Ambitious move to save world’s smallest porpoise, led by Hong Kong Ocean Park animal expert

Plan is to capture, house and relocate vaquitas, a species so threatened by fishing by-catch that its population has dipped below 30

PUBLISHED : Saturday, 10 June, 2017, 6:02pm
UPDATED : Monday, 12 June, 2017, 3:38am

A veteran Hong Kong animal care expert will help coordinate a daring project to capture and protect the world’s smallest cetacean – the vaquita, a porpoise indigenous to Mexico that is on the verge of extinction due to an illegal fisheries trade closely linked to the city.

The scheme by Mexican authorities, a first of its kind, will employ specially trained US Navy dolphins to locate the critically endangered marine mammal – found exclusively in the Gulf of California.

The porpoises will then be captured by scientists and housed in offshore sanctuaries until it is safe for them to be released again.

“[Vaquitas] have never been captured before and we don’t know whether they will survive in captivity, but it’s a gamble worth taking at this juncture because if we don’t, they will be gone,” Grant Abel, a director of animal care at Ocean Park, said.

He will assist in the husbandry, housing and general care of the animals.

The vaquita population has plummeted by 90 per cent since 2010 and fewer than 30 are estimated to be left. The steep decline has largely been fuelled by poaching of the equally endangered totoaba fish, which is valued for its swim bladder.

Vaquitas often get caught and die in gillnets – vertical panels of netting – set illegally for totoaba. Both species live in the same area, and the international trade in totoaba is banned.

Dried fish bladder, also known as maw, is commonly sold in Hong Kong. Totoaba bladders are prized delicacies, especially on the mainland, where they fetch sky-high prices.

Diplomats in Hong Kong, a key end market for fish maw, have been working to raise public attention. A joint screening of a documentary about saving the vaquita – Souls of the Vermilion Sea – as well as a presentation on the conservation plan, was held by the Mexican and US consulates last week.

Mexican envoy Damian Martinez Taguena stressed that catching totoaba had been made a federal organised crime two months ago and it was important to raise awareness on the demand side.

“Against all odds, it’s great how this is becoming very high profile and high priority, but it’s a shame that it’s only because of the urgency,” he said.

“The vaquitas are collateral damage,” Dr Lorenzo Rojas-Bracho, who chairs the International Committee for Vaquita Recovery advisory group, said. “The only option now is to buy time until the fisheries industry and authorities develop alternative fishing equipment.”

While a change in fishing gear would, in theory, solve the problem, Rojas-Bracho said it was “not as simple” – officials must guarantee that the livelihoods of local fishermen are not affected.

Last week, Mexico’s president Enrique Pena Nieto, multimillionaire Carlos Slim and Hollywood actor Leonardo DiCaprio signed an agreement to save the vaquita, with the goal to permanently ban gillnets in the upper gulf. A previous two-year ban was also recently extended by the Mexican government.

The first phase of fieldwork by Abel’s team will be from October to November. The group comprises about 40 experts and volunteers, who hope to capture at least 10 vaquitas and house them in protected 40-metre wide sea pens off the northwestern Mexican city of San Felipe.

“We hope to capture three to four initially. We’ll know if they’ll be able to acclimatise within a week to 10 days,” Abel said.

While acknowledging risks, he said captive conservation programmes have proved successful with similar species such as the finless porpoise in China’s Yangtze River, which are being gradually relocated to secure habitats.

“The ideal situation is that the animals survive and are relocated to a managed reserve.” According to Abel, they can then breed and multiply, albeit slowly – female vaquitas produce only one calf roughly every two years.

But at least one marine biologist is sceptical about the project’s chances of success.

Hong Kong cetacean expert Dr Samuel Hung Ka-yiu said the chances of the project succeeding were “close to zero” and argued that resources should be spent protecting and removing threats in the species’ natural habitat.

“Finding them and catching them is already very difficult. Porpoises are shy creatures and easily frightened,” he said. “Human handling in a semi-natural reserve will be almost ‘mission impossible’.”

Even if capture was successful, Hung feared the programme would reduce incentives to solve the problem of poaching and by-catch. He said a successful release would also depend on how protected the new environments were.

A similar attempt by Chinese authorities to conserve the Baiji dolphin in-situ in 2001 ended up in their functional extinction. One of the reasons was that fishing was still permitted in the protected area where the dolphins lived.

“If [a species] can no longer be released into the wild and function in an ecosystem, they are by definition functionally extinct. But this is not something everyone is willing to accept,” Hung said.