Movement and Habitat Use of Muskellunge in Green Bay, Lake Michigan.

GBFRM

July 2017 - July 2021

Green Bay and its tributaries support a world-class fishery for trophy muskellunge that attracts anglers from across North America. Management goals of Green Bay muskellunge aim to establish a self-sustaining population. However, the Lower Fox River and Green Bay muskellunge population is largely supported by stocking because natural recruitment is limited, possibly due to habitat limitations. While previous work has identified potential spawning locations, it is unknown whether muskellunge hatch at these locations and habitat attributes associated with successful hatching have not been determined. Moreover, spawning site selection in relation to stocking locations has not been quantified. We will identify spawning sites of tagged muskellunge (N = 60) using radio and acoustic telemetry and conduct spawning habitat surveys. Presence or absence of eggs and larvae at spawning sites will be used to develop predictive maps of suitable habitat throughout the Green Bay ecosystem. Identifying habitat conditions that result in the successful production of offspring is important for developing habitat improvement projects that aim to restore critical spawning habitat. Furthermore, understanding muskellunge behavior will help develop stocking strategies that aim to increase use of restored spawning habitat.

• Determine the proportion of muskellunge spawning in tributaries to lower Green bay or in Green Bay proper.
• Determine the proportion of muskellunge that return to stocking locations to spawn.
• Determine if muskellunge return to the same spawning locations in consecutive years (i.e, high site fidelity).
• Define habitat conditions that result in egg deposition and the successful hatching of muskellunge eggs.

• Daniel Isermann (Wisconsin Cooperative Fishery Research Unit) - dan.isermann@uwsp.edu

• University of Wisconsin-Stevens Point
• Wisconsin Department of Natural Resources