Conservation Status of Crayfishes of the United States and Canada

The American Fisheries Society (AFS) Endangered Species Committee herein provides a list of all crayfishes (families Astacidae and Cambaridae) in the United States and Canada that includes state and provincial distributions; a comprehensive review of the conservation status of all taxa; and references on biology, conservation, and distribution of crayfishes. The list contains 338 native crayfishes, of which 2 (< 1%) taxa are listed as endangered, possibly extinct; 65 (19.2%) as endangered; 45 (13.3%) as threatened; 50 (14.8%) as special concern; and 176 (52.0%) as currently stable. Limited natural range is implicated as the primary factor responsible for the noted imperilment of crayfishes; other threats include habitat alteration and the introduction of nonindigenous crayfishes. Using the best available information, we estimate that almost 50% of crayfishes in United States and Canada are in need of conservation recognition. We hope that this report spurs increased research efforts from aquatic biologists and pro-active actions by resource personnel, citizens, and lawmakers.