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

Wisconsin Fishery Project

Fish community dynamics in experimental, walleye-exploited lakes in Wisconsin

July 2009 - December 2012


Participating Agencies

  • Wisconsin Department of Natural Resources

Fish population size, size structure, reproduction, and recruitment, are highly dynamic and often fluctuate widely across years. Such population variability, in combination with intensive harvest from state and tribal users greatly increases the risk of overexploitation and possible fishery collapse. Regulations offer opportunities not only to prevent population collapse, but to maximize different de-sirable fish population characteristics such as size structure (i.e., larger fish), abundance, and catch rates, among others that offer a wide array of angling opportunities. Studying the effects of regula-tion changes insure that desirable outcomes are achieved and eluci-date under which conditions particular regulations should be imple-mented. The most effective way to measure the effects of natural population variability and regulation changes relative to exploita-tion is by studying them for a long period of time. There are at least eight different regulations that are applied to the management of walleye in northern Wisconsin with the intent of creating diverse fishing opportunities. Unfortunately, many of those regulations have not been evaluated. The Wisconsin Department of Natural Resources (then the Wisconsin Conservation Commission) estab-lished the Northern Highlands Fishery Research Area (NHFRA) in 1946 and the population size of walleye in Escanaba Lake has been estimated there annually since 1953. Until 2000, harvest of walleye was unlimited (no bag or size limits) and the population fluctuated annually. In 2000, as part of an overall exploitation study, a 28 inch minimum size limit was established to effectively reduce har-vest to near zero and to help create a trophy walleye fishery. The objective of this study is to evaluate how walleye and other species of fish have responded (e.g., abundance, growth) to the implemen-tation of the 28 inch minimum size limit using the long term data set available at Escanaba Lake.

Theses and Dissertations Publication Date
Haglund, Justin. 2013. Evaluation of a 71-cm minimum length limit and a 1-fish daily bag limit for walleye in Escanaba Lake, Wisconsin. M.S. Thesis. University of Wisconsin-Stevens Point. 120 . May 2013