Throughout his professional life, U.S. Forest Service researcher Wendell Haag has studied freshwater mussels in their hotspot of biological diversity, which extends across a vast swath of the southeastern United States.
Throughout his professional life, U.S. Forest Service researcher Wendell Haag has studied freshwater mussels in their hotspot of biological diversity, which extends across a vast swath of the southeastern United States. His more than 30-year career has been overshadowed by a single question: Why are the bivalves in this region disappearing?
Freshwater mussels are one of the most endangered groups of animals in the world. North America is currently home to more than 300 native species — many with colorful colloquial names like fuzzy pigtoe, purple warty back, fluted elephant ear, orangefoot pimpleback, pink heelsplitter, and monkeyface — of which 70 percent are either endangered, threatened, or of special concern. Some southeastern watersheds have seen losses of a third to half of their mussel species in the last half century; another 21 southeastern species are believed to be extinct, and dozens more persist only in fragments of their former range.
Threats to mussels come from many quarters — polluted runoff, the damming of waterways, warming water temperatures, pathogenic viruses, and invasive competitors — but an explanation for the extent of the U.S.’s most widespread die-off, which began decades ago in the Southeast, has remained out of reach.
Read More: Yale Environment 360
Dead freshwater mussels gathered from the Clinch River in Virginia. (Photo Credit: Meagan Racey / USFWS)
