Context:

A five-year study in the Sundarbans region has found that rising water salinity is threatening the habitat of Gangetic dolphins.

Threat Analysis:

• The study highlighted that earlier in 1879; these freshwater-loving mammals swam along the entire length of Ganga and Brahmaputra and all of their tributaries. From the delta of the Bay of Bengal up to the Himalayan foothills.
• Today at the merging of Ganga, Brahmaputra, and Meghna which form the Sundarban region, these dolphins struggle to survive.
• India’s “Dolphin Man” RavindraSinhahas observed that water diversion, commissioning of large barrages upstream have impacted the salinity profile of rivers downstream in central Sundarbans.
• The declining flow of the Ganga is the biggest threat to Gangetic dolphins along with water-intensive agriculture in the basin.
• Bihar constitutes 50% of mammals in the country. India’s only protected area for Gangetic dolphins is at VikramshilaGangetic Dolphin Sanctuary in Bihar.
• Asia’s First National Dolphin Research Centre is coming up in Patna to give a boost to the research and conservation of dolphins.

Other Threats:

• Biological resource use: Fishing & harvesting aquatic resources,
• Natural system modifications: Dams & water management/use
• Pollution: Industrial & military effluents, Agricultural & forestry effluents.