Introduction
The vaquita is a small marine mammal found in the Gulf of California which seems to be endangered. Very few people have gotten the opportunity to see this species and many people may not be able to see it now that its existence is becoming extinct.
The vaquita looks like a star curved stocky porpoise and it is the smallest of all the porpoises in the world. Its length is esteemed to be 150 centimeters which is equivalent to 4.92 ft. and weighs not more than 50 kilograms. Most parts of its body are grey in color and it has a smaller skull as compared to other porpoises.
It lives in shallow water (not more than 30 meters deep) found on the shoreline. It is even believed to survive in lagoons where the water can hardly cover its back. Most Vaquitas are found on the northern part of the Gulf of California within Colorado River. This paper will give more information about the vaquita, explain some of the reasons that are causing its decline, and highlight some of the steps taken by the Mexican government to conserve this rear species.
Social and Reproductive Life
The Vaquita appears to be a comfortable porpoise that like swimming but most of the time it is found relaxing leisurely along the shoreline. However, it is subtle and afraid of boats of all kind. If a boat appears near it, it either hides under water or moves to a different position. The Vaquita rises to the surface of the water to take in fresh air and then goes under water for a long period of time.
It likes feeding on fish species especially the smaller ones although it is known to be a nonselective feeder and can feed on almost anything that crosses its path. Vaquita either lives alone or in a group of not more than ten individuals; often they live in groups of three.
The Vaquita gives birth to its calves during spring and gestation normally takes about ten to eleven months. It is believed that Vaquitas mature sexually at the age of three to six years and female gives birth every year to a single calf. New born calves weigh about 7.5 kilograms and they are 2.5 ft long. Vaquita is believed to have a life span of about 21 years (Jefferson, et al 2008).
Reasons for its Decline
It is hard to find a person hunting Vaquita because many people do not know much about them. Actually their existence was realized in 1958, after a survey was carried out by dedicated scientists. Since then, other scholars have developed an interest on this rare species and are carrying out research to understand more about them and how their survival can be enhanced.
However, their existence is being threatened since they are normally trapped in gillnets that are used for fishing the totoaba which is also found in the Gulf of California. It is good to note that, this species reproduce very slowly because they are very few in number and therefore if one female Vaquita is trapped in gillnets, it poses a very great threat to their survival (Leatherwood, et al. 1988).
The population of the Vaquitas has been declined at a very high rate (15% every year). Their existence is mainly threatened by commercial fishing which take place within Colorado River. Commercial fishery for totoaba was recognized in 1970s but ceased in late 1970s. However, other species are being fished and this threatens the survival of the Vaquita. It is estimated that; the population of the vaquita may be declining at a rate of about eighty percent for the next 20 to 30 years which may render the species extinct.
Commercial fishing still stands as the greatest threat to the survival of the vaquitas although there are other threats such as habitat degradation, pollution, and inbreeding given that they population is very low. A lot of non environmental friendly waste is being damped in Colorado River which is a threat to the security of the vaquita. Many vaquitas have died from suffocation (given that they stay underwater for a longer period than they stay on the surface) and they are still facing the threat of environmental pollution.
Agricultural farming has also increased around the area with many farmers using water from Colorado River for irrigation (Reeves, et al. 2002). This has resulted in a decrease in the volume of water in the river thereby interfering with the habitat of the viquitas. Apart from the use of water, the use of fertilizers and pesticides is on the increase and most of these chemicals find their way into the river. This does not only cause death to the Vaquitas, but to all other aquatic animals.
Inbreeding is also a major reason for the decline of the viquitas. As seen earlier, a single calf takes about six years to mature and be able to reproduce. Also a female vaquita can only give birth to a single calf and this takes place annually especially during spring. Let’s assume there are about 100 female vaquitas out of the total population, this means that less than 100 calves will be born each year because the gestation takes almost one year and not all this vaquitas may be able to survive through out the year.
If then 70 calves are born each year, after six years we will have about 420 new vaquitas (holding all other factors constant). However, it is estimated that, the rate of death can go up to 84 individuals meaning that, all the calves may die before they are able to reproduce. The number of females may also decline or become extinct. It is therefore clear that, urgent conservation measures have to be taken if the population of the viquitas is to be maintained.
Conservation Efforts
Today, the number of Vaquita estimated to be alive varies from one hundred to three hundred. In 2000, a research was conducted by the Vaquita recovery committee which discovered that, about 40 to 80 Vaquitas die every year in the hands of commercial fishermen (Shirihai & Jarrett 2006).
A reserve was created on the northern side of the Gulf of California by the government of Mexico to prevent the extermination of the vaquitas. Trawlers were banned from fishing in the reserved area and with this ban; the number of Vaquita killed each year has reduced. However, most conservationists are still concerned about the survival of the vaquita especially now that the use of pesticides along the shoreline has increased and the flow of water from Colorado River has reduced mostly due to increased irrigation around the area.
The International Union for Conservation of Nature and Natural Resources (IUCN), believe that the Vaquita is the most endangered species of all the marine animals. An international committee formed by the Mexican government has established many steps that are aimed and conserving this rare species.
Other international bodies such as the United States, and Canada joined hands with Mexico and established a strategy that was aimed at supporting Mexico in its effort to protect the vaquitas (The Cousteau Society 2010). They consider the vaquita as the most endangered acquired mammal all over the world.
Conclusion
The Vaquita is a rare species of the porpoise family found in the Gulf of California within Colorado River. Its existence was realized in 1958 and since then its population seems to be declining instead of increasing. Many conservationists are concerned about the decline in population of the Vaquita and have taken time to study some of the major causes of this decline and are investigating on the measures that need to be taken to ensure that the vaquita does not become extinct.
The greatest threat to the survival of the Vaquitas is commercial fishing which is carried out in the northern part of the Gulf of California and some parts of the south. Other causes include increased irrigation, environmental pollution, and use of fertilizers and pesticide.
Through the Mexican government, some conservation measures have been taken which include conservation of reserves, and banning of trawlers in the conserved area. Other nations have realized the need of protecting these rare species and have joined hands with the Mexican government. With these measures being implemented and monitored closely, the future of the vaquita seems to be promising
Reference List
Jefferson, T. A, et al (2008). Marine Mammals of the World, a Comprehensive Guide to their Identification. Amsterdam: Elsevier.
Leatherwood, S., R. 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.
Reeves, R. R., et al. (2002). Guide to Marine Mammals of the World. New York: Alfred A. Knopf.
Shirihai, H. & Jarrett, B. (2006). Whales, Dolphins and Other Marine Mammals of the World. Princeton: Princeton University Press.
The Cousteau Society (2010). Vaquita conservation in Mexico. Web.