By Dan Gunderson, Minnesota Public Radio News

A new study finds walleye in the Mississippi River are consistently exposed to emerging contaminants such as pharmaceuticals. But the chemicals are apparently not affecting reproduction of the states iconic sport fish.

A broad range of chemicals can cause male fish to take on female characteristics. An earlier study of bass in the Mississippi found many male bass were developing female reproductive organs.

Researchers at St. Cloud State University wanted to know if those chemicals are affecting walleye reproduction. So they collected walleye for three years at six locations on the Mississippi, from Bemidji to Lake Pepin.

They examined the male walleye to see if reproductive organs were feminized, and also looked for genetic changes.

Read the full story at Minnesota.PublicRadio.org.