An extraordinary mission to save vaquita porpoises from extinction has got off to a promising start in the Gulf of California, where military dolphins are being used to help round up and capture the world’s rarest marine mammal and move them to a sanctuary.

Illegal fishing methods, including banned gillnets have seen the number of vaquita porpoises, known as the "panda of the sea" for their strange beauty, plummet so low there were fears none would be found. It is believed there is less than 30 vaquitas left in the wild.

But The Telegraph has learned from sources involved in the rescue mission that the first day out on the water on Friday produced “multiple sightings”.

US Navy dolphins have been trained to seek out the vaquitas and leap out of the water when they locate a specimen, alerting the capture team, which includes veterinarians.

The porpoises will be temporarily held in an ocean sanctuary off the coast of San Felipe while their natural habitat is made safe, including removing the threat of gillnets.

The enterprise is not without risk. Wild bottlenose dolphins have been known to hunt and kill porpoises, and nothing is known about how the vaquita will fare in captivity.