Nation Rare freshwater mussel may soon go extinct in these 10 states. Feds propose protection. July 25, 2023Natalie Neysa Alund, USA TODAYComments Off on Rare freshwater mussel may soon go extinct in these 10 states. Feds propose protection. The green floater, a small freshwater mussel in small streams and large rivers in the eastern U.S. is now 'threatened' under Endangered Species Act.