Key Findings:
- Total Count: 6,327 river dolphins recorded in the Ganga and its tributaries.
- Species Identified:
- Ganges River Dolphins: 6,324
- Indus River Dolphins: 3

Relevance : GS 3(Environment and Ecology)
- Distribution:
- Ganga main stem: 3,275
- Ganga tributaries: 2,414
- Brahmaputra main stem: 584
- Brahmaputra tributaries: 412
- Beas River: 101
- State-wise Dolphin Population:
- Highest in Uttar Pradesh, followed by Bihar, West Bengal, and Assam.
Survey Methodology:
- Conducted over a cumulative 8,507 km distance since 2021.
- Unlike land animals, dolphin counting is challenging due to:
- Underwater habitat and sporadic surfacing.
- Lack of unique identification markers like tiger stripes or elephant ears.
- Technology Used:
- Acoustic hydrophones (underwater microphones) to detect dolphin echolocation.
- Triangulation method with multiple observers to avoid double-counting.
Challenges & Conservation Concerns:
- Primary threat: Entanglement in fishermen’s nets.
- Emerging concern: Pollution impact on dolphin habitats under study.
- Local community involvement essential for conservation efforts.
Policy and Future Steps:
- Next survey: Planned after four years with trained personnel.
- Government response:
- Report released by PM Narendra Modi during the National Board for Wildlife meeting.
- Emphasis on schoolchildren visits to dolphin habitats for awareness.
- Conservation Focus: Gangetic states to play a major role in protecting dolphins.
Significance:
- Provides a baseline for future population tracking, though comparison with past data is difficult due to methodological differences.
- Key step in freshwater biodiversity conservation amid growing threats.