Project background
Common carp can harm lake water quality and macrophyte communities when their populations are abundant. Managing carp via removals or limiting their movement can be an effective tool to restore this lost lake functioning. The Lab to Lakes initiative is partnering with local managers to manage carp in two ecologically distinct systems; Lake Fremont (Sherburne County, MN) and the Chisago Chain of Lakes (Chisago County, MN), with a goal of reducing carp biomass and improving lake function within four years. Researchers will evaluate lake responses to common carp management by analyzing lake phosphorus cycling, water quality, as well as zooplankton and macrophyte species abundance and community composition. Researchers will continue monitoring four years from the onset of management over two phases, and will compare results to historical data where possible to provide more comprehensive evaluations of lake responses.
Project update; May 2026:
This project is building on existing statewide evaluation of common carp management effectiveness as it relates to improved lake function. Early results suggest that effectiveness may be more dependent on lake characteristics (e.g., starting clarity, nutrients, or watershed characteristics) than carp biomass reduction. Estimating carp biomass before and after removal is challenging and estimates are uncertain which limits the ability to quantify carp effects on lake function. This project, paired with the statewide analysis, will provide recommendations for:
key areas of uncertainty that could represent future research or areas where monitoring around projects needs to be intensified,
potential best practices for what kinds of lakes are most responsive to management, helping to allocate resources to where success is likely, and
provide a foundation for evaluating carp management in the context of many concurrent lake stewardship activities (e.g., alum treatment, aquatic plant management, and watershed management).