Growing Mussels for Healthier Waterways

The riverfront at Bartram’s Garden.

Bartrams Garden, the 2021 Recipient of PECs Special PlacesEnvironmental Partnership Award, is already an important resource for Southwest Philadelphia and the greater Philly area. Its riverfront campus includes historic buildings and gardens, an arboretum, and a community farm focused on promoting food sovereignty and health in the surrounding neighborhood. Bartrams Gardens newest project, a watershed education and restoration center, will continue its mission of community outreach and education while protecting the health of the Delaware River Basin and local ecosystems. The center, a collaboration between Bartrams Garden and the Partnership for the Delaware Estuary, will be built along the Schuylkill River on previously developed land and will feature the worlds first production-scale freshwater mussel hatchery.

This is big news for Philly-area wetlands and waterways. Though you might not expect it, freshwater mussels provide many important ecosystem services. Freshwater mussels are bivalve mollusks, like clams and oysters. They live in sandy stream- and riverbeds and filter water to extract small particles of food. In doing so, they also trap pollutants, like dirt and algae, before releasing the filtered water back into the river. Because of their water filtering abilities, freshwater mussels are critical to the health of our local ecosystems. A single adult mussel can filter 10-20 gallons of water a day!

A robust mussel population is indicative of good stream health. Unfortunately, freshwater mussels are one of the most threatened animals in the United States.

A robust mussel population is indicative of good stream health. Unfortunately, freshwater mussels are one of the most threatened animals in the United States one fifth of the 50 mussel species native to Pennsylvania are endangered. Their populations are currently in decline for several reasons. As larvae, freshwater mussels must attach to a fish in order to survive until they are large enough to settle on the bottom of a stream. Dams that prevent fish migration and other activities that reduce fish populations also reduce the number of available hosts for baby mussels. Erosion along riverbanks, dredging, and water pollution also reduce freshwater mussel populations.

Photo credit: Partnership for the Delaware Estuary

The mussel hatchery at Bartrams Garden will help rebuild mussel populations in Southeast Pennsylvania. Up to half a million baby mussels a year could be produced once the hatchery is up and running. Once they grow to juvenile size, they would be ready for relocation to restoration sites in local streams, wetlands, and waterways. Learn more about the project here.

There are many ways to help support freshwater mussel populations in Pennsylvania. Severe flooding and stormwater runoff can disrupt stream bottom stability and the clean water that mussels need to survive. Managing runoff, supporting healthy riparian buffer zones, and reducing water contaminants are all ways to help mussel populations thrive. On a larger scale, as the climate continues to warm, vulnerable species like freshwater mussels will be increasingly at risk. Supporting climate policy that helps avoid additional warming and reduces the risk of severe flooding and changes to coastline in the Delaware Estuary is another way to care for Pennsylvanias aquatic and wetland ecosystems.