Vaquita
Encyclopedia
The vaquita is a rare species of porpoise
. It is endemic to the northern part of the Gulf of California
. Estimates of the number of individuals alive range from 100 to 300. The word "vaquita" is Spanish
for little cow. Since the baiji (Lipotes vexillifer) is believed to have gone extinct in 2006, the vaquita has taken on the title of the most endangered cetacean in the world.
Other names include Cochito, Gulf of California Harbor Porpoise, Gulf of California Porpoise, Gulf Porpoise, Hafenschweinswal, and Marsouin du Golfe de Californie.
are proportionately larger than in other porpoises and the fin is taller and more falcate. The skull
is smaller and the rostrum
is shorter and broader than in other members of the genus.
. The vaquita lives in shallow, murky lagoons along the shoreline and is rarely seen in water much deeper than 30 meters; indeed, it can survive in lagoons so shallow that its back protrudes above the surface. The vaquita is most often sighted in water 11 to 50 metres deep, 11 to 25 kilometres from the coast, over silt and clay bottoms. Its habitat is characterised by turbid water with a high nutrient content. Other characteristics of its habitat are strong tidal mixing, convection
processes and high primary and secondary productivity.
.
, and it appears that the vaquita is a rather non-selective feeder on small fishes and squids in this zone. Like other cetaceans, the vaquita produces high-frequency clicks which are used in echolocation. This may be used to locate their prey, but several of the fish species it feeds on are known to produce sound and so it is possible that the vaquita locates them by following their sound, rather than by echolocating.
is probably 10–11 months. Maximum observed life span was 21 years.
s intended for capturing another species endemic to the Gulf, the totoaba
. CIRVA, the Committee for the Recovery of the Vaquita, concluded in 2000 that between 39 and 84 individuals are killed each year by such gillnets. The Vaquita is listed by the IUCN and the Convention on International Trade in the Endangered Species of Wild Fauna and Flora in the most critical category at risk of extinction. In order to try to prevent extinction, the Mexican
government has created a nature reserve covering the upper part of the Gulf of California and the Colorado River
delta. CIRVA is recommending that this reserve be extended southwards to cover the full known area of the Vaquita's range and that trawlers be completely banned from the reserve area. Even if the number of Vaquita killed by fisheries is reduced to zero, concerns remain amongst conservationists. Use of chlorinated pesticides, reduced flow of freshwater from the Colorado River due to irrigation, and depression due to inbreeding
may also have a detrimental effect.
The Vaquita is one of the top 100 EDGE Species
, meaning "Evolutionarily Distinct, Globally Endangered". Evolutionarily distinct animals have no close relatives and represent proportionally more of the tree of life than other species, meaning they are top priority for conservation campaigns.
On October 28, 2008, Canada, Mexico, and the United States, under the jurisdiction of the NAFTA environmental organization, the Commission for Environmental Cooperation, launched the North American Conservation Action Plan (NACAP) for the Vaquita. The NACAP is a strategy to support Mexico’s efforts to recover the Vaquita, which is considered the world’s most-endangered marine mammal. The U.S. government has listed the vaquita as endangered under the Endangered Species Act
.
Porpoise
Porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...
. It is endemic to the northern part of the Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
. Estimates of the number of individuals alive range from 100 to 300. The word "vaquita" is Spanish
Spanish language
Spanish , also known as Castilian , is a Romance language in the Ibero-Romance group that evolved from several languages and dialects in central-northern Iberia around the 9th century and gradually spread with the expansion of the Kingdom of Castile into central and southern Iberia during the...
for little cow. Since the baiji (Lipotes vexillifer) is believed to have gone extinct in 2006, the vaquita has taken on the title of the most endangered cetacean in the world.
Other names include Cochito, Gulf of California Harbor Porpoise, Gulf of California Porpoise, Gulf Porpoise, Hafenschweinswal, and Marsouin du Golfe de Californie.
Physical description
The Vaquita has a classic porpoise shape (stocky and curved into a star shape when viewed from the side). It is the smallest of the porpoises, a group of marine mammals that differ from dolphins in their stockier, robust body, lack of an elongated beak, and their distinctively shaped teeth. Individuals may reach a mature size of 1.2-1.5 m (4-5 ft) and may weigh 40-55 kg (90-120 lb). They have large black eye rings and lip patches. The upper side of the body is medium to dark grey. The underside is off-white to light grey but the demarcation between the sides is indistinct. The flippersFlipper (anatomy)
A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins , cetaceans A flipper is a typically flat limb evolved for movement through water. Various creatures have evolved flippers, for example penguins (also called...
are proportionately larger than in other porpoises and the fin is taller and more falcate. The skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
is smaller and the rostrum
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
is shorter and broader than in other members of the genus.
Habitat
The habitat of the vaquita is thought to be restricted to the northern area of the Gulf of CaliforniaGulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
. The vaquita lives in shallow, murky lagoons along the shoreline and is rarely seen in water much deeper than 30 meters; indeed, it can survive in lagoons so shallow that its back protrudes above the surface. The vaquita is most often sighted in water 11 to 50 metres deep, 11 to 25 kilometres from the coast, over silt and clay bottoms. Its habitat is characterised by turbid water with a high nutrient content. Other characteristics of its habitat are strong tidal mixing, convection
Convection
Convection is the movement of molecules within fluids and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids....
processes and high primary and secondary productivity.
Behavior
There are very few records of the Vaquita in the wild. It appears to swim and feed in a leisurely manner, but is elusive and will avoid boats of any kind. It rises to breathe with a slow, forward-rolling movement that barely disturbs the surface of the water, and then disappears quickly, often for a long time. It has an indistinct blow, but makes a loud, sharp, puffing sound reminiscent of the Harbour PorpoiseHarbour Porpoise
The harbour porpoise is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen...
.
Schooling
Like other phocoenids, the vaquita occurs singly or in small groups, usually from 1 - 3 individuals but as many as 8 - 10.Diet
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 CaliforniaGulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
, and it appears that the vaquita is a rather non-selective feeder on small fishes and squids in this zone. Like other cetaceans, the vaquita produces high-frequency clicks which are used in echolocation. This may be used to locate their prey, but several of the fish species it feeds on are known to produce sound and so it is possible that the vaquita locates them by following their sound, rather than by echolocating.
Reproduction
Most calving apparently occurs in the spring. GestationGestation
Gestation is the carrying of an embryo or fetus inside a female viviparous animal. Mammals during pregnancy can have one or more gestations at the same time ....
is probably 10–11 months. Maximum observed life span was 21 years.
Conservation
Vaquita have never been hunted directly. Indeed their continued existence was only confirmed by a dedicated survey in 1985. However, it is known that the vaquita population is declining. Estimates have placed the vaquita population at 567 in 1997 and 150 in 2007. The decline in the vaquita population is believed to be due to the animals becoming trapped in gillnetGillnet
Gillnetting is a common fishing method used by commercial and artisanal fishermen of all the oceans and in some freshwater and estuary areas. The gillnet also is used by fisheries scientists to monitor fish populations. Because gillnets can be so effective their use is closely monitored and...
s intended for capturing another species endemic to the Gulf, the totoaba
Totoaba
The totoaba or totuava is a marine fish of the drum family that is indigenous to the northern half of the Gulf of California in Mexico...
. CIRVA, the Committee for the Recovery of the Vaquita, concluded in 2000 that between 39 and 84 individuals are killed each year by such gillnets. The Vaquita is listed by the IUCN and the Convention on International Trade in the Endangered Species of Wild Fauna and Flora in the most critical category at risk of extinction. In order to try to prevent extinction, the Mexican
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
government has created a nature reserve covering the upper part of the Gulf of California and the Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
delta. CIRVA is recommending that this reserve be extended southwards to cover the full known area of the Vaquita's range and that trawlers be completely banned from the reserve area. Even if the number of Vaquita killed by fisheries is reduced to zero, concerns remain amongst conservationists. Use of chlorinated pesticides, reduced flow of freshwater from the Colorado River due to irrigation, and depression due to inbreeding
Inbreeding depression
Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. It is often the result of a population bottleneck...
may also have a detrimental effect.
The Vaquita is one of the top 100 EDGE Species
EDGE Species
Evolutionarily Distinct and Globally Endangered species represent a disproportionate amount of unique evolutionary history. They have few close relatives and are often extremely unusual in the way they look, live and behave...
, meaning "Evolutionarily Distinct, Globally Endangered". Evolutionarily distinct animals have no close relatives and represent proportionally more of the tree of life than other species, meaning they are top priority for conservation campaigns.
On October 28, 2008, Canada, Mexico, and the United States, under the jurisdiction of the NAFTA environmental organization, the Commission for Environmental Cooperation, launched the North American Conservation Action Plan (NACAP) for the Vaquita. The NACAP is a strategy to support Mexico’s efforts to recover the Vaquita, which is considered the world’s most-endangered marine mammal. The U.S. government has listed the vaquita as endangered under the Endangered Species Act
Endangered Species Act
The Endangered Species Act of 1973 is one of the dozens of United States environmental laws passed in the 1970s. Signed into law by President Richard Nixon on December 28, 1973, it was designed to protect critically imperiled species from extinction as a "consequence of economic growth and...
.
External links
- "Vaquita - Last Chance for the Desert Porpoise" is a documentary film and social media project about the critically endangered Vaquita
- US National Marine Fisheries Service Vaquita web page
- ¡Viva Vaquita! - a non-profit organization dedicated to preventing the extinction of the Vaquita porpoise
- Conservation of the vaquita, (2006), Rojas-Bracho et al., Mammal Review, 36:3, Pg 179.
- Evolutionarily Distinct and Globally Endangered species
- "Can Social Media Save Vaquita, the World's Rarest Porpoise?" on Treehugger