 13- to 16-inch range, but good fishing conditions can provide a better catch rate than expected," Nelson said.

The survey also tallied the highest yellow perch catches since the early 2000s, Nelson says, with numerous perch less than 10 inches documented.

That hopefully will result in some quality-sized perch in the next few years, he said.

Anglers last winter logged 2.6 million angler-hours on Lake of the Woods, based on results from a winter creel survey, slightly more than the six-year average of 2.4 million hours. Fishing pressure has exceeded 1 million hours every winter since 2000, the DNR said, with a steady increase every year. Pressure has exceeded 2.5 million hours each of the past three winters.

The increase in winter fishing pressure didn't translate into more fish kept last winter, the DNR said. Anglers last winter kept an estimated 260,000 pounds of saugers and 160,000 pounds of walleyes, both of which were below the six-year average of 352,000 pounds for saugers and 265,000 pounds for walleyes.

The DNR is planning another creel survey this winter on Lake of the Woods, Nelson says.

"We highly encourage folks to participate in the survey," he said. "Our interview process is very concise, and during busy periods, I'd expect the interviews to take less than a minute to conduct."