The tucuxi lives in both saltwater and freshwater and is found on the east coast of Central and South America. A riverine sub-species, S. f. fluviatilis is found in the Amazon River and its main tributaries in northern Brazil, Peru, Colombia, and Ecuador, as well as in the lower Orinoco River in Venezuela.
Comprehensive population estimates are not available and the IUCN classified the tucuxi as Data Deficient (2008). Although its population is not known, it is not thought to be immediately threatened.
Tucuxi are known to be distributed throughout the Amazon basin and possibly also in the Orinoco River. Direct kills by human are part of the dangers faced by this species because fishermen perceive them as competition and because they are used in traditional medicine; interestingly they are also protected in many parts of their range because of myth and legend.
Other threats to the tucuxi are pollution, accidental bycatch, entanglement in fishing gear, human disturbance, habitat deterioration, and fragmentation of populations by dam construction.