9/7/2019 7:30:00 AM Walleye population on the rise on the Minocqua chain Natural reproduction still not detected
Jacob Friede Of the Lakeland Times
In 2015, with the goal of boosting a depleted adult walleye population, all walleye harvest on the Minocqua chain of lakes, by angling and spearing, was shut down.
The regulation was a key component of a walleye rehabilitation project put into place by the Headwaters Basin chapter of Walleyes for Tomorrow (WFT), the Lac du Flambeau Band, the Great Lakes Indian Fish and Wildlife Commission (GLIFWC), and the Wisconsin Department of Natural Resources (DNR), and it protected a half decade of intensive stocking that put tens of thousands of extended growth walleye into the chain every year.
Those five years of fishermen's patience have made progress.
According to the recently publicized results of a spring 2019 snapshot survey conducted by GLIFWC and WFT on Lake Minocqua and Lake Kawaguesaga, walleye population numbers have significantly increased.
The population estimates indicate that on Lake Minocqua, which was fyke-netted and electrofished this past spring, there are about 3.7 adult walleye per acre. On Lake Kawaguesaga there were just under three adults per acre, although Kawaguesaga was only electrofished, which would lead to a lower estimate.
The population goals of the rehab project were three adult walleye per acre on Lake Minocqua and Kawaguesaga and two adult walleye per acre on Lake Tomahawk.
According to Mark Luehring, the inland fisheries biologist for GLIFWC, which led this past spring's survey on the chain, the numbers, though not at their historic levels, were progressive in terms of those goals.
"It's encouraging news, but it's not great news," Luehring said. "Minocqua was almost four times as many walleyes as when we started the project in 2015, and Kawaguesaga was about twice as many adult as when we started in 2015. So that's good. That's good growth in the population."
Stocked fish survival
Luehring also noted the higher adult population is evidence that many of the stocked fish are surviving.
According to the 2019 survey results the 2013 stocked class had approximate survival rates of 7.3% on Lake Kawaguesaga and 10.2% on Lake Minocqua. Those are strong rates. In 2013, 6,700 extended growth walleyes were stocked on Kawaguesaga and 13,596 were stocked into Minocqua.
The 2015 stocked class, however, showed much lower survival rates. Approximately 0.1% of 6,996 stocked fish have survived on Kawaguesaga while 0.5% of 13,377 stocked fish have survived on Minocqua. But this is most likely due to the fact that the 2015 class has not matured enough to show up on the spring spawning grounds and therefore were not located in the nets or during electrofishing.
Mike Vogelsang, DNR fisheries supervisor, said the stocking schedule, which puts 10 walleyes per acre on Lake Tomahawk in even number years and the same amount on Lake Minocqua and Kawaguesaga in odd number years, has the population on the right track.
"Any time you can start from essentially no walleye and build that population up to the level it is right now through stocking that's very good," Vogelsang said. "We still have a ways to go, especially with regard to Kawaguesaga, we're just a little bit below our goals there, but it's very, very encouraging, and it's really a testament to the fertility and productivity of the chain."
WFT's Headwaters Basin Chapter chairman Tom Kramer was satisfied with the progress of the population, but would eventually like to see the chain surpass the original goals of the project.
"It's better," he said. "But I'd like to see it up to four or five (walleye per acre)."
Joe Graveen, a Lac du Flambeau representative on the Voigt Task Force, also involved in the project, said the period of no spearing has been worth it, though he, like Kramer, would like to see even higher adult walleye population numbers.
"Even though those numbers came up, they're not quite where we want them to be," Graveen said.
Another year of closure
To give the chain a chance to continue increasing adult walleye population densities, all parties involved are in favor of keeping the chain closed for one more year, and the number one reason for that is a higher adult population density increases the chances of natural reproduction on the chain, which was a major goal of the project and something that has not been identified in the fall young-of-the-year surveys done on the lakes.
Those surveys are done in the fall before the stocking of the extended growth walleyes, and they're intent is to find age zero fish that have survived the summer. They are between five and seven inches. Because the stocking has not yet occurred, fish that size are clearly naturally produced.
"They come in shallow and feed, kind of in September and October, and so that's a good time to see if there's any juvenile walleye around," Luehring said.
Unfortunately only a handful of naturally produced juvenile walleyes were found during a DNR survey last fall. Vogelsang said a lot more is needed to be seen to indicate natural reproduction.
"To make a significant contribution from those natural fish, it would be nice to see something in the range of 10-15 young of year fingerlings per mile," he said. "If we go out there in a couple weeks and shock the entire shoreline of the chain, we'll add up the total number of young-of-year fingerlings that we catch and divide that by the miles of shoreline that we shocked and that provides us an index, or a catch per effort, and 10-15 would be a good number to see. That would be an indicator that, all right, we got natural reproduction back."
To get closer to those type of numbers, Kramer said WFT is absolutely pushing for one more year of closure.
"One more year at least," he said. "Until we know we've got a good amount of young-of-the-year that we're seeing that are hatching. You can't just stock and take. You've got to have that natural reproduction to keep the population going."
"Get those numbers up," he said. "Those numbers keep coming up and the natural reproduction kind of moves along."
The numbers that really need to go up are male walleyes. On good naturally reproducing lakes, more males than females are found on the spawning grounds. The 2019 survey results showed that there was a male to female ratio of .38 on Lake Kawaguesaga. On Lake Minocqua that ratio was .51.
"It's a little bit unusual to see more females than males in these population estimates which is what we saw this year," said Luehring, who went on to explain reasons why males typically dominate the spawning grounds. "The males mature probably a year to two years earlier than the females. That's two less years of mortality that they've had before they're mature ,and so there's probably a few more males overall that are mature in the population than females. And I think the other thing is it's behavioral. The males just kind of sit on the spawning grounds and wait for females to swim up and the females will swim up and usually release eggs and then move off the spawning grounds. You have a better chance of seeing the males."
For the sake of more male and female walleyes Luehring said one more year of closure would be beneficial.
"I think another year of closure would give the population an opportunity to grow a little bit more to continue to expand and hopefully increase adult density which could lead to a better chance of natural reproduction."
Keeping the chain closed another year would also allow Lake Tomahawk to be surveyed before the decision is made to open it up for harvest.
"We don't have any data yet on Lake Tomahawk, and the partner group was thinking, 'boy, it sure would be nice to have that as well before we open it so we know we're on the right track for all three lakes,'" Vogelsang said. "So, if assuming the chain is closed for another year, we would go into Tomahawk next spring and do a walleye population estimate out there. And that way we have current data on all the major water bodies on the chain which would be very helpful going into 2021."
Public input needed
In order for the chain to remain closed another year, the DNR would first hold a public meeting to gauge support. If the public opinion is favorable, the DNR could then enact an emergency rule that would extend the no- harvest regulation.
"Basically, what we want to do at this point is get the data out there. The info that GLIFWC collected this spring," Vogelsang said. "And talk about the proposal that we want to do, in other words keeping it closed for another year. Answer questions, listen to concerns, and if input is favorable to do that then certainly we would move forward with the emergency rule process."
Thanks to the collaborative efforts of the groups behind the rehab project, the Minocqua chain has made huge strides toward a walleye population comeback in just five years. It's now up to the local fishing community to decide if one more year of patience is worth seeing that success with natural reproduction.
The date, place and time for the meeting will be set soon.
Jacob Friede may be reached at firstname.lastname@example.org or email@example.com.
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