A banned pesticide named Aldrin was responsible for the deaths of mugger crocodiles (Crocodylus palustris) in the Chandraloi river of Rajasthan’s Kota district, an investigation has revealed.
A joint committee formed by the National Green Tribunal (NGT) found traces of Aldrin in the river water. The Rajasthan Forest Department, which filed a response with the tribunal, has accepted this finding but has refused to take responsibility for the same.
Aldrin is a pesticide from the organochlorine group. The Government of India has included it in the list of banned pesticides because it persists in the environment for a long time and pollutes soil and water. It gradually accumulates in the food chain and can have serious adverse effects on the nervous system of humans and wildlife. For this reason, its manufacture, import, and use were banned in India in the 1990s. Therefore, its presence in river water raises questions about how this chemical reached there, how long it has been present, and who is responsible for its accumulation.
The case began in December 2024, when four endangered mugger crocodiles, approximately six to seven feet long, were found dead in Kota’s Chandralok river. Earlier in 2022, approximately 50 crocodiles had died in the same river due to pollution from industrial waste. Mugger crocodiles are a protected species under Schedule I (C) of the Wildlife Protection Act, 1972, receiving the highest level of protection under the law.
The NGT took suo motu cognizance of the matter on December 19, 2024, and constituted a joint committee to investigate. The committee included representatives from the Rajasthan State Pollution Control Board, the Central Pollution Control Board, the state’s Chief Wildlife Warden, and a designated representative from the Wildlife Institute of India, Dehradun. The committee inspected the site on January 24 and 25, 2025, and submitted its report to the tribunal. A glaring contradiction appears in the responses filed with the tribunal by the Deputy Conservator of Forests (Wildlife), the District Magistrate, and the Divisional Forest Officer of Kota.
On the one hand, the response noted the joint committee’s conclusion that the presence of banned pesticides like Aldrin in the river water is a matter of serious concern. On the other hand, the forest department argued that it is not responsible, as regulation of pesticide use falls under the jurisdiction of the agriculture department, while industrial waste and pollution control are the responsibility of pollution control authorities.
The forest department also stated in its response that bio-assay tests conducted by the joint committee showed a 90 to 100 per cent survival rate of fish in water samples. It also stated that approximately 50 crocodiles remain alive at the habitat centre, which is considered a sign of a stable population.
The affidavit, citing another respondent, also argued that, based on these facts, water toxicity alone cannot be considered the cause of the crocodile deaths. But this raises a significant question. If the water wasn’t toxic enough to cause widespread mortality, how did a banned pesticide like Aldrin get into it? And if that wasn’t the cause, what caused the crocodile deaths? There are no clear answers to these questions.
The question of accountability also remains unanswered. While the investigation committee itself has documented the presence of banned pesticides in the river, it remains unclear who will investigate its source, which agency will be tasked with this, and who will be responsible for preventing such incidents in the future.
In its defence, the forest department also stated that it organised awareness meetings on the safe use of pesticides among farmers in the riverside villages. The department also presented the tribunal with a detailed account of the Reptile Awareness Campaign 2025-26, conducted between July 2025 and January 2026. This record includes events held in approximately a dozen schools in Kota, letters of thanks, and photographs.
This is where the forest department’s response is most questionable. In a case primarily concerned with the presence of banned pesticides in the river and the deaths of crocodiles, the department has submitted detailed documentation of a reptile awareness campaign, but has not mentioned any concrete and time-bound action plan for identifying the source of pollution in the river, investigating the presence of banned pesticides, regular water-quality monitoring, or crocodile conservation.
This response was filed with the NGT along with an affidavit from Deputy Conservator of Forests (Wildlife) Anurag Kumar Bhatnagar, confirming the facts presented. The matter is currently pending before the Principal Bench of the NGT.