Midwest Fish & Wildlife Conference 2018

AUTHORS. Daniel J. Dembkowski, Wisconsin Cooperative Fishery Research Unit; Daniel A. Isermann, USGS, Wisconsin Cooperative Fishery Research Unit; Steven R. Hogler, Wisconsin Department of Natural Resources; Keith N. Turnquist; Wisconsin Cooperative Fishery Research Unit; Wesley A. Larson; USGS, Wisconsin Cooperative Fishery Research Unit

ABSTRACT. The current conceptual model for Walleye Sander vitreus management in Green Bay is based on the assumptions that the recreational Walleye fishery in southern Green Bay is mostly supported by Walleye spawning in the Fox, Menominee, Oconto, and Peshtigo rivers and that Walleye spawning in these rivers do not substantially contribute to the fishery in northern Green Bay. To test these assumptions, we inferred movements of Walleye tagged in the Fox (N = 1,558), Menominee (N = 1,383), Oconto (N = 1,460), and Peshtigo (N = 1,705) rivers from angler tag return data. Tag return data obtained for N = 578 Walleye during 2012-2016 suggest that Walleye spawning in the four primary tributaries typically remain within southern Green Bay; only two Walleye were recovered north of the boundary between northern and southern Green Bay. However, this assertion may be confounded by the distribution of angling effort that provides tag returns. The primary question that remains regarding current assumptions is whether the Walleye fishery in southern Green Bay is supported primarily by fish spawning in the four primary tributaries, or if there are substantial contributions from fish spawning at other unknown locations. This question is being addressed through a mixed-stock assessment and evaluation of Walleye movements based on acoustic telemetry data. This additional study, which began in September 2017, will involve tracking movements of N = 300 Walleye for = 4 years and will seek to determine the contribution of different spawning stocks to the Walleye fisheries in northern and southern Green Bay, if Walleye spawning within a region or specific tributary are discrete stocks, if stock contributions in each zone vary among seasons, and if a measurable proportion of Walleye leave Green Bay after spawning and enter Lake Michigan.