Can scientists save the 'panda of the sea'?

Scientists have formulated a bold plan to save the vaquita porpoise – the world's smallest porpoise – which has been brought to the brink of extinction by Chinese demand for the rare totoaba bladder. 

The vaquita porpoise, sometimes known as the “panda of the sea,” has at least two things in common with its larger, furrier namesake: dark rings around the eyes and the threat of extinction by human activity.

Measuring just 4.5 feet long, the miniature porpoise may currently hold the record for smallest cetacean population, as well as body size. According to a new report by the International Committee for the Recovery of the Vaquita (CIRVA), as few as 30 individuals may remain. Current conservation efforts are proving ineffective, forcing scientists to resort to drastic measures.

Underwater microphones recording their characteristic dolphin-like echolocation clicks, which the vaquitas rely on to catch the small fish that they eat, reveal a drastic population decline of almost 40% per year from 2011 to 2016. CIRVA estimates that numbers have fallen 90 percent during this five-year period.

The vaquitas live only in the Gulf of California in northwestern Mexico, where illegal fishing poses a serious threat to their existence. While not valuable themselves, the swim bladder of the endangered totoaba fish sells for $10,000 in China, where it’s supposed medicinal properties make it a valuable soup ingredient. Totoaba are protected by law as well, but the lure of easy riches draws widespread attention.

"We absolutely have heard that cartels are involved in this trade," Erin Dean at the US Fish and Wildlife Service said of totoaba smuggling to NPR last year.

Fishermen hoping for a totoaba payday sometimes mistakenly catch the similarly sized vaquita in their large-mesh gillnets.

“We know what the problem is: it’s gillnets. We’ve known for 30 years that gillnets kill vaquita and we have done nothing, and I find that heartbreaking,” marine wildlife consultant at the Animal Welfare Institute Kate O’Connell told New Scientist.

The Mexican government is trying to help. In 2015 Mexican president Enrique Peña Nieto imposed a two-year ban on gillnets, deployed the navy to enforce fishing laws, and earmarked $72 million in fishermen aid, according to a press release.

But it isn’t enough. CIRVA calls the conservation measures “forceful and costly,” but inadequate. Three vaquita deaths by gillnet were confirmed last year, and the acoustic evidence is undeniable.

“Since we lost about half of the remaining vaquitas last year despite a gillnet ban, illegal fishing is clearly driving the species rapidly to extinction,” Barbara Taylor of the National Oceanic and Atmospheric Administration (NOAA) tells The Christian Science Monitor in an email.  

In just 15 days of patrolling during the fall, a coalition that included the Mexican navy found and destroyed dozens of active gillnets.

While CIRVA urges the government to make the gillnet ban permanent and step up enforcement, they also recommended a last-ditch effort that the committee itself recognizes is “extremely difficult and expensive,” with no guarantee of success: rounding up some of the porpoises and keeping them in open-sea pens or even pools on land. If they could breed safely in these semi-captive environments, individuals could eventually be released into future gillnet-free seas.

Some porpoises respond well to handling, but it can easily injure others, so capturing vaquitas would represent a huge risk to the already dwindling population. Nevertheless, scientists say we’re out of time. “We can’t afford to wait anymore. They’re going to be gone in a year or two,” Dr. Taylor told New Scientist.

Tracking down the slippery animal presents another set of challenges. So rare they were discovered only in the 1950’s, “a lot of fishermen still maintain to this day that they’re mythical,” Taylor said.  

But scientists have a plan. They’ll try fighting water with water, and employ easier-to-spot, US Navy trained dolphins to find the porpoises, as the Monitor reported last month.

Dolphins trained by the Navy’s Marine Mammal Program for tasks such as sniffing out underwater mines and enemy divers are going to be deployed in the Gulf of California, the only body of water where vaquitas live, in order to locate the last few dozen members of the elusive species – and help capture them.

After locating the rare porpoises, Jim Fallin of the US Navy Space and Naval Warfare Systems Center Pacific told the Associated Press, the dolphins could point the way "by surfacing and returning to the boat from which they were launched."

Vaquitas and totoabas aren’t the only marine life threatened in the region. Illegal gillnets also ensnare sharks, whales, and sea turtles. This danger makes the porpoises “a guardian for all those other species,” Taylor says.

But if current trends continue, the narrow window for saving them and promoting sustainable fishing practices will slam shut forever. Taylor calls the vaquitas’ outlook “desperate”, saying, “unless funds can be found for the effort to capture some and the highly skilled international team has good fortune with a very difficult task, the world will likely lose this species in the next few years.”

Interested parties can read more about the plan to save the pandas of the sea on the National Marine Mammal Foundation’s website.

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