Ganges River Dolphin Population Estimate

The Ganges river dolphin, a unique species found in the freshwater systems of India, has been the focus of a recent comprehensive survey. Conducted over several years, the study has revealed a total of 6,327 dolphins in the Ganga River and its tributaries. This is the first reliable estimate using standardised methods, marking milestone in conservation efforts.

Survey Methodology

The survey began in 2021 and covered a distance of 8,507 km.

Researchers used boats equipped with acoustic hydrophones to detect dolphin sounds. This method allows for better accuracy in counting, as dolphins are often submerged and can only be identified through their vocalisations.

Observers on the boats triangulated the presence of dolphins to avoid double counting.

Population Distribution

The survey identified 6,324 Ganges river dolphins and three Indus river dolphins.

The majority were found in Uttar Pradesh, followed by Bihar, West Bengal, and Assam.

The breakdown included 3,275 dolphins in the main Ganga river, 2,414 in tributaries, and smaller populations in the Brahmaputra and Beas rivers.

Dolphin Characteristics

Ganges river dolphins are adapted to freshwater environments. They are essentially blind and rely on echolocation to navigate and hunt. These mammals surface every 30 to 120 seconds to breathe. They typically live alone or in small groups, with mothers giving birth to one calf every two to three years.

Ecological Significance

As the National Aquatic Animal of India, the Ganges river dolphin is important indicator of river health. Their presence reflects the overall condition of the river ecosystem. Conservation efforts are vital for maintaining biodiversity and ensuring the sustainability of the Ganga River.

Major Threats

Dolphins face numerous threats, including accidental entanglement in fishing gear and poaching for their oil. Habitat destruction due to industrial development and pollution also poses risks. Efforts are underway to study the effects of these challenges on dolphin populations.

Conservation Initiatives

The Government of India has recognised the importance of protecting Ganges river dolphins. Initiatives like Project Dolphin and the Vikramshila Ganges Dolphin Sanctuary aim to safeguard their habitats. National Ganga River Dolphin Day is celebrated annually on 5th October to raise awareness.

Future Surveys

The next population survey is expected in four years. Continuous monitoring and research are essential for understanding population dynamics and implementing effective conservation strategies.