PHILADELPHIA Scientists working with the Partnership for the Delaware Estuary and The Academy of Natural Sciences have made an important discovery in the Delaware River between Chester, Pennsylvania, and Trenton, New Jersey: beds of freshwater mussels. This includes several uncommon species, two of which were previously believed to no longer exist in both Pennsylvania and New Jersey.
"Freshwater mussels are very sensitive to a variety of problems, including pollution, dams, water flows, loss of forests, and harvesting for their shells and as bait," said Dr. Danielle Kreeger, science director at the Partnership for the Delaware Estuary. "We have so few mussels left in almost all of our streams in the area, so to find seven species living together in dense communities right near Philadelphia was unexpected and cause for celebration."
Freshwater mussels are the most imperiled of all plants and animals in North America Nearly three-quarters of the continent's 300 species are in decline, and many are either extinct or headed toward extinction. In the Delaware River Basin, most of the one dozen native species are classified as reduced, threatened, or locally extinct. One of the basin's species is considered endangered at the federal level and others are listed as endangered at the state level. Water pollution and degraded habitats are the most common reasons for these declines. That is why scientists are so excited to find them in this stretch of the river.
One reason freshwater mussels may be doing better in the Delaware River compared to surrounding tributaries
is the fact that the Delaware is the longest free-flowing river east of the Mississippi. Dams often block fish from
swimming up the river, and this can interrupt the complicated breeding processes of freshwater mussels.
Mussels rely upon fish to carry their babies, or larvae, around, including upstream. Whenever dams block these
fish, they fail to deliver their payload of musse
|Contact: Carolyn Belardo|
Academy of Natural Sciences