Scientists are warning that the population of Mexico's endangered vaquita marina, the world's smallest porpoise, has fallen to alarmingly low levels and is heading toward extinction soon if drastic measures aren't taken.

A survey by the International Commission for the Recovery of the Vaquita found that as of December there were probably only about 60 of the shy, elusive creatures left in the upper Sea of Cortez. That's the only place where they are found.

Since that time three vaquitas were found dead during just three weeks in March by the Sea Shepherd Conservation Society.

The vaquitas are threatened primarily by gillnet fishing for the totoaba fish, another endangered species that is hunted in the same area.

The results of the survey were released Friday evening by Mexico's Environment Department.