The Oshkosh fisheries work unit and Asylum Bay operations staff have completed the 2021 walleye spawning stock assessment. The objectives of the survey included tagging adult walleye to estimate annual exploitation, evaluate size structure, conduct age and growth analyses on male aging samples and evaluate spawning marsh conditions. Survey efforts began on the Wolf River on March 21 and continued through April 5. Water level gauge height at the USGS New London site ranged from about 7 feet on March 21 to 6.2 feet on April 5.

The lack of rain and snow this year led to fairly low water levels on the Wolf River during the peak walleye spawn compared to recent years. Water levels and flow in the main marshes around New London and Shiocton were marginal. Generally, a gauge height of at least 7 feet is needed to provided marginal conditions, with more ideal marsh conditions occurring when gauge height surpasses 8 feet. 

In total, 3,703 adult male and 852 adult female walleye were sampled on the Wolf River. That was near the annual goal of tagging 5,000 in the Wolf River. In addition, 72 adult male and 9 adult female walleye were sampled on the upper Fox River near Princeton. Peak spawning activity was observed throughout the week of March  25 and mostly wrapped up by early April. The strong 2016 year class was well represented during survey efforts, with males ranging 13-15 inches and females ranging 15-18 inches.

Tagging efforts included continuing the reward tag study and the release of 100 male and 100 female reward tagged fish. These tags are worth $100 for anglers that catch and report a pink reward tagged fish. The tag reward for this year’s tags will expire on March 31, 2022 and are being paid for by Battle on Bago. This study will continue to provide more accurate annual exploitation and angler tag reporting estimates. DNR staff also conducted walleye electrofishing surveys on the Upriver Lake and Lake Winnebago.

The objectives of the survey primarily include tagging immature (unknown male or female) and immature female walleye to estimate annual exploitation. Adult males and females sampled are also tagged. Overall, 372 immature, 243 immature female, 119 adult female and 642 male walleye were sampled. Immature walleye sampled mainly ranged 11-14 inches and immature female walleye ranged 14-17 inches.

Anglers can report the catch of a tagged walleye, yellow perch, bass, or northern pike by mailing the catch information to the Oshkosh DNR office (625 East County Road Y, Oshkosh WI 54901), emailing it to DNRWINNEBAGOSYSTEMTAGRETURNS@wisconsin.gov or calling 920-303-5429. If you have any questions about the trawling report or this year’s survey update, please feel free to reach out.