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.