The vaquita is smallest of all the world's cetaceans—the order of animals that includes whales, dolphins, and porpoises.
The Mexican mammal is also perhaps the most seldom seen cetacean. Found within only 850 square miles (2,200 square kilometers) of the Gulf of California, the 5-foot-long (1.5-meter-long) animal was discovered by scientists only in 1958.
With its tiny range, the vaquita has probably always been small in number. But fishing has almost certainly caused the species to decline, perhaps beyond the point from which it can recover, scientists say.
Like other marine mammals, vaquitas can become entangled in fishing nets and drown when they are unable to swim to the surface to breathe.
Rojas Bracho said that, despite efforts to protect the species, "fishing effort has increased, and illegal fishing is a problem. So the risk factor has gone up."
In an attempt to protect the species, conservationists established a reserve area in the northern Gulf of California in 1993. But recent studies have shown that most vaquitas live outside of the reserve's zone of protection.
A new marine reserve established late last year by the Mexican government may offer more hope. The reserve bans certain types of fishing in an area where nearly 80 percent of vaquita sightings have occurred.
At the same time Mexico granted the equivalent of a million U.S. dollars to the state governments of Sonora and Baja California to compensate affected fishers.
Peggy Boyer is the director of the Intercultural Center for the Study of Deserts and Oceans, a Sonora-based research and conservation organization.
Her group is working with fishing communities to minimize adverse effects of the new reserve on the coastal economy and to develop alternative sources of income.
For example, in one community, part of the compensation money from the government may be used to promote ecotourism.
If the plan is approved, she said, "fishermen who retire their boats will receive new boats with more environmentally friendly motors outfitted for serving tourists rather than fishing."
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