The plot thickens with the non-appearance of the dolphins.
The Gangetic dolphin is almost completely blind. Evolving, as it has, in silty, murky environs for over 30 million years, it has all but lost its eyesight. Its eyes have no lenses and it can only sense the direction of diffused light. Sound is everything. It navigates, feeds, avoids danger, mates, breeds, nurses babies and lives by echolocation: dolphins send out sound waves that echo back, allowing them to sense where something is located.
What effects will the plan to make the Ganga a major waterway have on this endangered creature? How will dredgers and continuous navigation by large barges and tourist ships affect its population?
In March 2016, the government of India passed the National Waterways Act (NWA), which identifies 106 rivers that will be engineered into cargo-carrying waterways. The rationale is that shipping is “greener” than road traffic. But, says Kelkar, “There has unfortunately been barely any debate on the ecological and social risks the NWA poses to river biodiversity and to the communities that depend on the river.”
The importance of riverine ecology, and of the livelihoods it sustains, seems to be absent from the radar of not just administrative and political circles but also prominent environmental and scientific groups.
As per the plan, National Waterway 1 (NW1) will go from Haldia in West Bengal to Allahabad in UP along the Hooghly, Bhagirathi, and Ganga. It will involve the construction of more barrages along the river and heavy dredging of silt so that a width of 45m and a depth of 3m can be maintained throughout. This would enable passage for barges carrying 1,500-2,000 tonnes of cargo.
"Constructing more dams between Allahabad and Haldia will convert the Ganga into big ponds," Bihar's Chief Minister Nitish Kumar said last year. “It will adversely affect the river's ecosystem. We should allow uninterrupted flow of the Ganga waters.”
Kelkar, writing for the South Asia Network for Dams, Rivers & People, has analyzed the NWA and called out its implications. Now, as he and I sit by the Ganga watching the sun hemorrhage into the river, his observations come alive.
We see a dredger silhouetted against the fiery orange shimmer of the river. It scoops up sediment from the river bed and plumes it back into the main channel of the river. This is crucial to maintaining navigability of NW1, given the Ganga's heavy sediment load — it is also a potential death knell for aquatic species.
With Ganga being declared as National Waterway 1, dredging has become common in and around the Vikramshila sanctuary. This is causing changes in the river currents and endangering the lives of pilgrims and locals coming to the riverside for a dip.
Many species of fish live, feed and breed at the bottom of the river bed and under small rocks. Dredging disrupts and scoops out these breeding and feeding grounds, endangering the survival of the species, Kelkar explains.
As we travel along the river, a more sinister fallout of dredging comes to the fore. The plume that the dredger jets into the river's main channel settles further downstream and functions like a plug. This plug heightens the riverbed in the center and deepens it by the shores. Imagine a “W” shaped river bed with its elbows resting near the shores. The river, obstructed by these plugs and trying to find the path of least resistance, rushes into and over these deep channels, scouring off silt from under the concrete of the ghats.
This is where locals and pilgrims take a dip in the holy river. Thus far, no one had any reason to expect a sudden, deep drop off. But since December 2015, when dredging started to become regular in the reserve, there have been twenty deaths by drowning in Bhagalpur's Barari Ghat alone — people washed away because the ground beneath their feet was replaced by swift currents.
To state the obvious, dredging should not be happening in the sanctuary, much less during the vital fish-breeding season.
Ongoing research has predicted that Gangetic dolphins will become extinct from many rivers without adequate flow. Dredging and vessel engines can mask the dolphins' hearing of lower echolocation frequencies, which might severely limit their ability to find food and navigate. Also, the physical upheaval of river sediment caused by dredging seems to disturb river dolphins.
Writing about the negative impacts of heavy dredging on dolphins near Bhagalpur, Kelkar's team had this to say: “During intensive dredging operations, the surfacing frequency of river dolphins (breathing time between dives) reduced approximately 3 times as compared to a natural dive-rate of approx. 1.5-2.5 minutes during feeding peaks. In dolphins, this is a clear indication of stressful physiological and body conditions. Further, Ganges river dolphins are highly vocal in normal circumstances, but their acoustic activity was noted to be much lower than on an average non-dredging day. Further, river dolphin mortality due to boat propeller hits has been recorded on a couple of occasions from the same area. During the movement of tourist cruise ships, we observed that the impact of loud sounds produced by the engines lasted for over two minutes — in which river dolphin diving behaviour showed signs of suppression.”
Dredging, clearly, is not dolphin-friendly. Here's a statistic that heightens the worry over a distinct depression in sightings on our days in the sanctuary: over 90 percent of the endangered Gangetic dolphin population overlaps with the proposed National Waterways.
Even if the dolphins had to move, where would they go? The dredgers and barges would be everywhere.
(After I left, a short survey on this stretch of the river confirmed that the dolphin sightings in short stretches around Bhagalpur and Kahalgaon have fallen 66-75 percent. There have been whispers of dolphin deaths, which are still unconfirmed.)