Adult vaquitas are typically 1.2 to 1.5m in length with females being slightly larger than males. At birth their average length is 0.6-0.7m. Juveniles also have white spots on their dorsal fins.
Phocoena sinus has between 34-40 teeth which are unicuspid, or "acorn like" (Silber, 1990) and a blunted rostral profile. P. sinus are physically similar to the Harbor Porpoise (/Phocoena phocoena/) in many ways with an exception being that the vaquita is more slender. This has been explained in terms of their warmer habitat--the slender body increases surface area/volume ratio thus increasing heat dissipation in a warm environment. This explanation has also been used to explain the occurrence of larger appendages within this species (Hohn et al., 1996).
Range mass: 30 to 55 kg.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: female larger
An interesting feature of the vaquita is that it is the only species of porpoise that is found in such warm waters. Most phocoenids are restricted to water cooler than 20 degrees Celsius, vaquitas are unique in their ability to tolerate large annual fluctuations in temperature (Hohn, et al, 1996). The Gulf of California may experience temperature ranges from 14 degrees C in January to 36 degrees C in August. This may have an effect on the reproductive seasonality of this species.
Aquatic Biomes: coastal
The range of Phocoena sinus is extremely restricted. This species of porpoise is found only in the northern end of the Gulf of California. Phocoena sinus (commonly known as the vaquita) are found only in shallow water, close to shore.
Biogeographic Regions: pacific ocean (Native )
Vaquitas feed on teleost fishes and squid, which are found near the surface of the water. In several individuals the remains of Guld croakers were found.
Animal Foods: fish; mollusks
Primary Diet: carnivore (Piscivore )
This species is not used directly by humans. It is interesting in the sense that it is a unique phocoenid morphologically and behaviorally. The fact that it is limited in its range and is extremely endangered should encourage study of the vaquita.
An interesting side note concerning the survival of this species is that it is often directly tied to the survival of the endangered totoabo, a fish resembling the seabass. Totoabo have been widely fished as they are considered a delicacy. Unfortunately totoabo are similar in size and shape to vaquitas and they are often mistaken. In this manner, the more sought after totoabo are, the more bleak the chances of survival for vaquitas. Fishing for totoabo has become illegal but continues to occur on a wide scale. Conservation of these species must occur in tandem.
Perception Channels: tactile ; chemical
Vaquita are listed as critically endangered. They are perhaps the most endangered of the cetaceans with only a few hundred remaining. Phocoena sinus are often caught in fishing nets which are set to catch other marine animals, most often shrimp. This species becomes entangled either in the shrimp nets or within gillnet fisheries for sharks. It is estimated that 25-30 individuals drown each year as a result. To further complicate the situation, relatively few individuals reach maturity because of the high mortality of young individuals (they are highly susceptible to being netted), and the remaining older individuals are approaching the upper limit of their lifespan so as to be contributing little to future reproduction (Hohn et al, 1996).
US Federal List: endangered
CITES: appendix i
IUCN Red List of Threatened Species: critically endangered
P. sinus may interfere with human activity is in that it may inadvertantly become entangled in fishing nets set for shrimp, sharks, and totoabo causing a nuisance and possibly reducing catch during one net hauling.
Vaquitas are usually solitary. This would indicate a social system in which sperm competition is extremely important (Hohn et al., 1996). Within such systems, males attempt to maximize their fitness not by monopolizing access to females, but rather by mating with as many females as possible. As would be expected in multi-male breeding systems, male vaquitas have relatively large testes size in comparison to their body size.
Mating System: polygynous
Sexual maturity is believed to be reached between the ages of three and six years. Body mass may help to distinguish mature from immature specimens for both males and females (Hohn et al., 1996). Vaquitas have highly seasonal reproduction. During the spring there is a complete lack of larger calves. The mating period is from mid-April to May, with a gestation period of roughly 10.6 months. Births occur at the beginning of the following March. P. sinus have non-annual ovulation, thus they do not produce calves each year (Hohn et al., 1996). Females have one calf per pregnancy and lactate for less than one year.
Breeding season: The mating period is from mid-April to May
Average number of offspring: 1.
Average gestation period: 10.6 months.
Range weaning age: 12 (high) months.
Average weaning age: 12 months.
Range age at sexual or reproductive maturity (female): 3 to 6 years.
Range age at sexual or reproductive maturity (male): 3 to 6 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous
In 2012, Phocoena sinus was included among the world's 100 most threatened species, in a report by the IUCN Species Survival Commission and the Zoological Society of London.
The vaquita (/vəˈkiːtə/ və-KEE-tə; Phocoena sinus) is a species of porpoise endemic to the northern end of the Gulf of California in Baja California, Mexico. Reaching a maximum body length of 150 cm (4.9 ft) (females) or 140 cm (4.6 ft) (males), it is the smallest of all living cetaceans. The species is currently on the brink of extinction, and currently listed as Critically Endangered by the IUCN Red List; the steep decline in abundance is primarily due to bycatch in gillnets from the illegal totoaba fishery.[4][2]
The vaquita was defined as a species by two zoologists, Kenneth S. Norris and William N. McFarland, in 1958 after studying the morphology of skull specimens found on the beach.[5] It was not until nearly thirty years later, in 1985, that fresh specimens allowed scientists to describe their external appearance fully.[6]
The genus Phocoena comprises four species of porpoise, most of which inhabit coastal waters (the spectacled porpoise is more oceanic). The vaquita is most closely related to Burmeister's porpoise (Phocoena spinipinnis) and less so to the spectacled porpoise (Phocoena dioptrica), two species limited to the Southern Hemisphere. Their ancestors are thought to have moved north across the equator more than 2.5 million years ago during a period of cooling in the Pleistocene.[7][8] Genome sequencing from an individual captured in 2017 indicates that the ancestral vaquitas had already gone through a major population bottleneck in the past, which may explain why the few remaining individuals are still healthy despite the very low population size.[9]
"Vaquita" is Spanish for "little cow".[10]
The smallest living species of cetacean, the vaquita can be easily distinguished from any other species in its range. It has a small body with an unusually tall, triangular dorsal fin, a rounded head, and no distinguished beak. The coloration is mostly grey with a darker back and a white ventral field. Prominent black patches surround its lips and eyes.[11] Sexual dimorphism is apparent in body size, with mature females being longer than males and having larger heads and wider flippers.[8][12] Females reach a maximum size of about 150 cm (4.9 ft), while males reach about 140 cm (4.6 ft).[13] Dorsal fin height is greater in males than in females.[8][12] They are also known to weigh around 27 kg (60 lb) to 68 kg (150 lb). This makes them one of the smallest species in the porpoise family.[14]
Vaquita habitat is restricted to a small portion of the upper Gulf of California (also called the Sea of Cortez), making this the smallest range of any marine mammal species. They live in shallow, turbid waters of less than 150 m (490 ft) depth.[2] Vaquitas inhabit murky warm waters within 26 kilometres (16 mi) of the shoreline since there is high food availability and a strong tidal mix. Since they are able to survive in shallow waters, their triangle-shaped dorsal fin sticks out above water and they are commonly mistaken for dolphins.(Center for Biological Diversity, n.d)
Vaquitas are generalists, foraging on a variety of demersal fish species, crustaceans, and squids, though benthic fish such as grunts and croakers make up most of the diet.[2]
Vaquitas are generally seen alone or in pairs, often with a calf, but have been observed in small groups of up to 10 individuals.[2]
Little is known about the life history of this species. Life expectancy is estimated at about 20 years and age of sexual maturity is somewhere between 3 and 6 years of age.[15] While an initial analysis of stranded vaquitas estimated a two-year calving interval,[16] recent sightings data suggest that vaquitas can reproduce annually.[17] It is thought that vaquitas have a polygynous mating system in which males compete for females. This competition is evidenced by the presence of sexual dimorphism (females are larger than males), small group sizes, and large testes (accounting for nearly 3% of body mass).[16]
Because the vaquita was only fully described in the late 1980s, historical abundance is unknown.[18] Since 1983, all confirmed specimens, records, and sightings of P. sinus were evaluated. There were 45 records of P. sinus that were collected by skeletal remains, photographs, and sightings in 1983.[19] The first comprehensive vaquita survey throughout their range took place in 1997 and estimated a population of 567 individuals.[20] By 2007 abundance was estimated to have dropped to 150.[21] Population abundance as of 2018 was estimated at less than 19 individuals.[22] Given the continued rate of bycatch and low reproductive output from a small population, it is estimated that there are fewer than 10 vaquitas alive as of February 2022.[23][24][25] In 2023, it is still estimated that there are as few as 10 in the wild. [26]
Vaquitas reach sexual maturity from three to six years old. Vaquitas have synchronous reproduction, suggesting that calving span is greater than a year. Their pregnancies last from 10 to 11 months, and vaquita calves are nursed by their mothers for 6-8 months until becoming independent.[27] Vaquitas give birth about every other year to a single calf, usually between the months of February and April.[14][28] Because of their low reproduction rates, long gestation periods and larger species size, vaquitas are considered a K-selected species.[29] K-selected species are more vulnerable to extinction as they cannot repopulate at the rate of r-selected species.[30] Vaquitas are on the brink of extinction because their numbers are few and they cannot replenish their population fast enough to exceed the number of vaquitas dying off.
Anthropogenic effects of a rise in commercial fishing such as accidental bycatch, illegal fishing, and entanglement have been linked to the cause of their decline.[31] Shrimp fishing and gillnets create entanglement issues for the vaquita.[32] Aspects of illegal fishing include open access fisheries and absent fisheries management has correlated towards poaching of the main prey source of the vaquita.[33]
The drastic decline in vaquita abundance is the result of fisheries bycatch in commercial and illegal gillnets, including fisheries targeting the now-endangered Totoaba, shrimp, and other available fish species.[4][34] Despite government regulations, including a partial gillnet ban in 2015 and establishment of a permanent gillnet exclusion zone in 2017, illegal totaoba fishing remains prevalent in vaquita habitat, and as a result the population has continued to decline.[22] Fewer than 19 vaquitas remained in the wild in 2018. Large-mesh gillnets used in illegal fishing for totoaba caused an increase in the rate of loss of vaquitas after 2011.[35]
In 2021, the Mexican government eliminated a "no tolerance" zone in the Upper Gulf of California and opened it up to fishing.[36]
Given their proximity to the coast, vaquitas are exposed to habitat alteration and pollution from runoff. Pesticides present in the water as a result of runoff from agriculture are a threat as they can be ingested by the vaquitas, causing harm and even death. [37] Exposure to toxic compounds has also had a deleterious effect on vaquitas.[38] Bycatch, which is the incidental catch of non-target species in fishing gear, is not only the largest threat to the survival of the vaquita, but to all marine mammals around the world.[39][40] A series of simulations in a 2022 study indicate that the species has a chance to survive and recover if all bycatch is halted, despite the presence of other threats.[41] However, the biggest threat still towards vaquita are fisheries. Northern fishing fleets have had an indirect positive impact mainly on marine mammals, because fishing on predators like sharks reduces its predatory negative impact on those groups. Although the predation of sharks towards vaquita do result in a decline in population and is seen as an alternate threat, northern fishing fleets also negatively impact this small marine mammal because the negative influence of incidental catch is greater than the positive influence of predation reduction by shark fisheries.[42]
Populations that experience a sudden decline in numbers are often more vulnerable to other threats in the future due to a bottleneck of genetic diversity within the reduced population. The reduced gene pool lowers the rate of adaptation and increases the rate of inbreeding. This phenomenon is attributed to the anthropogenic Allee effect, specifically on the end where small population size leads to low species fitness because of a lack of genetic diversity and the potential for inbreeding. Because of their small population size, vaquitas are experiencing a negative Allee effect, attributing to even smaller population growth rates, driving them further into extinction. [43] However, a 2022 study on the genetic diversity of the vaquita suggests that the marine mammal’s historically small population ensures it is unlikely to greatly suffer from inbreeding depression.[41]
Attempts to start a population in captivity have proved to be more threatening to the population than helpful. A November 2017 effort ended up traumatizing and killing one female vaquita, as well as invoking unnecessary stress onto a juvenile.[44] Still, creating a captive population could be used as a last attempt resort to save the species and to further education on vaquitas.[45]
The vaquita is listed as critically endangered on the IUCN Red List, which is only one level above being completely extinct in the wild. It is considered the most endangered marine mammal in the world. The vaquita has been listed as critically endangered by the IUCN Red List of Threatened Species since 1996.[2] The vaquita is at risk of extinction due to its small population size.[31] It was approximated at one point that there were 150 individuals.[21]
The species is also protected under the US Endangered Species Act, the Mexican Official Standard NOM-059 (Norma Oficial Mexicana), and Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES).[3]
For a small population such as the vaquita to recover after a severe decline in population size is very difficult. This conservation status is strongly influenced in part of the species reproductive biology. The large amount of unknown surrounding the key reproductive parameters of the vaquita makes understanding its potential for recovery even harder.[2]
The vaquita, is found only in the upper Gulf of California, Mexico area.[46] The vaquita is at risk of extinction due to its small population size.[31] It was approximated at one point that there were 150 individuals left with a 10% annual decline within their population[21] Anthropogenic effects of a rise in commercial fishing such as accidental bycatch, illegal fishing, and entanglement have been linked to the cause of their decline.[31] Shrimp fishing and gillnets create entanglement issues for the vaquita.[32] Aspects of illegal fishing include open access fisheries and absent fisheries management has correlated towards poaching of the main prey source of the vaquita.[33] The swim bladders of the Totoaba macdonaldi are being sold on the black market by cartel for profit.[32]
The Mexican government, international committees, scientists, and conservation groups have recommended and implemented plans to help reduce the rate of bycatch, enforce gillnet bans, and promote population recovery.
Protection efforts throughout Mexico have taken place in order to preserve the population. In 2017, the Government of Mexico created established it as a felony to remove endangered species.[33] Alongside this, the Government of Mexico also made a public agreement to prohibit gillnet use.[33] Efforts are proactive in incentive applications to fisheries in a system of trade-offs that benefit fishermen and the vaquita.[47]
Mexico launched a program in 2008 called PACE-VAQUITA in an effort to enforce the gillnet ban in the Biosphere Reserve, allow fishermen to swap their gillnets for vaquita-safe fishing gear, and provide economic support to fishermen for surrendering fishing permits and pursuing alternative livelihoods.[48] Despite the progress made with legal fishermen, hundreds of poachers continued to fish in the exclusion zone. Poaching continues as the swim bladders of totoaba can sell for anywhere from $20,000 to upwards of $80,000, and they are often referred to as the "cocaine of the sea."[49] A back market for totaba swim bladders has developed fairly recently in China (including Hong Kong). In 2017, poachers received up to US$20,000 for a kilogram of totoaba swim bladders, with some making as much as $116,000 in one day.[50]
The swim bladders of the Totoaba macdonaldi are being sold on the black market by cartel for profit.[32] With continued illegal totoaba fishing, which is largely motivated by sales to the Chinese market where it is used in traditional medicine, and uncontrolled bycatch of vaquitas, the International Committee for the Recovery of the Vaquita (CIRVA) recommended that some vaquitas be removed from the high-density fishing area and be relocated to protected sea pens. This effort, called VaquitaCPR,[51] captured two vaquitas in 2017: One was later released and the other died shortly after capture after both suffered from shock.[52]
Local and international conservation groups, including Museo de Ballena and Sea Shepherd Conservation Society, are working with the Mexican Navy to detect fishing in the Refuge Area and remove illegal gillnets.[48] In March 2020, the U.S. National Marine Fisheries Service (NMFS) announced a ban on imported Mexican shrimp and other seafood caught in vaquita habitat in the northern Gulf of California.[53]
In response to the dire circumstances facing the vaquita as by-catch of the illegal totoaba trade, in 2017 Earth League International (ELI) commenced an investigation and intelligence gathering operation called Operation Fake Gold, during which the entire illicit totoaba maw (swim bladder) international supply chain, from Mexico to China, has been mapped and researched. Thanks to the confidential data that ELI shared with the Mexican authorities, in November 2020, a series of important arrests were made in Mexico.[54]
To date, efforts have been unsuccessful in solving the complex socioeconomic and environmental issues that affect vaquita conservation and the greater Gulf of California ecosystem. Necessary action includes habitat protection, resource management, education, fisheries enforcement, alternative livelihoods for fishermen, and raising awareness of the vaquita and associated issues.[2] Jaramillo-Legorreta, et al., stated in 2007 that captive breeding programs were not a viable option for saving the species from extinction.[55]
The Secretariat of Environment and Natural Resources (SEMARNAT) announced on February 27, 2021, that it may reduce the protected area for the vaquita in the Sea of Cortés as there are only ten of the porpoises left and it may never recuperate its historical range.[56]
Beginning in July 2022, the Mexican government placed 193 concrete blocks in the Gulf of California no-tolerance zone, intended to allow the detection of nets by acoustic sonar and prevent further entrapment of vaquitas.[57]
Protection efforts throughout Mexico have taken place in order to preserve the population. In 2017, the Government of Mexico created established it as a felony to remove endangered species.[33] Alongside this, the Government of Mexico also made a public agreement to prohibit gillnet use.[33] Efforts are proactive in incentive applications to fisheries in a system of trade-offs that benefit fishermen and the vaquita.[47]
Creating protected areas is always an option for conservationists, but because the vaquita's range is so small, there would be no use in trying to establish habitat corridors. One option for conservationists could be trying to create buffer zones near the coast in which pesticides harmful to vaquitas are restricted or even unavailable in order to enhance the protection value of the vaquita's range.
Roughly 80% of shrimp caught in the northern end of the Gulf of California, which has a high aquatic mammal bycatch rate, is consumed in the United States. As such, U.S. consumers of this shrimp are likely contributing to the vaquita extinction crisis. The Marine Animal Protection Act of 1972, which forbids foreign fishers from exporting seafood with high levels of marine mammal bycatch, may allow for better efforts to preserve endangered vaquitas.[58]
The vaquita (/vəˈkiːtə/ və-KEE-tə; Phocoena sinus) is a species of porpoise endemic to the northern end of the Gulf of California in Baja California, Mexico. Reaching a maximum body length of 150 cm (4.9 ft) (females) or 140 cm (4.6 ft) (males), it is the smallest of all living cetaceans. The species is currently on the brink of extinction, and currently listed as Critically Endangered by the IUCN Red List; the steep decline in abundance is primarily due to bycatch in gillnets from the illegal totoaba fishery.
