Vaquita

Name and taxonomy

Two zoologists, Kenneth Norris and William McFarland, named the species in 1958 from skulls picked up on a beach. Scientists had no fresh specimen to describe until 1985, nearly thirty years later. The type locality is Punta San Felipe on the north-east shore of Baja California. The species name sinus is probably the Latin word for a bay or gulf.

Vaquita means little cow in Spanish, and Mexican fishermen also call it cochito, little pig. English names include Gulf porpoise and Gulf of California harbour porpoise. It sits in the genus Phocoena with the harbour porpoise and two southern species. The genus belongs to the porpoise family, Phocoenidae, within the toothed whales. No subspecies are recognised.

Evolution and relatives

The vaquita's closest relative is Burmeister's porpoise of South America. The spectacled porpoise of the Southern Ocean is a more distant cousin. Both live south of the equator, so the vaquita's ancestors probably crossed the tropics from the south. That crossing is thought to have happened during a cool spell of the Pleistocene, more than 2.5 million years ago. A porpoise that reached the Gulf was probably then cut off from its kin by warm water.

A genome from an animal caught in 2017 showed that the species passed through a severe bottleneck long ago. Harmful genes were probably purged during that ancient crash. That may be why the last few animals still appear healthy despite the tiny population. A 2022 study concluded that inbreeding is unlikely to doom the species if the nets stop.

Appearance

Adults measure 120 to 150 centimetres from snout to tail. Females grow larger, to 150 cm, while males reach about 140 cm. An adult weighs 30 to 55 kilograms, though some records run from 27 to 68 kg. A newborn calf is about 0.6 to 0.7 metres long. The body is stockier than a dolphin's but more slender than a harbour porpoise's.

The back is dark grey, the sides paler, and the belly pale grey or white. Black patches ring the eyes and the lips, and a dark stripe runs from the chin to each flipper. Calves are born darker and fade as they grow. The head is blunt, with no beak. The triangular dorsal fin rises up to 15 cm, about a tenth of the body length, and stands taller in males. Each half of each jaw holds 16 to 22 small spade-shaped teeth.

Habitat and range

The vaquita has the smallest range of any cetacean. It lives only in the northern tip of the Gulf of California, the sea that some maps call the Sea of Cortez. The core of that range lies just south of the Colorado River mouth, off San Felipe. Old reports from the southern Gulf and the Tres Marias Islands were mistakes. GBIF holds records from 2 countries, Mexico and the United States, and nearly all of them are Mexican.

The water there is shallow, mostly under 40 metres deep and never more than 150. It is thick with silt, rich in plankton and very productive. Sea temperatures swing from about 14 degrees Celsius in January to 36 in August. Most porpoises stay in water cooler than 20 degrees, so the vaquita is the only one that lives in such heat. Its slender body and large fins probably help it shed heat.

Diet and hunting

The vaquita is an opportunist that takes whatever small prey lives near the sea floor. Grunts and croakers, two families of bottom fish, make up most of the diet. Gulf croaker remains have turned up in several stomachs. It also eats squid, including the small Lolliguncula squids, and crustaceans such as shrimp. Only a handful of stomachs have ever been examined, so the full menu is unknown.

Like other porpoises, it finds prey with clicks of echolocation in water too murky for sight. A foraging animal surfaces 3 to 5 times and then dives for several minutes. Groups of 10 or more sometimes gather where food is plentiful, but they soon break up.

Behaviour and social life

Vaquitas are usually seen alone or in pairs, often a mother with her calf. Small groups of 2 to 4 occur, and loose feeding gatherings can reach 10. No animal has ever been tagged, so nothing is known about individual movements or home ranges. Photographs of fin marks can tell individuals apart.

The species is shy and hard to approach. It surfaces with a low roll that makes no splash and no visible blow. It keeps hundreds of metres from boats with a running engine, though it may come near a small idling boat. It never rides bow waves, and no one has seen one breach or leap. All of this makes it one of the hardest cetaceans to study.

Communication and senses

The vaquita uses sonar to find its way and to talk to its own kind. Like other porpoises, it produces narrow, high-pitched clicks that people cannot hear. Underwater microphones pick up those clicks, and since 2011 acoustic monitoring has been the main way to count the population. In 2023 the navy heard clicks outside the protected zone and widened the area guarded by net-snagging blocks.

Sight matters little in water this cloudy, and vision is probably weak. The black patches around the eyes and lips may help calves recognise their mothers. No one has recorded a vaquita call that carries over a distance, and it is thought to be a quiet animal.

Reproduction and life cycle

Both sexes mature at 3 to 6 years old. Mating runs from mid April to May, and pregnancy lasts about 10 to 11 months. One source puts gestation at 10.6 months. Most calves are born between February and April, a tight season. A female bears a single calf and nurses it for 6 to 8 months, and no longer than a year.

Early work on stranded animals suggested a calf every other year. Recent sightings of mothers with calves suggest that some females can breed every year. Mating is thought to be polygynous, with males competing for females. The evidence is indirect: females are larger, groups are small, and the testes weigh nearly 3% of the body.

Life expectancy is estimated at 20 years. The oldest known animal was 21. Slow breeding and a long pregnancy make the species a poor candidate for a fast recovery. Even so, monitoring in 2025 found 7 to 10 individuals and new calves.

Predators and threats

Large sharks are the only known natural predators. Shark fishing in the northern Gulf has probably reduced that pressure. But the nets that catch sharks catch porpoises too, and the harm far outweighs any benefit.

Drowning in gillnets is the cause of death in almost every carcass examined. For decades the shrimp fishery and nets set for sharks and rays did most of the damage. One early estimate put the loss at 25 to 30 animals a year. After 2011 the illegal fishery for totoaba took over as the main killer. The totoaba is a large drum fish whose dried swim bladder is smuggled to China for use as a delicacy and a folk medicine. In 2017 poachers were paid up to 20,000 US dollars for a kilogram of bladders.

Large-mesh totoaba nets are the right size to trap a porpoise by the head or flippers. Farm runoff carries pesticides into the Gulf, and the toxins can harm the animals. A tiny population also faces the risk that too few animals meet to breed.

Population and conservation

No one knows how many vaquitas there were before fishing began, because the species was described so late. The first full survey, in 1997, estimated 567 animals. By 2007 the estimate had fallen to 150, and by 2018 to fewer than 19. Fewer than 10 were thought to survive in February 2022. A 2024 survey saw at least 6 to 8 animals and at most 9 to 11, the lowest count ever. The survey area was small, so some animals may have been outside it.

The IUCN has listed the vaquita as Critically Endangered since 1996. It is on CITES Appendix I, on the US Endangered Species Act, and on Mexico's own list of species at risk. In 2019 UNESCO placed the Gulf islands World Heritage Site on its list of sites in danger.

Mexico launched the PACE-Vaquita programme in 2008, paying fishermen to give up gillnets or their permits. A partial gillnet ban came in 2015 and a permanent exclusion zone in 2017. Hundreds of poachers kept fishing anyway. In 2017 a rescue project called VaquitaCPR caught two animals for a sea pen, and one died of shock. Since 2022 the navy has sunk 193 concrete blocks with hooks that tear illegal nets, and boat numbers fell at once. A 2022 model found that the species can recover if all bycatch stops.

Relationship with humans

People have never hunted the vaquita or used it for anything. Fishermen see it only as a nuisance that fouls a net and spoils one haul. Its whole story with people is one of accidental killing. The totoaba fishery that first drowned porpoises was banned in 1975, then returned as a black market.

Cartels run the modern trade, and the bladders have been called the cocaine of the sea. One investigator in 2017 traced the supply chain from Mexico to China, and arrests followed in 2020. In 2020 the United States banned imports of shrimp and other Mexican seafood taken from vaquita waters. About 80% of the shrimp from the northern Gulf is eaten in the United States, so American diners are part of the problem.

Sea Shepherd and the Museo de Ballena work with the Mexican Navy to find and pull illegal nets. In 2024 Colossal Biosciences said it would bank vaquita cells and watch the animals with drones and hydrophones. Scientists warned in 2007 that captive breeding was not a way out, and the 2017 capture proved them right.

In culture and myth

The vaquita probably has no place in old folklore. It was unknown to science until 1958, it is seldom seen, and the fishing towns of the Gulf are young. Any tale about it is probably a modern invention. Its symbolism belongs to the conservation movement instead.

In Mexican Spanish the animal is the little cow, or cochito, the little pig. Campaigners call it the panda of the sea, for the black rings around its eyes. It is also called the desert porpoise, because its sea is ringed by the Sonoran Desert. The group Viva Vaquita runs an International Save the Vaquita Day each year.

The 2019 documentary Sea of Shadows, directed by Richard Ladkani, followed the fight against the totoaba cartels. It won an audience award at Sundance and a Cinema for Peace award in 2020. In Chinese tradition, a dried fish maw is a prized delicacy and a tonic, and that belief drives the trade that kills the porpoise.