By Dr. Becker
In 2016, I wrote about the grave dangers facing Mexico’s vaquita marina, the world’s smallest porpoise. At the time, Mexican government scientists estimated the animals faced imminent extinction within five years — and possibly by 2018 — if increased protections weren't made.
There were an estimated 60 vaquitas, also known as the Gulf of California harbor porpoise, left in the wild at that time, but this number is now estimated at closer to 30, based on an estimate garnered by monitoring their echolocation clicks.1
The animals only live in the northern end of the Gulf of California, typically alone or in groups of up to three. They’re shy and rarely seen, and now researchers are proposing keeping some in captivity to prevent them from disappearing entirely.
Last-Ditch Attempt to Save Vaquitas: Keep Them in Captivity
Advisers to the Mexican government have proposed an emergency action to save the species: capturing several vaquitas and keeping them in a captive sea pen until their environmental risks can be reduced.
The plan includes training U.S. Navy dolphins to locate the vaquitas, which would then be kept until, hopefully, the vaquitas’ population stabilized, via captive breeding and conservation efforts, and they could be returned to the wild.
“Even in the best of scenarios, breeding in captivity is unlikely to restore the population. A female vaquita gives birth to one calf every two years on average,” The New York Times noted.2
In addition, there are many unknown factors and risks involved, such as whether the dolphins would be able to find the vaquitas and, if so, how they would fare in a captive environment.
“If we continue on the path we’re on, we’ll have no vaquitas in two years,” Barbara Taylor, a marine mammal expert at the National Oceanic and Atmospheric Administration, told the Times. “If you get a negative result in any one of these steps [to keeping vaquitas in captivity], it’s basically game over.”3
If the plan moves ahead, it would be the first time such an effort was undertaken for a marine mammal, but other forms of conservation management are underway for other endangered species, like the California condor.
In a sad example of what can happen if scientists wait too long to intervene, in Australia conservationists spent months planning and gaining permissions for a captive-breeding program for the critically endangered Bramble Cay melomys, small mouse-like rodents known to live only on an approximately 9-acre low-lying island, Bramble Cay, in Australia's Great Barrier Reef.
Unfortunately, by the time the scientists arrived there to try to save the species, no signs of the rodents remained, and they were declared extinct in early 2017.
What's Causing Vaquitas to Vanish?
Illegal gillnetting for a critically endangered fish, the totoaba, is responsible for the rapid decline in vaquita populations. Both fishing for totoaba and the use of gillnets are currently illegal, but the fish are sought for their swim bladder, which are dried and sold illegally on the black market in China, nonetheless.
One pound of tortoaba swim bladder can bring a fisherman about $4,000, which is about half a year's income for a typical fisherman in the area.4 The use of gillnets, which are vertical nets designed to catch fish by their gills, is incredibly problematic, as it's estimated that 1 out of 5 vaquitas get caught in the nets and drown.5
According to data from the Mexican government’s National Ecology and Climate Change Institute (INECC), illegal totoaba fishing has killed off 90 percent of the vaquita population since 2011.6
In May 2015, a two-year ban on gillnets was put into place by the Mexican government, and the vaquita protection area was increased 10-fold to encompass 5,000 square miles.
The Mexican government is also compensating local fishing communities for lost income, and the Mexican Navy is in place to enforce the gillnet ban. However, environmental groups are concerned the ban is not enough to prevent vaquitas' extinction.
“We see illegal activity almost every day,” Oona Layolle, the leader of the Sea Shepherd campaign patrolling the area, told the Times.7
The International Committee for the Recovery of the Vaquita (CIRVA) has called for stronger protections, including a permanent ban on gillnets, to protect the species from extinction and help their recovery, but even if a ban is put in place, it must be enforced to make a difference.
As the Times reported, “Despite a promise last year by President Enrique Peña Nieto, the government has yet to act on the gillnet ban. Without that, warn conservationists, there is no way to begin to save the vaquita.”8
Vaquitas Were Just Discovered in 1958
It would be tragic for vaquitas to disappear from the Earth. There’s so much left to be understood about these charismatic creatures, which were only discovered in 1958.
The World Wildlife Fund has also called on governments to take urgent action to save them upon news that their population declined by 50 percent in the last year alone:9
“The only way to save the vaquita from extinction is if the Mexican government bans all fisheries within vaquita habitat. Such a ban must be fully carried out by law enforcement. And economic alternatives must be found for fishing communities so they may have more sustainable livelihoods.
Other governments must also do their part. The U.S. needs to immediately stop transborder shipments of totoaba products. China should end to the illegal transport and sale of totoaba products. All three governments must take action immediately.”
As the current most endangered cetacean in the world, the fear is that the species may soon follow the fate of the Chinese river dolphin, or baiji, which were declared extinct in 2006; human activities, including heavy ship traffic, overfishing, dam-building and environmental degradation were largely blamed for the dolphins’ tragic demise.10