Second Nationwide Dolphin Survey — Tracking India's National Aquatic Animal

🗞️ Why in News Union Minister Bhupender Yadav launched India’s second nationwide riverine dolphin survey from Bijnor, Uttar Pradesh, led by the Wildlife Institute of India. The first survey (2021–23) counted approximately 6,327 dolphins — the updated survey will provide current population, distribution, and threat data for India’s national aquatic animal.

The Gangetic River Dolphin: India’s National Aquatic Animal

The Gangetic River Dolphin (Platanista gangetica) holds the distinction of being India’s National Aquatic Animal — designated in 2009. Found in the Ganga-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of India, Nepal, and Bangladesh, this species is among the world’s most critically imperilled freshwater mammals.

Key Characteristics

• Virtually blind: The Gangetic dolphin has non-functional lens; its eyes lack a lens and only detect light direction — not form. It navigates entirely by echolocation (biosonar) — emitting ultrasonic clicks and reading the echoes
• Freshwater specialist: Obligate freshwater species; cannot survive in marine environments
• Distinctive appearance: Elongated snout (rostrum), flexible neck (can rotate 90 degrees — unusual among cetaceans), grey to brownish skin
• Diet: Fish, crustaceans, turtles, small waterfowl
• Lifespan: ~28–30 years

IUCN and Legal Status

• IUCN Red List: Endangered
• CITES: Appendix I (trade prohibited)
• Wildlife Protection Act, 1972: Schedule I (highest protection; hunting = minimum 7-year imprisonment)
• National Aquatic Animal: Designated by Government of India, 2009
• State Animal of Assam and Bihar

Distribution and Habitat

River System Coverage

The dolphin’s range in India spans several major river systems:

The Chambal River harbours the healthiest dolphin sub-population in India — protected by the National Chambal Sanctuary and by the river’s relative cleanliness (one of India’s least polluted major rivers).

Population Trend

• Historical: Once ranged across the entire Ganga-Brahmaputra system; population likely in the tens of thousands before the 20th century
• 2021–23 survey (first national): ~6,327 individuals — a fragmented population across multiple sub-populations
• 2012 estimate (Brahmaputra only): ~1,800 dolphins
• Trend: Increasing in some protected stretches (Chambal, parts of Ganga near Patna); declining in fragmented or heavily disturbed reaches

The Second National Survey: Methodology and Significance

Survey Design

The Wildlife Institute of India (WII) leads the survey using standardised methodologies:

• Distance sampling: Trained survey teams on boats count dolphins seen on both sides of the river, applying detection function corrections
• Occupancy surveys: Assessing which river stretches dolphins occupy
• Photo-ID cataloguing: Individual dolphins identified from dorsal fin notches
• Acoustic monitoring: Passive acoustic recorders capture echolocation clicks

Why the Second Survey Matters

1. Baseline update: The 2021–23 survey provided India’s first scientifically rigorous national estimate. The second survey will establish trend data — whether populations are growing or declining
2. Project Dolphin assessment: PM Modi launched Project Dolphin on World Environment Day 2020, modelled on Project Tiger. The survey tracks whether Project Dolphin interventions (anti-poaching, habitat protection, community involvement) are working
3. Ganga rejuvenation metric: Dolphin population trends are the most reliable biological indicator of Namami Gange programme effectiveness — more meaningful than water quality data alone
4. Policy input: Results will inform Protected Area (PA) boundaries, river development project EIAs, and sand mining regulation

Threats: What Imperils the Dolphin?

Direct Threats

• Bycatch and deliberate fishing: Dolphins are incidentally caught in gill nets; their oil (blubber) is illegally used as fish bait and catfish lure in some areas — a significant mortality source
• Entanglement: Fixed set nets and drift nets are lethal traps

Habitat Degradation

• Barrages and dams: India has 4,000+ large dams; many on dolphin rivers. Dams create barriers that fragment sub-populations (genetic isolation), trap dolphins in seasonally dry reaches, and alter sediment regimes. The Farakka Barrage has been a major divider between upper and lower Ganga dolphin populations
• Siltation and flow reduction: Groundwater extraction and upstream water diversion reduce river depth, exposing dolphins to boat propellers and predation
• Water quality: Industrial effluents (mercury, PCBs), agricultural runoff (pesticides), and untreated sewage accumulate in dolphin tissue (bioaccumulation at the apex of the food chain)

Infrastructure-Induced Threats

• Sand mining: Unregulated riverbed sand mining destroys dolphin spawning and foraging habitat; increases boat traffic
• Navigation and shipping: The National Waterways development (especially NW-1 on the Ganga) is expanding river traffic, increasing noise pollution and propeller-strike risk

Project Dolphin and Conservation Architecture

Project Dolphin (launched June 5, 2020) provides a dedicated conservation programme structure:

• National survey mandates (of which this is the second)
• Anti-poaching task forces and rapid response teams
• Community-based conservation (fishermen as Dolphin Mitras)
• Awareness and education programmes in riparian communities
• Dedicated funding through National Mission for Clean Ganga (NMCG)

Dolphin Mitras: A community monitoring network where local fishermen are trained to report dolphin sightings, deaths, and threats — functioning as early warning systems.

Ecological Role: Indicator and Keystone

The dolphin’s value goes beyond its charisma. As an apex predator in riverine ecosystems, it regulates fish populations, keeping prey species from over-dominating. As an indicator species, its presence — and health — reflects the overall ecological integrity of the river system:

• A river with healthy dolphin populations has adequate fish stocks, acceptable water quality, and minimal chemical contamination
• A river from which dolphins have disappeared signals severe ecosystem degradation

This makes the dolphin a practical tool for water quality assessment — correlating dolphin survey findings with Namami Gange monitoring data provides a multi-dimensional picture of Ganga restoration progress.

UPSC Relevance

Prelims: Gangetic Dolphin status (National Aquatic Animal 2009; IUCN Endangered; Schedule I WPA; CITES App I); Project Dolphin launch (World Environment Day, June 5, 2020); 2021-23 survey count (6,327); WII role; State animal of Assam and Bihar; Chambal — best-preserved dolphin habitat; Farakka Barrage as population barrier Mains GS-3: “Critically evaluate the threats to the Gangetic river dolphin and assess the effectiveness of Project Dolphin as a conservation intervention.” | “How do freshwater apex predators serve as indicators of river ecosystem health? Discuss with reference to the Gangetic river dolphin.” Essay: “A river’s health can be read in its dolphins — India’s national aquatic animal mirrors the state of its most sacred rivers.”

📌 Facts Corner — Knowledgepedia

Gangetic River Dolphin:

• Scientific name: Platanista gangetica | Order: Artiodactyla (Cetacea) | Family: Platanistidae
• Status: National Aquatic Animal (India, 2009); Endangered (IUCN); Schedule I WPA 1972; CITES Appendix I
• State animal: Assam (Susu) and Bihar
• Special feature: Virtually blind; navigates entirely by echolocation
• Population (2021-23 survey): ~6,327 individuals nationally

Distribution:

• Best habitat: Chambal River (National Chambal Wildlife Sanctuary — MP/Rajasthan/UP)
• Other rivers: Ganga mainstream, Ghaghra, Son, Brahmaputra, Kosi, Gandak, Rupnarayan
• Countries: India, Bangladesh, Nepal

Key Conservation:

• Project Dolphin: Launched June 5, 2020 (World Environment Day) by PM Modi
• Model: Based on Project Tiger architecture
• Key implementing body: WII (Wildlife Institute of India) — autonomous institute under MoEFCC
• Dolphin Mitras: Community-based fishermen monitoring network
• Namami Gange: National Mission for Clean Ganga (NMCG) — funds dolphin conservation

Threats:

• Bycatch, deliberate killing for fish bait
• Dam/barrage barriers (Farakka Barrage — major Ganga barrier)
• Sand mining, sedimentation
• Industrial + agricultural pollution (bioaccumulation)
• Increasing river traffic (National Waterways programme)

National Waterways concern:

• NW-1 (Ganga, Allahabad-Haldia, 1,620 km): JMVP (Jal Marg Vikas Project) under Sagarmala Programme
• Large vessel traffic increases noise pollution and propeller-strike risk for dolphins

Other Relevant Facts:

• Farakka Barrage (West Bengal): 2,240 m long; divides upper and lower Ganga dolphin populations
• Irrawaddy Dolphin: A different species found in coastal/estuarine India (IUCN: Endangered)
• BNHS: Bombay Natural History Society — also works on dolphin/river conservation
• Second largest freshwater cetacean range (after Amazon river dolphin/boto)

Sources: Insights on India, WII, PIB