PW Partners to Reintroduce Mussels int PW County Streams

From a recent NVRC press release:

The Northern Virginia Regional Commission (NVRC) secured a watershed restoration grant of $75,000 from the National Fish and Wildlife Foundation's Chesapeake Watershed Investments in Landscape Defense (Chesapeake WILD) Program.

This funding, part of 25 grants announced in the 2023 round, supports an innovative project to reintroduce native freshwater mussels into Prince William County's restored streams. This project a partnership with Prince William County Department of Public Works, U.S. Fish and Wildlife Service's Harrison Lake National Fish Hatchery and George Mason University's Potomac Environmental Research and Education Center (PEREC). Last month about 150 young mussels were placed in baskets and placed into four stream sites to kick off this restoration effort.

Nicknamed “nature’s water filters,” freshwater mussels are environmental superheroes. A single adult mussel can filter up to 8-15 gallons of water per day, removing various pollutants. This boosts water clarity, improves habitat for fish and other wildlife, and strengthens the entire aquatic ecosystem. Mussels help improve water quality through filtration and denitrification—the process in which nitrogen is removed from water by transforming into gas. Mussels filter water preventing nutrients and other harmful pollutants from flowing downstream. They also removes potentially harmful debris like silt and algae and plastics, which improves water clarity. Mussels provide food for aquatic species, and their beds are a source of habitat for small species.

A Three Phase Plan for Success

Phase I, Site Assessment: Mussel biologists scouted Prince William County’s streams, analyzing water quality, substrate, flow patterns, and existing aquatic life to pinpoint the best homes for mussels.

Phase II, Controlled Release and Monitoring: This is where we are now! About 150 one year old hatchery-reared and tagged mussels have been placed in specialized baskets at four sites. The team will monitor their growth, survival, and adjustment to their new homes before releasing them more broadly.

Phase III, Full Reintroduction and Monitoring: If all goes well with the test group of mussels, more tagged hatchery-reared mussels will be released into the streams. Ongoing monitoring will track mussel population health and measurable improvements in water quality, providing valuable data for future restoration efforts across the Chesapeake watershed.

Looking Ahead:

This isn’t just a local win. As these natural water filters establish themselves in Prince William County streams, the downstream benefits will contribute to the region and the Chesapeake Bay. The success of this initiative will hopefully pave the way for similar mussel reintroduction programs across the region and state to improve our local streams with an innovative approach. I am hopeful that Chestnut Lick (which runs through my back yard) will also receive baskets. 

Contamination by fecal coliform bacteria is the most common cause of water quality violations in Virginia streams. According to DEQ and the United States Geologic Survey “Although fecal coliform bacteria are not necessarily dangerous to humans, their presence in streams indicates that the water is contaminated with fecal waste from warm-blooded animals. For this reason, fecal coliform bacteria are known as ‘indicator organisms;’ their presence in recreational waters indicates an increased risk to human health.”

Prince William County is subject to four separate TMDLs that assign WLAs for discharges of bacteria to impaired waters. The WLAs are assigned in aggregate to multiple MS4 permit holders within Prince William County’s geographic boundary. Prince William County is also under the EPA Chesapeake Bay cleanup mandate.