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.
Oreochromis niloticus has been transported around the world because of its high value for fisheries and aquaculture. Climate match to the contiguous U.S. is high. The species has already established wild populations in Florida, Alabama, and Mississippi, with the climate match suggesting highest risk of further establishment in the Southeast and California. Impacts of O. niloticus in its introduced range include eutrophication of waterbodies through its influences on the plankton community, competition with native fishes, hybridization with native fishes, and in some cases, reduced fishing success. Overall risk posed by this species is high.