Very Short Question and Answers - Rivers in Trouble - Gharials and Birds of the Yamuna

Gharials (Gavialis gangeticus) are critically endangered crocodilians with long, thin snouts, found in the rivers of northern India and Nepal.

They primarily inhabit clean, fast-flowing freshwater rivers with deep water pools.

Habitat destruction, overfishing, poaching and illegal trade, climate change and floods, and human disturbance.

Industrial waste, sewage, and agricultural runoff pollute rivers, degrading water quality and their habitat.

They disrupt river flow and nesting sites, damaging breeding areas and reducing habitat suitability.

Deep pools are essential for their survival, offering suitable habitat and refuge.

It reduces their fish prey and gharials can get accidentally caught and killed in fishing nets.

Gharials are hunted for their skin and body parts used in traditional medicine, and their eggs are stolen for consumption and trade.

Erratic monsoons and flash floods wash away nests, while rising temperatures affect breeding cycles and egg incubation.

Boating and river traffic disturb them, and encroachments on riverbanks reduce basking and nesting areas.

National Chambal Sanctuary and Katarniaghat Wildlife Sanctuary.

It began in 1975 and helped increase gharial numbers, though significant threats remain.

They breed gharials in captivity and release them into the wild to help restore populations.

It receives industrial waste, untreated sewage, and plastic, leading to high levels of toxic chemicals, heavy metals, and ammonia.

Birds ingest contaminated water and accumulate heavy metals like mercury, lead, and arsenic, causing organ damage and poor reproduction.

Pollution kills fish, insects, and aquatic plants, leaving fish-eating birds like kingfishers, herons, and cormorants with insufficient food.

Avian botulism has been linked to bird deaths in Delhi’s stretch of the Yamuna.

They coat feathers, reducing flight and insulation, making birds weak and vulnerable to predators.

Shrinking wetlands and encroachment cause migratory birds like flamingos, pelicans, and bar-headed geese to avoid the river, disrupting their seasonal patterns.

In 2021, over 100 migratory birds were found dead near Delhi’s Yamuna due to suspected avian botulism. Measures: enforce pollution control laws and run sewage treatment plants; also restore wetlands and support community/NGO clean-up initiatives.