Ongoing surveys of the mussel population in Pennsylvania’s Delaware River Basin have begun to produce results that bode well for the health of the waterway. Researchers from the Patrick Center for Environmental Research in the Academy of Natural Sciences of Drexel University and from the Partnership for the Delaware Estuary, who have monitored local waterways for more than 20 years, found several species of the freshwater bivalves living near Philadelphia. Their discovery was surprising — because mussels were long thought to have disappeared from the area — and extremely welcome, because the creatures have a remarkable capacity to filter contaminants from water.

ferrofluid on silicon wafer


Gallons of water each mussel can filter daily


Species of freshwater mussels found living near Philadelphia.


Percentage of species that are threatened or endangered


Years a freshwater mussel can live


Approximate mussel species in North America