'Mr. Walleye's' work is a legacy for the lakes

Denny Schupp
Denny Schupp, 75, spent nearly 50 years on the state's lakes as a fisheries biologist with the Minnesota DNR. His work has left a legacy of knowledge that's still being used today.
MPR Photo/Tim Post

Denny Schupp sits at a wooden table on his screened porch, dressed in a plaid blue shirt and tan suspenders. A cool morning breeze flows from nearby Upper Cullen Lake. The half-dozen fishing poles standing in a corner by the door tells visitors a serious fisherman lives here.

Years of fishing trips with his father and grandfather gave Schupp a deep love for Minnesota's lakes. He knew that's where he wanted to spend his life. But he didn't know it was an option until he saw a movie in a University of Minnesota classroom in the early 1950s.

Denny Schupp
Denny Schupp has lived on Upper Cullen Lake North of Brainerd since 1961.
MPR Photo/Tim Post

"The movie was of two people on a lake survey," Schupp says. "I looked at these two young fellas out there lifting nets, pulling out fish on a beautiful lake and I said, 'You mean I can make a living doing this?'"

After that revelation, Schupp embarked on a college career that gave him a biology degree in 1955, and a job at the DNR shortly after graduation.

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One of his first assignments was Lake Mille Lacs, where anglers were complaining about a year of awful walleye fishing. He was put in charge of counting anglers and the fish they caught. That's easy to do on an small lake, but Mille Lacs is 200 square miles. So the innovative young biologist developed a new process to determine fishing pressure.

"The method I came up with was to divide the lakeshore into segments of about one to three miles long. We'd count the number of boats landing in these sections during a given period of time, and then also contact and interview anglers coming off the lake for how long they had fished, how much they caught and how big were the fish they had caught," Schupp says.

It's a process the DNR still uses today on Minnesota's big walleye lakes.

Over the years Schupp was sent to several of those big lakes, usually when fishing was poor. He calls them Dead Sea years.

A young Denny Schupp
Denny Schupp tagging walleyes on Leech Lake in the mid-1960s. The photo ran in a magazine called Fins and Feathers in 1977.
Photo courtesy Denny Schupp

Whether it was Lake Mille Lacs, Leech Lake, Lake of the Woods, Lake Minnewaska or Lake Osakis, Schupp's introduction to a community usually began with a contentious meeting.

"We usually came in as the guys in the black hats, because those meetings didn't happen unless fishing had been lousy. I think the attitude of some people was 'You guys have fouled up, you didn't do your job,'" Schupp says.

At most of the meetings, Schupp says anglers wanted the DNR to fix poor fishing by stocking their lake. But he says fishing problems on a lake rarely could be fixed that easily. The mystery usually involved too much fishing, too little habitat, or the amount of natural food available for fish.

"If we explained to them what we were learning as we were going on, that would give you some credibility and they'd give you a little more leeway on doing your work. Eventually I began to feel very comfortable in those communities, and felt I was being accepted as part of the community," Schupp says.

Over the years Schupp has seen more anglers embrace conservation. He says that's made the job of a fisheries biologist easier.

He's been retired for a few years, and now spends time talking to lake associations about how residents can keep their lakes and the fish in them healthy.

In retirement Schupp doesn't have to worry about those tense meetings anymore, but he's more than willing to offer advice to former colleagues over a cup of coffee.

And of course there's plenty of time for the occasional walk down to the lake to catch a walleye.