Gharial conservation should extend to unprotected rivers

Gharial conservation should extend to unprotected rivers

Subject: Environment

Section: Species in new

Context:

• The gharial population, a critically endangered species and the only surviving member of the genus Gavialis, has seen a significant decline from 5,000 individuals in the 1940s to just a few hundred today.

Details:

• Focusing on the Gandak River, a transboundary tributary of the Ganga flowing through Bihar and Uttar Pradesh, the study highlights that gharials tend to avoid areas with human activity, preferring undisturbed riverine habitats with deeper pools.
• The presence of human settlements near riverbanks, fishing activities, fishing nets, feral dogs, cattle, river braiding, and changes in river flow due to damming are identified as major threats.
• These factors not only disturb the gharials but also potentially impact their physiology by reducing their basking time.
• While the Gandak River hosts a small but robust population, most gharials are found in the Ganga and its tributaries, including the Chambal, Girwa, and Son rivers.

Surviving in unprotected habitats:

• The Gandak River, unlike the protected Chambal sanctuary, presents unique challenges for the gharials inhabiting its waters due to its unprotected status.
• It’s believed to host the second-largest gharial population in India and the only breeding population in a non-protected area, with a 2020 survey recording 259 individuals.
• However, there’s scepticism regarding these numbers due to the practice of releasing gharials into the river, which doesn’t necessarily mean they remain or thrive there.
• Despite these challenges, the Gandak River, mostly unprotected and human-dominated, except for the Valmiki tiger reserve and Sohagi Barwa wildlife sanctuary, is crucial for the conservation of gharials.

Threats to the gharial population:

• Gharials, large piscivorous reptiles, are keystone species in freshwater river systems, historically widespread but now limited to India and Nepal.
• They face threats from extensive fishing, which impacts their food supply, and from fishing nets, which can lead to entanglement and drowning.
• Sand and boulder mining disrupt their nesting patterns, and feral dogs pose a threat to their eggs.
• The study also points to the impact of changing river flow dynamics on gharial survival.
• Damming and barraging alter water flow, affecting the river’s natural system crucial for gharials. River braiding, caused by flood inclination and sudden irrigation discharges, complicates population estimates and threatens younger gharials.

About Gharial: 

• It is a fresh-water crocodile which lives in deep fast-flowing rivers.
• Features: Compared to alligators and crocodiles, a Gharial has a very long and narrow snout (instead of a broad snout).
• Distribution: 
  • Globally Gharial is found only in India and Nepal.
  • In India their major population occur in three tributaries of the Ganga River: the Chambal and the Girwa Rivers in India and the Rapti-Naryani River in Nepal.
  • The Gharial reserves of India are located in three States – Uttar Pradesh, Madhya Pradesh and Rajasthan.
• Conversation status:
  • IUCN: Critically endangered.
  • Wildlife (Protection) Act, 1972: Schedule I
  • CITES: Appendix I
• Conservation Initiatives:
  • Breeding Centres of Kukrail Gharial Rehabilitation Centre in Lucknow, Uttar Pradesh.
  • National Chambal Sanctuary (Madhya Pradesh).

Source: Mongabay