North America has lost nearly 3 billion birds since 1970, according to a 2019 study in Science led by Kenneth Rosenberg, a decline that spans farmland, forest and grassland species alike. In one Pennsylvania river system, though, a different trend is underway. Freshwater mussels and the eastern hellbender, the continent’s largest salamander, are turning up again in water that acid mine drainage once made lethal to them.
Colcom Foundation, the Pittsburgh-based funder behind that recovery, has spent nearly two decades directing grants toward the Western Pennsylvania Conservancy’s watershed remediation work on the Clarion River. Acid mine drainage treatment systems installed there under that partnership have coincided with the documented return of both species to stretches of river once too polluted to sustain them.
Freshwater mussels make an even harder case for recovery than the hellbender does. They spend most of their lives filtering water through a single spot on the streambed, unable to relocate if conditions turn hostile, and many species need a specific host fish to complete their life cycle before they can spread to new stretches of river. A mussel population reappearing in a given reach of the Clarion is a sign that water quality there has been stable, not just improving, for long enough to support a creature that can’t simply swim away from a bad year.
Why the Eastern Hellbender Became a Test Case for Colcom Foundation’s Approach
The eastern hellbender is a useful barometer for river health precisely because it’s so hard to please. Adult hellbenders range from 12 to 29 inches long, and the species breathes entirely through its skin. As the U.S. Fish and Wildlife Service put it in the announcement of the species’ proposed federal listing, “cool and clear water is important because hellbenders breathe through their skin, which contains numerous folds to increase oxygen absorption.” Sediment and pollution that other species tolerate can suffocate a hellbender outright.
That vulnerability is why the numbers behind the Fish and Wildlife Service’s December 2024 proposal to list the eastern hellbender as endangered across its 15-state range are so stark: of 626 historically documented populations, only 371 remain, and of those survivors, just 45 are considered stable while 218 are declining. More than a year after the proposal, the agency still hasn’t issued a final rule. It missed a December 2025 deadline, and the Center for Biological Diversity sued in February 2026 to force a binding timeline for a decision.
What Species Recovery Signals About Colcom Foundation’s Regional Strategy
Colcom Foundation’s own environmental philosophy links wildlife decline directly to regional population growth and development pressure, a philosophy rooted in the I=PAT framework that researchers Paul Ehrlich and John Holdren introduced in a 1971 Science paper connecting human impact to population, affluence and technology. The foundation applies that framework both nationally and locally, funding a specific set of Pennsylvania nonprofits, including the Western Pennsylvania Conservancy, Foundation for Pennsylvania Watersheds, and Allegheny Land Trust, that carry out the on-the-ground remediation the philosophy calls for.
On the Clarion River, that remediation is already measurable. Freshwater mussels and eastern hellbenders, two of the region’s most pollution-sensitive species, are documented living again in stretches of river once too degraded to support them, a direct result of the acid mine drainage treatment Colcom Foundation and the Western Pennsylvania Conservancy have funded there for nearly two decades.
