Mussels In The Delaware River

This summer we’ve had some exciting finds along the banks of the Delaware River along our Greenway. Our North Delaware Riverfront Greenway is part of the East Coast Greenway and a growing area for a variety of native flora and fauna. These pictures show four freshwater bivalves that live offshore.  The top two are native Alewife Floaters (believed to be locally extinct in Pennsylvania until recently). The third we believe to be a native Green Floater (endangered in NJ, imperiled in PA and likely extinct in DE).  The bottom bivalve is a non-native clam called Asiatic Clam.

Mussels are important to the ecosystem of the Delaware River along our Greenway because they act as  filter feeders that “clean” the water which they live in. They do this by removing solids such as dirt algae and other pollutants.  They suck water in to trap the solid and then release filtered water back into the environment.  Each mussel filters several gallons of water each day.  One mussel bed in Southeast PA was found to remove 26 metric tons of solids from the water in a single summer season. Our discovery of these rare mussels in our section of the Delaware River is a sign of the river’s improving health for all species. (Source: Freshwater Mussels of the Delaware Estuary: Partnership for the Delaware Estuary)
With the help of groups like The Partnership for the Delaware Estuary, Pennsylvania DEP Coastal Resources Monitoring Program, NOAA, and  Fairmount Waterworks, the mussel populations are gaining more attention and leading to conservation efforts that allow the populations to begin to grow again, making for cleaner water for all of us!