For half a decade now, biologists have been predicting and fearing the extinction of the critically endangered vaquita (Phocoena sinus)—the smallest of the world’s seven porpoise species. The vaquita lives in the northern upper end of the Gulf of Mexico between Baja California and the Mexican mainland. In August 2023, the International Whaling Commission, in a first-of-its-kind declaration in its 70-year history, issued an “extinction alert” for the vaquita. What occasioned this alert was a new report that estimated only 8–13 individuals of the species remaining in their natural habitat. Moreover, breeding in captivity has so far not succeeded.
While this population estimate underscores the dire situation the species is in, it nevertheless gives hope for the vaquita’s survival. In 1997, the population comprised around 570 individuals. In 2018, it was estimated that fewer than 20 individuals remained, with an annual rate of decline close to 50 percent. Two years later, the estimated population size was down to eight individuals, though healthy calves were sighted. The current estimate also includes the healthy calves. Moreover, a recent analysis suggests that, despite its small size, the population is not prone to inbreeding depression—which is caused by a lack of genetic variation in the population, and which can lead to reduced survivability and fertility of the offspring.
Thus, given the tenacity of this species at the brink of extinction, it is imperative to redouble our conservation efforts. Unfortunately, policy formulation, let alone implementation, is far from straightforward, requiring consideration not only within the Mexican context but also globally, particularly in relation to the medicinal beliefs and food preferences among the wealthier classes of China.
The vaquita is close to extinction because of gillnet fishing of another critically endangered species; the fish totoaba (Totoaba macdonaldi), which shares its marine habitat. Between November and May each year huge gillnets—each sometimes over 600 metres long—are dropped into the water to trap the totoaba. The vaquita and many other marine mammals, including whales and dolphins, probably as many as 300,000 of them, are also trapped in these nets as bycatch each year, only to be later discarded. Totoaba fishing has been illegal in Mexico since 1975 and gillnets have been banned since 1998.
In 2017, the Mexican government enacted a small “No Tolerance Zone” that excluded all fishing activities in part of the upper Gulf of Mexico to create a refuge that comprises the most important habitat for the species. However, in order to appease local fishermen whose livelihoods were supposedly threatened, the government of President López Obrador rescinded the policy in 2021. Meanwhile, conservation NGOs, most notably the Sea Shepherd Conservation Society, have had violent encounters with these fishermen and those behind them.
Beginning in the 1920s, the totoaba was originally fished for its meat. However, that market was soon superseded by the Chinese appetite for its swim bladders, which are considered as status symbols and consumed in multiple ways. The bladders are believed to have medicinal value, including increasing longevity and vigour, despite a lack of credible scientific evidence. Highly prized, these swim bladders can fetch up to US$ 80,000 per kilogram in China.
Local conservationists in Baja California do not blame the fishermen who carry out the illegal gillnet fishing, but rather the organised cartels originating in China, that control the lucrative trade. Gillnets are expensive equipment and fishing with them is also an expensive enterprise; without funding from these cartels, local fishermen cannot afford to engage in this activity. Obtaining gillnets from the cartels engenders debt that the fishermen are then forced to pay off by extracting totoaba swim bladders. For the vaquita—and the totoaba—to survive, this dynamic must be disrupted.
Three recent developments provide some guarded reasons for optimism. The first and most controversial of them is the permission granted in 2022 by the Standing Committee of the Convention on International Trade in Endangered Species (CITES) to Earth Ocean Farms, a Baja-based aquaculture company to legally trade in captive-bred totoaba. The hope is that the captive harvest will drive down prices and decrease the incentive for illegal fishing. Meanwhile, recently developed technology will make the products traceable and allow for accurate monitoring of the legal trade. However, critics maintain that this technology is far from perfect. The legal trade may as well spawn an even larger market in China and increase the scope of illegal fishing.
Second, there is some indication that the Mexican authorities are finally cracking down on illegal gillnet fishing in the upper Gulf. In 2018, several Chinese nationals involved in the illegal totoaba trade were arrested in Mexico. Since 2020, using information collected by NGOs such as Earth League International, authorities have also arrested several Mexican cartel members. Many, if not most, of the biggest totoaba traffickers are now in jail. Despite the decision to allow fishing again in the former No Tolerance Zone, Mexican authorities, in August 2022, deployed 193 concrete blocks with three-metre metal hooks to entangle gillnets in the upper Gulf. If these efforts continue, there is hope that the reign of the illegal totoaba cartels will be over and both the vaquita and the totoaba can avoid extinction in the immediate future.
Third, there has also been some cooperation from Chinese authorities. In December 2018, Chinese customs authorities confiscated 444 kilograms of totoaba swim bladders illegally smuggled from Mexico and worth an estimated US$ 26 million. The illegal totoaba market in Mexico immediately collapsed. Though the market subsequently recovered, continued cooperation from China along with the other two measures may well save the vaquita from extinction. Or so we hope.
Further Reading:
Robinson, J. A., Kyriazis, C. C., Nigenda-Morales, S. F., Beichman, A. C., Rojas-Bracho, L., Robertson, K. M., Fontaine et al. 2022. The critically endangered vaquita is not doomed to extinction by inbreeding depression. Science 376: 635–639.
Rojas-Bracho, L., B. Taylor, C. Booth, L. Thomas, A. Jaramillo-Legorreta, E. Nieto-García, G. C. Hinojosa et al. 2022. More vaquita porpoises survive than expected. Endangered species research 48: 225–234.
Taylor, B. and L. Rojas-Bracho. 2023. Vaquitas continue to surprise the world with their tenacity. IUCN–SSC Cetacean Specialist Group. https://iucn-csg.org/vaquitas-continue-to-surprise-the-world-with-their-tenacity/. Accessed on 9 September, 2023.
