 Lakeland Currents, your public affairs program for North Central Minnesota, produced by Lakeland PBS, with host Ray Gildow. Production funding for Lakeland Currents is made possible by Bemidji Regional Airport, serving the region with daily flights to Minneapolis-Saint Paul International Airport, for information available at BemidjiAirPort.org. Closed captioning for Lakeland Currents is sponsored by Niswa Tax Service, tax preparation for businesses and individuals, online at NiswaTax.com. Hello again, everyone, and welcome to Lakeland Currents. Minnesota's state fish is the walleye. And whenever we have a program about walleye, it has a very wide attendance, I think, of our shows, because there's so many people who fish walleyes in Minnesota. And it's just there's so many interesting things developing. If you look at Malax Lake and the controversies that are there, and you look at a lot of the climate change issues and how it's affecting lakes. So it's always interesting to have people on the show who are experts in walleyes. And my guest today is an expert in walleyes. And there's Doug Schultz, who is the area fishery supervisor from the Walker area. And Leech Lake is under his supervision, so to speak. Welcome to the show, Doug. It's good to have you back on. You were on a couple years ago. Yeah, thanks, Rick. And what's changing? And we're going to talk a little bit about Leech Lake. And then you are also the co-chair of a program on walleye stocking in Minnesota. Is that correct? Yeah, our walleye technical committee, which is our internal group of walleye biologists, you know, most of us in Minnesota are walleye biologists to some extent. And then we work on walleye specific issues around the state. So we'll talk about that a little bit later. Yeah, well, and I suppose maybe sometimes I focus too much on Leech Lake, because you also have other lakes in the area besides Leech. You don't go to Winnie. That's in a different zone. Yep, that's Grand Rapids. But we have a woman lake, for example, a very prominent walleye and small-wealth bass lake, a 10-mile lake, which is another very large and popular body of water. You know, basically my work area is the southern two-thirds of Kass County. So roughly a line from Bacchus in north is mine. And then you get a little bit south of Bacchus. So Pine Mountain is in your area too? Pine Mountain, yeah, that's one of my more southern lakes. So tell us a little bit about your background, Doug. I grew up in Alexandria, or went to high school in Alexandria, grew up on a dairy farm over there. You know, grew up fishing and hunting, like a lot of folks in Minnesota did. My mom actually came from a resort background and went to South Dakota State University for my bachelors, and a master's at Southern Illinois, worked on an evasive Asian carp while I was there. And then bounced around a few times when I came back to Minnesota after grad school and landed in Walker in 2007 as a large lake biologist on Leech. And I've been the area supervisor now since I think 2011. Oh, okay. So it's been a few years now. So you came in at the tail end of the controversy, sort of where the fishing was so tough on Leech Lake? Yeah, it was still pretty controversial as first, you know, probably four years I was there. But you know, the fishing had picked up starting I think in 2007 and 2008 and 2009 and 2010 were pretty red hot in terms of a wall I bite. And then we've really settled back down into our new normal, which has been pretty doggone good. It's kind of interesting because I've fished that lake most of my life. And I remember the years when the lake supposedly collapsed and we couldn't even catch a perch. I remember going out with my son-in-law and trolling with crawlers and we couldn't even catch a perch bite. But then a year or two later, man, we were catching perch, 11, 12, 13 inch perch. So they were there. We just didn't figure out how to get them, I guess. And I think I found that true as a guide that over the years sometimes the DNR will give reports about a lake and they'll say the numbers of walleyes or bass aren't really good. And if anglers aren't catching them, they just don't believe that report. What causes those ups and downs in a lake typically? Well, a couple of different moving parts to that question. The first one, obviously, is recruitment or the number of young fish coming into the fishable population. They really don't count until they're big enough to catch, right? At least from a fishing perspective. So are you looking then at 12, 13 inch fish? Is that what you would count? Well, for walleyes they'd be roughly age two. It is when they start becoming fully recruited to the population. And depending on what part of the state you're in, southern half of the state, you're maybe going to be about 13 inches, age two. Northern half of the state, roughly north of 210, age two is going to be closer to about 11, 12 inches as you move north. So age three is when they really first start hitting the fishery in those northern lakes. So the number of young fish entering the population, that's the first driver. Because if you don't have young fish entering the population, you're not going to have those fish available for anglers to catch. And then the second is, and keeping it very simple here, forage availability, particularly during the summer. If you have a really big perch hatch, for example, that can really shut down a summer bite. And it's our job to make sure the fish are there. We cannot control the bite and we can't control a folks fish. And so when you hit those tough conditions, you really got to look at what you're doing and maybe consider doing something different and something you haven't done before. For example, changing the crank baits in the evenings, mid-summer. A lot of times that can be the trigger to make something happen. It really forces you to get out of your element sometimes if you're not having success. But it also forces you to become a better fisherman. Is the primary forage base on Leech Lake for walleyes, is it still perch? Yes. And how is the Cisco population on the lake? Really good. We have not had a summer kill for five, six years now. So the Cisco population has really rebounded nicely. Saw a lot of one-year-olds out there in the Gillnet survey last, back in September. So that one's really plugging along fine and hanging around seven, eight fish in that. This is the most sustained it's been. Going back to the 1990s. Very much weather-related. Very much dependent on summer kill. If we don't have a summer kill, you'll knock out a pretty good year class every once in a while and be able to persist. Far as Cisco go over in a really good spot. But perch really are the mainstay in most of the lakes in terms of forage base. The mainstay forage in most of the lakes in Minnesota. So our management actions that affect perch, obviously will end up impacting the other predators in the system at some point. Do you feel on Leech Lake that anglers affect the population very much? Of perch, we don't have enough evidence yet to probably point that finger. The walleye fry stocking we did back in the 2000s, where we were marking fry so we could estimate total fry density in the system during those years. There was a pretty strong negative relationship between total walleye fry density and the number of perch basically recruiting to the population four years later. The higher the walleye fry density in a given year, again because we were artificially inflating it, there are just two in those young year perch down. So about four years later when they are reaching the fishery, there's not as many of them. The perch are down. Exactly. But this year you said that looks like there was a real good perch hatch this spring. Yep. So we do trawling, which is basically like a big shrimp trawl that we drag on the bottom of the lake for standardized locations and duration. And we saw the highest abundance that we've seen for young year perch in the last five or six years. Wow. So a pretty good hatch of perch this year. Growth on them was phenomenal. That's some of the fastest growth we've ever seen. Really? Yeah, they must have come off at just the right time when the weather really straightened out and had a good summer. So they're looking very promising. And we also ended up having a record walleye hatch this year too in our trawl catch rate. Really? Young year walleyes was the highest we've ever seen. Ever? Ever. Wow. It blew the old historical high out of the water. The old high was 500 and some an hour and this was 775 an hour. Wow. A tremendous amount of young year walleyes out there. Growth suffered a little bit because of that. Too many. A lot more miles to feed. So not a big surprise there, but it's predicted to be above average at worst year class and it could be a pretty big one. So two or three years down the road it could be pretty darn good. I know I had Mark Bachigalupi on here, the Brainerie area fishery supervisor. And he said they measured a couple of muskies that they put in the gall lake last year. And they doubled their length in one year because he thought the forage basin gall was very similar. So that forage base has a lot to do with how fast these walleyes grow, doesn't it? Forage base is one of that. Density is another. Again, the more miles you have to feed the less there is to go around. So growth will end up suffering if there's too many miles out there. And then the other is just age. Young fish, their goal is to get as big as they can, as fast as they can. In doing so, you have more forage options available because your mouth size is bigger, gape. So the bigger you are, the easier it is to keep yourself full, right? And then the other is the bigger you are, the harder it is that you're going to be predated on by somebody bigger than you. So growth is really key in the first few years of life for any species. That's when most of the growth occurs. As they hit sexual maturity, so for walleyes we're talking roughly age two to age three for males, females are age three to age four typically. That energy starts going into reproduction, and so growth rates will start slowing down. What are you seeing in leech with a small, large bass population? We're not seeing it in our gear yet. Historically they've always been there, kind of just that random occurrence in the background. We're not seeing them increase in our gear yet, but anglers are telling us they're running into it more often. And I caught one last year off of two points, fishing for walleyes. They're out there and it's not going to surprise me if they take off. You mentioned climate change, AIS is another one of those things that really changes the lake. Climate change is another one. Smallmouth in particular expected to be one of the big winners out of some of the change that is coming. We have zebra mussels in Leech Lake now, and we found villagers in 2016 for the first time. And then this fall we had our first adults on a boat that had been moored in the lake the past two summers. So that was our first occurrence of adults. Obviously they're going to have big impacts on water clarity, and smallmouth in particular seem to do very well when the water clears up. And that's not just what we've seen here in Minnesota. That's Minnesota, Wisconsin, Michigan. Across the range smallmouth do very well as water clears up. And that lends also to the talk about changes in our walley populations looking ahead. Again, as our water clears up and our summers also become a little bit warmer, but walley production is not as high with clearer water. And again, that's something we're seeing in multiple states, not just in Minnesota. We've done a good job of cleaning up our impacts around the lake. Septic systems have gotten cleaner, we're no longer straight pipe and effluent. And our water quality is coming back to probably what it used to be historically. And in a lot of cases walley management is changing a little bit. We're not having the success, particularly with stocking that we used to in some of those cases. So that's just a tidbit that I'm sure we'll probably touch on in the future when we have more information. But as lakes change, the fish populations in them are going to change with it. We've already seen that in the Brainerd area with the clearing up of the lakes. It's made it a lot more difficult in the summer to fish walleyes. And it's made them go to different places than we used to see them. So it's an unfortunate evolution of what's going on. What would you say would be the top three walley lakes in your area, in your zone? Well, obviously Leech. And then if we put that kind of in its own class, the next three women lake right now is absolutely cranking. That's one that, you know, we did similar fry marking out there and deliberately manipulated total fry density using what we were putting in. And what we found was, again, that same thing we had talked about before, the higher the fry density, the slower the growth and actually the worse the recruitment was to the population a few years later. So we backed our fry stocking down quite a bit out there and it's really responded well. Is there any natural reproduction going on? Yeah, there's always some going on in the background and it varies from very little to a lot. So our new plan now with how our stocking fry out there is really aiming for that midpoint on a consistent basis. So we're stocking 500 fry per little acre every year and it's because of the egg take operation, it's always been annual stocking anyway, but the densities have been quite a bit higher, as much as 5000 fry per little acre, so 10 times higher. And we were basically just swamping the system. So that 500 fry per little acre, when we look at that as a function of recruitment of those year classes, that's really the sweet spot that we saw out there. So that's our aim point and that way if we have, with the exception of really high natural reproduction, if we have any of that moderate to below, we're really in a good spot as a whole. And it's been working well. We've just got a monster year class of one year olds out there right now, so in about two more years. So it's about 2019, that one's really going to turn on. And what would you consider probably the third best lake? There's a handful of them, 10 miles, one of them that's very consistent. Very clear lake? Yeah, very clear, deep. And that's one actually where walleye fingling stocking has worked better than anything else we've tried. Again, a little bit of reproduction going on in the background, but not consistent. And fingling stocking in that case has worked well. That's one of the lakes, and we'll get into this with the Auxiliary Walleye Program. That's one of the lakes where we doubled the stocking rate of fingerlings, because fingerlings were already working, so more fingerlings might work better, right? That's what a lot of AWP was. Double the rate of fingerlings and let that run for about 10, 12 years, and it just didn't move the needle. So went back down to our traditional one pound every other year rate, and expect that one to just keep clicking along. So do you survey all these lakes every fall in your area? Oh, not even close. So you just kind of a rotation? Yeah, Leach is annual. A woman has been annual because of the Frye study. We're going to go to every other year, I think, after next year on that one. And then the restaurant are roughly a three to five year rotation, three to six years. And then that's on the walleye lakes. And then we have a bunch of bass panfish lakes that we just don't get into very often, the 200, 300 acre lakes. We'd like to be in there more, but there's just not enough time and not enough bodies. How about when you look at the musky populations, are you doing most of that survey stuff in the spring? And what are you finding on Leach Lake with the musky population? Well, that's one we can't survey effectively. A couple of reasons. One is it's 112,000 acres, and it takes a lot more bodies than we have. Two is the exposure to the wind. On a lot of cases, we would expect to run into problems with nets getting rolled, and you end up with mortality issues then when that happens. And then the third one is a lot of the, and apparently the most limiting factors, a lot of the spawning habitat is actually offshore. So Leach, as you know, has those big long sloping flats in a lot of places, and a lot of the spawning habitat is in fact on those. Well, we only have 100 foot leads on our nets. And in some cases, we're a quarter mile offshore is where the muskies are actually at. We just can't get to them effectively. So, you know, unfortunately that's one we just, it's always on our wish list of things we'd like to do, but we logistically, we just can't come up with a good way to do it. It's like going out on 112,000 acres to find a deer. They're just moving all over. Yeah, yeah. And you know, we've got a pretty good idea of where to look. It's just being able to get your hands on enough of them to make it informative. That's the biggest limitation. We did do egg take out there again last year, this last spring. We do that once every four years for the statewide musky program. And, you know, that went well. I think we handled probably about 40 fish again, which is normal for us. And, you know, our best day was, I think, right away when we got going and then the weather started cooling off, so catch rates tailed. But yeah, it's, you know, as far as we can tell, everything's great. And, you know, what we've been hearing from anglers is there's still seen a lot of fish in the mid-thirties and low-thirties, which, you know, those would be in that, you know, roughly four or five-year-old range. So that's the ones that are coming up. Yeah, that's interesting. Well, let's talk a little bit about your estate task force that you're involved with. What's the purpose and what is it exactly? So the Walleye Technical Committee was, and we actually have these technical committees for, you know, all the major sport fish species in the state. So I believe there's a catfish one. The Walleye one, the pike, muskie, and bass, and I think panfish as well. So those were formed, almost all of them back in about 2013 by fisheries chief, Dirk Peterson, at that time. And the charge to the Walleye Technical Committee, one of our charges, to evaluate the Accelerate Walleye Program, and particularly the higher-fingling stocking densities, is dumping in more fish having the desired effect of increase in abundance and availability to anglers. So we got started on that, you know, probably by 2014 with pulling data together, things like that. And that was a slow and painful process, which Dale Augston, which is a research co-chair on the committee, on the management co-chair, Dale did a lot of that heavy lifting in the background. And you got it to a point where we could look at it from a statewide, you know, broad statewide perspective. And the net change in gill net catch rates, just as the blunt metric, the net change was zero. It was a perfect bell-shaped curve centered on zero. So as many lakes had increased, you know, for the number of lakes that increased, we had pretty much the same number of lakes that decreased. And the bulk of them, 75% of them were in that, plus or minus three fish per net range, which depending on where your starting point is, that is or is not a meaningful number. So it was pretty obvious to us as a group that the best way to tackle this was at the individual lake level. And that's, you know, what I and Dale and then Dave Weitzel, who's not on the technical committee, but he's the area supervisor in Grand Rapids, we hashed out an Excel-based program where we can enter in our gill net survey data. And, you know, this is where the us aging fish becomes very important because then we're able to compare your classes and, you know, the relative strength of them within that lake. You know, we drafted that program, got that out in the hands of our areas for them to use, and that's the tool we're using to evaluate stocking in the state now. So they, you know, put all the data in and they look at it and recruitment is one of the big ones. You know, we're stocking an individual year class with our stocking efforts. If it's working, then those stock year classes should be stronger than non-stock year classes or year classes that were stocked with something different, right? And that's, you know, basically you look at it and say, well, are they stronger or not? And then there's some empirical methods to do the same thing, working with the average values and stuff like that. And so we rely on our recruitment patterns, our stock year classes, or the year classes stocked at a higher rate, stronger than what they were otherwise. We have our overall, while I gill neck catch, is index of abundance. We also include growth rates in that while I growth rates, because if we're overdoing it and food's becoming limiting, we'll see growth rates slow down. The reason that's important is, you know, if it takes them an extra year because of that to reach the fishery, all natural mortality is always happening anyway. So whatever gains we might have had with the extra numbers, we end up losing over the course of that extra year just because of natural mortality alone. And it's also a pretty good indication if you're limiting forage for walleyes, you're probably going to have the same effect on pike and some of the other predators in the system. Our perch catch rates are also one we rely on in that method. Forage availability, when we have higher perch numbers, we tend to do better with walleye management, vice versa. That's a really important part of that equation. So anyway, we got that in the hands of our area supervisors and they already knew which lakes were getting stocked at a higher rate, which weren't. And, you know, fed the data in and they each made their own decisions and own conclusions on an interpretation on what the outcome was. So, you know, in summary, there's 254 lakes statewide that fit this approach. And of those 254 lakes, about 70% of the time we failed to move the needle by dumping more fission. You know, 50% of them, if I remember right, about 50% of them were unchanged and about another 25% actually declined and went the wrong direction. So, in a lot of those lakes, we're simply going back down to our historical half-pound annual equivalent rate. So we're still stocking them. We're just not dumping in twice as many for the same outcome. Because it just didn't pay off. Yeah, it's, you know, the purpose of dumping fish in is to have more fish available. And then you did identify some lakes, too, I believe, where you're just not going to stock anymore. Yeah, that was only eight lakes total out of the whole group. And those were lakes that we've already tried to fry. We've already tried fingerlings. We've tried a high density and that didn't work. And then the fingerlings at a high density also didn't work. You know, those are, you know, by and large bass pan fish lakes by design. You know, we managed to force walleyes in there for, you know, probably the past 30, 40 years. But it's, you know, with climate change and some of these other changes that are happening, it's just not sustainable anymore. So, but you're also identifying some lakes, I believe that you're going to maybe do more stocking because you think there will be a value to it. Yeah, there's a handful that were identified for increasing a little bit. That was, you know, maybe five lakes, something like that. And then there was about another 30% of lakes, probably 40% of lakes were, you know, no change. They felt it was management objectives were being met, so they left it alone. So, it's pretty interesting that you're doing this as a statewide perspective. Probably it's never really been done before, has it? Not at this level. Yeah. You know, we've had different studies. You know, Brad Parsons' 50 Lake Study, for example, that was, you know, 50 lakes scattered around the state where, you know, they manipulated stocking densities and stuff like that. And it looked at it under the microscope. This is a more broad approach, but it still drills down to the lake level. You know, the increase in stock, the fingerling stocking density, that was, that change was made statewide with a broad brush approach. And it didn't have similar broad brush impacts, you know, at least what we were looking for. So it did not make sense to, you know, equally, you know, make the same change going the other direction, particularly on those lakes where we did have success. And those are obviously going to be maintained. Now, when you do research on the lakes, what data is available online? How do people get to that? Well, that's the lake survey data information. The report Dale and I, the summary report we've pulled together, I don't think that's been made available yet. Not yet. I would expect that will probably be posted on the DNR website. Okay. So good stuff, interesting information. And as scientists, you're always trying to understand what's going on. And now climate change is throwing another little loop in there, making it more complex. Really interesting information. And I go to those websites often to try to find out what's going on on the lakes and appreciate all the work that you guys do. It's a very, very challenging job. Yeah. But it's good information. Yeah, thank you. And you know, if folks have a question about their specific lake, just touch base with the area supervisor for that lake and have a good discussion like we did today. Great. Well, thanks for jumping on with us, Doug. Appreciate it very much. Yeah, thanks for having me. You've been watching Lakeland Currents talking about what you're talking about. I'm Ray Gildow. So long until next time.