Sex Ratio Skewed in Some Hatchery Raised Walleye

Mar 19, 2021

Credit 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.

Surveys of naturally reproduced walleye generally show sex ratios closer to a one-to-one male to female or ratios skewed towards males.

Currently, there is no evidence to suggest that skewed sex ratios exist in other hatchery-reared species. 

Now, the DNR will do more work to better understand the issue.

It is unknown whether an uneven sex ratio exists in hatchery-reared fry or small fingerling walleye.

The DNR will also be looking into that.

Tags: