The vaquita, the world’s smallest porpoise, has been pushed to the brink of extinction by illegal gillnet fishing and there are just 30 left in the wild.

The Mexican government and conservation groups have launched an unprecedented plan to save the species by transporting as many as possible to a protected marine reserve.

“The @VaquitaCPR team has managed to capture another vaquita marina,” Mexican Environment Minister Rafael Pacchiano tweeted, adding that the animal is in the care of veterinarians.

A six-month old calf — the first vaquita ever captured — was caught last month but had to be released as it was too young to be separated from its mother.

However the second porpoise “is an adult female and of reproductive age,” Pacchiano said on Twitter. “It’s a great achievement that fills us with hope.”

The initiative, which began field operations in October, is attemptng to locate the remaining vaquitas using acoustic monitoring, visual searches and dolphins trained by the US navy.

Captured vaquitas will be transported to a marine sanctuary, where it is hoped they will breed before being released back into the wild.

The vaquita has been nearly wiped out by gillnets used to fish for another species, the also endangered totoaba fish, whose swim bladder is considered a delicacy in China and can fetch $20,000 per kilogram.

In June, Mexico announced a series of measures to protect the vaquita, including a permanent ban on gillnets in its habitat.

In all, the government has committed more than $100 million to protecting the vaquita while supporting the local fishing community.