Sex Ratio Skewed in Some Hatchery Raised Walleye

Mar 19, 2021
Wisconsin DNR Facebook

The Wisconsin Department of Natural Resources wants to figure out why some hatcheries produce more female walleyes than males.

The DNR conducted a preliminary analysis of hatchery-reared extended growth walleye sex ratios in 2019.

That led to more in-depth research in the fall of 2020, including additional walleye from both the Art Oehmke hatchery in Woodruff and Governor Thompson fish hatchery in Spooner.

These preliminary investigations indicated hatchery-reared extended growth walleye showed sex ratios favoring females.

iStock/ Willard

Katherine and Clear Lakes in Oneida County and Laura and Anvil Lakes in Vilas County all have the same problem.

Their once productive walleye population hasn’t been producing much these days.

John Kubisiak is a DNR Fisheries Team Supervisor. He doesn’t know what is causing the decline.


The Wisconsin DNR is in the process of updating its 20-year-old Walleye Management Plan.

WXPR reported this when public comment opened back in September. Since then, the DNR has done 7 of the 13 regional meetings and gotten more than 1,600 comments through the online form.

DNR Senior Fisheries Biologist Max Wolter is the co-leader of the DNR’s walleye management team.  He says the feedback the DNR has gotten so far has been very helpful.

Wisconsin DNR

Five years ago, the DNR put restrictions on walleye on the Minocqua Chain of Lakes.

Walleye populations had dropped significantly. In an attempt to revive the population, the walleye became catch and release only on the chain.

Since then, the population has recovered.

But the DNR isn’t sure if it’s recovered enough to lift that the catch and release regulations.


It’s been more than 20 years since the current DNR walleye management plan in Wisconsin was created.

A lot has changed since then including the current state of the walleye population.

“When we think about northern Wisconsin, there’s some very specific issues that walleye are facing that just didn’t exist in the 90s that we need to take into account with our plan. That includes lower rates of natural reproduction and more reliance on stocking,” said Max Wolter. Wolter is a fisheries biologist with the DNR and he’s the co-leader of the Wisconsin DNR walleye management team.

Ben Meyer/WXPR

Are the Northwoods walleye you catch safe to eat, or do they have too much mercury?

The answer is tied to several factors, but new research shows a surprising variable might have the biggest effect.

The water level of the lake where you caught the fish could tell you more about its safety than anything else.

The realization of the connection started years ago, when lakes researcher Dr. Carl Watras found an interesting trend.

Greg Matzke

Perhaps more than any other fish, northern Wisconsin identifies with the walleye.

But walleye populations in many local lakes have been struggling.            

Some are even at risk of disappearing completely, as the populations are no longer naturally reproducing.

Fisheries biologists have had to get creative to try to address the problem, and they’re doing it in different ways in different parts of the Northwoods.

The Minocqua chain is a prime example.


DNR Wardens are heightening their presence on the Minocqua-Tomahawk chain of lakes this summer to enforce catch-and-release rules for walleye newly in place this year.  

As DNR Warden Dave Walz explains, a collaborative plan with the Great Lakes Indian Fish and Wildlife Commission calls for extra monitoring to ensure no fish are taken.  

Walleye Rules Draw Optimism and Concern at Public Hearing

Jun 13, 2015
Natalie Jablonski / WXPR News

People have until June 30th to submit written comments to the state DNR on how walleye are being managed in northern Wisconsin’s ceded territory.  That includes feedback how specific lakes should be regulated.

A public hearing held Friday on the topic drew few participants, with just four members of the public attending.  


The state Natural Resources Board has implemented  a plan supporting a five year catch-and-release only walleye fishery on the Minocqua and Tomahawk chain of lakes. The plan was brought forward by Northwoods angling groups, community leaders and Chippewa tribal leaders with support from DNR as part of a plan to restore natural walleye reproduction. The Lac du Flambeau Band of Lake Superior Chippewa  agreed not to harvest these lakes during the rehabilitation plan.


The Minocqua and Tomahawk Chain of Lakes are likely to have a catch-and-release only season for five years under a proposal going to the Natural Resources Board next month. But as part of the same proposal, all waters in the Ceded Territories in Wisconsin would have a standard three-walleye daily bag limit.

DNR spokesperson Joe Hennessy says bad walleye reproduction in the last couple of years has also led to the change on the Oneida county chains. He says the Lac du Flambeau Band of Lake Superior Chippewa have also agreed not to harvest on those waters during the five years.

Eric Engbretson / US Fish and Wildlife Service

Wisconsin’s Natural Resources Board has again laid the groundwork for giving more flexibility to the DNR, when it set bag limits for walleye later this spring.

The agency adjusts harvest regulations on northern lakes in the ceded territory, after the state’s Chippewa tribes declare how many fish they plan to harvest. 

As Fisheries Management Section Chief Steve Hewett explains, a scope statement passed Wednesday means DNR could later decide to use size limits or season restrictions to help control angler walleye harvest.    

Eric Engbretson / US Fish and Wildlife Service

Researchers at the Wisconsin DNR are looking for answers as to why walleye populations are declining in the state.

DNR Research Scientist Gretchen Hansen says adult walleye numbers are declining statewide by an average of two percent per year. 

“So there’s a lot of variability.  So in some lakes, populations are going up, but in the majority of lakes populations are going down.  And a lot of that is driven by failed recruitment, so failed reproduction.” 

Oakley Originals-Flickr

14 of 21 lakes named yesterday receiving higher daily walleye bag limits are in Oneida, Vilas and Price counties.

The DNR announced changes Monday increasing daily limits from one to two on 21 lakes. May 28, Governor Walker approved an emergency rule adopted by the Natural Resources Board allowing the increases.

DNR to Consider Raising Bag Limits on More Lakes

May 28, 2014

A few more lakes could still see higher bag limits for walleye. 

The state Natural Resources Board has approved an emergency rule that gives the DNR slightly more leeway in adjusting bag limits for nontribal anglers.