Wildlife & Biodiversity

Killing the Ganges river dolphin, slowly

The impact of the Jal Marg Vikas Project on Ganges River dolphins, in both the Ganga and Brahmaputra, could be catastrophic

 
By Ravindra Kumar Sinha
Last Updated: Friday 31 August 2018
Ganges Dolphin
A Ganges River Dolphin        Credit: Ravindra Kumar Sinha A Ganges River Dolphin Credit: Ravindra Kumar Sinha

Waterways are the best and cheapest mode of transport. Considering this, the Union government enacted the National Waterways Act, 2016, under which 111 inland waterways have been declared as National Waterways (NWs), in addition to the five existing NWs, across 24 states, for utilising them as an environment-friendly and sustainable mode of transport. Out of the 116 inland waterways, 38 are or were the habitat of the river dolphin.

The Jal Marg Vikas Project has been commissioned for capacity augmentation of NW–1 (theGanga river) from Haldia (West Bengal) to Varanasi (Uttar Pradesh), with an objective to facilitate the movement of 1,500–2,000 tonne vessels. The project has been undertaken with the technical and financial support of the World Bank at an estimated cost of Rs. 4,200 crore. It is scheduled to be completed in six years.  Under this project, various sub projects include fairway development, construction of multi-modal terminals at Varanasi, Sahibganj (Jharkhand) and Haldia and a new navigation lock at Farakka (West Bengal).

Similarly, the National Waterway- 2 is in the Sadiya-Dhubri stretch of the Brahmaputra river in Assam. It extends from the confluence of the Kumdil and Brahmaputra rivers near Sadiya to the beginning of the river island Majuli and from there, through all the channels of the Brahmaputra on either side of Majuli, up to the island’s end and then up to the international border downstream of Dhubri.

To enable the passage of barges carrying 1,500-2,000 tonnes of cargo, the river stretch should have a width of 45 metres and a depth of 3 metres, for which large-scale dredging and construction of barrages, lock gates and ports will be required for large transport vessels to transit from Haldia to Allahabad in the Ganga and Dhubri to Sadiya in the Brahmaputra. There is strong reason for concern that the environmental impacts could be catastrophic for river dolphins and other aquatic biodiversityas well as fisheries vital to the food security of the country. Dolphin habitats are likely to be destroyed and wiped out in these stretches of the rivers. If there is no habitat, there will be no dolphins left to save.

India’s rivers support high levels of biodiversity, including globally endangered species such as the country’s National Aquatic Animal, the Ganges river dolphin, the fish-eating crocodile—the Gharial, and numerous freshwater turtles, fishes, and birds. These species are already threatened by population reductions, and by alterations and river flow regulation, besides, degrading river water quality due to pollution. In many areas, their populations have been locally extirpated or persist only in very small numbers. Waterway development in 1,620 kms of the Ganga Basin and 891 km of the Brahmaputra Basin would degrade the habitat and further fragment the populations of Ganges River dolphins.  It is a matter of deep concern that the proposed scale of waterway development has the potential to cause the extinction of several endangered species, including the Ganges river dolphin.

A few critical aspects to be considered here:

  • Lack of water—Existing demand for fresh water in India has caused many rivers to dry up completely or be left with very little flow during the dry season. The declining river flow is already a severe problem for river dolphins, freshwater fisheries and biodiversity and further waterway development will aggravate existing threats to fish and endangered riverine species more generally.
  • Capital dredging—Capital dredging will be required for deepening, widening and straightening waterways. This practice reduces the hydro-geomorphological complexity and variability of the river habitat which supports productive fisheries and the prey of Ganges river dolphins and Gharials. Dredging also destroys benthic (river bed) flora, fauna and their habitats full of organic detritus. Many river fauna including some fishes are detritivores feeding on detritus. These biota serve as food for fishes and other vertebrates including dolphin. Additional problems for riverine wildlife caused by capital dredging are high levels of noise which adversely affects the blind Ganges dolphins whose vital activities depend on echolocation.
  • Barrages—they create a physical barrier and divide dolphin population in several mega-populations making the population vulnerable.
  • Vessel Traffic—Endangered riverine wildlife, including Ganges river dolphins, will be at increased risk of being struck by vessels and of being displaced from critical habitat by vessel-induced disturbance.
  • Pollution—Fuel leaks and oil spills appear unavoidable on account of the planned traffic load. Plans to transport 300 million tonnes of coal to power plants in states per year (by 2020) through the waterways are a major concern due to pollution from coal dust.

Certainly, the picture looks extremely grim for the Ganges river dolphin.

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