A new walleye sonic tagging study is underway on the upper Fox River to evaluate adult walleye movement and habitat use on the system including Lake Puckaway and Buffalo Lake. The upper Fox River walleye spawning run has become less predictable in recent years. Fishways have also been installed to improve fish passage including at Eureka in 1993 and more recently in Princeton and Montello. Many of the historical walleye spawning marshes are located downstream of Princeton on the upper Fox River, but walleye should now have access to upstream reaches with the recent Princeton and Montello fishways. Therefore, it is important to evaluate if walleye movement and habitat use has changed on the upper Fox River. The study will help guide management and habitat restoration efforts on the on the upper Fox River and will also compliment sonic tagging studies being conducted on the Lake Winnebago System.

Department staff and volunteers conducted electrofishing surveys on Lake Puckaway and the upstream river area on October 13th and 26th. There were 16 adult walleye tagged with internal sonic tags on Lake Puckaway that included 8 males ranging 14.7-19.0 inches and 8 females ranging 20.5-25.4 inches. As part of this study, the upper Fox River acoustic receiver network now covers from the mouth of the upper Fox River at Lake Butte des Morts upstream to Portage. Sonic tagged fish that swim by the acoustic receivers (about a ¼ mile read range or line of sight) will be detected with a fish ID, date, and time stamp. Sonic tagging efforts are planned to continue on the upper Fox River area in 2023. This study is currently being funded by the Department, the Natural Resource Damage Assessment, and Walleyes for Tomorrow. We hope to expand the project with more partners as the project continues.

All sonic tagged fish are also marked with an orange loop tag near the dorsal fin that reads, RESEARCH REWARD. Anglers that happen to catch a sonic tagged fish are asked to record the tag number information and approximate length, take a picture with the fish and close up of the both sides of loop tag showing the number, and report their catch. If the fish is released please leave the loop tag intact. If the fish is harvested please contact the DNR, the internal sonic tags have a 3 year battery life and may be able to be reused. Anglers that report the catch or harvest of a loop tagged fish and have proper confirmation (the physical loop tag or picture with fish and verifiable loop tag number) will receive a $100 reward (reward expires Dec. 31, 2025). To report tags and catch information, anglers can email the information to DNRWINNEBAGOSYSTEMTAGRETURNS@wisconsin.gov, call 920-303-5429, or mail to the Oshkosh DNR office (625 East County Road Y, Oshkosh WI 54901).