Desert Diaries

A Tale of Two Fishes with a Porpoise (and Purpose)

Net Loss by Rachel Ivanyi

Many people feel a special affinity for marine mammals. If you’re like me, you once dreamed of being a marine biologist and working with dolphins or whales. (This seems to be especially true for girls.)  The interplay of otherness and familiarity between humans and cetaceans engages the heart and the mind. It is therefore especially sad to witness one of these animals so close to extinction in our own backyard.

Only four to five feet long, the vaquita is the world’s smallest porpoise. Its entire population lives in a 1500 square-mile area east of San Felipe, Baja California, in the northern Gulf of California. It is estimated that there are fewer than 30 vaquita left.

Vaquitas usually occur individually or in small groups, often just a mother and her calves. They don’t splash or jump, and they steer clear of boats, making them difficult to observe. However, they haven’t been able to evade gillnets set for fish and shrimp, and great numbers of them have drowned entangled in these nets.

The first official survey in 1997 put the vaquita population at 567, a number that probably already reflected declines due to their deaths in gillnets. Estimating numbers of this notoriously elusive porpoise relies on observations from boats and under-water acoustic recording devices.  In 2005, the Mexican government set aside a Vaquita Refuge, but illegal gillnet fishing continued and by 2008, vaquita numbers were about 245. The most intensive survey ever was completed two years ago, producing a population estimate of less than 60. Two years later, we have lost more than half of these individuals.

CIRVA/NOAA Fisheries, Southwest Fisheries Science Center

Illegal fishing for another rare fish—the totoaba—is the main cause of the recent decline in the vaquita population. Totoaba (Totoaba macdonaldi) are large fish, up to 6 feet long and 200 pounds. Severe overfishing led to the listing of the totoaba as an endangered species in 1975. Although totoaba populations initially were on the rise, illegal fishing has intensified as new economic incentives have emerged. Totoaba swim bladders are now worth up to $5,000 per kilogram and can command as much as $100,000 on the black market in China where they are used in medicinal soups and even stockpiled as speculative investments.

How did the Chinese develop an appetite for a fish endemic to a small patch of sea half-way around the world? Totoaba were introduced to the Chinese market after the decimation of the other fish in our tale, the bahaba, whose swim bladder formerly filled this market niche. In Hong Kong, the bahaba was noted as “commercially extinct” in 1997.

Announced in April 2015, Mexico’s “Program on the Comprehensive Care of the Upper Gulf,” is designed to save both vaquita and totoaba while providing sustainable solutions for local communities. The plan includes expansion of the refuge, a strict ban on gillnet and longline fishing for two years, financial compensation to fishers (including investment in alternative gear), community-based surveillance, and other efforts to combat the illegal totoaba trade. However, illegal fishing for totoaba and associated deaths of vaquita have continued. Conservationists continue to push for a permanent ban on gillnets and increased enforcement, as rebuilding the vaquita population will take decades.

The Mexican Navy continues to arrest poachers setting both shrimp and totoaba nets in the refuge area. In addition to increased enforcement, the Mexican government and Mexican and international NGO’s are collaborating on testing of “vaquita-safe” fishing gear and the development of alternative income sources for coastal communities.

Most recently Mexico is coordinating a plan to capture, enclose and try to breed vaquita in a netted area in their native waters in order to save the species. It is a controversial proposition, as it has never been done before for this species, and it risks killing or injuring some of the few remaining animals. However the alternative is guaranteed extinction.

The purpose of this tale is to raise awareness of the global social, economic, and ecological web in which this small porpoise is entangled. Other coastal cetaceans around the world face similar pressures. So what can we do?

Can the vaquita be saved? Will it come back from the brink like some other marine mammals in our region, including grey whales and elephant seals? Or will it follow the Yangtze River dolphin, the first cetacean to become extinct due to human activity? Around the world, thousands of dolphins and porpoises drown in gillnets every year. With public support, and international cooperation on sustainable fisheries, Mexico could become the first country to solve this problem.

Written by Debra Colodner, ASDM Director of Conservation, Education, and Science.