A vaquita swims in the foreground while fishing boats ply their trade in the distance.
Vaquitas have never been hunted directly, but their population is declining, largely due to animals becoming trapped in illegal gillnetsintended for capturing the totoaba, a large critically endangered fish of the drum family endemic to the Gulf. A trade in totoaba swim bladders has arisen, driven by demand from China (where they are used in soup, being considered a delicacy and also thought to have medicinal value), which is greatly exacerbating the problem.[4][5]

Estimates placed the vaquita population at 567 in 1997.[18] Estimates in the 2000s ranged between 150[20][21] to 300.[21]

With their population dropping as low as 85 individuals in 2014,[22] inbreeding depression has probably begun to affect the fitness of the species, potentially contributing to the population's further decline.[23]

In 2014, estimates of the species' abundance dropped below 100 individuals.[4] An international vaquita recovery team concluded that the population is decreasing at a rate of 18.5% per year, and "the species will soon be extinct unless drastic steps are taken immediately."[5]Their report recommended that a ban on gillnet fishing be enforced throughout the range of the vaquita, that action be taken to eliminate the illegal fishery for the totoaba, and that with help from the U.S. and China, trade in totoaba swim bladders be halted.[4][5]

On 16 April 2015, Enrique Peña Nieto, President of Mexico, announced a program to conserve and protect the vaquita and the similar-sized totoaba, including a two-year ban on gillnet fishing in the area, patrols by the Mexican Navy and financial support to fishermen impacted by the plan.[24][25] However, some commentators believe the measures fall short of what is needed to ensure the species' survival.[26]

In early May 2016, the IUCN SSC – Cetacean Specialist Group reported that the vaquita population had dipped to around 60 remaining individuals. This represents a 92% decline from the 1997 population level. In March 2016 alone, at least three vaquitas drowned after being entangled in gillnets set for totoaba.[6] The report concluded that the gillnet ban would need to be extended indefinitely, with more effective enforcement, if the vaquita is to have any chance of long term survival. Otherwise, the species is likely to become extinct within 5 years.[6]