AGENCY AND USER RAMIFICATIONS OF CLIMATE CHANGE EFFECTS ON WISCONSIN WALLEYE FISHERIES FROM PRESENT TO END OF CENTURY

Recreational fisheries, like many social-ecological systems, will experience varied impacts from climate change. In freshwater systems, a warming climate is expected to lead to generally warmer water temperatures. Climate vulnerable species like Walleye (Sander vitreus) that rely on cool, well-oxygenated, waters are threatened by these changes, and so too are the cultures and economies supported by them. Here, random forest models were developed to predict the ability of individual lakes around Wisconsin to support self-sustaining and put-grow-take fisheries now and in the future. These models build upon existing models of recruitment success by integrating connectivity to fluvial populations and modeling adult presence/absence in addition to natural recruitment. The results of these models are used to classify lakes into those that lose self-sustaining walleye populations and those that lose adult populations altogether, resulting in lost opportunities for tribal harvesters and anglers. Using these classifications, the cost of maintaining walleye populations via stocking in lakes that lose natural recruitment can be estimated. The model predictions and stocking cost estimates developed here support proactive planning of management strategies for individual walleye populations around the state. Given resource limitations and the climate reality in many lakes, this work can assist decision makers in developing strategies for determining where and when to stock, as well as where and when to stop stocking.

Primary Presenter: Colin Dassow, Wisconsin Department of Natural Resources (colin.dassow@wisconsin.gov)

Authors:

Colin Dassow, Wisconsin Department of Natural Resources  (colin.dassow@wisconsin.gov)

Ralph Tingley, United States Geological Survey  (rtingley@usgs.gov)

Gretchen Hansen, University of Minnesota  (ghansen@umn.edu)

Alexander Latzka, Wisconsin Department of Natural Resources  (alexander.latzka@wisconsin.gov)

Craig Paukert, USGS Cooperative Fisheries Research Unit at the University of Missouri  (paukertc@missouri.edu)

Matthew Diebel, United States Geological Survey  (mdiebel@usgs.gov)

Gregory Sass, Wisconsin Department of Natural Resources  (gregory.sass@wisconsin.gov)

Abigail Lynch, United States Geological Survey  (ajlynch@usgs.gov)