Tilapia were introduced into Florida in the 1960s and can be found extensively in tropical/sub-tropical regions of the US, Central and South America, Africa, and Eurasia. However, their native range is typically represented in parts of Africa and the Middle East. Tilapia are widespread and have abundantly populated Florida’s canals, ponds, rivers, streams, lakes, and springs. Sensitivity to salinity varies greatly between species, and some species of tilapia can fully tolerate seawater in marine environments. The most common food consumed by tilapia are green algae, diatoms, plankton, and small invertebrates living in/on bottom detritus. The diet of tilapia often overlaps that of native fish like largemouth bass, which can create a potentially detrimental competition with native fish species.
Why no info on exotic invasive species and the potential threat to our springs? Large schools invade spring runs seeking thermal refuge in winter, then damage the bottom and smother the eggs of sunfish and bass by digging large nests. Silver Glen Springs has at times looked like a minefield with all the tilapia nests. Volusia Blue Spring has been overrun with Blue Tilapia and Sailfin Suckermouth Catfish.
U.S. Fish and Wildlife Service:
Summary of Risk to the Contiguous United States
Oreochromis aureus has been transported around the world because of its high value for fisheries and aquaculture. Climate match with the contiguous U.S. is high, reflected in the successful establishment of the species in Florida, Texas, Arizona, Nevada, and California. This species carries with it several potential threats to native species, including resource competition, hybridization, and disease, and it has been implicated in declines of native fish and mollusks. Overall risk posed by this species is high.
Thank you for your feedback on our online Springs Fish ID guide. You are right that Tilapia are an invasive species and do cause issues to our native fish and springs ecosystems. We are in the process of updating the information on our “Blue Tilapia” page to better reflect these facts. FSI is dedicated to springs science and education in efforts to protect our springs – we appreciate your interest in helping us provide the best information possible to support this effort!