The Duck River mussel population has diminished drastically due to industrialization. Since Congress passed the Clean Water Acts in 1972 and 1973, studies have shown significant declines and extinctions of mussels and snails.
- Species richness and abundance declines
- Clean Water Act 1972
- Endangered Species Act 1973
- Normandy Dam Built
- TVA began monitoring 22 sites above Columbia, TN due to Columbia Dam in 1979
- Species richness remained stable, but mussel abundance increased in 1988
-TVA Reservoir releases improvement initiative
- Normandy discharge regulation and improved dissolved oxygen
- Survey led by Steve Ahlstedt led to the finding of 54 species, 32 of which were below Centerville, TN
- Significant increase in species richness and abundance compared to 1979/1988; though there was a loss of 21 species since surveys began
- Reintroduction Plan finalized
- Reintroductions introduced of several species in 2013
- Densities of most species stable since 2010, although there are some declines in 2020
- The Duck River reached historical drought in 2024 creating a drastic decrease in richness and abundance of mussel species
