Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.
Dikerogammarus oskari is an amphipod that has only been reported from the southern Caspian Sea, near Azerbaijan and Iran. Little information is available for this species and georeferenced occurrences are currently lacking. D. oskari has not been reported anywhere outside of its native distribution, therefore, history of invasiveness is classified as No Known Nonnative Population. The climate match for the contiguous United States was categorically High with the highest matches occurring in the Intermountain West. However, D. oskari is only known from brackish water associated with the Caspian Sea. The climate match does not account for salinity tolerance. It is uncertain if D. oskari could become established in portions of the United States where the climate match was high, but only freshwater habitat exists. Further, the climate match was based on generalized occurrences because no georeferenced occurrences were available. The certainty of this assessment is Low due to a lack of information. The overall risk assessment category for D. oskari is Uncertain.
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Uncertain Risk
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