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

The Wisconsin DNR is working to restore muskellunge in the Lower Fox River and Green Bay ecosystems. Natural reproduction of muskellunge is limited, so this effort largely relies on stocking juvenile fish. Defining habitat availability and selection are the first steps in implementing habitat improvements that can effectively benefit natural reproduction. Some previous research provides initial insights regarding potential muskellunge spawning habitat, but this work did not encompass all tributaries where spawning may occur, did not address spawning site selection in relation to stocking location, and did not verify that larvae emerged at putative spawning locations. Our primary objectives are to: 1) determine the proportion of muskellunge spawning in tributaries to lower Green Bay or in Green Bay proper; 2) determine if adults return to stocking locations to spawn; 3) define habitat conditions that result in successful hatching and 4) quantify the availability of viable spawning habitat in tributaries. Our goal is to provide resource agencies with specific recommendations for future habitat projects that have the greatest potential to increase natural reproduction of muskellunge. We will provide habitat maps depicting probability of muskellunge egg deposition and/or larval production. Specifically, we will identify those areas where the probability of these events might increase with changes to habitat conditions and we will also have identified what changes in conditions need to be made. Therefore, we will be able to provide recommendations regarding both the “where” and “how” aspects of future habitat improvements. Specific recommendations might include additions of woody cover, efforts to increase aquatic plant growth, flow/wave diversion and these recommendations could vary by location. After the project is complete, we hope to work with WDNR and other partners in providing guidance and information in developing new habitat improvement projects.