Cooperative Fish and Wildlife Research Units Program: Minnesota
Education, Research and Technical Assistance for Managing Our Natural Resources

Minnesota Project

Improving stock assessment of Walleye for Mille Lacs Lake.

September 2023 - June 2026


Participating Agencies

  • Minnesota Department of Natural Resources

The Walleye fishery in Mille Lacs Lake has declined since the 1990s. The decline coincides with a variety of changesincluding: warming temperatures, increases in smallmouth bass, invasion of zebra mussels in 2005, invasion of spiny waterflea in 2009, changes to northern pike abundance, along with changes to the fishery (both in gear types and management).The fishery (along with northern pike, yellow perch, cisco and burbot) is co‐managed by tribes signatory to the 1837 Treatyand the state (through Minnesota Department of Natural Resources or MNDNR), based on legal agreements. The walleyefishery has consisted of a recreational and joint tribal fishery since 1998. The population of walleye is estimated annuallythrough a statistical catch at age (SCAA) model (previously a Virtual Population Analysis or VPA). The assessment modelswere reviewed in 2001 (VPA) by James R. Bence and Terrance J. Quinn II and again in 2014 (SCAA) by a blue ribbon panel(Paul Venturelli, James Bence, Travis Brenden, Nigel Lester, and Lars Rudstam). A variety of recommendations were madein those reviews for future data collection and future research to ensure the stock assessment model is as accurate aspossible, and this project will focus on improving some aspect of the stock assessment.