A River Dolphin's Ear-View Of India's Waterways Development Plans

A river dolphin took a tired lunge before diving into the Hooghly river next to a noisy, mammoth, crowded vessel ferrying passengers on National Waterway No. 1 (NW-1) in Kolkata. Its tail stood up stiff, flicking wildly, straight out of the water before it dived down headfirst. Such a dive indicates acute distress in dolphins. It heaved, surfacing after seven minutes, a longer interval than normal. How could we know what had happened?

- Nachiket Kelkar

The dolphin is a difficult cetacean to study; in the murky waters it inhabits, it is impossible to see the animal underwater. Just a few glimpses of surface activity are usually visible. Although it has evolved to be effectively blind in the sediment-laden Indus-Ganga- Brahmaputra river systems, it can ‘see’ using high frequency echolocation clicks. Two bony crests in front of the skull help focus the click trains it emits from its larynx. The dolphin clicks and listens all the time. The river dolphin’s ‘ear-view’ refers to understanding the potential impacts of waterways on river biodiversity from a sensory perspective, keeping an ear to the water.

SYSTEMATIC DEGRADATION

To begin finding answers, we must zoom out and travel upstream to the Farakka Barrage. Completed in 1975, this barrage was meant to halt and divert the waters of the Ganga (flowing into Bangladesh) through a feeder canal and navigation lock to flush out accumulated silt that was threatening the viability of the Kolkata port. The Farakka feeder canal was a key link of NW-1 on the Ganga, designated in 1982. The NW-1 runs for 1,620 km. from Allahabad in Uttar Pradesh to the Haldia port downstream of Kolkata. Of course, the Farakka Barrage failed to meet its objective, with the Kolkata port’s condition not improving and sediment dredging costs continuing to accumulate. The current state of Farakka’s navigation lock reveals that no lessons were learnt (See Box 1: India’s National Waterways Act of 2016).