In addition to annual summer surveys on Devils Lake, fisheries workers for the North Dakota Game and Fish Department in Devils Lake conduct regular population assessments on Lake Irvine and Stump Lake.
Walleye abundance in Lake Irvine is lower than in Devils Lake, but most of the fish are in the 15- to 20-size range, according to Todd Caspers, district fisheries biologist for Game and Fish in Devils Lake.
Overall, fisheries workers sampled 18.5 walleyes per net in Lake Irvine this summer. That’s slightly below average, Caspers said, but the size of the walleyes makes the shallow lake a draw for anglers who can get their boats in the water.
“That’s kind of normal up there,” Caspers said. “There’s usually a good amount of those nice keeper-size fish.”
On the downside, boat access on Lake Irvine is limited.
“It’s still pretty poor access,” Caspers said. “The makeshift boat ramp area is pretty much unusable right now with the lower water levels.”
Adventurous anglers will dump their boats off a road on the east side of the lake, Caspers said.
Walleyes on Stump Lake, at an average of 19.2 per net, are above the long-term average of 17 based on this year’s survey results, Caspers said. The number of 20- to 25-inch walleyes, at 2.5 per net, also is above the long-term average of 1.
“There are a fair number of those nicer fish, which has kind of been the trend” on Stump Lake, Caspers said. “”We have seen more nicer fish out there as the population matures.”
Stump Lake is too saline to support natural walleye reproduction and is almost entirely reliant on stocking, Caspers said.
Game and Fish stocked 550,400 walleye fingerlings in Stump Lake in 2019, 827,330 fingerlings in 2018 and 669,976 in 2017.
The assessments on Irvine and Stump are one-day surveys, Caspers said. A few highlights:
Walleyes are doing well on Irvine, but pike numbers were down during this summer’s assessment, Caspers said. Game and Fish sampled 4.7 pike per net, which is below average, but that’s not necessarily a bad thing, Caspers said.
Pike in Irvine tend to be skinny and in poorer condition than pike in Devils Lake, he said.
“(Irvine) tends to be pretty turbid so the pike probably don’t feed as effectively,” he said.
Crews traditionally don’t sample many perch in Irvine, Caspers said, and this year’s survey produced 1.7 per net, which is slightly better than the average of 0.8.
Most of those perch were in the 12- to 15-inch range.
“It’s kind of the way it usually goes,” Caspers said. “You don’t see very many, but they’re nice-size fish when you do see or catch one.”
Crews didn’t catch any white bass this summer on Irvine, he said.
As in Devils Lake, walleyes in the 10- to 15-inch range outnumbered the “keeper”-size 15- to 20-inch fish in Stump Lake, Caspers said. At 3.2 fish per net, the number of walleyes in the 15- to 20-inch range was down from the average of 4.6, a trend Caspers said surprised him.
“I kind of think there’s more fish out there than that,” he said. “That’s what the netting (results) said so that’s the number you’ll get. There’s error involved in these surveys.”
Numbers of 20- to 25-inch walleyes and 25- to 30-inch walleyes both are above average, he said.
Perch numbers, overall, were at 9.5 per net, down slightly from the average of 11.7. Perch in the 5- to 8-inch range, at 8.1 per net, were most abundant. The survey yielded an average of 1.3 perch in the 8- to 10-inch range, down from the average of 2.4; and 0.2 perch of 10 to 12 inches, down from the average of 1.1. Crews didn’t catch any 12- to 15-inch perch on Stump this year.
“It really wasn’t that good of a perch catch on Stump, either,” Caspers said.
Crews sampled an average of 2.2 pike per net, down from an average of 3.5, and 1.5 white bass per net, up from an average of about 1. As in Devils Lake, a majority of the white bass sampled were in the 12- to 15-inch size range from a banner hatch in 2015. Caspers said.