Know

An abrupt flight to Sambhar

Payel Majumdar Upreti | Updated on November 29, 2019 Published on November 29, 2019

Victims of turbulence: Volunteers undertake daily combing operations to clear bird carcasses from the lake to curtail the spread of infection   -  PTI

Why have 20,000 migratory birds dropped dead at India’s largest inland salt water lake? The Rajasthan government and wildlife authorities are shooting in the dark to contain the outbreak of avian botulism

It was not a sight that the volunteer at an animal rescue outfit would forget in a hurry. Rohit, a member of the Jaipur-based NGO Raksha, spotted a dead migratory bird — a Eurasian teal — on the shores of the Sambhar Lake in Rajasthan back in May, and feared the worst. He notified the forest authorities. But it was only after the birds started dropping dead in their thousands in the catchment areas across the lake that the alarm bells started ringing.

So far, over 20,000 birds have been found dead in Sambhar, about 80 km from Jaipur, and the nearby area of Nawa on the banks of the lake. The forest department says that the maximum number of deaths — 1,829 — occurred on November 15, and even now about 100 birds are found dead every day.

“They could be found on the edges of the lake, gasping for breath, legs seized, trying to clear out of the water,” a member of the State Disaster Response Force (SDRF) says. “The ones that could not make it to the shore could be found floating in the shallow water of the lake. Some would be found on the shore, lying on their chest or on one side.”

Daily combing operations are being conducted in the lake by volunteers. The dead birds are being burnt and buried to ensure that other birds are not infected. The eastern part of the lake is more affected by the still unexplained catastrophe. Areas of the lake in Ajmer district have reported no casualties and herbivorous birds such as flamingos are believed to be safe.

“There are no casualties in the freshwater lakes around Sambhar,” says Ushma Patel, a veterinary surgeon volunteering in the rescue operations at the site. “While casualties as high as 3,000 birds are reported every year during the kite festival [when birds are killed by the sharp strings attached to the kites], this scale of death is definitely a first in the country,” she adds.

The Sambhar Lake is one of the 27 Ramsar Convention wetland sites in India. The Unesco convention is an intergovernmental environment treaty that was signed in Ramsar, Iran, in 1971 to identify wetlands and work towards global cooperation in their conservation. It is also an Important Bird Area (IBA) — one of the 12,000 such designated areas in the world. An IBA is seen as an important region for bird conservation.

Nervous flutter

Every year, from November to March, about 2,00,000 migratory birds across 65 species arrive at the Sambhar Lake area. Among them are the great crested grebe, little grebe, little cormorant, black stork and great white pelican.

But Sambhar has its share of problems. India’s largest inland saltwater lake is surrounded by huge salt pans. A large part of the lake — about 90 sq km — is the property of Hindustan Salts Ltd., a public sector undertaking established in 1958. The company mines the salt sources in Sambhar and other areas. But illegal salt mining is rampant in the region, point out conservationists, worried over the wetland area’s environmental degradation. Groundwater is diverted for such activities, they complain.

The avian deaths have turned the lens on the region, with ecologists hoping that the government would now put an end to illegal mining and take more measures to safeguard avian and marine life.

Rescue mission

Meanwhile, the authorities are attempting to stem the epidemic through makeshift arrangements. Rajendra Jhakar, a ranger with the state forest department overseeing rescue operations at the lake, says various arms of the government are working to save the birds.

“The animal husbandry department, forest department, the nagar palika parishad [municipal council] and the SDRF [disaster response force] are all working together to stem the epidemic,” he says, adding that the Indian Veterinary Research Institute (IVRI) in Izatnagar in Uttar Pradesh has confirmed that the deaths were caused by avian botulism, a bacterial infection. The birds may have been infected by bacteria in the marine life that they fed on.

Members of state departments, birdwatchers as well as volunteers from Raksha and the Wildlife Trust of India, another non-profit, assist the government in the operation.

Hunting a cause: The Kathroda nursery,15 km from the lake, is the nerve centre for rescue operations   -  PAYEL MAJUMDAR UPRETI

 

The Kathroda nursery, 60 km from Jaipur and about 15 km from the lake in the Dudu forest range, is the nerve centre for rescue operations. Three wards have been set up in the government-run plant nursery, with equipment crowd-sourced by volunteers and government departments. A bird ICU has been equipped with an incubator to keep the critical birds at a certain temperature to fight hyperthermia, along with an oxygen incubator, saline drips, heaters and infrared lamps. Since the equipment is limited, birds are being treated in batches.

Two makeshift caged areas have been created to house the recuperating birds. They are being provided with a dry and wet area, shade and food, and are constantly monitored by veterinarians. A cage has been built on the lake’s shores to help treated birds return to the wild.

Symptoms and cure

Experts are still debating what caused the avian botulism epidemic. The initial lab results from the National Institute of High Security Animal Diseases in Bhopal, Madhya Pradesh, ruled out avian flu, as had earlier been feared, and subsequent reports confirmed that the birds were hit by avian botulism — typical symptoms of which include weakness, lethargy and inability to fly.

“Even though botulism was not diagnosed earlier, we had started working in that direction since we were sure it wasn’t a viral infection as plant-eating birds such as flamingos were largely unaffected,” says Dr Kishore Kumar Dariya, veterinary doctor with the government’s animal husbandry department. “The symptoms were also similar to botulism outbreaks in other parts of the world.”

The birds are receiving supportive treatments as there is no cure for avian botulism. They are administered antibiotics, multivitamins, eye drops, fluid and oxygen as well as nutritious feed.

Fight to live: Birds are administered antibiotics, multivitamins, eye drops, fluid and oxygen   -  PAYEL MAJUMDAR UPRETI

 

“[Nutrient-rich] feed imported from the US is being provided to the really critical birds. Others are being given liquid versions of a local concotion that uses planktons from their natural diet,” says Patel, who works with Wildlife Trust of India. “But there are seven strains of clostridium botulinum and we don’t have labs in the country to test which kind has affected the bird population here.”

The experts are also wondering how far they can go in providing feeds for the critical birds. “The question also arises as to the extent we can and should intervene since these are birds in the wild. We have to ensure we don’t change their natural diet and behaviour as much as possible,” Patel says.

Another doctor at the site points out that the birds show signs of distress when there is too much human interference. “So, the volunteers make sure they are handled only once a day. All activities, including their treatment and feeding, are done in that period, after which they’re left alone to recuperate,” she says.

Nature speaks

The experts are looking at the role of rainfall in the spread of the epidemic. The region recorded a high rainfall this season, which attracted a large number of birds. But coupled with the ensuing rise in temperature, it may have provided a favourable environment for bacteria to propagate.

“This season, temperatures are a clear two degrees higher than normal, favouring an outbreak of phytoplanktons and other invertebrates, which prospered in the new saltwater beds that were formed after a gap of two decades,” Patel says. Once these dried up, infection could possibly have spread when migratory birds fed on either the invertebrates or other dead carcasses of birds.

Adds Ashok Kumar Mahariya, an officer of the Indian Forest Service, “The worry currently is to contain the outbreak since more birds are expected to visit the area in the near future.”

The lake’s environmental degradation due to neglect has long been a topic of discussion among birdwatchers and conservationists. They point out that the government has done little to redress the situation. Ecologists stress the need for veterinary hospitals on the outskirts of the lake. They want Hindustan Salts Ltd. to help in the lake’s upkeep, and demand action against illegal salt mines.

Even though Sambhar is a Ramsar wetland and an IBA, no government body has been formed to ensure its maintenance and revival. Ecologists hope that the death of 20,000 birds will, if nothing else, shake the government out of its apathy.

Published on November 29, 2019
  1. Comments will be moderated by The Hindu Business Line editorial team.
  2. Comments that are abusive, personal, incendiary or irrelevant cannot be published.
  3. Please write complete sentences. Do not type comments in all capital letters, or in all lower case letters, or using abbreviated text. (example: u cannot substitute for you, d is not 'the', n is not 'and').
  4. We may remove hyperlinks within comments.
  5. Please use a genuine email ID and provide your name, to avoid rejection.