Home | Getting Here | About San Felipe | Weather | News | Photo Gallery | Fishing | Business Guide | Contact Us | Articles/Stories

The critically endangered Vaquita

A dead vaquita caught in a 15 cm. mesh totoaba net in 1985 (Foto Ing. Alejandro Robles González de Conservation International México)

 

 

The Vaquita (Phocoena sinus) is a very rare species of porpoise first scientifically identified in 1958. It is found nowhere else on earth but the waters off San Felipe and has now become the most critically endangered species in the world.

At a meeting on Wednesday 24 January at the Birch Aquarium/Scripps Institution of Oceanography in La Jolla, we learned that the previously most critically endangered porpoise, the Yangtze River Baiji, appears to now have gone extinct. A team of thirty scientists spent much of November and December 2006 searching up and down the Yangtze River in China, from Shanghai to the Three Gorges Dam project, and covered nearly 3500 km of water looking for the Baiji. Not a single specimen was sighted. As a result, the baiji has been declared extinct and the vaquita has the dubious honor to have been moved up into the number one position on the endangered species list.

The vaquita grows to about 1.5 m in length and a weight of 50 kg. Visually, they are easily identified by the black coloring around the eyes and mouth, no beak and an atypically large dorsal fin. They appear to have poor eyesight, characteristic of a species that spends its life in relatively turbid water and finds food by echo location. It is believed that a female can produce one calf per year with a gestation period of 10-11 months. The maximum lifetime of an animal is reported to be 21 years. Juveniles are observed to have white spots on their dorsal fins.

Examination of stomach contents of 34 dead animals has shown that vaquitas are relatively indiscriminate feeders. Virtually any variety of fish that live near or on the gulf bottom, in addition to squid and crabs, appears to be tolerated (17 species were found in one animal) .

The vaquita is the only porpoise species found in warm waters (the upper gulf reaches 35 C, 95 F, during the summers and most porpoises live only in waters under 20C). It appears also to live only in relatively shallow waters (<50 m) and close to shore (<40km).

Pictures of vaquitae that were caught in gill nets are shown to the right. Virtually all photographs of the vaquita are of dead animals. The first picture of a live vaquita was taken by Gustavo Ybarra off the San Felipe coast in 2003.

Recent studies by Lorenzo Rojas-Bracho and Armando Jaramillo-Legorreta of the Marine Mammal Program at the Instituto Nacional de Ecología and Randall Reeves of the Okapi Wildlife Associates in Quebec, Canada, published in the journal Mammal Review, have investigated the possible causes of death.

Theories that the decreasing fresh water flow from the Colorado river, pollution due to increasing coastline development and inbreeding (loss of genomic variability) have largely been discounted. The prime problem is fishing with gill nets. Today the vaquita is observed mainly around the waters between San Felipe and Puertecitos.

 

 

The (now extinct) Baiji from the Yangtze River with her pronounced beak © baiji.org

The beakless Vaquita

Vaquita killed in gill nets © 1985 CI, Alejandro Robles

Population and Range

The total population of vaquita is presently estimated to be only around 200-300 individuals, well under the 600 identified in the 1997 survey, and it is believed that some 40-80 per year are killed in fishing nets.

Observations and analysis by D'Agrosa, Vidal and Graham in 1994 showed that vaquita are caught and die in all sizes of mesh gill nets, whether drifting or anchored, demersal or surface. Some 92% of vaquitas killed in 1993 were captured in nets set on the bottom, 8% in surface nets. In total, 75% were caught in drift nets, 25% in set nets. For the species to survive, scientists calculate that this fishing-related death rate must be reduced to zero immediately.

The range of the vaquita (green hatches) is shown to the right in a small graphic from a study in the mid-1990's. At that time, their distribution in the upper gulf was assumed to be equally probabale from Puerto Penasco on the Sonoran coast to San Felipe and Puertecitos on the Baja California side of the gulf. The range of the endangered totoaba (dark red) appears to be much larger, and recent evidence (2006) seems to indicate that there are large populations of totoaba in the relatively deep waters between the Midriff islands and the Baja coast.

What is unusual is that the vaquita appears to have always stayed in the very north of the Gulf of California (as evidenced by the distribution of skeletal remains). It has never ventured further south even though the avaliable food for its diet is plentiful throughout the Sea of Cortez. Hence, some other phenomenon (e.g. temperature, tidal range, salinity) must be at work to reinforce the vaquitas preference for the extreme northern gulf.

Range of the Vaquita and Totoaba in the Gulf of California (Sea of Cortez)

A more detailed analysis of the reported sightings of the vaquita is shown to the right and it is apparent that over 90% are in the lighter shaded polygon adjacent to the San Felipe shoreline. There are also reported findings of several old skulls of dead animals on land, primarily close to the beach campos north of San Felipe; presumably indicating that fishing camp residents found it necessary or worthwhile to carry the catch hundreds of meters inland before discarding inedible items.

A significant increase in the reported catch of vaquita took place during 2003-2004 and, in retrospect, this could be related to the dramatic rise in tourism, real estate development and settlement of a new, affluent, population of northamericans in the San Felipe region. Anecdotally, it is reported that the demand for totoaba also went up at this time.

In 1993, then-president Carlos Salinas de Gortari established the Biosphere Reserve in the northern gulf as part of the negotiations for the approval of the North American Free Trade Agreement. However, enforcement of the regulations on fishing in this reserve have been sporadic. At present it is reported that only a single officer, stationed in Puerto Penasco, is available to patrol the biosphere reserve.

Sightings of the Vaquita

 

Some 50,000 people in Baja California and Sonora are estimated to have their livelihood tied, in some way, to the fishing activities in the zone north of the San Felipe-Puerto Penasco line. In particular, the indigenous population of Cucapa indians in the estuarine area of the Colorado and around Golfo de Santa Clara rely almost entirely on the northern gulf for their livelihood.

Three air surveys in late 2005 observed an average of 512 pangas and 46 shrimp trawlers working in the reserve between October and December with 48 pangas and 3 trawlers even fishing in the "nuclear" zone involving the Colorado delta.

The Mexican Government has been very proactive in responding to the petitions of the scientific community and has decreed that the ecological booundary will be expanded down to the line from Puertecitos to Puerto Penasco in five years.

The first phase of this is to protect the primary area of the vaquita and an official publication was made by the Instituto Nacional de Ecologia (29 Dec 2005) for the establishment of the boundaries shown to the right. This should cover virtually all of the vaquita territory.

A trust fund is being established to compensate fishermen in the region for not fishing in the zone. One million dollars has already been assigned to re-educate and re-train the people affected by the existing biosphere limits and to attempt to phase in tourism-related jobs to replace the lost fishing opportunities.

Over the next five years, it is hoped that a trust fund totalling $30 million dollars can be assembled. Agreements have been signed by the various fishing cooperatives and the state and federal governments but, again, enforcement of these agreements is very difficult and alternative jobs need to be found for the fishing communities that will be deprived of their source of income.

Fishing community documents

The 2003 meeting

 

comments and feedback - see "contact us"

 

The designated vaquita refuge zone

(Diario Oficial 29 Dec 2005)

1/28/2007 apc