About

• Design & Operations of hatcheries in Wisconsin has resulted in walleyes stocked that are female and are most likely triploid (sterile).  I suspect that this has been happening since the conception of hatchery production in the early 1900’s. This is caused by the early handling and incubation of the eggs when brought to the hatcheries from the spawning crews. Temperature and pressure changes during early fertilization and egg incubation can cause this triploid condition.
• Walleye were first stocked in Wisconsin lakes, reservoirs, and rivers in the early 1900’s as sac fry or post larval sac fry soon after they emerged from the egg incubating hatching jar.  If zooplankton food was not available immediately available after they absorbed their egg sac and began feeding, they would cannibal each other and both perish. The survival of these sac fry in lakes was probably minimal in contributing to the walleye fishery at that time.
• Next in the 1930’s & 40’s coop rearing ponds were used or constructed to raise the sac fry to small fingerlings. Methods of fertilization of these ponds were developed to stimulate large zooplankton populations to avoid post larval cannibalism.  At 2-3” walleye small fingerlings are stocked out into lakes as they again cannibalized as the zooplankton food populations drop in these ponds … as zooplankton now becomes too small as a food source for their growing needs.
• From early on walleye hatchery production Wisconsin Natural Resources Administrative Code law required 10% of sac fry to be returned to lake or waterbody of spawning origin. After small fingerlings were produced in coop rearing ponds or WDNR hatchery ponds 3% were required to be returned the waterbody of origin. Even in the early 1980’s WDNR hatchery methods and  stocking operations of walleye sac fry and fingerlings did not follow this code. This did not allow for maintaining genetic integrity of natural stocks.
• Success of stocking these two sizes of hatchery-reared walleye was minimal even after coop rearing ponds were replaced by large investments into onsite hatchery ponds in Spooner and Woodruff from the 1940’s to 1990’s. Also, crews from these hatcheries spent a great deal of time summer seining and trapping minnows and forage fish in both public lakes and private coop ponds to feed both hatcheries reared large fingerling muskellunge and extended growth walleyes. This practice of taking forage from natural populations had to have effects on the lake’s fisheries.
• In the late 1990’s WDNR was pressed to raise larger fingerlings (extended growth) this corresponded to increases evaluation of the walleye fisheries in their northern U.S. because of the Voight decision. The success of  walleye post larval fry and small fingerling stocking contributing to the fishery was found to be limited.  A large amount of money was invested in the hatcheries at Spooner and Woodruff to increase hatchery production of extended growth fish walleye. The WDNR manual code provisions of returning walleye fry and fingerlings to the lake of egg origin disappeared even though it was never critically followed at any time in hatchery history.
• WDNR created their first Walleye Management Plan in 1998 to address problems developing in their management. More money was directed to hatcheries  to increase walleye production.  Also, walleye populations assessments in the wild increased by both the Great Lakes Indian Fish & Wildlife Commission and the Wisconsin DNR that centered around a Total Allowable Catch (TAC) of 15” adult walleye.
• A collaborated 2019 paper entitled Production dynamics reveal hidden overharvest of inland recreational fisheries was written by Holly S. Embke. It speculated on the reason for an approximately 36% decline in stocks of walleye in northern Wisconsin inland lakes and river ecosystems over the last 2 decades. “ Hidden Overharvest”  could only speculate the potential reasons for the declining walleye fisheries but pointed to declining natural recruitment during the first year with possible unproved reasons such as reduced habitat from lakeshore development, climate change, invasive species, competition from other species, on top of analyzed overharvest.
• In the 2023 released WDNR Walleye plan it stated that approximately 80% of the adult walleye in the GLFWC and WDNR populations surveys they conducted in the ceded territory have been found to be FEMALES ( in natural populations the ratio should be 50% Female and 50% Male}. Also, since 1998 when required DATCP samplings of extended growth walleye fingerlings for disease in the DNR Spooner and Woodruff hatcheries 100% have been found to be FEMALES.
• In 2022 the retired Lac du Flambeau fish biologist admitted all the extended growth walleye coming out of their walleye hatchery were also FEMALES.

Note: Ramification of stocking triploid (sterile) female or all female walleyes (that grow faster and compete with the reproducing walleye and other fish in Northern Wisconsin) where nutrients available for growth is limited in the clear and pristine lakes of the ceded territory are now appearing in the lakes of Northern Wisconsin.

This is especially a serious problem affecting the natural reproducing fish populations in lakes. Removal of spawned fish eggs from a waterbody, targeting males during spearfishing, and returning triploid (sterile) female or all female fish to a lake  over time would create the sex ratio imbalance observed in 15” plus walleye.

We suspect intraspecific competition between these sterile stocked fish and other reproducing walleyes and interspecific competition with other fish in these relatively clear and infertile water have seriously affected the population dynamics of the fisheries. In more fertile waters, such as the Fox River Winnebago River system the problem of this sterile triploid production would not be as evident.  Walleye Restoration Foundation, Inc. was created to correct this problem and to provide alternate solutions to restore our northern Wisconsin fisheries.