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 proactive actions by resource personnel, citizens, and lawmakers.