The Indian Gharial: Saving the slender snouted river hunter in a changing climate

The Indian gharial (Gavialis gangeticus) is an ancient predator, a reptile that outlived the dinosaurs yet may not outlast us. It is one of India’s most unusual river creatures—ancient, elusive, and perfectly built for life in water. Once sharing the earth with dinosaurs, this crocodilian now glides quietly through the rivers of northern India, a specialist fish-hunter with a long, narrow snout and sharp teeth that make it unmistakable. Its bulbous nose tip, called the ghara after the traditional clay pot, gives it a distinct charm.

That slender snout is not just striking, it’s a tool of precision The gharial is nature’s answer to high-speed fish catching. Packed with needle-like teeth and supported by a strong neck, it allows the gharial to snap up fish in fast, flowing waters. While adults prefer the deep stretches of rivers, they also wander into calm lakes and bends, while young ones seek shelter in backwaters and sandbanks during the monsoon.

When nesting season arrives, females ascend to the sun-warmed sandbanks and lay around 40 eggs in sandy riverbanks. Once the rains set in, they leave the eggs behind, and the hatchlings emerge alone, instinctively finding their way into the river’s currents. But the gharial’s survival depends entirely on the health of the river. Sand mining, fishing nets, and dams threaten its future, while thriving populations signal that a river is alive and well. Where gharials flourish, fish are plentiful, waters run clean, and the ecosystem thrives.

Their story is no longer just about survival against hunters and nets, it is about navigating rivers reshaped by people and by climate.

Gharials help keep rivers clean

The Indian gharial isn’t just a cool-looking crocodile, it’s one of nature’s most important river guardians. Gharials help keep rivers clean by eating dead animals. This removes rotting matter, stops the spread of disease, and keeps the water fresh for fish and other creatures. They love fish, but not too much of one kind. Gharials eat just enough to stop any one fish species from taking over, helping many kinds of fish thrive together.

As they swim and hunt, gharials move nutrients from the bottom of the river to the top, and vice versa. This keeps food available for all river life, from tiny plants to big fish. If gharials are around, it usually means the river is clean, wild, and well-balanced. That’s why scientists see them as “indicator species”, animals that tell us how healthy the environment is.

The gharial map is shrinking

The gharial used to live across many big rivers in the Indian subcontinent—like the Indus, Ganges, Mahanadi, Brahmaputra-Meghna, and maybe even the Irrawaddy. Back in the 1940s, there were about 5,000–10,000 of them, but their numbers dropped sharply due to people hunting them for skin and medicine, stealing their eggs, and accidentally killing them with fishing tools.

Once found across five South Asian countries, gharials are now extinct in Myanmar, Bhutan, and Pakistan. Today, they survive in fragmented pockets of India and Nepal, with the Chambal River hosting the largest remaining population.

Anthropogenic activities are pushing the gharials to the edge

Gharials have weak leg muscles and they only get out of water to bask in the sun or nest on sandy banks. Dams and barrages fragment river habitats, cutting off breeding grounds and migration routes. Sudden water releases during monsoons wash away eggs and hatchlings, leaving little chance for survival. 

Reduced river flows due to water diversion for irrigation and urban use turns vibrant rivers into stagnant pools, unsuitable for gharials. Lower flow means less oxygen and fewer fish, their primary food source. Gharials favour steep, sandy riverbanks as breeding and nesting habitats. Modification of these habitats due to river flow alterations poses a significant impact on gharial population. 

Sand mining and embankments erase the nesting spots of the gharials as they need steep, sandy banks. Embankments and riverbank farming alter landforms, making nesting impossible. Pollution and sewage also affect the gharials negatively. Toxic runoff and untreated waste poison the water, affecting fish and gharials alike. Pollution also disrupts nutrient cycles, weakening the entire ecosystem.

Increased intensity of fishing where gharials reside can reduce the amount of fish available for them leaving the gharials hungry and stressed.  Fishing nets also endanger gharials and their long snouts make them vulnerable to getting caught in the nets, and gharials often die or sever their snout while disentangling from the nets. 

Gharials have lost a significant portion of their nesting habitat along the Chambal and Son rivers, deemed to be protected as sanctuaries, to rampant sand mining. 

Efforts to save them are gradually yielding results

India launched a number of conservation strategies such as assisted translocation programs, and the protection of suitable natural habitats to support the gharial population and its restoration in the wild. Between 1975 and 1982, India established 16 captive breeding and release centers and five gharial sanctuaries. Key breeding centres include Deori Gharial Breeding Centre (Madhya Pradesh) and the Kukrail Rehabilitation Centre (Lucknow) where hatchlings are raised in captivity and released into natural habitats. The Gandak River in Bihar has become a major breeding site for gharials. 

Madhya Pradesh has the title of ‘gharial state’, as it hosts over 80 percent of India’s gharials. This has happened due to decades of conservation efforts in the state. Today, the species survives primarily in five sites:

• National Chambal Sanctuary

• Katerniaghat Sanctuary, UP

• Chitwan National Park, Nepal 

• Son River Sanctuary, MP

• Satkosia Gorge Sanctuary, Odisha 

While these efforts have been instrumental in preventing the immediate extinction of the gharial and have contributed to its recovery in recent years, climate change is presenting a new set of challenges.

Gharials vs climate change: Who’s winning?

Climate change is however shifting the game board and little is known of how it may affect the gharial in the long run. A new study titled 'Riverine realities: Evaluating climate change impacts on habitat dynamics of the critically endangered gharial (Gavialis gangeticus) in the Indian landscape' published in Animals harnesses Species Distribution Models (SDMs) to map out the gharial’s current habitats and predict future conditions under two major climate scenarios:

• SSP245 (2041–2060): a moderate-emissions future

• SSP585 (2061–2080): a high-emissions, worst-case trajectory

Using data from across the Ganges, Brahmaputra, and Mahanadi river basins, the models reveal how changing climates could shape the gharial’s future. 

The study finds that: 

• Currently, only 46.85 percent of the area has been found to be a suitable habitat for the gharials

A total of 37,487 sq. km has been found to be a suitable habitat for the gharial within the Ganges-Brahmaputra-Mahanadi River basins in India. Uttar Pradesh stands out as having the largest suitable area, encompassing approximately 10,954 sq. km for housing the species, followed closely by Madhya Pradesh (10,797 sq. km). Rajasthan, Uttarakhand, Assam, and Bihar also show significant areas of suitable habitat for the gharials.

• Climate changes may lead to increase in suitable habitat areas for the gharials by 2080

The projected suitable habitat range for the gharial is expected to expand by 36.42 percent to 145.16 percent under future climatic scenarios compared to the current extent. The most pronounced increase is observed during the 2061–2080.

• States like Madhya Pradesh, Uttar Pradesh, and Assam may become new strongholds for gharials

The state of Madhya Pradesh will show a 73.27 percent increase in suitable habitat during the years 2041–2060, rising to 131.80 percent by 2061–2080. Similarly, significant expansions are anticipated in Assam, Uttarakhand, and Bihar, with increases of up to 165.01 percent, 316.87 percent, and 188.51 percent during the years 2061-2080 respectively. Uttar Pradesh is projected to experience a 47.85 percent reduction in suitable habitat during the 2041–2060 timeframe followed by a recovery, with a 33.79 percent increase by 2061–2080 compared to the present scenario. 

• Odisha and Rajasthan may lose critical habitat due to unfavourable shifts in temperature and rainfall patterns.

This increase in suitable habitat under future climatic scenarios shows that the gharial may  withstand, adapt to, or recover from the impacts of climate change in the future. While this habitat expansion sounds promising, the study emphasises that it’s not a green light for passive conservation. Species like the gharial depend on highly specific ecological conditions—including river flow, prey availability, and nesting grounds. Without on-ground verification, these new “suitable zones” could remain theoretical.

The researchers urge for the need to have:

• Ecological and genetic assessments to ground-truth model predictions.

• Prioritisation of Lower Ganges, Mahanadi, and Brahmaputra systems for targeted protection and possible gharial translocation.

• Engagement with conservation networks like the IUCN-SSC Crocodile Specialist Group for adaptive, location-specific strategies.

This research thus redefines how we think about species conservation in the era of climate change. It doesn’t just map decline—it reveals potential lifelines. But making those lifelines real will require swift, science-backed action.