Vaquita

The vaquita, or Phocoena sinus, is a shy species of porpoise and unfortunately is also the world’s rarest marine mammal. They are only found in the northern Gulf of California in Mexico in a small 1,519 square mile area. In fact, they have the smallest range of any marine mammal. They are 5 foot long, dark grey porpoises with white and grey markings on their undersides. Young vaquitas are darker and have a grey fringe. Females are longer than males, but males have larger fins. Vaquitas also have larger dorsal fins than other porpoises, possibly there reduce body temperature. It is hard to find and observe vaquitas because they travel alone or with pairs, avoid boats, small size, and when they come up for air, they barely break the surface. Vaquitas can live up to 21 years. Females give birth every other year, and pregnancy lasts between 10-11 months. They eat small fish, crustaceans and cephalopods. They were first documented in 1958, and have experienced a rapid decline since. In 2016, an estimated 30 vaquitas remained; in 2018, 19 were left; and the most recent 2020 estimates suggest that less than 10 vaquitas remain.

There is only one reason for the vaquita’s decline: bycatch in fishing gear. Although researchers have considered other reasons such as lack of Colorado River flow decreasing prey, pollutants, and low genetic diversity, no examined vaquitas show signs of malnutrition, pollutants, or inbreeding; in fact, vaquitas have one of the lowest levels of pollutants in their environment.

Vaquitas are mostly threatened by bycatch in gillnets, a type of fishing gear used for catching a critically endangered fish, totoaba, as well as for shrimp and other fish. Totoaba and vaquita are similar sizes, so vaquita are often caught and killed in the totoaba gillnets. Although fishing for totoaba is illegal and use of gillnets has been banned from many places, illegal fishing still continues. The totoaba’s swim bladder - their air-filled sac that lets them float - is in high demand in China because of its purported medicinal value. Fishermen can get $8,500 for a kilogram of swim bladder. Trade in totoaba is banned by CITES, but still continues. Vaquitas are also caught and drowned in abandoned totoaba nets.