(a) Proportion of freshwater bivalves in different threat categories globally according to the International Union for Conservation of Nature. Numbers in parentheses are the number of mussel species in that geographic region. (b) Proportion of freshwater mussel species in the United States that are extinct, federally listed as endangered or imperiled, considered vulnerable according to the Nature Conservancy (G1-G3 species not federally listed), or may be secure. (c) Declines in freshwater mussel density and species richness between 1990–1992 and 2003–2005 across 10 monitoring sites in the Kiamichi River, Oklahoma, United States.

Figure from: Vaughn, C.C. and TJ. Hoellein. 2018. Bivalve impacts in freshwater and marine ecosystems. Annual Review of Ecology, Evolution, and Systematics 49:183-208.