The vaquita ( / v ə ˈ k iː t ə / və- KEE -tə ; Phocoena sinus ) is a type of porpoise found only in the northern part of the Gulf of California in Baja California, Mexico. It grows up to 150 cm (4.9 ft) long for females or 140 cm (4.6 ft) long for males, making it the smallest living member of the cetacean group, which includes whales, dolphins, and porpoises. This species is very close to extinction and is classified as Critically Endangered by the IUCN Red List. The large decrease in its population is mainly because of accidental trapping in gillnets used in the illegal totoaba fishery.
Taxonomy
In 1958, two scientists, Kenneth S. Norris and William N. McFarland, identified the vaquita as a separate species by studying the shape and structure of skull bones found on a beach. Scientists did not fully describe the vaquita’s outside appearance until 1985, when fresh samples were available for study.
The genus Phocoena includes four types of porpoises. Most live in coastal waters, while one species, the spectacled porpoise, prefers open ocean areas. The vaquita is most closely related to Burmeister’s porpoise (Phocoena spinipinnis) and less closely related to the spectacled porpoise (Phocoena dioptrica). These two species live only in the Southern Hemisphere. Scientists believe the vaquita’s ancestors moved north across the equator more than 2.5 million years ago during a cold period in the Pleistocene. DNA analysis from a vaquita captured in 2017 showed that the species’ ancestors experienced a major drop in population size long ago. This event may explain why the small number of remaining vaquitas are still healthy despite their low population.
The word "vaquita" means "little cow" in Spanish.
Description
The vaquita is the smallest living species of cetacean and can be easily recognized by its unique features. It has a small body, a tall triangular dorsal fin, a rounded head, and no visible beak. Its fur is mostly gray, with a darker back and a white underbelly. Dark patches surround its mouth and eyes. Differences between males and females include body size, with adult females being longer than males and having larger heads and wider flippers. Female vaquitas grow to about 150 cm (4.9 ft), while males reach about 140 cm (4.6 ft). Males also have taller dorsal fins than females. Vaquitas typically weigh between 27 kg (60 lb) and 68 kg (150 lb). This makes them one of the smallest species in the porpoise family.
Distribution and habitat
The vaquita's habitat is limited to a small area in the upper Gulf of California, also known as the Sea of Cortez. This is the smallest range of any cetacean species, and they live in shallow, cloudy waters that are less than 150 meters (about 490 feet) deep.
Behaviour and ecology
Vaquitas eat a wide range of foods, including many types of fish that live near the ocean floor, along with crustaceans and squids. Most of their diet consists of bottom-dwelling fish such as grunts and croakers.
Vaquitas are usually seen alone or in pairs, sometimes with a calf. They have been observed in small groups of up to 10 individuals.
Scientists know little about the life history of this species. Vaquitas are estimated to live about 20 years and reach sexual maturity between 3 and 6 years old. Early studies suggested they give birth every two years, but recent observations show they may reproduce each year. Males compete for females, which is shown by females being larger, small group sizes, and large testes that make up nearly 3% of their body weight.
Vaquitas reach sexual maturity between 3 and 6 years old. They give birth around the same time each year, which means the time between births is more than a year. Their pregnancies last 10 to 11 months, and calves are nursed by their mothers for 6 to 8 months until they become independent. Vaquitas give birth about every other year to a single calf, usually between February and April. Because of their low reproduction rates, long pregnancy periods, and larger size, vaquitas are considered a K-selected species. K-selected species have few offspring but care for them a lot, making them more vulnerable to extinction compared to species that reproduce quickly. Vaquitas are on the brink of extinction because their numbers are very low and they cannot reproduce fast enough to replace individuals who die.
Threats
Vaquitas live near the coast, which makes them vulnerable to changes in their habitat and pollution from runoff. Pesticides from agricultural runoff enter the water and can be swallowed by vaquitas, causing harm or death. Exposure to toxic chemicals has also harmed vaquitas. Bycatch, which is when non-target animals like vaquitas get caught in fishing nets, is the biggest threat to vaquitas and other marine mammals worldwide. A 2022 study showed that if bycatch stops completely, vaquitas might survive and recover, even with other threats. However, fishing activities remain the main danger to vaquitas. Northern fishing fleets have indirectly helped marine mammals by reducing predator numbers, such as sharks, which can harm vaquitas. However, the harm caused by accidental catches in fishing gear is greater than the benefit of fewer predators.
When populations drop quickly, they become more at risk from future threats due to reduced genetic diversity. A smaller gene pool makes it harder for species to adapt and increases inbreeding, which can weaken the population. This is called the anthropogenic Allee effect, where small populations struggle to survive because of low genetic diversity. Vaquitas, with their small population, face a negative Allee effect, which slows their population growth and increases extinction risks. However, a 2022 study found that vaquitas’ historically small population may reduce the chance of severe inbreeding issues.
Efforts to breed vaquitas in captivity have caused more harm than help. In 2017, an attempt to capture vaquitas led to the death of one female and stress for a young vaquita. Still, creating a captive population might be considered as a final option to save the species and raise awareness about them.
Human activities, like commercial fishing, have contributed to vaquita declines. Accidental bycatch, illegal fishing, and entanglement in nets are major causes. Shrimp fishing and gillnets often trap vaquitas. Illegal fishing practices, such as unregulated fisheries and poor management, have led to the overfishing of vaquitas’ prey.
The sharp drop in vaquita numbers is mainly due to bycatch in commercial and illegal gillnets, including those targeting the endangered Totoaba, shrimp, and other fish. Despite government rules, such as a partial gillnet ban in 2015 and a gillnet-free zone in 2017, illegal Totoaba fishing continues in vaquita habitats, causing population declines. By 2018, fewer than 19 vaquitas remained in the wild. Large-mesh gillnets used for illegal Totoaba fishing increased vaquita losses after 2011.
In 2021, the Mexican government removed a "no tolerance" fishing ban in the Upper Gulf of California. In 2022, the navy placed concrete blocks with rebar hooks in the main vaquita habitat, which was declared a zero-tolerance fishing area in 2020. These blocks damage gillnets and reduced fishing boat activity in the area. In November 2023, the navy expanded the area where blocks were placed, planning to continue until June 2024. Concerns remain that the hooks might create ghost nets, and the navy and Sea Shepherd have removed trapped nets from the hooks.
Conservation
The vaquita was only fully described in the late 1980s, so scientists do not know how many lived in the past. In 1983, 45 records of the vaquita were collected through skeletal remains, photos, and sightings. The first full survey of vaquitas in their habitat happened in 1997, estimating 567 individuals. By 2007, the population dropped to about 150. In 2018, scientists estimated fewer than 19 vaquitas remained. By February 2022, it was estimated that fewer than 10 vaquitas were alive. In 2023, scientists still estimated as few as 10 vaquitas remained in the wild. A 2024 survey found at least 6 to 8 vaquitas (with a maximum of 9 to 11), but this number might not reflect a real decline because the survey area was small, and vaquitas move in and out of the region.
The vaquita is listed as critically endangered on the IUCN Red List, which means it is one step away from extinction in the wild. It is the most endangered marine mammal in the world. The vaquita has been on the IUCN Red List since 1996. Its small population size puts it at risk of extinction.
In 2019, the UNESCO World Heritage Site where the last vaquitas live was declared a World Heritage Site in Danger. The vaquita is also protected under the Endangered Species Act of 1973, Mexico’s NOM-059 standard, and Appendix I of the Convention on International Trade in Endangered Species (CITES).
It is very hard for a small population like the vaquita to recover after a major decline. This is partly because scientists know little about the vaquita’s reproduction. The vaquita lives only in the upper Gulf of California, Mexico. Human activities, such as accidental trapping in fishing nets, illegal fishing, and entanglement, have caused its population to drop. Shrimp fishing and gillnets are major causes of entanglement. Illegal fishing, including unregulated fisheries and lack of management, has led to the poaching of the vaquita’s main prey, the Totoaba fish. Totoaba swim bladders are sold on the black market for profit, with prices reaching up to $80,000 per kilogram.
The Mexican government, scientists, and conservation groups have worked to reduce bycatch, ban gillnets, and help the vaquita recover. In 2017, Mexico made it illegal to remove endangered species and banned gillnet use. A program called PACE-VAQUITA, started in 2008, helped fishermen replace gillnets with safer gear and provided support for alternative livelihoods. However, poaching continues because Totoaba swim bladders are valuable. In 2020, an investigation called Operation Fake Gold mapped the illegal trade of Totoaba swim bladders from Mexico to China. This led to arrests in Mexico.
Efforts to protect the vaquita have not yet solved the complex problems affecting its survival. Solutions include protecting habitats, managing resources, educating people, enforcing fishing laws, and helping fishermen find other ways to earn a living. In 2021, Mexico considered reducing the protected area for vaquitas due to their low numbers. In 2022, the Mexican government placed concrete blocks in the Gulf of California to detect illegal nets. In 2023, a survey found the vaquita population had stabilized since 2021. In 2024, Colossal Biosciences announced a project to protect the vaquita using genetic research and technology.
About 80% of shrimp caught in the northern Gulf of California, where vaquitas are often trapped, is sold in the United States. U.S. consumers of this shrimp may be contributing to the vaquita’s decline. The Marine Mammal Protection Act of 1972 prohibits foreign fishers from exporting seafood that harms marine mammals.