Q. Other than poaching, what are the possible reasons for the decline in the population of Ganges River Dolphins?

  1. Construction of dams and barrages on rivers
  2. Increase in the population of crocodiles in rivers
  3. Getting trapped in fishing nets accidentally
  4. U se of synthetic fertilizers and other agricultural chemicals in crop-fields in the vicinity of rivers

Select the correct answer using the code given below.

  • 1 and 2 only
  • 2 and 3 only
  • 1, 3 and 4 only
  • 1, 2, 3 and 4

Answer: (c) 1, 3 and 4 only

Ganges River Dolphins
  • Scientific Name: Platanista gangetica
  • The Ganges River Dolphin was officially discovered in 1801.
  • Ganges river dolphins live in the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh.
    • The Ganges river dolphin can only live in freshwater and is essentially blind.
    • They hunt by emitting ultrasonic sounds, which bounces off of fish and other prey, enabling them to “see” an image in their mind. They are also called ‘susu’.
  • Population of Gangetic river Dolphin is 1200-1800.
  • Significance:
    • It is a reliable indicator of the health of the entire river ecosystem.
    • It was recognised as the National Aquatic Animal in 2009, by the Government of India.
  • Threats:
    • Bycatch: These dolphins and people both favor areas of the river where fish are plentiful and the water current is slower. This has led to fewer fish for people and more dolphins dying as a result of accidentally being caught in fishing nets, also known as bycatch.
    • Pollution: Industrial, agricultural, and human pollution is another serious cause of habitat degradation.
    • Dams: Construction of dams and other irrigation-related projects make them susceptible to inbreeding and more vulnerable to other threats because they cannot move to new areas.
      • Dolphins below a dam are threatened by heavy pollution, increased fishing activities and vessel traffic. They also have less food because dams disturb the migration, breeding cycles and habitat of fish and other prey.
  • Conservation Status:
    • Indian Wildlife (Protection), Act 1972: Schedule I.
    • International Union for the Conservation of Nature (IUCN): Endangered.
    • Convention on International Trade in Endangered Species (CITES): Appendix I (most endangered).
    • Convention on Migratory Species (CMS): Appendix II (migratory species that need conservation and management or would significantly benefit from international co-operation).
  • Steps Taken:
    • Project Dolphin: The Prime Minister announced the government’s plan to launch a Project Dolphin in his Independence Day Speech 2020. It will be on the lines of Project Tiger, which has helped increase the tiger population.
    • Dolphin Sanctuary: Vikramshila Ganges Dolphin Sanctuary has been established in Bihar.
    • Conservation Plan: The Conservation Action Plan for the Ganges River Dolphin 2010-2020, which “identified threats to Gangetic Dolphins and impact of river traffic, irrigation canals and depletion of prey-base on Dolphins populations”.
    • National Ganga River Dolphin Day: The National Mission for Clean Ganga celebrates 5th October as National Ganga River Dolphin Day.