Rare Blind Dolphins Have a Reason to Hope

The endangered freshwater dolphins of the Indus River have lost 80 percent of their natural habitat, but a solution as simple as water conservation could be the key to their future.

A blind dolphin swims along the Indus River in the southern Pakistani city of Sukkur. (Photo: Rizwan Tabassum/AFP/Getty Images)

Oct 2, 2015· 4 MIN READ
Richard Conniff is the author of House of Lost Worlds: Dinosaurs, Dynasties, and the Story of Life on Earth and other books.

If you recall the emotional impact of the 2009 documentary The Cove, you know how horrible it is to witness the spectacle of hunters trapping and slaughtering dolphins. But it was also gratifying to our feelings of outrage, because it seemed like something we could fix, through public exposure and international pressure.

It’s infinitely harder to come to terms with the fate of animals like the blind dolphins of the Indus River in Pakistan and India. Nobody stabs or beats them to death anymore. Hunting ended by law in the early 1970s. But that is not exactly saving the subspecies. Instead, the Indus River dolphins are on the Red List of endangered species. They have lost 80 percent of their old home range, which once extended almost 2,200 miles from the Arabian Sea to the foothills of the Himalayas.

Starting in the early 20th century, construction of irrigation dams began subdividing the dolphins’ habitat into a current total of 17 segments. Ten of them are now devoid of dolphins. According to a new study in the journal Biological Conservation, 1,200 to 1,750 individuals survive—with 70 percent of them confined to a single 118-mile stretch of river.

That raises the disheartening prospect that the river dolphin could join Mexico’s vaquita and China’s baiji, or Yangtze River dolphin, on the spiral down to extinction.

I phoned lead author Gill Braulik, who spent years doing fieldwork on the Indus for WWF-Pakistan. She looks at the dolphin’s plight from a different perspective—an upbeat one: The dolphins are still there, they have proved resilient in the face of appalling change, and if the world decided to take action on their behalf, they could survive indefinitely. There is hope.

These river dolphins belong to a group of freshwater dolphins that emerged about 29 million years ago, tens of millions of years before marine dolphins. They grow to about seven feet in length, live perhaps 35 years, and hunt by highly sophisticated echolocation (their eyes are rudimentary pinholes, because vision would be a useless extravagance in the heavily silted waters of the Indus). Their long, toothy snout ends in the characteristic upturned “smile” of other dolphin species. By rights, they should be the charismatic poster species for saving the ecosystem.

Their ecosystem is in dire need of saving: The dams have already destroyed a shad migration that once supported a major local fishery. Hunting has largely eliminated mugger crocodiles, as well as two species of otter. Once abundant freshwater turtles have fallen victim to a booming Chinese traditional medicine trade. The gharials, another crocodile species, are gone from the Indus, along with most of the large riverside animals—tigers, leopards, cheetahs, and Indian rhinos. That makes the river dolphin not just the top predator but the sole remaining large aquatic species in the entire Indus River system, and one of only five freshwater dolphins in the world.

The problem for the river is the booming human population. Pakistan is home to 188 million people and is on track to top 307 million by midcentury. They depend on the Indus River for the overwhelming majority of their drinking water, as well as for food, the economy, and intermittent electric power. The dams back up the river water and divert it into a complicated system of irrigation canals to support the cultivation of wheat, sugar cane, and cotton on the Indus plains. Parts of the river system downstream run dry for much of the year.

The farms being fed by this irrigation rely increasingly on pesticides, which quickly find their way into the river. Cities upstream also dump 90 percent of their municipal and industrial wastewater into the river without treatment. The dolphins are thus “exposed to some of the highest levels of pollution of all cetaceans,” according to the new study, and their tissue is loaded with heavy metals, DDT, PCBs, and other toxic substances.

In addition to the agricultural dams, Pakistan now has plans to install 19 hydropower dams on the river or its tributaries over the next 10 years, and India has other such projects in the works upstream. Trying to stop those dams is not realistic and might prove counterproductive, according to Braulik.

“Water is so enormously political and emotional in Pakistan because it’s so limited,” she said. “Everybody knows about the river; that’s where the water for the country comes from. You talk to shopkeepers in the bazaar, and they know about withdrawals.”

So where’s the hope for the Indus River blind dolphin?

First, there are people in Pakistan who care passionately about dolphin conservation. In 1974, Pakistan designated an Indus Dolphin Reserve upstream of the city of Sukkur, and volunteers there regularly take schoolchildren out onto the river to see the dolphins. The reserve’s dolphin population has steadily increased, despite the lack of regulations on fishing or other threats. (In a 2011 case, fishers dumped insecticides directly into the river to increase their catch, accidentally killing six dolphins in the reserve.)

The strength of the population in some areas of the river opens up the possibility of translocations, according to Braulik and her coauthors. It wouldn’t require taking dolphins out of the fast-flowing river, which would be hazardous for dolphins and conservationists alike. But river dolphins sometimes get trapped in irrigation canals, and WWF-Pakistan and the Sindh Wildlife Department already rescue them from otherwise certain death. Translocating those dolphins to river segments that now have as few as 10 individuals could keep those populations going and prevent inbreeding.

But the bigger change would require substantial investment—first for the complicated research to find out what kind of flow the dolphins need to survive, and then to introduce the concept of water conservation. Pakistan now focuses all its efforts on taking more water from the river and the aquifer and almost nothing on conserving what it already takes. But researchers have been pointing out since the 1980s that 40 percent of the water being taken from the Indus now goes to waste. Improvements such as properly lining irrigation canals could save an estimated 14.8 billion cubic meters of water—and dolphin habitat—a year.

What can individuals do? Donating to WWF-Pakistan is one way to help. Another hands-on approach is to travel to the Indus River and do the work of dolphin rescue firsthand.

That’s what came to mind for study coauthor Randall Reeves: “Young people willing to go to a really risky place on behalf of wildlife, people who have a commitment, a desire, a willingness, and a dedication” can join those already working in Pakistan and make a difference, “not just for dolphins but for wildlife generally. It can be done.”

Without that kind of commitment, the 29-million-year history of the Indus River blind dolphin might come to a conclusion this century.