Only 60 Vaquita Porpoises Are Left on Earth

International body calls on the U.S. Mexico and China to take stronger action.

<p>Paula Olson/NOAA</p>

Members of a major international treaty have called on the United States, Mexico and China to work harder to end the trade in a species of fish called the totoaba -- because the fishery is driving a species of porpoise toward imminent extinction.

Measuring about 5 feet from its snub nose to the top of its tail, the porpoise -- called the vaquita (Spanish for "little cow") -- is limited in range to the upper Gulf of California. Listed as Critically Endangered on the IUCN Red List, it's now, following the extinction of the baiji or Yangtze River dolphin in 2006, the most endangered marine mammal in the world. In 1997, an international team of scientists estimated that just 567 vaquitas remained; 15 years later, that figured had dropped to 200. In 2014, the number was estimated at just half that, with fewer than 25 reproductively mature females. In May of this year, the number dropped still further, with just 60 now estimated to be alive.

The reason is the totoaba, a large species of fish that is also endemic to the Gulf of California and which is itself critically endangered. Totoabas were heavily fished in the 1940s, but overfishing and habitat change caused an estimated 95 percent decline in their numbers. The decline of vaquitas began when the totoaba fishery was at its peak, as they drowned in nets set to catch the fish. The much-diminished porpoise population continues to be affected, because even as totoaba numbers declined, their value increased.

The reason for the ongoing interest in catching the totoaba is its swim bladder, which can fetch up to $20,000 in China, where it is valued both as a delicacy and for alleged medicinal properties. The fish are caught in Mexico, generally trucked to American ports and then transported to Asia.

RELATED: Mexico Uses Drones to Protect Vaquita Porpoise

Mexican President Enrique Pena Nieto imposed a two-year ban on gillnets in April 2015, established a 5,000--square-mile vaquita protection area, deployed a navy patrol ship and agreed to compensate fishermen for foregoing the use of gillnets. Two months ago, the government launched three drones to scour the area day and night. Yet still the fishery continues: navy sailors told AFP earlier this year that they continued to find gillnets every day, and the Mexican environment ministry said that 600 nets had been seized during the past year.

A team of scientists did manage to spot a number of the elusive porpoises in 2015 -- perhaps as many as 25. They may prove to be among the last to do so: it has been estimated that, at present rates of decline, the vaquita will become extinct by 2018.

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