What If Gone

Species → Ganges River Dolphin

Ganges River Dolphin

Platanista gangetica

3,607 individuals (Ganges-Brahmaputra-Meghna basin)
Extinction risk Endangered
WaterwayPredatorUmbrella species
Ganges River Dolphin (Platanista gangetica)
Photo: Kukil Gogoi, Wikimedia Commons (CC BY-SA 4.0)

What if it disappeared?

Impact Moderate
Ongoing

Functionally blind — its eyes have no lens and can only sense the direction of diffuse light — the Ganges river dolphin hunts and navigates entirely by echolocation, continuously emitting high-frequency clicks suited to the short detection range imposed by shallow, turbid water.

Documented
Detail

Jensen, F.H., Rocco, A., Mansur, R.M., Smith, B.D., Janik, V.M. et Madsen, P.T. (2013). Clicking in Shallow Rivers: Short-Range Echolocation of Irrawaddy and Ganges River Dolphins in a Shallow, Acoustically Complex Habitat. PLoS ONE, 8(4), e59284.

The measured clicks have a mean centroid frequency of 61.4 kHz and a mean source level of 183.3 dB (up to 191 dB), emitted at a median interval of just 27.8 milliseconds — a continuous emission pattern, unlike the spaced-out bursts of oceanic dolphins, adapted to detecting prey at very short range in silty water over more than 30 million years of evolution.

Across the Ganges-Brahmaputra basin

Declared India's national aquatic animal in 2009 to symbolize the health of the entire Ganges system, the dolphin now numbers only about 3,600 individuals across the whole basin — a population roughly halved compared with previous decades.

Documented
Detail

Sinha, R.K. et Kannan, K. (2014). Ganges River Dolphin: An Overview of Biology, Ecology, and Conservation Status in India. Ambio, 43(8), 1029–1046.

The species serves as an indicator of the health of the river ecosystem as a whole: dams fragment its habitat and isolate subpopulations, industrial and agricultural pollution accumulates in water its vision cannot detect, and bycatch in fishing nets remains a direct cause of mortality poorly quantified across the entire basin.

Not measured to date

What the disappearance of the Ganges river dolphin would change for the fish and shrimp it eats, or for the structure of the river it inhabits, has never been directly measured — its well-established role as a bio-indicator of river health says nothing about its functional role as a predator in the food chain.

Insufficient

Documentation

Last verified: August 14, 2026