"In 2016, biologists and fishermen across the country started to notice something disturbing. Freshwater mussels were dying in large numbers. NPR National Correspondent Nathan Rott tells us about the unsolved mystery surrounding the die-off, the team racing to figure it out, and why mussels are so important for the health of our streams and rivers."

Nathan Rott and Maddie Sofia report for NPR March 10, 2020. [2]