First comprehensive survey of India’s River Dolphins

Why in the NEWS?

• Prime Minister Narendra Modi released the results of the first comprehensive population estimate of river dolphins – Gangetic and Indus dolphins – in India.

Key Points:

• In a significant step towards the conservation of river dolphins – Gangetic and Indus dolphins – in India, a comprehensive survey was conducted between 2021 and 2023.
• The survey, conducted by the Wildlife Institute of India under the Union Environment Ministry, aimed to accurately assess the population, regional distribution and environmental challenges of these endangered aquatic mammals.
• The report discusses in detail the objectives, methods, key findings, challenges and policy aspects of conservation.

What will you read next in this topic?

1. Objective, importance of the survey and context of Wildlife Protection Act, 1972.
2. Survey area and data collection
3. Policy Direction for Conservation and Impact of Wildlife Protection Act, 1972

Objective, importance of the survey and context of Wildlife Protection Act, 1972.

Objective and significance:

• Population estimation:
  • To find out the accurate number of dolphins in the Ganga, Brahmaputra, and Beas river areas of Punjab between 2021 and 2023.
  • To document the current status of endangered species and their distribution.
• Environmental risks and challenges:
  • To assess problems such as pollution, river bed mining, reduction in water depth, habitat loss, prey loss and climate change.
  • To formulate necessary policy suggestions for conservation based on these threats.
• Policy guidelines:
  • The data obtained from this survey will enable the government and conservation agencies to formulate effective policies that improve the habitat and conservation of dolphins.

Context of Wildlife Protection Act, 1972:

• Legal framework for protection:
  • The Ganges dolphin and the Indus dolphin have been declared endangered under the Wildlife Protection Act, 1972.
  • The Act provides the highest legal protection to these species, prohibiting activities such as hunting, illegal trade and habitat loss.
• Protection and enforcement:
  • Under the Act, conservation agencies and forest departments carry out regular inspections, monitoring and enforcement to preserve the habitat of these species.
  • This legal framework not only ensures the safety of dolphins but also plays a vital role in conserving their habitat.

Survey area and data collection

Regional coverage:

• Ganga River Basin:
  • A total of 7,109 km of the Ganga main stream and tributaries were covered, covering various stretches of Uttar Pradesh, Bihar, Jharkhand, West Bengal, Madhya Pradesh and Rajasthan.
• Brahmaputra River:
  • A detailed survey was conducted of 1,297 km area including the main stream and tributaries (e.g. Subansiri, Kulsi, Beki, Kopili, Barak).
• Beas River (Punjab):
  • In a 101 km stretch of Punjab, very few Indus dolphins (only 3) were found.

Methods of data collection:

• Visual survey by boat:
  • Visual counts by boat were conducted in 28 rivers.
  • Dolphins surface for only 1.26 seconds, allowing for observer error.
  • In difficult stretches of the river, where water opacity was high, special lighting and surveillance cameras were also used.
• Road Mapping:
  • 30 river segments were mapped by road, collecting extensive geographic data.
• Acoustic Survey (Hydrophone Technique):
  • When analysing the sounds recorded by hydrophones, individual dolphins were identified by measuring the frequency, repetition and interval of sound waves.
  • The algorithms used in the acoustic data played a key role in correcting potential double counting errors by understanding the differences between sounds.

Policy Direction for Conservation and Impact of Wildlife Protection Act, 1972

Need for Conservation:

• Gangetic and Indus dolphins have become highly vulnerable due to challenges such as pollution, illegal mining and habitat loss.
• These factors are leading to a decline in their population, necessitating immediate and effective measures to conserve these species.

Contribution of Wildlife Protection Act, 1972:

• This Act provides the highest legal protection to dolphins, preventing hunting, illegal trade and other harmful activities.
• Conservation agencies and forest departments ensure protection of their natural habitat through regular monitoring and legal action under this Act.

Future Policy Direction:

• Regular Surveys:
  • Periodic comprehensive surveys will help assess changes in dolphin populations, enabling prompt conservation measures.
• Technological Up gradation and Training:
  • The accuracy of surveys can be increased by using better hydrophones, digital mapping, and machine learning based data analytics.
  • Also, improving training of observers and experts will reduce errors.
• Policy reforms and public awareness:
  • Pollution control, water resource management and river bank protection should be improved based on the data obtained.
  • The importance of dolphins can be highlighted by raising public awareness through local communities and educational institutions.