Prince William County Launches Mussel Pilot Study to Support Stream Health

Prince William County’s Department of Public Works, Environmental Management Division (EMD), in partnership with the U.S. Fish and Wildlife Service (USFWS) and the Northern Virginia Regional Commission (NVRC), has recently introduced freshwater mussels into several restored streams throughout the County as part of a pilot project. The goal of this initial introduction is to evaluate whether the native Eastern Elliptio mussel can survive in local waterways, which will guide future mussel introduction projects.

As part of the study, mussels were obtained from the USFWS Harrison Lake National Fish Hatchery and deployed in specially designed mussel cages across four selected stream sites. Each site contains four cages, with about a dozen mussels in each, providing a secure, controlled environment to monitor growth and survival. The mussels will be checked periodically to assess their health, shell growth, and adaptation to the streams.

Before deployment, EMD conducted thorough environmental assessments at four potential sites, including eDNA testing and electroshocking, to confirm the presence of host fish. These fish are a crucial part of the Eastern Elliptio mussel lifecycle, as they provide the necessary conditions for mussels to reproduce and thrive. Upon verifying host fish populations at each location, the mussel cages were subsequently deployed.

The freshwater mussel introduction project is made possible through collaboration with several partners, including Broadwater Innovations, NVRC, the U.S. Fish and Wildlife Service, the National Fish and Wildlife Foundation, and Dominion Energy. Together, these organizations are helping Prince William County explore innovative ways to enhance the biodiversity, water quality, and resilience of local streams.

Now that all stream sites are stocked with mussels, the project team eagerly awaits the first monitoring event to gather data on their survival and growth. This study represents an exciting step forward in the County’s ongoing commitment to local water quality improvement and restoration of aquatic ecosystems.