CARP MANAGEMENT AND WATER QUALITY RESTORATION DEMONSTRATION PROJECT

The Stormwater Innovation Center (SIC) is exploring the relationship between water quality and the presence of common carp in Roger Williams Park (RWP) ponds. Common carp, often referred to as “ecological engineers,” can negatively impact aquatic ecosystems by disturbing bottom sediments, uprooting aquatic plants, increasing turbidity, and releasing nutrients that contribute to harmful cyanobacteria blooms.

To better understand the role of carp in the RWP pond system, electrofishing surveys were conducted in the RWP ponds and zoo pond in 2024, identifying a significant population of large common carp. These findings, combined with research on the ecological impacts of high carp biomass, informed the next phase of the project: a targeted carp management and water quality restoration demonstration project. In summer 2026, project partners began implementing a selective carp management approach in the RWP zoo pond. Using a specialized box net system provided by Carp Solutions, partners are safely capturing common carp and relocating them to Polo Lake, a connected pond within the RWP pond system. A barrier has been installed to prevent carp from returning to the zoo pond.

Throughout this demonstration project, partners will monitor changes in water quality, aquatic vegetation, cyanobacteria levels, and native fish populations in the zoo pond to evaluate how reducing carp biomass influences ecosystem health. Carp tissue samples are also being analyzed for contaminants to determine whether removed fish may have potential future beneficial uses, such as fertilizer, compost, or other applications. The long-term goal of this project is to better understand the role of carp management in improving urban pond ecosystems and determine whether larger-scale management strategies could benefit the health of the RWP pond system and similar ponds in the region.

Project Partners:

Roger Williams Park Zoo
Providence Parks Department
The Nature Conservancy
Audubon Society of Rhode Island
Carp Solutions
EPA Region 1 Laboratory
Pawtuxet River Authority and Watershed Council

This project is funded through an EPA 2025 Southeast New England Program (SNEP) Watershed Implementation Grant administered by Restore America's Estuaries

Additional Resources

This project builds on research and management approaches developed by experts in common carp ecology, including work by Carp Solutions. While many studies have focused on Midwestern lake systems, this demonstration project is applying these approaches to better understand carp management in southern New England ponds. Explore relevant research below:

Bajer et al. (2009): Effects of a rapidly increasing population of common carp on vegetative cover and waterfowl in a recently restored Midwestern shallow lake
Hundt et al. (2022): Social associations in common carp (Cyprinus carpio): Insights from induced feeding aggregations for targeted management strategies
Bullers et al. (2026): Synchronization of common carp (Cyprinus carpio) feeding aggregations through acoustic conditioning in a natural lake setting