New Round Goby Emergency Rule In Effect On The Winnebago System

Wisconsin Department of Natural Resources (DNR) enacts an emergency rule regarding the capture and take of the invasive round goby in the Winnebago System

Beginning June 19, a new DNR emergency rule will allow anglers in the Winnebago System (Lake Winnebago, Lake Butte des Morts, Lake Winneconne, Lake Poygan, and the Upper Fox River) waters to keep in their possession any harvested round gobies provided that the fish are eviscerated, decapitated or had their gills removed. Since a round goby population has not been established in these waters, angler harvest and reporting of all gobies taken will serve as a critical tool for tracking the presence of round gobies in the Winnebago System. The rule will be in effect June 19 – Nov. 16, 2026.

A round goby from Lake Winnebago was first reported by an angler and confirmed by Oshkosh DNR staff on June 2, 2025, and additional gobies have been caught and reported by anglers since this initial capture (read here for more information on the timeline of goby discovery in the Winnebago System), but there are still unknowns regarding if/how the goby overwintered and the status of the population.

What To Do If You Catch A Round Goby

Anglers that capture a suspected round goby in the Winnebago system should decapitate or eviscerate the fish or remove the gills and report it to the DNR. The best way to report the goby is to use the DNR’s Online Goby Reporting Tool, which prompts the angler to include a photo to facilitate ID verification, and will prompt a contact from DNR staff. Anglers may also bring suspected goby specimens to the DNR’s Oshkosh office to facilitate ID verification by freezing or putting the deceased specimen on ice in a plastic bag. The office is open 8:30 a.m. – 4 p.m., Monday through Friday. Any round gobies captured downstream of the Neenah or Menasha dams or in Little Lake Butte des Morts do not need to be reported, as it is not a part of the Winnebago System and these areas are known to have a verified and established population of round goby.  Gobies captured in Green Bay or Lake Michigan also do not need to be reported.

Before reporting, take a moment to make sure the fish is not one of Wisconsin’s native sculpins. Mottled sculpin and slimy sculpin are both native Wisconsin fish. They have separate pelvic fins and a scaleless body. They are typically between 2 to 4 inches in length.

Round gobies are an invasive species that range in size from 3 to 6 inches and have a blotchy gray appearance. They can be identified by a single, scallop-shaped pelvic fin on the belly of the fish. (Fun fact: No other native Great Lakes fish possess the single pelvic fin.) They have a black spot on the front dorsal fin, frog-like raised eyes and thick lips.

Preventing The Spread

Prevention remains the best way to help protect Wisconsin’s waters, as round gobies are nearly impossible to eradicate once they have been established. Anglers are reminded to never use round gobies as bait, release fish from one lake into another or throw unwanted bait into the water. Round goby are a restricted species in Wisconsin, meaning they cannot be transported, transferred or introduced. A deceased goby can be legally transported to a DNR office for identification.