The Vaquita: The World's Most Endangered Porpoise
With fewer than 100 individuals left, the vaquita is the most endangered marine mammal, but has the potential for a hopeful future.
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Endangered Marine Mammal
Seafood for the Future (SFF), the Aquarium of the Pacific’s sustainable seafood program, recently launched public outreach efforts to raise awareness of the vaquita, an endangered small porpoise native to the Gulf of California.
With fewer than 100 individuals remaining, the vaquita is the most endangered marine mammal in the world and has the potential to represent a story of tragedy or of a hopeful future.
Artist’s Drawing of Vaquita
Image by © Aquarium of the Pacific
The Vaquita and the Totoaba
The vaquita has a very limited range, living only in the northern portion of the Gulf of California.
Within these Mexican waters, the vaquita is often unintentionally caught in gillnets set to harvest shrimp and other species. This “incidental take” of vaquita is the primary threat to its survival.
The vaquita’s future is directly tied to one fish species in particular—the totoaba. An endangered species in the croaker family, the totoaba, like the vaquita, only lives in the upper Gulf.
Caught in the Crossfire
The gillnets set for this large fish often catch vaquitas as well, killing them faster than they can reproduce.
The totoaba is targeted to meet the growing demand for its swim bladder in Asia, where it is thought to be a remedy for skin conditions, infertility, and poor circulation. Mexican cartels are purported to control this illegal and lucrative trade of totoaba swim bladders, paying fishermen and sneaking the contraband into California to be shipped to China, where the swim bladders are reportedly sold at a price of around $4,000 or more per pound.
In the Wild
Image by Todd Pusser
In 2015 the Mexican government instituted a two-year ban on all gillnet fishing within the vaquita’s range.
Additionally, the government provided increased enforcement through military presence aided by drones and satellites to monitor the protected area. Despite these efforts, illegal totoaba fishing continues. There is still hope, however. If the gillnet ban is successful, it is likely the vaquita population will recover, as research indicates that the species is not susceptible to issues associated with inbreeding and their habitat appears to be healthy.
Two other species found off the coast of Baja California, the northern elephant seal and gray whale, have recovered from low population numbers as a result of successful protections enforced by the Mexican government.
Additionally, vaquita-safe technology may be on the rise.
The gillnet ban has given researchers an opportunity to inform conservation efforts and the development of vaquita-safe alternative gear types to ensure fishermen are able to generate sufficient income while simultaneously reducing their impact on the vaquita population.
The Mexican government is providing financial compensation to fishermen for losses incurred from this ban, helping fishermen in the region change their practices to produce “vaquita-friendly” seafood through the use of alternative gear.
Threats & Conservation
Image by Paula Olson
Choose Responsibly Sources Seafood
The vaquita provides a message for consumers—it is important to choose responsibly sourced seafood and support fishermen working hard to provide sustainable seafood.
A vaquita-safe logo for fish caught by fishermen using alternative gear may hit the market in the near future. You can also support groups working to protect the vaquita. The Aquarium is working with a growing number of supporting institutions in the U.S. and Mexico to share the vaquita’s story with the public. San Diego Zoo Global, World Wildlife Fund Mexico, and Pronatura are three goups working in the communities in Mexico that surround the vaquita habitat.
You can view the Aquarium’s PSA about the vaquita at here.
Restricted to northwestern corner of Gulf of California (Sea of Cortez) and, perhaps, the Colorado River Delta.
Vaquita live in shallow lagoons no more than 25 km (16 mi) from shore where there is a strong tidal mix. Although they can survive in lagoons that are so shallow that their back protrudes above the surface of the water, they prefer water that is 10 to 28 m (33 to 92 ft) deep.
Vaquita have the typical robust body shape of a porpoise with the middle of the body measuring about 68% of the body length. They have little or no beak with a slight protrusion of the upper jaw at the base of the melon. Their dorsal fin is upright with a straight vertical or slightly curved (falcate) rear margin and bumps and whitish spots on the leading edge. Their dorsal fin is relatively large when compared to that of other porpoise species.
They are dark gray on their upper body and halfway down their sides where the coloration fades to a lighter gray. The throat and belly are streaked with white. There is a dark stripe extending from the middle of the lower jaw to the front of the flippers. They have black eye and chin patches and black lips. Juveniles are darker than adults.
Adults are 1.2-1.5 m (3.9-4.9 ft) long and weigh about 45 to 50 kg (99 to 110 lb). Females tend to be larger than males.
Examination of stomach contents of dead animals has shown that vaquitas are not picky about their diet, eating a variety of fish species (17 species found in one animal) that live near or on the gulf bottom. They also eat squid and crabs.
Little is known about vaquita reproduction but researchers believe it is probably similar to that of harbor porpoises. If that is true, then sexual maturity is reached at three to five years of age and the gestation period is probably about 11 months. Births occur in February-April, peaking in late March to early April. Newborn calves are 70-78 cm (31-38 in) long and weigh 7.5 kg (17 lb). The calf probably nurses for six to eight months.
Many scientists believe that vaquita will become extinct because the genetic pool is too small for effective reproduction
Vaquita are shy, rather secretive animals. They have been observed singly, in pairs, and in groups of up to seven animals. They generally do not engage in acrobatics at the surface of the water, emerging from beneath the surface with a slow, forward-rolling movement that barely disturbs the water’s surface, taking a breath, and then quickly disappearing in a quiet dive.
These porpoises echolocate using a series of high frequency clicks.
The closest porpoise species to vaquita geographically is central California’s harbor porpoise which is 2500 km (1500 mi) distant, however, they are more closely related morphologically to Burmeister’s porpoise which occur from Peru southward, 5000 km (3000 mi) away. It is thought that vaquita evolved from an ancestral population of Burmeister’s porpoise that moved northward into the Gulf of California one million years ago.
Vaquitas are the only porpoise species adapted to living in warm water. Most porpoises inhabit water that is cooler than 20oC (68oF) whereas vaquita are able to tolerate water that fluctuates from 14oC (57oF) in the winter to 36oC (97oF) in the summer.
Image by Paula Olson
These porpoises may live 20 years if they escape gillnets.
Vaquita and totoaba (Totoaba macdonald), a large sea bass species, share habitat, the northern or upper area of the Gulf of California and that sharing of habitat is the major reason why vaquita may become extinct. Today both vaquita and totoaba are listed as critically endangered on the IUCN Red List of Endangered Species and as endangered under the U.S. Endangered Species Act and by the Mexican government. Additionally vaquita are protected under the U.S. Marine Mammal Protection Act.
Commercial fisheries used gill nets to harvest totoaba and vaquita are very vulnerable to entanglement in such nets. Like all cetaceans vaquita do not have gills as fish do—they breathe air. Once entangles in a net, they cannot surface for air. While use of large mesh gill nets was banned, smaller nets still entangle vaquita as bycatch. Overfishing of totoaba resulted in ban on harvesting this species but illegal poaching continues. For almost five decades various measures have been instituted to save vaquia from extinction as shown in these chronological list but they have not halted the decline of this porpoise.
Learn more at the Aquarium of the Pacific