29/12/2016 4:00 AM AEDT

Mexico Makes A 'Risky' Last-Ditch Attempt To Save The Vaquita, The World's Smallest Porpoise

There are fewer than 60 of the planet's rarest marine mammal. Scientists hope their capture plan will change that.

A critically endangered vaquita entangled in a gill net. In recent years, the hazards facing vaquitas have only intensified, prompting a “catastrophic decline” of the species.

The vaquita, the world’s smallest porpoise, has never been caught alive. But with fewer than 60 of the species now left on Earth, scientists are embarking on a “risky” mission to capture as many of them as they can in a last-ditch effort to save the animal from extinction.

The International Committee for the Recovery of the Vaquita, or CIRVA, a conservation group that the Mexican government established in 1997, will spearhead the launch of the rescue program in the spring.

“It would involve locating them, capturing them and putting them in some kind of protective area,” CIRVA chairman Lorenzo Rojas-Bracho told The Associated Press of the plan this month.

Scientists from around the world, including acoustic monitoring and porpoise capture experts, will lead the effort, Rojas-Bracho said. “The team is the best that can be put together in the world. It is the ‘dream team,’” he told the AP.

The vaquita, a tiny stubby-nosed porpoise, is found only in Mexico's Gulf of California.

Vaquitas live exclusively in Mexico’s Gulf of California and have been under serious threat since the 1990s. Gill nets that local fishermen set to catch shrimp and fish, including the critically endangered totoaba, have been their primary nemesis. The porpoises get trapped in these nets and drown.

In recent years, the hazards facing vaquitas have only intensified, prompting a “catastrophic decline” of the species. Demand for the totoaba, also endemic to the Gulf of California, has been the main driver of this collapse.

The fish’s swim bladder, also known as maw, is considered a delicacy in parts of Asia. Known as “aquatic cocaine,” it can sell for as much as $10,000 a kilogram, or almost $5,000 a pound.

In May, CIRVA announced that due to the totoaba trade and unsustainable fishing techniques, fewer than 60 vaquitas ― and possibly as little as eight breeding females ― remain in the wild. That’s a decline of more than 92 percent since 1997.

Without prompt and concerted efforts to protect the species, vaquitas will be extinct by 2022, the group said.

Dried the dried maws of the critically endangered totoaba fish, like these pictured with shark fins in Hong Kong, sell for thousands of dollars on the black market in Asia.

A series of conservation efforts have since been rolled out in an attempt to prevent the wiping out of the species. In October, the International Whaling Commission, with support from Mexico and the United States, approved measures including an emergency resolution to permanently ban gill net fishing from the vaquita’s range, remove existing gill nets and clamp down on the illegal trade of totoaba.

Mexico’s environment ministry said on Dec. 15 that it had managed to remove more than 100 so-called “ghost” fishing nets from the vaquita’s habitat —which had been dumped or lost at sea. Mexican authorities have also been using drones with high-resolution cameras to detect illegal fishing in the Gulf. 

CIRVA’s new plan to capture vaquitas and breed them in captivity is the latest, and most dramatic, conservation effort to date.

The Mexican Navy has been patrolling the Gulf of California to arrest fisherman who are illegally catching totoaba. 

Scientists say it’s unclear how successful the capture program will be, given that vaquitas have never been kept in captivity. Animals could die in the attempt, potentially precipitating the species’ extinction. And some experts have expressed concern that the health of the Gulf itself could also be threatened if teams remove the marine mammal. Without the protected vaquita to worry about, fishermen could wipe out the totoaba and other species, conservationists warn. 

Captivity is “not a desirable or practical option for the vaquita,” Omar Vidal, Mexico director of the World Wildlife Fund, who opposes the plan, told the AP. “We must strive to save this porpoise where it belongs: in a healthy Upper Gulf of California.”

CIRVA has acknowledged the risks of the plan, but said the potential “salvation” of an entire species ultimately outweighs the dangers. 

“Capturing them is a very difficult decision. It implies risks, but it won’t be rushed. In any sign of stress, we will let them be free,” Rojas-Bracho said, according to the AFP this week. “We don’t know what will happen. But we hope that it can be the difference between its extinction and its salvation.”