PDE leads surveys of freshwater mussel populations throughout the Delaware Estuary watershed to fill vital data gaps. The last comprehensive survey of freshwater mussels in Pennsylvania, for example, was conducted prior to 1919. PDE conducts rapid surveys to find mussels over large areas and detailed surveys at specific sites to calculate the amount, sizes, and health of mussels. Water quality benefits provided by mussels can be estimated using information from these detailed surveys. Many partners have assisted PDE in mussel surveys in recent years, most notably the Academy of Natural Sciences of Drexel University. The Environmental Protection Agency and Philadelphia Water Department have also supplied essential support. We are also grateful to the state agency staff in Delaware, New Jersey and Pennsylvania for supplying PDE with data, helpful suggestions, and survey permits.
PDE and partners have made some startling discoveries over the years. Seven native species were found in healthy mussel beds along the Delaware River between Trenton and Philadelphia. Included were two species that had been believed to be locally extinct, and several other species found were state listed as rare, threatened or endangered. These finds offer hope that these species can eventually be reintroduced into streams from which they have been lost. A more rigorous scientific survey in 2012 revisited these discovered beds to learn more. For a summary of the current estuary-wide mussel status, click here.
Photo Credit Kathleen LaForce