Science & Environment

Fight to save endangered Indian dolphin

River dolphin Sanjay Das
Image caption The dolphins grow to about 2.5m in length

The Ganges River Dolphin is one of the world's most endangered freshwater mammals.

Its numbers in South Asia have plummeted in recent decades. But Indian conservationists working on the Brahmaputra River hope to reverse the dolphin's decline by mobilising riverside communities to protect these amazing cetaceans.

"We named one dolphin Rosie. I think Rosie is arriving here," said conservationist biologist Abdul Wakid, pointing to rippled brown water where Rosie had just surfaced, "She's really big."

You have to be quick to see a Ganges River Dolphin. The sliver of back and tiny dorsal fin slipped beneath the surface within a second. At about 2.5m, Rosie is about as long as this species of freshwater dolphin grows.

Despite her name, she's black in colour - distinct from the Pink River Dolphin of the Amazon River system.

There used to be a blue-grey freshwater cetacean in China not so long ago - the Yangtze River Dolphin or Baiji.

The International Union for the Conservation of Nature (IUCN) declared that species to be functionally extinct in 2007. Decades of hunting, harmful fishing practices, increasing boat traffic, pollution and dam building pushed the Baji to evolutionary oblivion.

In Assam in northeast India, Abdul Wakid and his team at the conservation organisation Aaranyak are working to try to prevent the same fate for Ganges River Dolphin in the Brahmaputra river system. The threats to the Ganges River Dolphin are identical.

Wakid had brought me to a dolphin hot spot - a stretch of a Brahmaputra tributary near the village of Kukurmara where herons called from within the lush bankside foliage and kingfishers shot across the brown muddy water.

Image caption The crew undertook educational "dolphin dramas" in waterside villages

And there were dolphins. Several adults surfaced repeatedly as they foraged for fish, a couple of oar's length from our boat. Further downstream, two juveniles leapt half clear of the water - a split second chance to see the narrow, elongated snouts that are characteristic of river dolphin species.

This glorious spectacle can be enjoyed at fewer and fewer spots in the river dolphin's range of Brahmaputra and Ganges river systems. Biologists estimate that the total population in both river ecosystems in India, Nepal and Bangladesh is about 2,000.

The majority are in the Ganges system, where, according to Abdul Wakid, the extinction threats are at their most intense.

However, the Brahmaputra is not a safe haven. In 2008 Abdul Wakid undertook a comprehensive count of river dolphin in the mainstream of the Brahmaputra in Assam and additional surveys in the two tributaries still inhabited by the dolphins. The tally came to a disappointing 300.

For the Discovery programme, broadcast on the BBC World Service, he told me: "We surveyed a 1,050 kilometre stretch of the river. It's the mighty Brahmaputra. It can be 18 kilometres wide in places. In that big river system, 300 is nothing.

"We had many dolphins two or three decades ago. When we talk to the older people in the riverside villages, they say there were many, many dolphins in the past."

Plan of action

New figures on the river dolphin population in this region will be published soon. In February, Wakid and his colleagues at Aaranyak spent the entire month, chugging slowly down the Assamese stretch of the Brahmaputra to India's border with Bangladesh, systematically counting as many dolphins as they could spot along the way.

As well as logging all dolphin sightings, the crew took water pollution measurements and documented dolphin-unfriendly human activities such as certain fishing practices, river sand mining and bank-side construction projects as the boat moved downstream.

It is this systematic mapping of dolphin numbers to ecosystem degradation which helped to bring the Zoological Society of London (ZSL) on board the project. The findings, said ZSL's Lucy Boddam-Whetham, will be presented to state and national governments in the form of a river-wide plan of action.

Image caption The mosquito netting used to fish has such narrow mesh nothing can escape it

"The Brahmaputra river system is huge and we might find that population numbers might be stable or increasing in one area, but decreasing in others," she said.

"We need to say why is that a decrease or why is that an increase. The ultimate goal of this project is to develop a conservation action plan that can be implemented by government to protect not only the river dolphin but also to sustainably manage the fisheries and other natural resources here in the Brahmaputra."

The project's argument is that recreating a Brahmaputra with a thriving population of river dolphins is a de facto means of rebuilding a clean and healthy ecosystem - with enough fish for all.

We saw one distinctly unsustainable fishing practice in action from Aaranyak's dedicated dolphin survey vessel in the river's mainstream. This is the use of great swathes of blue mosquito netting to catch fish. The mesh size is so narrow; nothing escapes this kind of fishing gear.

"It's so small that it can even catch fish eggs, fry and fingerlings. So they catch everything," said Abdul Wakid.

Angry reaction

All generations of fish are scooped out in these nets. The practice profoundly erodes the amount of food available to the dolphins. And not just the fish stocks for the cetaceans, said Wakid: "It's a very concerning matter for all of us. They (the fishermen) are actually depleting resources for themselves."

The practise of mosquito net fishing spread into Assam from neighbouring Bangladesh. Each year, Aaranyak finds that it has spread ever further upstream as more Assamese fishermen adopt it. The authorities have banned this fishing gear although we watched two groups of fishermen deploying their unmistakable blue nets in the river on the outskirts of Guwahati.

Image caption Sand mining represents another threat to the dolphin's habitat

Another common fishing technique kills dolphins directly. These are gill nets, which are made of filaments so fine that dolphins can't detect them. Ganges River Dolphins have only vestigial eyes and are effectively blind.

They primarily sense the world with echolocation. They fail to notice the gill nets and become entangled. Adults are usually powerful enough to escape. The new generation, the calves, however remain trapped and they drown. The gill net is the single greatest killer of dolphins in the river.

Ganges river dolphins are also deliberately hunted, despite being a protected species under Indian law. The poachers extract oil from the dolphin's body as the flesh starts to rot, and use it in a special kind of fishing bait.

The pungent oil has the dual function of binding scraps of poultry and fish waste into a solid lump of bait and being particularly attractive to a large species of catfish. The fish commands a good price at the markets.

The dolphin oil bait is localised to a handful of communities in the Lower Brahmaputra. Aaranyak is trying to persuade them to halt the practice.

The group's researcher Chandan Ri has worked in the villages, studying the tradition and talking to its 100 or so practitioners about its illegality and impact on the dolphin population. Chandan sometimes receives an angry reaction.

"There were a couple of incidents when fisherman came and told me: I need to support my family so what do I do?"

But Chandan Ri told me that the usual response to his questioning is more positive. "People are welcoming. They confessed that they had done this (dolphin hunting) in the past and say they don't want to carry on doing it in the future."

Local hands

Aaranyak regards community engagement and involvement as an essential component of its conservation approach. As well as conducting the dolphin count this year, the survey boat and crew undertook a dolphin "yatra", travelling 900km of the river to stage "dolphin dramas" and other educational events in waterside villages.

In recent years, the organisation has also encouraged the establishment of a network of many community-based dolphin conservation groups throughout the river system. Local villagers, who include fishermen, regularly survey local dolphin numbers and deaths for Aaranyak.

They also educate their neighbours about the dolphins, their part in the ecosystem and about practises which are good and bad for the dolphins' survival.

Aaranyak also works with these communities to explore ways of making a living from the river other than fishing. This includes river dolphin ecotourism.

Image caption Aaranyak has a dedicated survey vessel at its disposal

According to Lucy Bodman-Whetham of ZSL: "The one very nice and unique thing about this project is that with the dolphin conservation network, which is community-based, we are putting the responsibility in the hands of the local communities in many different areas of the Brahmaputra river.

"I think that's a really key thing to make sure they are feeling empowered and responsible for the dolphin rather than us just trying to enforce it on them. I think that's what's make the difference here."

Some dangers to the dolphin lie out of the hands of riverside communities. Large river construction projects such as hydroelectric dams are planned for sections of the Brahmaputra.

They threaten to reduce river levels and fragment the dolphin populations, making local extinctions more likely. So the conservationists also have to persuade state and national government, as well as villagers.

Aaranyak's aim is to get everyone on board with the idea that restoring a healthy population of river dolphins in the Brahmaputra through sustainable practices and development would have the effect of creating a more productive river system for people as well as animals.

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