Conservationists have deployed a new vessel in the fight to save the world's rarest marine mammal from extinction due to illegal fishing in Mexico's Gulf of California.

The ship's arrival comes at a "critical time" for the vaquita porpoise, which counts Leonardo DiCaprio among its celebrity defenders, the Sea Shepherd Conservation Society said Wednesday.

A joint effort by the marine wildlife group, the Mexican navy and other partners known as "Operation Miracle" has reduced illegal fishing activity that threatens the vaquita by more than 70 percent in the past year, it said.

"This is encouraging news, but we always have to do better," said Sea Shepherd chairman Pritam Singh, who welcomed officials and the media onboard the Seahorse, escorted by naval vessels, for a presentation this week.

"We chose and refitted the Seahorse specifically for its design and capacity, both of which will dramatically increase our effectiveness and ability to protect the vaquita in 2023," he added.


A handout picture released by the Mexican Secretary of Environment and Natural Resources shows scientists with a six-month-old vaquita porpoise calf in the Gulf of California, in Mexico, in 2017 / © Semarnat/AFP/File

Known as "the panda of the sea" for the distinctive black circles around its eyes, the vaquita has been decimated by gillnets used to catch totoaba, a large fish whose swim bladder is prized in China thanks to its supposed medicinal properties.

Conservationists have previously been involved in a number of violent confrontations with fishermen while working with Mexican authorities to remove illegal nets.

The vaquita, the smallest porpoise on the planet, has been listed as critically endangered by the International Union for Conservation of Nature since 1996.

There are estimated to be fewer than 20 individuals left in a small area in the Gulf of California, the only place in the world where the vaquita is found, according to Sea Shepherd.