Delaware River Basin Mussels: Freshwater Species of the Week

A freshwater mussel filters the water from the bottom of a stream. Photo: U.S. Fish and Wildlife Service Southeast


I am writing this post from a bus that is cruising through Delaware. A little while ago we went over a high bridge, and I got a spectacular view of an orange sunset over the mighty Delaware River.

It was a postcard-quality scene, until I looked out the opposite window, and saw a sprawling chemical plant perched on the opposite bank. It reminded me that human beings have left quite a footprint on the densely populated East Coast.

According to the World Wildlife Fund’s ninth Living Planet Report (released this week), freshwater ecosystems are home to about 10% of all known animal species, although they comprise only about 1% of the Earth’s surface. Yet 2.7 billion people live in river basins that are already subject to water scarcity.

According to the report, the freshwater species index has seen the biggest drop (37%) since 1970, with the tropical freshwater index falling by 70%.

In a wonderful story published today on Newsworks, author Carolyn Beeler points out that freshwater mussels are among the most imperiled of all species in North America. “Of nearly 300 species nationwide, it is estimated that at least 70 percent are extinct, endangered, or in need of protection,” she writes.

However, the Partnership for the Delaware Estuary is mobilizing volunteers to assess the populations in the Delaware River Basin. One mussel counter, 11-year-old Ben Sniegowski, said, “They told us to look in areas where it’s slow-moving water. They can just bury themselves in silt or sand.”

As we’ve discussed here in Water Currents before, freshwater mussels serve important ecosystem functions by filtering the water. Although they generally aren’t considered good eating by people, they are an important food source for a wide range of animals.

A century ago, naturalists recorded about a dozen species of mussels in the Delaware River Basin, but now scientists can routinely only find one, thanks to decades of pollution, dam building, and other stresses.

In 2007, the Partnership for the Delaware Estuary began restoration programs to rehabilitate streams in the area and grow mussels in hatcheries. The group is now calling on citizen scientists to look for mussels and submit data sheets, so scientists can figure out the best places to reseed them.

Grab some boots and pitch in!


Brian Clark Howard is a writer and editor with He was formerly an editor at The Daily Green and E/The Environmental Magazine and has contributed to many publications, including,,,, Yahoo!, MSN and elsewhere. His latest book, with Kevin Shea, is Build Your Own Small Wind Power System.


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