9 November 2020.

Introduction:

• ,At the end of  the Ganga Utsav  celebrations which mark the 12th anniversary of declaring the Ganga as a national river, the Wildlife Institute of India (WII) in the second phase of its survey of the entire main stem of the Ganga river has found that 49 per cent of the river has high biodiversity.
•  The biodiversity sightings, including of the Gangetic Dolphin and otters, have increased in the river.
• Scientists at the institute say that this indicates reducing pollution levels and a healthier state of the river.

Highlights:

• The study was initiated by WII on behalf of the National Mission for Clean Ganga, one of the flagship projects undertaken by the Ministry of Jalshakti.
•  The first phase of the survey was carried out between 2017-2019.
• This is the first study ever done in the country on the entire river, and the first also of all its biodiversity.
• Ten per cent of the high biodiversity areas fall alongside national parks and sanctuaries such as Rajaji national park in Uttarakhand, Hastinapur wildlife sanctuary in UP and Vikramshila gangetic Dolphin sanctuary in Bihar.
• The high biodiversity stretches have been divided into six zones – Devprayag to Rishikesh (61 km), Makdumpur to Narora (147 km), Bhitaura to Ghazipur (454 km), Chhapra to Kahalgaon (296 km), Sahibganj to Rajmahal (34 km) and Baharampur to Barackpore (246 km).
• Some key aquatic and semi-aquatic species such as the Gangetic Dolphins, gharials, otters, turtles and various species of water birds that were disappearing have come back.
•  Nesting colonies of the Indian Skimmer. Seibold’s, a species of water snake, disappeared 80 years ago and has now resurfaced.
• . Many other species have started travelling back from tributaries to the main stem of the river, indicating improving water quality.

Major threats

• According to the study the major threats of biodiversity of rive Ganges are sand mining, construction of dams and barrages, bank alteration loss of suitable habitat conditions.
• The United Nations Environment Programme stated that the decline of biodiversity of freshwater species is the highest of all the other species.
•  The highest loss of biodiversity was reported in the Indian subcontinent.