Will the world’s smallest and rarest porpoise still swim the waters of the Gulf of California two years from now?

That’s the question for the vaquita, arguably the world’s most endangered marine mammal, which experts say has an extremely narrow window in which to avoid extinction.

The tiny Mexican porpoises—which reach less than five feet in length—were probably never extremely common, but their population has crashed over the past five years. Acoustical surveys conducted in 2014 and 2015 revealed that there are probably fewer than 100 vaquitas left.

“We lost 70 to 80 percent of the vaquitas in the past five years,” Barbara Taylor, leader of the marine mammal genetics group at the National Marine Fisheries Service, said recently at the Conference on the Biology of Marine Mammals in San Francisco, where vaquitas were one of the major topics of conversation. “It was a spectacular, shocking loss.”

Taylor said conservationists had begun to be hopeful about vaquitas after several years of efforts to protect them from nearby fisheries, which had traditionally used gill nets to catch shrimp and fish in the same waters in which the vaquitas swim. Hundreds of vaquitas have died in gill nets over the past few decades, and in 2013 the Mexican government announced a three-year plan to phase out the use of those nets and protect the porpoises.

Then a new threat emerged. Beginning around 2012, some fishers had started illegally targeting another critically endangered species called the totoaba. Air bladders from these six-and-a-half-foot-long fish are valued in traditional Chinese medicine and sell for upwards of $3,800 a pound.

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Biologists blame totoaba gillnet fishing, which has been banned since 1993, for driving the rapid decline in vaquita populations. Lorenzo Rojas-Bracho, the research scientist who leads the international vaquita recovery team, said the fish bladders aren’t even necessarily being sold as medicine right away. He reported that some people in China are buying totoaba as investments, banking on higher prices as the species becomes even rarer.

As with most wildlife crime, punishments for illegal totoaba fishing are almost nonexistent. Rojas-Bracho reported that anyone caught with totoaba might face a $500 fine and no jail time—no disincentive when fish bladders command sky-high prices.

That could change. Rojas-Bracho said the Mexican Congress has recently voted on legislation, not yet enacted as law, that would make totoaba fishing and smuggling a crime with punishments equivalent to that of cocaine trafficking.

“The timing of this new law couldn’t be better,” Taylor said, as totoaba have just begun their annual breeding season. “They come up into the shallow waters where the Colorado River used to come out into the Gulf of Mexico,” she said. “That’s where they spawn. Totoaba are just showing up, and they’ll be there for the next three months.” Getting the law on the books in time to stop or limit poaching in that area would be vital not just for totoaba but any vaquita swimming nearby.

Meanwhile, efforts continue to find new, safer technologies to allow the fishing industry to continue in the Gulf without harming more vaquitas. The Mexican government passed a temporary ban on gill nets in May, but that expires in just 18 months. That may not be enough time. Rojas-Bracho said a permanent gill net ban must be enacted, and that funding is necessary to develop more alternative fishing techniques, such as the small-scale trawling net that has already been approved for catching shrimp. “We have a good solution for shrimp, but not for fish,” he said. Another trawl for fish is being tested.

Taylor, meanwhile, pointed out just how badly the recent resurgence in totoaba fishing has affected vaquitas. They take about six years to reach reproductive age, and research indicates they only give birth every two years, compared to annually for other porpoise species. “It would take 40 years for us to regain what we’ve lost in the past five years,” she said.

Reporting for this story was made possible by a fellowship from, funded by the Packard Foundation.