Enhancing Habitat and Diversity in Cattail-Dominated Shorelines

In this phase, this project aims to provide robust ecological data to evaluate whether small-scale, mechanical cattail harvesting can enhance fish habitat while minimizing unintended impacts on non-target species.

MAISRC researchers are addressing a critical information gap by studying the effects of invasive cattail removal on nearshore plant and fish communities in Minnesota lakes. This project aims to provide robust ecological data to evaluate whether small-scale, mechanical cattail harvesting can enhance fish habitat while minimizing unintended impacts on non-target species. The findings will inform regional park staff, the Minnesota Department of Natural Resources (MNDNR), lake associations, and lake property owners across Minnesota about the potential benefits and trade-offs of cattail removal along lakeshores, an area where little information currently exists. 

Researchers will sample environmental variables, plants, and fish at paired sites where cattails have been retained and removed, building on study sites established during the project's initial phase. A new treatment—an uninvaded plot—will be added to assess whether cattail removal helps restore lakeshore ecosystems to a state resembling areas free from invasion. Seasonal fish habitat use will be monitored to understand how fish interact with the different treatment plots. Specific goals include:

  • Understanding if mechanical cattail removal can restore ecological function of nearshore lake ecosystems in Minnesota. 
  • Comparing cattail retained and cattail removed areas to uninvaded nearshore lake zones to determine if cattail removal restores these ecosystems to uninvaded conditions. 

  • Understanding how cattail management affects fish use of nearshore lake zones.

     

Project Information

Project manager: Amy Schrank, Extension Program Leader; Assistant Professor, Fisheries and Aquaculture Extension Educator, Minnesota Sea Grant

Project team: 

Project partners:

  • Minnesota DNR
  • Voyageurs National Park
  • Washington County Park


Funded by: MAISRC and the Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources

Project timeline: 2024-2025

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Phase I

Project manager: Amy Schrank, Extension Program Leader; Assistant Professor, Fisheries and Aquaculture Extension Educator, Minnesota Sea Grant

Project title: Enhancing Habitat and Diversity in Cattail-Dominated Shorelines

Project team: 

  • Daniel Larkin, project co-manager, assistant professor, Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota.
  • Brendan Nee, project team member, master's student, Department of Fisheries, Wildlife, and Conservation Biology, Diversity Scholar and Dobie Fellow, University of Minnesota.
  • Michael Tuma, project team member, master's student, Department of Fisheries, Wildlife, and Conservation Biology, University of Minnesota.
  • Kailyn Schmitt, project team member, undergraduate student, Swenson College of Science and Engineering, University of Minnesota Duluth.
  • Dylan Dahn, project team member, undergraduate student, Swenson College of Science and Engineering, University of Minnesota Duluth.


Funded by: MAISRC and Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources.

Project timeline: 2021-2023

Key findings:

Removing cattails led to increased dissolved oxygen levels and a resurgence of native plants in the nearshore zones. Fish communities also changed, with some removal sites showing higher fish abundance and an increase in minnow species. These results indicate that mechanical cattail removal can help restore nearshore lake ecosystems with minimal negative impacts on other species. By allowing more dissolved oxygen into the nearshore zones and creating space for native plants to regrow, cattail removal enhances high-quality fish habitat. 

The findings from this study can directly inform Minnesota Department of Natural Resources (MNDNR) policies and management strategies regarding cattail removal for lake restoration efforts across the state.