MEXICO CITY — U.S. Navy-trained dolphins and their handlers will participate in a last-ditch effort to catch, enclose and protect the last few dozen of Mexico's critically endangered vaquita porpoises to save them from extinction.
International experts confirmed the participation of the Navy Marine Mammal Program in the effort, which is expected to start sometime this spring.
Jim Fallin of the U.S. Navy Space and Naval Warfare Systems Center Pacific said Tuesday that the dolphins' participation is still in the planning stage.
The dolphins will use their natural sonar to locate the extremely elusive vaquitas, then surface and advise their handlers.
"Their specific task is to locate" vaquitas, which live only in the Gulf of California, Fallin said. "They would signal that by surfacing and returning to the boat from which they were launched."
The dolphins have been trained by the Navy for tasks like locating sea mines.
The vaquitas, the world's smallest and most endangered porpoise species, have been decimated by illegal fishing for the swim bladder of a fish, the totoaba, which is a prized delicacy in China.
Although the vaquita has never been held successfully in captivity, experts hope to put the remaining porpoises in floating pens in a safe bay in the Gulf of California, also known as the Sea of Cortez, where they can be protected and hopefully breed.
Lorenzo Rojas-Bracho, chairman of the International Committee for the Recovery of the Vaquita, wrote that "an international group of experts, including Navy personnel, have been working on two primary goals: determining the feasibility of locating and catching vaquitas, as a phase One. And as a second phase, to determine the feasibility of temporarily housing vaquitas in the Gulf of California."
Rojas-Bracho said the effort by the international team of experts "would involve locating them, capturing them and putting them in some kind of protective area," probably a floating enclosure or pen in a protected bay where they would not be endangered by fishing nets. Mexico has banned gill nets that often trap vaquitas in the area, but has had trouble enforcing it because the totoaba draws very high prices on the illegal market.
"At the current rate of loss, the vaquita will likely decline to extinction by 2022 unless the current gillnet ban is maintained and effectively enforced," Rojas-Bracho wrote.
According to rough estimates, with vaquita population numbers falling by 40 percent annually, and only 60 alive a year ago, there could be as few as three dozen left.
Some experts, like Omar Vidal, Mexico director of the World Wildlife Fund, oppose the capture plan, which could risk killing the few remaining vaquitas and open up a free-for-all of illegal fishing once they are removed from their natural habitat. "We must strive to save this porpoise where it belongs: in a healthy Upper Gulf of California," he said.
Catch-and-enclose is risky. The few remaining females could die during capture, dooming the species. Breeding in captivity has successfully saved species such as the red wolf and California condor, but the vaquita has only been scientifically described since the 1950s and has never been bred or even held in captivity.
Experts including Rojas-Bracho; Barbara Taylor, leader of Marine Mammal Genetics Program at the National Oceanic and Atmospheric Administration; and Sarah Mesnick of the NOAA's Southwest Fisheries Science Center, stressed that the capture program "should not divert effort and resources away from extension and enforcement of the gillnet ban, which remains the highest-priority conservation actions for the species."
Veterinarians will evaluate vaquitas' reactions and release stressed individuals, they wrote. Should a death occur, the team will re-evaluate the sanctuary strategy.
"It is important to stress that the recovery team goal is to return vaquita from the temporary sanctuary into a gillnet-free environment," they wrote.