What is the primary threat to the endangered vaquita porpoise?

The primary threat to the endangered vaquita porpoise is bycatch in gillnets. Vaquitas become accidentally entangled in fishing nets, cannot reach the surface to breathe and drown.

The vaquita lives only in the northern Gulf of California, also known as the Sea of Cortez, in Mexico. Its restricted range makes the species especially vulnerable to local fishing activity. Large-mesh gillnets used illegally to catch totoaba are particularly dangerous; the totoaba’s swim bladder is highly valuable on illegal markets, and vaquitas can become trapped in the same nets.

Gillnet restrictions and protected zones have been introduced, but illegal fishing has continued. The vaquita’s decline has been extraordinarily rapid, and only a tiny number are believed to remain in the wild. Scientists have concluded that stopping bycatch is the essential requirement for the species to survive and recover.

Pollution, habitat alteration and other pressures may also cause harm, but they are not considered the main driver of the vaquita’s population collapse. Boat strikes and climate change are therefore not the canonical answer to this question.