AUTHORS: Mac McPherson, University of Illinois Urbana-Champaign; Cory D. Suski, University of Illinois Urbana-Champaign; Aaron D. Shultz, Great Lakes Indian Fish and Wildlife Commission; Adam Ray, Great Lakes Indian Fish and Wildlife Commission
ABSTRACT: One of the fundamental tenets of Anishinaabe philosophy is the commitment to stewardship of natural resources, emphasizing the imperative to ensure their availability for the benefit of the next seven generations. Throughout the Ceded Territory, Ogaa (walleye, Sander vitreus) populations have been declining due to a variety of known and unknown factors. One of the primary factors is the warming of the atmosphere corresponding increases the water temperature linked to climate change. Another factor is indirect mortality as a result of catch and release fishing regulations and practices. In central Wisconsin, the management of ogaa populations is a collaborative effort between the tribes and the state of Wisconsin; however, the existing regulatory frameworks fail to adequately account for post-release mortality. The goal of this study is to elucidate the potential relationship between angling practices and subsequent post-release mortality rates across different water temperatures in ogaa populations. To achieve this, walleye was angled from various lakes in Wisconsin under differing thermal conditions and subsequently maintained in net pens to assess post-release mortality rates; concurrently, a control group of ogaa was obtained through electrofishing to serve as a baseline for comparative analysis. The findings from this study, focus on two different handling techniques, angling (high stress) and electrofishing (low stress) at different water temperatures from the spring through fall 2023 on Tenderfoot Lake along the border of Wisconsin and the Upper Peninsula of Michigan. Preliminary analysis indicates that mortality rates for specific fish size increase significantly when water temperatures exceeded 21.1̊C. The results from this study have potential to inform future regulatory decisions, particularly in the context of climate change, thereby contributing to the long-term sustainability of ogaa population for the benefit of the next seven generations.
