Threatened species of Phocoena sinus

This species may have been subject to high levels of mortality in the gill-net fishery for totoaba (Totoaba macdonaldi) in the 1960s and early 1970s (prior to a ban on totoaba fishing). Incidental fishing mortality continues to be associated with shark gill-net fishing and illegal totoaba fishing. Based on its limited range and history of incidental mortality, several national and international organizations have concluded that P. sinus is in danger of extinction, and the species is included in the list of U.S. Endangered Species. No population estimates have been made to date, and the present and historical range of the species is currently the subject of debate. Researchers who have conducted surveys agree that the species is rare. Given the limited range of P. sinus, habitat quality may play a major role in determining the size and health of the population.

The vaquita (Phocoena sinus) is a small porpoise found only in the northern Gulf of California. The vaquita has the most limited range of any marine mammal.

A lower limit on population size might be 50-100 individuals. It is not possible to estimate a reliable upper limit on population size based on available information.