The U.S. and Mexican governments have agreed to permanently ban gillnetting throughout the range of the world's smallest and rarest porpoise. Nighttime fishing is also banned. Still, there are maybe 80 individuals - but that's probably high. One leading cetologist, Dr. Robin Baird told me he thought it closer to 50.
The story of the vaquita is worth revisiting. When I wrote Rumors of Existence in 1996, I called it “the world's newest and rarest porpoise.” Its tale begins with a single skull found on the beach in the Gulf of California. That discovery was made in 1950, but another eight years passed before Kenneth Norris and William McFarland had enough information to present the vaquita, or Gulf of California porpoise, to the scientific world.
At five feet long or less, and never weighing much over a hundred pounds, the vaquita was indeed tiny by cetacean standards. Its size may have helped it keep hidden: so, undoubtedly, did its shyness. The animal generally avoids boats, an unusual trait for a porpoise (but a wise one). Local fishermen did know it existed, and it was they who called it vaquita, or "little cow."
This porpoise is mainly light gray, although the color usually darkens from the dorsal fin to the tail. The belly is white, and there are dark ovals around the eyes. In addition to accidental catches in gillnets, the porpoise has declined as the Gulf's ecology has suffered due to overfishing and agricultural runoff, and the food supply is dwindling. The vaquita is unusually vulnerable to such threats because it does not migrate: in fact, it has the most restricted range of any marine mammal in the world.
When I wrote that book, the population was estimated at 200 to 400. Think about how sharply it's declined despite the actions of conservationists, scientists, and governments. It's pretty scary. And the newest measures may or may not be in time.
Some early sources I used:
Brown, Martha. 1987. "Searching for the Vaquita," Defenders, May-June
Mulvaney, Kevin,et. al.. 1990. The Greenpeace Book of Dolphins. New York: Sterling Publishing Company.