Dunkard Creek is welcoming back an old friend -- one that has been missing for nearly 15 years: rare, endangered freshwater mussels.

In 2009, a golden algae bloom swept through Dunkard Creek, a 43-mile-long waterway that runs along the Pennsylvania-West Virginia border. The U.S. Fish & Wildlife Service (FWS) reported that ichthyotoxin -- a substance toxic to fish and other aquatic life -- killed tens of thousands of fish, mussels, and invertebrates. For years, the creek remained a ghost town for wildlife.

But now, there is a reason to celebrate. In July 2025, FWS's White Sulphur Springs National Fish Hatchery, in partnership with the Pennsylvania Department of Environmental Protection and the Pennsylvania Fish and Boat Commission, restocked the creek with more than 10,000 fatmucket mussels. This marks a significant milestone in a decade-long effort to revive the ecosystem.

"These freshwater filtering friends play a special role in keeping the environment healthy," USFWS posted on X. "It's a serious concern that 300 species of freshwater mussels are among the most vulnerable animals in North America."

In total, conservationists have reintroduced over 31,000 mussels representing six species since 2015. Their presence helps filter pollutants, improve water clarity, and create healthier conditions for fish and other wildlife -- benefits that ripple outward to the surrounding communities that rely on the creek.

This comeback demonstrates what's possible when long-term restoration projects get the time and resources they need. Mussels are some of the most imperiled animals in North America, but their recovery can improve drinking water, support recreation, and boost local economies.

Similar wins have been happening across the world. Conservationists in Sweden have helped bring Atlantic sturgeon back from the brink, while projects in the U.K. to restore oyster reefs are cleaning coastal waters and protecting shorelines.