Baudette, Minn. — DNR Fisheries officials say most conclusions drawn from sampling of Lake of the Woods walleyes this past spring, summer, and fall point to a population that’s healthy, and a lake that’s in recent years been quite consistent in the fish-producing arena.
In fact, data indicate the gill-net catch in the lake that takes in about 320,000 acres of surface water and borders the provinces of Ontario and Manitoba (two-thirds of Lake of the Woods is in Canada) was the highest in the past 15 years, at about 23 per gill net. The long-term average is about 15, according to the DNR.
That’s just one factor DNR officials consider in the management of Lake of the Woods, one of 10 lakes in the department’s “large lake” program. Other indicators, too, were positive.
“We’re comfortable with where we’re at,” said Tom Heinrich, DNR large lake specialist for Lake of the Woods, in Baudette. He said the gill-net catch of walleyes from the lake was a bounce-back from last year, though he believes 2014 – as well as net catches in 2011 and 2012 – better represent walleye numbers in Lake of the Woods.
“I think this year really reflects what’s going on,” he said, adding that timing, fish location, or other factors might’ve contributed to last year’s lower-than-expected catch.
The DNR typically sets 64 gill nets during a fish assessment, 52 of those near shore, and another 12 off shore. Heinrich said it takes crews just under three weeks to complete the net assessment.
There’s more, though, to how closely the department examines walleyes, as well as sauger and pike, sturgeon, and, to a degree, perch.
Seining (nets used to “sweep” beach areas) and trawling (cone-shaped nets pulled behind boats; some rigged for shallow, some for deep water) are used to determine the strength of respective year-classes of walleyes and sauger, according to Heinrich. They’re used in July and August.
Gill-netting is conducted beginning in early September.
There’s also some electrofishing that’s done in the spring, Heinrich said.
According to a status report compiled by Heinrich, “This assessment monitors the size structure of the mature (spawning fish) segment of the walleye population.”
Gill nets are size-selective gear, he said, and usually only capture walleyes up to 22 to 25 inches. Electrofishing “focuses on spawning fish that have outgrown gill nets,” he said.
“The most recent samples depict a walleye population that has changed a great deal since the first electrofishing survey was conducted in 1982,” Heinrich wrote in his report. “One of the highlights of the current spawning population is that it has more large fish in it. In 1982, the most common length of female walleyes sampled was 17 inches. Recently, that has increased to about 26 inches.”
The DNR’s Baudette fisheries office also, thanks to funding restored following the recent license fee increase, conducts creel surveys, twice every four years.
Says the report: “The most important information that creel survey provides on Lake of the Woods is level of harvest. If harvest can be maintained at or below the target, fish populations will remain abundant and healthy …”
Given the information gathered, DNR officials are able to offer anglers some idea of what to expect when they fish the lake.
Predicting angler success, the report says, is difficult due to biological and environmental factors that influence such success.
“However, the sizes of the fish anglers can expect to catch is very predictable,” the report says.
This winter, the report says, anglers can expect to catch good numbers of fish from 8 to 10 inches (2013 year-class), and 12 to 15 inches (2011 year-class).
Further, “Trophy-size walleyes (longer than 28 inches) are about as abundant as anglers have come to expect, and walleyes up to 31 inches are caught annually.”
The DNR manages Lake of the Woods walleyes with a “target harvest” in mind. “The target harvest is based on a number of physical and chemical lake characteristics, and is simply the estimated poundage of fish that can safely be harvested in a year, on average,” Heinrich’s report states.
As for sauger, DNR sampling found the population remains high, at about 15 caught per gill net lift. From 1968 through 2011 the average catch rate was 13.6 sauger per net.
Creel information indicates wintertime anglers will keep walleyes and sauger once they’re in the 11- to 12-inch range. During the open-water season, they’re a bit more selective, depending on the quality of the bite, with fish anywhere from 12 to 14 inches being the lower end of the “keepable” threshold.
For about a decade now, a “slot limit” has protected Lake of the Woods walleyes 19.5 to 28 inches long (it’s likely seldom sauger reach the lower end of that slot). One walleye over 28 inches may be possessed. For Lake of the Woods, the combined walleye and sauger limit is eight (no more than four can be walleyes) from Dec. 1, 2014 through April 14. The open-water limit is six, combined (no more than four walleyes).
Heinrich said the slot limit, when it came to be, wasn’t meant to change the size structure of walleyes. Instead, it was meant to keep the harvest below the target. Anglers preferred the slot over reduced bag limits.
Fishing pressure on Lake of the Woods has been consistent for a number of years now, according to Heinrich.
“The overall pressure is much higher in the winter than in the summer,” he said.
It’s estimated about 800,000 “angler hours” are spent on Lake of the Woods in the summertime. In the winter, the total is 1.5 million to 2 million angler hours, Heinrich said.
“An unfortunate side-effect of the high angler use in the winter is the disturbing amount of trash left on the ice, which then washes up on local beaches in the spring,” Heinrich wrote in his report.
County and state officials have teamed with Lake of the Woods Tourism Bureau officials, he said, to address the problem.