Partnership aims at saving freshwater mussels

Beyond some rocks, to the side of a riffle, in the knee-deep water of Tacony Creek, community watershed specialist Alex Cooper leaned over, dug around in the bottom, and planted a freshwater mussel.

It was an act of optimism.

Freshwater mussels - which, unlike their saltwater brethren, are inedible - are a definitive sign of a healthy stream. But more than indicators, they're enablers, each filtering about 10 gallons of water a day.

In 1919, when the zoologist Arnold Edward Ortmann surveyed Pennsylvania streams for mussels, many species were plentiful. The animals can live up to 80 years. But dams, water pollution, and sundry other ills that have beset modern waterways have caused freshwater mussels to all but disappear.

Surveyors now find only sparse remnant populations. For three years, hard as they looked, volunteers for the nonprofit Tookany/Tacony-Frankford Watershed Partnership spotted none.

Freshwater mussels are considered the most imperiled of all plants and animals, with 75 percent of 300 North American species in trouble, said Danielle Kreeger, science director of the Partnership for the Delaware Estuary, a congressionally designated science group.

"There is national interest in restoring mussels," Kreeger said. You can have fish and macroinvertebrates, "but if you don't have 80-year-old mussels, of different species, in abundance . . . you don't have a restored stream."

The estuary partnership is leading an effort to return mussels to the region's streams.

The project has its roots in an almost magical moment in the summer of 2010, when Kreeger and other researchers were exploring the Delaware River north of Philadelphia. She had seen some empty mussel shells along the bank. Were mussels in the river?

Not in the shallow water, it turned out, but Kreeger put on snorkel gear and dived toward the bottom in deeper water. She was astonished to see a swath of mussels: seven species, including two thought to be locally extinct.

It was a good sign for the Delaware, but did it mean more than that? What if these animals could jump-start repopulation efforts in nearby streams?

In 2011, mussels were planted in Ridley and Chester Creeks. Within a month, the rains of Hurricane Irene and tropical storm Lee flooded both creeks, but some survived.

In 2012, Kreeger seeded more in Skippack Creek in Montgomery County. Then came Hurricane Sandy. Again, some survived.

In 2013, mussels were put into White Clay and Red Clay Creeks in Delaware. Soon came flooding from another storm, but the mussels hung on.

Kreeger estimates that the reseeding - 1,000 mussels into 11 streams in Delaware and Pennsylvania in three years - has cost about $40,000, largely from a coastal zone management grant awarded by the Pennsylvania Department of Environmental Protection.

The immediate goal is to see if the mussels will grow in those streams. If so, the waterways would be candidates for full-scale restoration efforts.

For that, "we need to make babies," Kreeger said. "We don't like to do what we're doing now, where we tap into a healthy population."

The animal's biology works against it. Mussels can't move upstream on their own, but depend on fish to transport them. Each mussel species has a specific fish that the larvae latch onto, falling off only after they mature. By then, presumably, the fish has moved and the population spreads.

In a three-year project, a Cheyney University professor and his students figured out how to breed mussels in the lab. Now, what's needed is funding, Kreeger said.

The Philadelphia Water Department, a partner in the reseeding effort, sees large, viable mussel beds in the region's streams - even near water intakes - as benefiting customers.

"There are far too few people who understand that the diversity of life in these creeks and streams is important to overall water quality," said Karen Young, an educator at the Fairmount Water Works Interpretive Center at the Schuylkill's Fairmount Dam, near the Art Museum. "If you have the right things in the streams . . . that bodes well . . . when we turn the taps on."

A few weeks ago, Kreeger and Kurt Cheng, a Drexel University graduate student and science fellow at the estuary partnership, dived into the Delaware and brought up 400 mussels.

Volunteers scrubbed and tagged them, gluing to each shell a tiny chip about the size of a grain of rice. This will help researchers, with devices resembling metal detectors, find the mussels months, even years, from now.

Some of the mussels went into Ridley and Skippack Creeks, and along the Delaware. The remaining 50 were placed in two spots in the Tacony by Cooper, of the Tookany/Tacony-Frankford Partnership, and others.

Kreeger intends to come back in the fall and next spring to count survivors and measure their growth.

Julie Slavet, Tookany/Tacony-Frankford's executive director, sees the project as "another way of saying to people, 'We're doing everything we can to bring your creek back to health.' "

Nonetheless, she added, "we want people to be realistic. . . . This is an experiment."

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