OSHKOSH, Wis. (WFRV) — The Wisconsin Department of Natural Resources (DNR) is ramping up monitoring efforts after confirming the presence of the invasive round goby in Lake Winnebago for the first time.
An angler first reported catching a round goby near the Bowen Street Fishing Pier in June. Since then, DNR crews have confirmed at least 10 additional round gobies from the same location.
Former Green Bay School board member charged with election fraud
“This is a small invasive fish that actually originates in the Black and Caspian Seas,” Patrick Siwula, an Aquatic and Invasive Species Biologist for the DNR, said. “They were first found in the Great Lakes outside Detroit in the late 1990s.”
The round goby has since spread throughout Lake Michigan and tributaries such as the Fox River, despite lock closures and dams designed to slow their movement. In 2015, they crossed a barrier in the Lower Fox River and established themselves in Little Lake Butte des Morts, but for nearly a decade, none had been reported in the Winnebago system.
“We’re still in the assessment phase,” Siwula said. “We want to know if they’re localized to this location or if they’ve spread elsewhere in the system.”
Round gobies, typically 3–6 inches long, can outcompete native fish for food and habitat while preying on the eggs of sport and panfish species. Once they become established, they are nearly impossible to remove.
“Once they get in, there’s no getting them out,” DNR Fisheries Biologist Angelo Cozola said. “We’ll just have to monitor and see what impact they will have.”
The DNR is asking anglers to report any round goby sightings using the online reporting tool. Any round gobies caught should be killed before being brought to a DNR service center for verification.
Harmful blue-green algae bloom confirmed in Green Lake, community advised to avoid visible spots
“We have signs posted throughout the system with instructions,” Siwula said. “Take a picture of the fish, and the system will pin your location and send it to us automatically.”
For now, DNR teams plan to continue targeted monitoring to determine the extent of the invasion and whether containment measures are needed.
