Species that are considered high risk have a well-documented history of invasiveness in at least one location globally, and a high or medium climate match to the contiguous United States.
Pontogammarus robustoides is an amphipod native to areas around the Black, Caspian, and Azov seas in southeastern Europe and western Asia. P. robustoides may provide a food base in polluted waters and may be a vector of fish parasites. Documented impacts of P. robustoides invasion in Europe include declines in native amphipods and isopods, significant control of algal growth, and changes in water quality. Although it inhabits freshwater and brackish environments in its native range, it can survive considerably higher salinities and thus is a candidate for transoceanic transport and invasion of North America via ballast water. Climate match to the contiguous U.S. is medium, with highest match in the Great Lakes region. However, only one georeferenced occurrence was available for the native range, so the estimated climate match may be an underestimate. Overall risk posed by this species is high because of the multiple, well-documented impacts it has had where introduced and its medium climate match to the contiguous U.S.
Publication date
Type of document
High Risk
Program
