Project managers: Przemek Bajer and Peter Sorensen

Funded by: Riley-Purgatory Bluff Creek Watershed District

Description: This project, a contract with the Riley-Purgatory Bluff Creek Watershed District, focuses on developing control techniques for common carp and improving water quality. Common carp cause great damage to water quality, aquatic vegetation, and waterfowl populations in shallow lakes and wetlands.

When this research and work began, there were 30,000 adult common carp in Lake Staring. Since 2008, MAISRC researchers have developed several methods to effectively remove adult carp, including telemetry-guided winter seining, identifying processes that control the recruitment of young and access to the carp nursery area, and determining seasonal movement patterns and overwintering sites. Using a combination of these techniques, the carp population was reduced to 6,000. However, to achieve desired improvements in water quality, the carp population needs to be reduced to (and maintained at) 2,000 individuals.

Because this is a complex watershed with annual spawning migrations and a lack of native predators, effective and sustained carp control will require a well-coordinated approach to both remove adults and suppress the production and/or movement of their young. This project includes estimating out-migration rates of age-0 carp, establishing the efficiency of adult carp removal using winter seining and baited traps, documenting the movement of carp within the watershed to determine the efficacy of a carp barrier, and developing a carp population dynamics model.

This project is being conducted in conjunction with another MAISRC project, Restoration and maintenance of native macrophytes in lakes, which studied the response of native aquatic plants to carp removal.

Project start date: 2008

Project end date: 2015

Final report: Development and implementation of a sustainable strategy to control common carp in the Purgatory Creek Chain of Lakes

Progress and updates:

• Elucidating the mechanism underlying the productivity-recruitment hypothesis in the invasive common carp (Published paper)
• Low downstream dispersal of young-of-year common carp from marshes into lakes in the Upper Mississippi River region and its implications for integrated pest management strategies (Published paper)
• Biological invasion by a benthivorous fish reduced the cover and species richness of aquatic plants in most lakes of a large North American ecoregion (Published paper)
• New MAISRC research shows invasive common carp more damaging to biodiversity than human development (MAISRC newsletter)
• Modeling the potential for managing invasive common carp in temperate lakes by targeting their winter aggregations (Published paper)
• Partial migration to seasonally-unstable habitat facilitates biological invasions in a predator-dominated system (Published paper)
• Partial migration: new findings suggest management opportunities for common carp (MAISRC Newsletter)
• Across-ecoregion analysis suggests a hierarchy of ecological filters that regulate recruitment of a globally invasive fish (Published paper)
• MAISRC researcher leads a collaborative team to explain the enigma of common carp invasions (MAISRC Newsletter)
• Study shows how common carp became invasive (MAISRC in the News)
• Success! Common carp under control in Riley Chain of Lakes (MAISRC Newsletter)
• Effects of common carp on phosphorus concentrations, water clarity, and vegetation density: a whole system experiment in a thermally stratified lake  (Published paper)