Gulf of California Harbor Porpoise / Vaquita / Cochito (Phocoena sinus)
Did You Know?
· The vaquita is one of the most endangered cetaceans in the world. It is also the smallest known cetacean and has the most limited range of any marine cetacean.
Vaquitas, also known as the "Gulf of California porpoise" or "Cochito," are elusive and timid members of the porpoise family. They were first described by western scientists in 1958 based on several skulls. This species is the smallest known cetacean. These porpoises reach about 4-5 ft (1.2-1.5 m) in length and weigh 65-120 lbs (30-55 kg). Females are generally slightly larger than males.
Vaquitas have compact, robust bodies and a rounded head with little or no beak. Their triangular "falcate" dorsal fin is proportionately tall and is located in the middle of the back. This species' complex coloration consists of various shades of dull gray that transition from dark on the dorsal side to pale on the ventral side of the body. The lips, chin, and eye ring are black. Individuals get lighter in color as they age, and the face is usually pale.
This species of porpoise is usually found either singly, in pairs, or in small social groups of 7-10 individuals. These shy animals will typically avoid vessels. They are not usually active at the surface and are often difficult to observe visually due to their cryptic behavior.
Vaquitas spend relatively long periods of time underwater to opportunistically feed on a variety of small schooling fish (e.g., croakers and grunts), crustaceans, and cephalopods (e.g., squid and octopus). They have 16-22 pairs of small spade shaped teeth in the upper jaw and 17-20 pairs in the lower jaw that are used to capture prey.
Vaquitas become sexually mature at 3-6 years of age. After a gestation period of about 10-11 months, females typically give birth every other year to a single calf that is about 2.5 ft (0.7-0.8 m) long and weighs about 16.5 lbs (7.5 kg). Calving usually takes place between the months of February and April. These cetaceans have an estimated lifespan of at least 21 years.
This species is "endemic" to the shallow, murky coastal waters of the Gulf of California off of the Baja Peninsula in Mexico. They are usually found in waters less than 165 ft (50 m) deep and within 13.5 nautical miles (25 km) of the shore (Shirihai and Jarrett 2006).
Vaquita Range Map
(click for larger view PDF)
The vaquita's distribution is restricted to the upper portion of the northern Gulf of California, mostly within the Colorado River delta. They are commonly seen between San Felipe Bay and Rocas Consag in the western upper portion of their range (Jefferson et al. 2008). The historical distribution of this species may have been much larger, at one time extending south along the Mexican mainland to the Tres Marias Islands and Banderas Bay (Leatherwood et al. 1988).
The vaquita's population has been in decline since at least the 1940s, and could be declining by as much as 15% each year. At current rates, the vaquita population may be reduced by more than 80% over the next 10-30 years and is in danger of extinction. The current total population of the vaquita is estimated between 500-600 individuals (Jefferson et al. 2008).
Commerical fishing is by far the greatest threat to individuals, their habitat, and the species overall survival. In the 1920s, a commercial fishery using gillnets for the now-endangered totoaba (a large sea bass) was established (Reeves et al. 2002). While the commercial fishery for totoaba ceased in the 1970s, other fishing still continues. Vaquitas are incidentally taken as "bycatch" in local gillnet and trawl fisheries. It is estimated that at least 30-85 individuals are taken incidentally each year. Other possible threats to this species include environmental pollution, habitat degradation, and inbreeding due to low population numbers (Jefferson et al. 2008).
The International Union for Conservation of Nature and Natural Resources (IUCN's) Red List of Threatened Species considers this species "Critically Endangered." Mexico has taken steps to protect the vaquita by establishing the International Committee for the Recovery of the Vaquita (CIRVA) as well as a bio-reserve in the upper portion of the Gulf of California in order to conserve and protect the endangered totoaba and vaquita and other threatened wildlife.
|ESA Listing Rule||50 FR 1056||01/09/1985|
- NMFS Southwest Fisheries Science Center Vaquita Case Studies of the Population Identity Program
- Marine Mammal Commission Vaquita Information
- U.S. Fish & Wildlife Service Cochito Species Profile
- Ocean Biogeographic Information System (OBIS-SEAMAP) Gulf of California Harbor Porpoise Species Profile
- Reeves, R. R., P. A. Folkens, et al. (2002) Guide to Marine Mammals of the World. New York, Alfred A. Knopf. p. 464-465.
- Jefferson, T. A, M. A. Webber, and R. L. Pitman. (2008). Marine Mammals of the World, A Comprehensive Guide to their Identification. Amsterdam, Elsevier. p. 288-289.
- Leatherwood, S., R. R. Reeves, et al. (1988). Whales, Dolphins, and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters: A Guide to Their Identification. New York, Dover Publications, Inc. p. 208.
- Shirihai, H. and B. Jarrett (2006). Whales, Dolphins and Other Marine Mammals of the World. Princeton, Princeton University Press. p. 254-255.
Updated: December 12, 2012