By Kirsti Marohn

MPR News/90.1 FM

On the choppy waters of Mille Lacs Lake, Tom Jones steers a 26-foot aluminum boat within arm’s reach of a bright orange buoy.

Greg Berg and Kris Nissen lean over the side and start hauling in a 250-foot gill net hand over hand. The net has holes of different sizes in the mesh designed to catch different types of fish.

“This is probably one of the heavier nets we’ve had this year so far,” said Berg, an assistant area fisheries supervisor with the Department of Natural Resources, as he pulls it in. “A lot of it’s tullibees. Some pretty nice walleye in there too.”

The gill netting is part of the DNR’s annual fall assessment on Mille Lacs Lake, which has been underway since early September.

“They catch all the species in the lake pretty well, which is kind of the point, is to get a picture of the forage fish and game fish and everything that’s out there,” Berg said.

With tighter walleye regulations on Mille Lacs the last few years, the DNR’s work is under intense scrutiny. The data collected during this survey will be used to determine next year’s safe harvest limits. It also will help provide clues for what’s causing the lake’s walleye population to decline.

Jones, treaty coordinator for the DNR’s northeast region, has been surveying Mille Lacs for almost 20 years. In that time, he’s seen lots of changes.

“We’ve seen the walleye go from real big heavy walleye,” he said. “And now there tend to be skinny walleye, which is why the bite is so good. The walleye are hungry. So even though there’s fewer walleye, because they’re so hungry, anglers are finding them easier to catch.”

Jones many factors could have caused the lake’s walleye to decline over the past decade.

The water is clearer, and there are fewer small forage fish for the walleye to eat, he said. More recently, the lake has become infested with invasive species like zebra mussels and spiny waterfleas, which compete for the same resources down the food chain.

There’s also been an increase in smallmouth bass, possibly due to climate change, Jones said.

“The warmer water favors warmer water species,” he said. “In Mille Lacs, we’ve seen an increase in bass, a decrease in tullibee, a decrease in burbot. Burbot are almost gone from Mille Lacs.”

But area business owners have been skeptical of the DNR’s findings, saying the walleye fishing on Mille Lacs is as good as it’s been in years.

Dean Hanson, owner of Agate Bay Resort and co-chair of the Mille Lacs Fisheries Advisory Committee, said some of the gill net locations were picked 40 years ago ‐ before GPS technology.

Since then, the DNR has added more nets in deeper water offshore. But Hanson said there are still too many in the shallows where there aren’t walleye anymore.

“They’re not going to show that they found many fish,” he said. “But that’s not going to convince me that there’s no walleyes in the lake. I just see too many healthy fish out there for that to be in the case.”

In response to such skepticism, this year outside experts will review the DNR’s science and management of Mille Lacs. DNR officials hope that will help rebuild trust.