A newly launched effort to find critically endangered vaquita marina porpoises has already spotted three of the elusive, almost-never-seen creatures in Mexico's Sea of Cortez.

The Environment Department announcement came late Thursday.

Nobody is quite sure how many vaquitas remain in the Sea of Cortez, also known as the Gulf of California. It's the only place they are found. Experts have estimated that few than 100 vaquitas survive.

The world's smallest porpoises, they are elusive, shy and seldom seen.