Ecological Risk Screening Summary - Blue Tilapia (Oreochromis aureus) - High Risk

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 aureus, Blue Tilapia, is a freshwater fish native to northern and western Africa and the Middle East. This species is widely used in aquaculture and has also been intentionally introduced to promote commercial and recreational harvest, resulting in O. aureus becoming established in many countries outside of its native range. Some of these nonnative populations occur in unique thermal refuges such as warm water discharges from power plants. In the United States, O. aureus was introduced through both intentional and unintentional means. It is established in at least 10 States and at least 9 States regulate its possession. Studies have documented negative competitive interactions between this species and native fish species. The History of Invasiveness for Oreochromis aureus is classified as High. The climate matching analysis for the contiguous United States indicates establishment concern with a high climate match found for much of the southern and western contiguous United States. The Certainty of Assessment for this ERSS is classified as High due to the abundance of information available on the species biology, distribution, and impacts of introductions. The Overall Risk Assessment Category for Oreochromis aureus in the contiguous United States is High.