The vaquita (Phocoena sinus) is a small marine mammal endemic to the shallow, turbid waters of the Upper Gulf of California, Mexico. It is the world’s smallest porpoise, reaching a maximum length of about five feet and possessing a robust, stocky body. Its most recognizable features are the dark rings encircling its eyes and a dark line extending from its chin to the pectoral fins. This rare porpoise, whose name translates to “little cow,” is currently recognized as the most endangered marine mammal globally, restricted to an extremely limited habitat where the Colorado River once met the sea.
The Current Population Estimate
The population of the vaquita has reached an alarming level, confirming the species is teetering on the brink of extinction. A visual survey conducted in May 2024 provided a minimum estimate of only six to eight unique individuals remaining in the wild. This figure represents a slight decline from the 2023 estimate, which placed the population between eight and 13 animals.
Scientists rely on a combination of visual sightings during dedicated surveys and Passive Acoustic Monitoring (PAM) to track the elusive porpoise. Acoustic devices are deployed across the Vaquita Refuge to record the high-frequency clicks the animals use for echolocation, providing data on their presence and distribution. The count is considered a minimum due to the difficulty of sighting the naturally shy animals in their small, often murky habitat. The population has plummeted from an estimated 600 individuals in the late 1990s.
The Primary Threat: Illegal Gillnet Fishing
The decline of the vaquita population is attributed almost entirely to accidental entanglement and subsequent drowning in illegal fishing gear known as gillnets. These nets, which are typically made of monofilament line, are designed to catch fish by snagging their gills as they try to swim through the mesh. Unfortunately, the nets are non-selective, and the vaquita’s small size and restricted range make it particularly susceptible to becoming bycatch.
The primary driver of this illegal activity is the presence of the totoaba fish, which shares the vaquita’s habitat in the Upper Gulf of California. Fishermen illegally target the totoaba for its swim bladder, a highly prized commodity in Asian black markets where it is falsely believed to have medicinal properties. This lucrative, illicit trade has created a massive black market demand that fuels the deployment of large-mesh gillnets, which are the exact type that most effectively ensnare and kill the vaquita.
Once entangled in the mesh, the vaquita, like all marine mammals, cannot surface to breathe and quickly suffocates. The illegal nature of the fishing operations, which often occur at night to avoid detection, also leads to the abandonment of nets, creating deadly “ghost nets” that continue to kill marine life indiscriminately. The scale of this organized criminal trade in totoaba swim bladders has made enforcement extremely challenging, directly preventing the vaquita from recovering.
Urgent Conservation Strategies
The fight to prevent the vaquita’s extinction is concentrated on eliminating gillnets within its small remaining habitat. A core strategy involves protecting the Vaquita Refuge, particularly the Zero Tolerance Area (ZTA), where the last individuals have been consistently sighted. Enforcement efforts have been bolstered by the Mexican Navy, which has deployed hundreds of concrete blocks embedded with large metal hooks across the ZTA.
These gillnet-entanglement devices are designed to snag and destroy illegal nets, creating a physical deterrent for poachers operating in the refuge. Conservation efforts also focus on the development and implementation of alternative, vaquita-safe fishing gear to replace gillnets for local fishermen. Programs are underway to test and promote “net zero” techniques that allow for sustainable fishing without posing a threat to the porpoise.
International cooperation plays a significant role, with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) applying pressure on Mexico to curb the illegal totoaba trade. The immediate necessity remains the complete removal of all gillnets and robust, continuous enforcement. The vaquita’s survival hinges on successfully maintaining a gillnet-free sanctuary where the remaining individuals can reproduce.