The State of Crayfish in the Pacific Northwest

We summarize the state of knowledge on crayfish in the Pacific Northwest region of the United States and Canada, emphasizing distributions and conservation status of native species, as well as known introductions and distributions of alien crayfishes, and reviewing fishing regulations relevant to crayfish across five states and provinces. We found the present distribution and ecology of native crayfishes in this region to be poorly known, inhibiting accurate conservation assessments and management. The number of alien crayfishes established in the region, ranging in distribution from localized to widespread and including several major invasive species, now exceeds the diversity of native crayfishes. The treatment of crayfish by fishing regulations and laws varies among states and provinces, potentially impairing successful management and conservation of these species in shared ecosystems such as the Snake and Columbia rivers. We conclude with recommendations for crayfish management and regulation, and a call for more research on the ecology of crayfish in the Pacific Northwest.