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Saltwater crocodiles losing nesting ground in Sundarbans due to climate change: Govt report
Saltwater crocodiles, the world's largest crocodiles that are found in the Sundarbans in West Bengal, are losing their nesting grounds due to effects of global warming and climate change on the fragile delta ecosystem, a government report flagged on Monday. A saltwater crocodile. (AFP File)
The report, titled 'Population Assessment and Habitat Ecology Study of SaltWater Crocodiles in Sundarbans 2025', said that there are around 220 to 242 saltwater crocodiles in the entire Sundarbans. In 2024, their population stood between 204 and 234.
It also stated that there could be multiple reasons behind the shrinking of suitable nesting sites, including climate change induced factors such as rising sea level, warming of estuarine water and increasing salinity.
Nesting females are often found to be straying further inland near human habitations in search of fresh water (such as ponds) and higher grounds to lay eggs and raise their hatchlings, leading to increasing human-crocodile interactions in the delta. Around 70 crocodiles, many with their eggs, have been rescued from human habitations in the last three years, officials said.
'Most of the crocodiles were rescued during May and June, which coincides with the nesting season, and a majority of them were females. This suggests that suitable nesting habitats in the forested islands are becoming increasingly scarce,' the report stated.
The data came up during a population assessment exercise done in the delta between December 2024 and February 2025. At least 23 teams scoured the banks of the creeks for around 1,168 km looking for crocodiles; Sundarbans is crisscrossed by creeks for around 1,800 km.
Saltwater crocodiles are the largest of all crocodilians and the largest reptile in the world. They are one of the apex predators in the Sundarbans and play a vital role in maintaining the health of the aquatic ecosystem by eating carcasses and other wild remains in the water. They are listed under Schedule I of Indian Wildlife (Protection) Act, 1972, meaning they have the highest level of protection in India.
'Increasing sea levels reduce the nesting habitats available for the saltwater crocodiles which prefer nesting sites which are not influenced by tides. Apart from this, the increasing temperatures and erratic rainfall patterns may also have an impact on the incubation of the eggs of the species in the longer run as sex of the reptile individuals depends on the incubation temperature,' the report added.
Analysis of the data has revealed that these crocodiles prefer creeks, which are less than 180 metres in width and a salinity level between 9 and 23 PPT during the winter season.
The study has suggested that there is an immediate need to identify and map all the possible and potential nesting habitats — high lying mounds, chotoks and vegetative areas in the forested islands that need extensive protection and management so as to have sustainable breeding and nesting of crocodiles in Sundarbans
'We would soon launch a two-year survey to locate the existing nesting sites and to map the potential nesting sites in Sundarbans. The sites would be maintained and monitored by the forest department. Mounds may be created at these sites and the preferred vegetation may be developed. We will ensure that there is minimal human interference near those sites,' said Nilanjan Mallick, director of Sunderban Biosphere Reserve.
