Freshwater mussels are bivalve mollusks just like oysters, clams, and saltwater mussels. Unlike saltwater bivalves, freshwater mussels live in our local streams and rivers. They provide valuable “ecosystem services” or natural benefits such as strengthening streambeds by keeping soils in place and providing food and habitat needed by other animals and plants. As filter-feeders, mussels supply another important service by cleaning the water in which they live. They suck water in and trap solids such as dirt, algae and other pollutants then release the clean filtered water back into the environment. One mussel bed studied in Southeast PA was found to remove 26 metric tons of solids from the water in a single summer season; this is as much as five grown elephants!
Freshwater Mussel Decline
Nearly 300 mussel species are native to North America and over a dozen of these species were historically found in streams throughout the Delaware Estuary. Unfortunately, very few species are commonly found in Pennsylvania, New Jersey, and Delaware. The decline of mussels can be blamed on a combination of known and unknown factors including polluted water, toxic spills, over-harvesting for bait, loss of forests along streams, loss of fish hosts needed for reproduction and dams that block fish passage.
PDE’s Work with Mussels
PDE recognizes the need to conserve existing mussel populations and restore native freshwater mussels to the Delaware Estuary and River Basin. PDE scientists conduct surveys to collect data on where mussels currently exist, what species are abundant, and how healthy the populations are. PDE teaches mussel workshops to train citizen scientists to help in these efforts (See Mussel Volunteer Website). Scientists also assess current stream health throughout the region. If a stream is healthy and has contained mussels in the past, PDE will attempt to restore native freshwater mussels to the area by transplanting mussels from an existing nearby healthy population. PDE’s work to understand, conserve, and restore native freshwater mussels results in improvement in all around ecosystem health including cleaner water and better habitat for other animals in our streams and rivers.
PDE's plan for freshwater mussel restoration: Click Here