Is Vaquita still recoverable or is it now doomed?



by LORENZO CIOTTI

Is Vaquita still recoverable or is it now doomed?

Vaquita existence was only confirmed by a study carried out in 1985. It is known that the vaquita population is declining and that this fact is due to entrapments in fishing nets positioned to catch another endemic species of the Gulf, the totoaba.

CIRVA, the Commission for the Recovery of Vaquita, came to the conclusion in 2000 that every year between 39 and 84 individuals are killed in these networks. It is classified by the IUCN and the Convention on International Trade in Threatened Species of Wild Fauna and Flora in the most critical category at risk of extinction.

In an effort to try to prevent extinction, the Mexican government has created a nature reserve that covers the upper Gulf of California and the Colorado River Delta. CIRVA claims that this reserve covers the entire southern part of the porpoise's known range and that fishing nets are completely banned from the protected area.

Even if the number of porpoises killed by fishermen were reduced to zero, there would still be risks for conservationists. The use of chlorinated pesticides, reduced Colorado River freshwater flow due to irrigation, and the depression due to inbreeding also have detrimental effects.

The Gulf of California porpoise is in the top 100 EDGE (Evolutionarily Distinct, Globally Endangered) species. Evolutionarily distinct animals have no close relatives and represent the tree of life variety more than other species, which means a top priority in conservation campaigns.

According to American geneticist Jacqueline Robinson of the University of California, the few remaining vaquita units have DNA that is too uniform to hope to rebuild a healthy population. There are few reports of this cetacean in the wild.

It appears to swim and feed slowly, but it is elusive and avoids boats of all kinds. It emerges to breathe in a slow, forward motion, which barely moves the surface of the water, then quickly disappears for a long time. It has an invisible breath, but which causes a loud, dry and snorting noise reminiscent of that of the porpoise.

It lives in low and dark lagoons located along the coast and is rarely seen in waters deeper than 30 meters; in fact, it can survive in water so shallow that its back protrudes from the water. Other characteristics of its habitat are a strong tidal excursion, strong convection processes and primary and secondary productivity.