Vaquitas : The world's rarest marine animal
ABOUT VAQUITAS
DISCOVERY
Vaquitas (Phocoena sinus), are a species of porpoise native to the northern Gulf of California in Baja, Mexico. They belong to the genus Phocoena, in which they are closely related to the Burmeister’s porpoise (Phocoena spinipinnis), whose range is limited to the Southern Hemisphere. It is hypothesized that their ancestors have moved north across the Equator 2.5 million years ago during the Pleistocene era.
In 1958, zoologists Kenneth S. Norris and William N. Mcfarland identified vaquitas as a species after studying the morphology of skull specimens found on the beach. However, it was not until 30 years later that new specimens of the vaquita allowed scientists to fully describe the external appearance of the vaquita in the late 1980s. Eventually, in 1983, 45 records of the P. sinus were collected, including skeletal remains, photographs, and sightings.
DESCRIPTION
As the smallest living species of the cetacean family, vaquitas can be easily distinguished from any other species in its range. It has a small body with a tall, triangular dorsal fin, a round head, and no distinguished beak. It is grey-coloured, with a white underbelly and black coloration surrounding its eyes and lips. Females can grow up to a maximum size of about 150 cm (4.9 ft), while males can grow up to 140 cm (4.6 ft). Vaquitas are also known to weigh around 27 kg (60 lbs) to 68 kg (150 lbs), hence being the smallest species of the porpoise family.
HABITAT
The habitat of vaquitas is limited to a small region of the upper Gulf of California, known as the Sea of Cortez, hence residing in the smallest range of any cetacean family. They live in shallow and clouded waters of less than 150 m (490 ft) in depth.
In terms of their diet, it mainly consists of benthic fish such as grunts and croakers, as well as a variety of demersal fish species, crustaceans, and squids. Vaquitas are also mostly observed travelling alone or in pairs with their calf. However, vaquitas have also been observed in small groups consisting of up to 10 individuals. Little is known about their life history, but their life expectancy is estimated to be at about 20 years.
ENDANGERMENT
Vaquitas are on the brink of extinction and are currently classified under the critically endangered spectrum. The dramatic decrease in the population of vaquitas is primarily due to bycatching and the usage of gillnets inillegal totoaba fisheries, which are also unsustainable practices. However, vaquitas also face other threats such as habitat alteration and pollution from runoff due to their proximity to the coast. Exposure to toxic compounds such as pesticides from agriculture present in the runoff is a threat as ingestion can cause harm and even death for vaquitas.
IS THERE A SOLUTION?
In 1997, the first comprehensive vaquita survey throughout their range estimated their population at 567 individuals. By 2007, the population was estimated to have decreased to 150 individuals. In 2017, genome sequencing of vaquitas indicated that their ancestry has experienced a major decrease in the population in the past, which explains why the remaining vaquitas are still healthy despite the small population size of vaquitas. As of 2018, the population was estimated at less than 19 individuals. Today, due to the continued rate of illegal bycatching and decreasing rates of reproduction output from a small population, it is estimated that there are only less than 10 individuals of vaquitas living in the wild as of February 2022.
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