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After 29 Million Years, A River Dolphin Faces Risky Future

Posted by Richard Conniff on October 2, 2015

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

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

My latest for Takepart:

If you recall the emotional impact of the 2009 movie “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, with a bit of public outrage and international pressure.

It’s infinitely harder to come to terms with the fate of an animal like the blind dolphin of the Indus River in Pakistan and India. Nobody stabs or beats them to death any more. Hunting ended by law in the early 1970s. But that is not the same thing as 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 2200 miles from the Arabian Sea to the foothills of the Himalayas.

Beginning in the early twentieth century, irrigation dams have repeatedly sub-divided the dolphin’s habitat, into a current total of 17 segments—10 of them now devoid of dolphins. According to a new study in the journal Biological Conservation, anywhere from 1200 to 1750 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 will join Mexico’s vaquita and China’s baiji, or Yangtze River dolphin, on the spiral down to extinction. But when I phoned lead author Gill Braulik, who spent years doing field work on the Indus for WWF-Pakistan, she remarked that this is also, from another perspective, an upbeat story: 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 animal for saving the ecosystem.

It is an ecosystem 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. Formerly abundant freshwater turtles have lately fallen victim to a booming Chinese traditional medicine trade. The gharials, another crocodilian, 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 of course the booming human population. Pakistan is home to 188 million people today, but on track to top 307 million by mid-century. 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 down stream 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. Upstream cities 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 nineteen hydropower dams on the river or its tributaries over the next ten years, and India has other such projects in the works upstream. Trying to stop those dams is not realistic and might prove counter-productive, 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.” Everyone also lives with an electrical system that routinely goes off for two or three hours at a time. “So that’s a big issue, especially when the temperature hits 45 degrees (113 degrees Fahrenheit) and there are no fans. It drives people completely mad, and makes them very angry.”

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, fishermen actually 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 Braulik and her co-authors. 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 Sindh Wildlife Department already rescue them from otherwise certain death. Translocation 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 second 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 like 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. Given the geopolitical mess in the region, it’s hard to recommend actually going to the Indus River to do the work of dolphin rescue firsthand. But that’s what came to mind for co-author Randall Reeves: “Young people willing to go to 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 will almost certainly come to an end in this century.

2 Responses to “After 29 Million Years, A River Dolphin Faces Risky Future”

  1. […] Sourced through Scoop.it from: strangebehaviors.wordpress.com […]

  2. […] “Beginning in the early twentieth century, irrigation dams have repeatedly sub-divided the dolphin’s habitat, into a current total of 17 segments—10 of them now devoid of dolphins. According to a new study in the journal Biological Conservation, anywhere from 1200 to 1750 individuals survive—with 70 percent of them confined to a single 118-mile stretch of river.”  strangebehaviors.wordpress.com […]

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