Vaquita

About the Species

The vaquita is a shy member of the porpoise family. Vaquitas are the most endangered of the world’s marine mammals. Less than 30 vaquitas remain in the wild, and entanglement in gillnets is driving the species toward extinction.

Vaquitas have the smallest range of any whale, dolphin, or porpoise. They only live in the northern part of the Gulf of California, an area that is rich in fish and shrimp. Fishing is thus a major source of income for the people there, who almost exclusively use gillnets, but vaquitas can also become accidentally wrapped in the nets and drown.

The decrease in the vaquita population is also related to the totoaba, a large fish that also only lives in the Gulf of California. The totoaba is listed as endangered in Mexico and the United States and is protected by the Convention on the International Trade in Endangered Species. Because totoaba and vaquita are similar in size, gillnets set for totoaba are the deadliest for vaquitas. Fishermen illegally catch totoaba for its swim bladder (an air-filled sac in the totoaba’s body that helps it float), which they sell to China at high prices. In China, the swim bladders are used in soup with purported medicinal value. Thousands of swim bladders are dried and smuggled out of Mexico—sometimes through the United States.

Scientists agree that for vaquitas to survive in the wild, gillnet fishing must end within vaquita habitat. Mexico is responding to this crisis and breaking new ground in conservation activities. The Mexican government has worked with scientists, nongovernmental agencies, and foundations to ban most gillnets. Unfortunately, their actions did not stop the population decline. In April 2015, President Peña Nieto traveled to San Felipe, one of the main fishing towns off the Gulf of California, to announce a 2-year emergency gillnet ban throughout vaquita habitat. The President also announced that the government would pay fishermen for their loss of income. In September 2015, the Mexican government conducted a survey of the vaquita population using both ship-based monitoring and sound-based detectors throughout vaquita habitat.

In July 2017, a federal agreement permanently banned all gillnets except those used for fishing two species: curvina and sierra. The effect of this ban on the decline of vaquitas remains to be seen.

Status

Although we know that the vaquita population has been decreasing since the first full abundance estimate in 1997, it is likely that the population has been decreasing since gillnets started being used in the 1940s. Between 1997 and 2008, vaquitas decreased at about 8 percent per year, a figure consistent with the estimated decline that would result from the amount of gillnetting for shrimp and finfish. Acoustic monitoring between 2011 and 2016 recorded an increased rate of decline to about 40 percent per year. The estimated number remaining in November 2016 was about 30 individuals, making vaquitas the most endangered marine mammal in the world.

Appearance

The vaquita is about 5 feet long and is one of the smallest members of the dolphin, whale, and porpoise family. Females are longer than males, but males have larger fins.

Vaquitas have small, strong bodies with a rounded head and no beak. They have black patches around their eyes and lips and small, spade-shaped teeth. Vaquitas also have triangle-shaped dorsal fins in the middle of their backs, which are taller and wider than in other porpoises. These fins might allow vaquitas to reduce their body temperatures in warm water. Vaquita backs are dark gray, while their bellies are a lighter gray.

Behavior and Diet

Vaquitas are often found alone or in pairs. These shy animals usually avoid boats with active engines. They are difficult to observe because of their small size, inconspicuous and slow surface rolls, small group size, and avoidance of motorized vessels.  

Vaquitas feed on small fish, crustaceans (such as shrimp), and cephalopods (such as squid and octopi).

Where They Live

The vaquita has the smallest geographical range of any marine mammal. It only lives in the northern part of the Gulf of California in Mexico. Most vaquitas live east of the town of San Felipe, Baja California, within a 1,519-square-mile area that is less than one-fourth the size of metropolitan Los Angeles. This area also includes the Delta of the Colorado River Biosphere Reserve, one of the earth’s most diverse marine habitats. The delta includes many types of fishes, birds, marine reptiles, and marine mammals.

Lifespan & Reproduction

Vaquitas can live for at least 21 years. They reach sexual maturity when they are 3 to 6 years old. Pregnancy lasts about 10 to 11 months, and females are thought to give birth every other year to a single calf that is about 2.5 feet long and 16 pounds. Females usually give birth between February and April.

Threats

Entanglement

The only known threat to the vaquita is getting caught in fishing gear, especially gillnets.

Once scientists recognized the vaquita as a species, they also realized that small-scale and commercial fisheries were accidentally catching vaquitas. From the mid-1930s to the mid-1970s, the gillnet fishery for totoaba severely overfished vaquita. Even after this fishery closed in 1975, many vaquitas continued to die in illegal totoaba nets and gillnets set for shrimp and fish.

A study dedicated to estimating the mortality rate of vaquitas from gillnets demonstrated that vaquitas died in every type of gillnet. The highest rate was in totoaba nets, but for many years the numbers of totoaba and totoaba nets were so low that the highest numbers of vaquita deaths were inferred to come from the much more common gillnets set for shrimp. The rate of decline between 1997 and 2008—derived from both visual and acoustic monitoring—is consistent with the level of fishing in this period without inferring any other threat to the species.

Illegal fishing for totoaba has significantly increased since about 2011 due to Chinese demand for its swim bladder. Fishermen can earn up to $8,500 for each kilogram of totoaba swim bladder. This amount is equal to a large percent of a year’s pay from legal fishing.

Other Threats

NOAA Fisheries and its partners have examined other potential threats to vaquitas, which have all been dismissed. People often cite the lack of Colorado River flow, which could potentially decrease vaquitas’ food supply, as a threat. But no vaquitas that were examined after being killed in gillnets showed any signs of malnutrition that might be expected if habitat issues were causing the decline. Vaquitas also have among the lowest levels of pollutants in their habitat, and although they show low genetic diversity, the cause of the low diversity is consistent with a naturally rare species. Finally, most of the vaquitas recovered from gillnets were young and had no apparent health issues that might indicate inbreeding depression.

Scientific Classification

Kingdom	Animalia
Phylum	Chordata
Class	Mammalia
Order	Artiodactyla
Family	Phocoenidae
Genus	Phocoena
Species	sinus