French Creek, which could accurately be described as an old-growth river because of the low level of manmade disturbance it has seen, may hold the key to restoring rare populations of animals into other parts of the Upper Allegheny and Upper Ohio river systems.

Along its 117 miles, from western New York across northwestern Pennsylvania, the river is home to more than 28 freshwater mussel species, including 13 that are listed as endangered in Pennsylvania and the federally endangered northern riffleshell and clubshell. These two species are critically imperiled, having lost more than 95 percent of their historic range. Freshwater mussels are vulnerable to changes in their surroundings. But their beds in French Creek – still occupied by individuals of varying ages, some 60- to 70-years-old – may have gone largely undisturbed for thousands of years.

Other parts of the Upper Allegheny and Upper Ohio river systems, where the same mussels once were abundant, have not fared as well. French Creek is now seen as a conservation refuge for species that could be reintroduced back into other parts of the river systems to again provide their river-cleansing benefit as they filter water to feed themselves.

The healthy, but fragile, French Creek also supports rare fish found in only a handful of other rivers. And, because some of those brightly colored darters rarely stray very far from home, they are extremely sensitive to changes in the river’s environment. The hellbender, Pennsylvania’s largest salamander, inhabits French Creek as well, feasting on crayfish, which are yet one more pollution-sensitive family of animals.

The Nature Conservancy has been active in the Pennsylvania portion of the French Creek watershed since helping the Western Pennsylvania Conservancy acquire land near Lake Pleasant in 1995. (The Central and Western New York chapter began work in its part of the watershed in 1991.) The Conservancy worked with various partners to protect both the Pennsylvania and New York portions of the extraordinary watershed. Whether planning for reintroduction of freshwater mussels elsewhere  by tapping the surviving populations in French Creek or engaging local farmers in sustainable management practices or monitoring and removing zebra mussels from the river, the Conservancy remains dedicated to this national treasure and surrounding communities.

What You’ll See
Twenty-eight species of freshwater mussel. A wide variety of darters, including the Tippecanoe darter, found nowhere else in Pennsylvania except French Creek and the upper Allegheny River. Numerous aquatic insects, reptiles and amphibians, including hellbenders, which are Pennsylvania’s largest salamanders. Birds, including American bittern, least bittern, black tern, short-eared owl, sedge wren, marsh wren, osprey and bald eagle. Plants of special concern, including rush aster, cuckooflower, vanilla sweet grass and Beck’s water marigold.

Threats
Water pollution, including runoff from poorly planned development. Dams and stream channel alteration. Invasion by non-native species. Unsustainable agricultural and forestry practices.

Action
Mapping mussel populations. Monitoring and removing zebra mussels. Evaluating agricultural practices that affect water quality. Identifying areas of high risk for hazardous spills and runoff. Determining best approaches for the reintroduction and relocation of rare mussels. Working with interested landowners to preserve sensitive riparian forests through conservation easements and other land protection methods
 

Nature picture credits: (top to bottom, left to right): Photo © George C. Gress/TNC (Confluence of French Creek with the Allegheny River); Photo © Dave Herr (American Bittern).