Vaquita

The vaquita (Spanish: ; Phocoena sinus) is a species of porpoise endemic to the northern part of the Gulf of California that is on the brink of extinction. Based on beached skulls found in 1950 and 1951, the scientific description of the species was published in 1958. The word vaquita is Spanish for 'little cow'. Other names include cochito (Spanish for 'little pig'), desert porpoise, vaquita porpoise, Gulf of California harbor porpoise, Gulf of California porpoise, and gulf porpoise. Since the baiji (Yangtze River dolphin, Lipotes vexillifer) is thought to have gone extinct in 2006, the vaquita has taken on the title of the most endangered cetacean in the world. It has been listed as critically endangered since 1996. The population was estimated at 600 in 1997, below 100 in 2014, approximately 60 in 2015, around 30 in November 2016, and only 12-15 in March 2018, leading to the conclusion that the species will soon be extinct unless drastic action is taken. An estimate released in March 2019, based on acoustic data gathered in the summer of 2018, is that a maximum of 22 and a minimum of 6 vaquita porpoises remain, with the IUCN supporting roughly about 10 individuals. A further estimate released in July 2019 concluded that the population size in autumn 2018 was about 9. The population decrease is largely attributed to bycatch from the illegal gillnet fishery for the totoaba, a similarly sized endemic drum that is also critically endangered. The population decline has occurred despite an investment of tens of millions of dollars by the Mexican government in efforts to eliminate the bycatch. A partial gillnet ban was put in place for two years in May 2015; its scheduled expiration at the end of May 2017 spurred a campaign to have it extended and strengthened. On 7 June 2017, an agreement was announced by Mexican president Enrique Peña Nieto to make the gillnet ban permanent and strengthen enforcement. As well as the Mexican government and various environmental organizations, this effort will now also involve the foundations of Mexican businessman Carlos Slim and American actor and environmental activist Leonardo DiCaprio. However, the July 2019 report indicated that the gillnet ban had had no effect on the ongoing rate of decline of about 50% per year. A protective housing/captive breeding program, unprecedented for a marine mammal, has been developed and is undergoing feasibility testing, being now viewed as necessary to rescue the species. However, the sea pen housing needed to implement this strategy is not expected to be available until October 2017, which is feared may be too late. Additionally, the ability of the vaquita to survive and reproduce while confined to a sanctuary is uncertain. The Mexican government approved the plan on 3 April 2017, with commencement projected to begin in October 2017.In November 2017, the attempt to capture wild vaquitas for captive breeding and safekeeping was suspended following the death of a female vaquita. The adult female died within hours of being captured. In December 2017, Mexico, the United States and China agreed to take further steps to prevent trade in totoaba bladders. Despite its extremely low population, reports indicate the small number of surviving vaquita are still relatively healthy and able to breed. However, the intensifying poaching and the extremely low population make it likely that the species will go extinct unless drastic measures are taken. If the species does go extinct, it will likely be the first cetacean to do so since the baiji. Vaquitas are the smallest and most endangered species of the infraorder Cetacea and are endemic to the northern end of the Gulf of California. The vaquita is somewhat stocky and has a characteristic porpoise shape. The species is distinguishable by the dark rings surrounding their eyes, patches on their lips, and a line that extends from their dorsal fins to their mouths. Their backs are a dark grey that fades to white undersides. As vaquitas mature, the shades of grey lighten. Female vaquitas tend to grow larger than males. On average, females mature to a length of 140.6 cm (55.4 in), compared to 134.9 cm (53.1 in) for males. The lifespan, pattern of growth, seasonal reproduction, and testes size of the vaquita are all similar to that of the harbour porpoise. The flippers are proportionately larger than those of other porpoises, and the fin is taller and more falcated. The skull is smaller and the rostrum is shorter and broader than in other members of the genus. The porpoise genus Phocoena comprises four species, all of which inhabit coastal waters, two each in the northern and southern hemispheres. Vaquitas are believed on the basis of morphological and genetic evidence to be most closely related to Burmeister's porpoise (P. spinipinnis) of South America. Their ancestors are thought to have crossed the equator during a cooler period of the Pleistocene. Vaquitas use high-pitched sounds to communicate with one another and for echolocation to navigate through their habitats. They generally feed and swim at a leisurely pace. Vaquitas avoid boats and are very evasive. They rise to breathe with a slow, forward motion and then disappear quickly. This lack of activity at the surface makes them difficult to observe. Vaquitas are usually alone unless they are accompanied by a calf, meaning they are less social than other porpoise species. They may also be more competitive during mating season. They are the only species belonging to the porpoise family that live in warm waters. Vaquitas are non-selective predators. Like other Phocoena, vaquitas are usually seen singly. If they are seen together, it is usually in small groups of two or three individuals. Less often, groups around ten have been observed, with the most ever seen at once being 40 individuals. Vaquitas tend to forage near lagoons. All of the 17 fish species found in vaquita stomachs can be classified as demersal and or benthic species inhabiting relatively shallow water in the upper Gulf of California. Vaquitas appear to be rather non-selective feeders on crustaceans, small fish, octopuses and squid in this area. Some of the most common prey are teleosts (fish with bony skeletons) such as grunts, croakers, and sea trout. Like other cetaceans, vaquitas may use echolocation to locate prey, particularly as their habitat is often turbid.