VAQUITA } Phocoena sinus
The scientific name Phocoena is from the Latin word “porpoise” or “pig fish.” Sinus means “cavity,” a reference to the Gulf of California. Put together, Phocoena sinus is the “porpoise of the Gulf of California.” The species is also known as the cochito, yet this common name is used to describe several marine animals in the geographic area. The name vaquita was popularized from local fishermen’s name for the species.
DESCRIPTION: Stocky and sleek, the vaquita is among the smallest living cetaceans, measuring less than five feet in length and weighing no more than 120 pounds. Vaquitas are medium to dark gray in color above, fading to an off-white hue on their undersides. They have pronounced lip patches, large, black eye rings, and a dark line running from their chins to the base of their flippers. The vaquita has a classic porpoise shape, yet compared with its relatives, the species has slightly larger flippers, a smaller skull, and a tail fin that is taller and more curved.
HABITAT: Vaquitas inhabit murky waters between 30 to 90 feet deep and within 16 miles of the shoreline, where there is strong tidal mixing and high food availability. They can survive in lagoons so shallow that their backs will poke above the water’s surface. The vaquita is unique among porpoises in that it lives in warm waters and is able to tolerate large fluctuations in temperature.
RANGE: The vaquita has a very small and specific range, encompassing a mere 1,500 square miles. Though the vaquita may have formerly occurred throughout the Gulf of California, the species today has the most limited distribution of any cetacean and is restricted to the northwestern corner of the gulf. It is primarily found around the Rocas Consag archipelago east of San Felipe in Baja California and near the Colorado River Delta.
MIGRATION: This species does not migrate.
BREEDING: Mating between vaquitas takes place in the spring or early summer, and following a gestation period of approximately 11 months, young are born the following year. Young vaquita calves are nursed for several months before being weaned. Females give birth to one calf about every two years. Calves weigh approximately 20 pounds at birth.
LIFE CYCLE: Little is known about the lifespan of the vaquita. Longevity of the species is estimated at 21 years, with reproductive maturity probably occurring at six years of age.
FEEDING: Vaquitas feed on squid, crabs, and small, bottom-dwelling fish. They are believed to be non-selective feeders.
THREATS: In imminent danger of extinction, the vaquita population is threatened by incidental bycatch in illegal and legal gillnets, commercial shrimp trawls, damming of the Colorado River and decreased freshwater input into the upper Gulf of California, coastal development, lack of genetic variability, pollution, and pesticides.
POPULATION TREND: Vaquita populations took a nosedive with the modernization of the commercial fishing industry in the Gulf of California in the 1940s. Every census in recent decades has estimated the vaquita population at less than 1,000 individuals. The vaquita has been classified as critically endangered on the IUCN Red List of Threatened Species since 1996. In 2007, the entire population was estimated to be only 150 individuals and declining rapidly.