On November 10, some villagers near Sambhar Lake alerted officials of animal husbandry department about mass death of birds. A team comprising of revenue, forest and veterinary officials visited the site and collected samples. From next days, officials, NGO volunteers began collecting carcasses and burying them in deep pits of 10 feet with salt and lime. Some birds were rescued – they had flaccid legs, wings and neck, were gasping, had diarrhea and dehydration. Since then around 20,000 carcasses have been buried near the lake site, and experts from several organizations have made many rounds of the lake to study the biggest mortality of birds in last four decades.
The Indian Veterinary Research Institute (IVRI) in Bareilly (Uttar Pradesh) conducted two rounds of autopsies to conclude the cause of death was botulism, a neuromuscular illness caused by bacterium Clostridium Botulinum. Earlier, Bhopal-based National Institute of High Security Animal Disease (NIHSAD) ruled out avian flu. Scientists have said botulism is not contagious but they are worried about clearing the area of all carcasses because the disease spreads from maggot-infested carcasses: birds that are insectivorous or omnivorous got the disease and herbivores remained safe.
Sambhar Lake is among the two Ramsar sites in Rajasthan; the other is Keoladeo National Park in Bharatpur. A Ramsar site is a wetland of international importance according to the convention on wetlands signed in Ramsar town of Iran in 1971. Sambhar was designated a Ramsar site in 1990 but the government did not look after this wetland all these years, and therefore when the tragedy struck, it took it more than a fortnight to even notice it. According to the IVRI report, the birds began to die around 15 days before November 10.
Sambhar Lake attracts migratory birds categorized as water fowls and shore birds from Siberia, Russia, China and Himalayas. The birds include Northern Shovelers, Kentish Plovers, Common Teals and Common Sandpipers. Resident birds, including Ruff, Pied Avocets, Whistling ducks, Coots, greater and lesser flamingos, also visit the wetland spread over 240 sq km across Jaipur, Ajmer and Nagaur districts.
Four seasonal rivers – Mendha, Rupangarh, Kharian and Khandel – and numerous rivulets and surface runoff feed the India’s largest inland saline wetland. A large part of the lake has been given to Sambhar Salts Limited (SSL), a subsidiary of public sector enterprise Hindustan Salts Limited, for production of salt.
Salt manufacturing at Sambhar is considered to have begun during the time of Emperor Akbar (1542-1605), who recorded revenue of Rs 2.5 lakh. His great grandson Emperor Aurangzeb increased it to Rs 15 lakh annually. Rulers of Marwar (Jodhpur) and Dhundhar (Amer-Jaipur) continued to extract it as shaamlaat (common resource) until the British stepped in and appointed RM Adam as Assistant Salt Commissioner at Sambhar.
Adam’s records (1873-74) reveal all about salt extraction, sale and price. He turned out to be an avid bird watcher and left behind a comprehensive list of species that he observed around this habitat. Many of those animals and birds are no more observed there, indicating deterioration in habitat. Harkirat Singh Sangha observed 83 species of water fowl were observed at Sambhar.
Monsoon has been erratic near Sambhar. So the lake remains dry for long spells. Yet mining of underground water continues unabated. Salinity, as intrinsic character here, varies and may be alarming. Cases of bird mortality hint at it.
Scientists from Wildlife Institute of Indian in Dehradun, Salim Ali Centre of Ornithology and Natural History (SACON) in Coimbatore, IVRI in Bareilly, Bombay Natural History Society (BNHS) and Rajasthan University of Veterinary and Animal Sciences (RAJUVAS) in Bikaner visited the lake to study the mass mortality.
Earlier, the environment ministry rated Sambhar Lake among the worst wetlands in the country. Following the ratings, the National Green Tribunal (NGT) took suo motto cognizance of a report in Hindustan Times and issued notices to Centre and state. The Rajasthan High Court is also hearing a suo motto petition on Sambhar and has appointed amicus curiae to assist it. The amicus curiae report has made several suggestions to prevent a recurrence of mortality.
Ecologists suggest a management plan with emphatic reliance on ecosystem based approach for Sambhar, like that of the Chilika Lake in Odisha. Sambhar can be rejuvenated by setting up an authority. Politicians need to realize that a new management idiom and better planned process will facilitate salt entrepreneurs make more money, offer greater job opportunities to local village people, and open up new avenues of business. They call for forest department designating Sambhar as a conservation reserve to balance the demand-supply equation through ecological processes.