Do schools and golf courses represent emerging pathways for crayfish invasions?

Prevention is frequently promoted as the most desirable management strategy for biological invasions. Crayfish introductions are typically associated with aquaculture and bait bucket releases, but here we report two alternate pathways that may be responsible for the recent invasion of Procambarus clarkii (Girard, 1852) and Orconectes virilis (Hagen, 1870) in Washington State, U.S.A. Using distributional data and personal interviews we identified (1) school science programs, which use crayfish as laboratory organisms, as a likely pathway of introductions, and (2) golf courses bordering lakes, in which ponds have been constructed and are suspected to be stocked with O. virilis to control aquatic macrophytes. Particularly concerning, we found the highly invasive crayfish Orconectes rusticus (Girard, 1852) in use as a laboratory organism at multiple schools, although this species is not known to be established in the region. Vector management is critical for interrupting the transfer of invasive species, and our study has identified two emerging pathways that require greater research attention and stricter regulation.