The Vaquita is a small porpoise endemic exclusively to the shallow, turbid waters of the northern Gulf of California, Mexico. It is the smallest of all cetaceans and is globally recognized as the most critically endangered marine mammal species. Its existence is confined to a tiny geographic area, intensifying the severity of its conservation crisis.
The History and Outcome of Captivity Attempts
An emergency conservation program known as VaquitaCPR (Conservation, Protection, and Recovery) was launched in 2017 as a last-resort effort to save the species from immediate collapse. The plan involved locating and capturing individuals to temporarily relocate them to secure, floating sea pens in the upper Gulf of California. The ultimate goal was to hold a small population in a protected environment until the threat of illegal fishing in their natural habitat could be eliminated.
This ambitious, multi-national initiative successfully located and captured two Vaquita individuals during its field operations. The first captured individual was a juvenile female, which was quickly released after veterinarians noted signs of severe agitation and stress. Shortly thereafter, a second individual, an adult female, was captured and brought into human care.
The adult female responded poorly to the confinement and handling by the conservation team. Despite immediate and intensive veterinary intervention, the porpoise’s condition deteriorated rapidly. The animal ultimately died while the team was attempting to return her to the wild.
Following this devastating outcome, the VaquitaCPR operation was immediately suspended on the unanimous recommendation of its lead scientists and an independent review panel. This decision was based on the unacceptable risk of further mortality to the tiny remaining population. Consequently, there are no Vaquita in human care anywhere in the world, and the emergency program to establish a captive population was halted.
Biological Sensitivity: Why Captivity Failed
The failure of the VaquitaCPR program highlighted the extreme physiological fragility of the species, which makes it uniquely unsuitable for ex-situ (captive) conservation. Vaquita are highly sensitive to the stress associated with being chased, caught, and handled by humans. This sensitivity proved to be a fatal factor during the 2017 rescue attempt.
The adult female that died was determined to have succumbed to capture myopathy, a condition where muscle damage, organ failure, and shock occur following extreme stress or exertion. This physiological reaction is a known risk in many wild animals, but it was particularly pronounced and rapid in the Vaquita. The juvenile captured earlier exhibited such distress that scientists made the precautionary decision to release her after only four hours in care.
The porpoise’s nervous temperament and inherent physiological response to confinement demonstrated that the very act of rescue posed a risk that outweighed the potential benefits. The stress hormone cascade and subsequent organ damage caused by the capture techniques, even those designed to be minimally invasive, were too much for the animal’s system to bear.
Current Status in the Wild and Primary Threats
With the failure of the captive program, all conservation focus has reverted to protecting the remaining population in its natural habitat. The most recent estimates indicate that the total number of Vaquita remaining in the Gulf of California is fewer than 10 individuals, including mothers and calves. This critically low number confirms the species’ place on the brink of extinction.
The overwhelming primary threat to the Vaquita is entanglement and subsequent drowning in illegal fishing nets. Specifically, large-mesh gillnets are illegally set to catch the endangered Totoaba fish, which shares the Vaquita’s habitat. The swim bladder of the Totoaba is highly valued in traditional Chinese medicine, driving a lucrative black-market trade that has created immense pressure on the species’ small range.
Despite government-established protected zones and permanent gillnet bans, the illegal Totoaba trade persists, and Vaquita continue to die as bycatch. Current conservation efforts are focused on intensive monitoring, the removal of illegal and “ghost” nets by patrols, and the deployment of large concrete blocks equipped with hooks in a Zero Tolerance Area (ZTA) to snag and destroy illegal nets.