Cause of Botulism

Ingestion of a toxin produced by the bacterium Clostridium botulinum, leads to paralysis and potentially fatal outcomes for birds.

Toxin Types

There are seven types of botulism toxins (A-G).

Wild birds are affected by type C and type E.

Source of Bacteria

Bacterial spores are widespread in wetland sediments and found in most wetland habitats, including invertebrates like insects, mollusks, crustaceans, and many vertebrates, including healthy birds.

Contributing Environmental Conditions

High water temperatures and low oxygen levels in the water are thought to contribute to toxin production.

Location

About 80 km southwest of Jaipur, in east-central Rajasthan.

Features

• Largest inland salt lake in India.
• Represents the depression of the Aravalli Range.
• Historically worked by the Mughal dynasty and later owned jointly by Jaipur and Jodhpur princely states.

Ramsar Site

Wetland of ‘international importance’ under the Ramsar Convention, declared in 1990.

Rivers

Receives water from six rivers: Samaod, Khari, Mantha, Khandela, Medtha, and Roopangarh.

Vegetation

Predominantly xerophytic plants (adapted for dry conditions).

Fauna

• Flamingoes, pelicans, and waterfowls are common.
• In 2019, 22,000 migratory birds died due to avian botulism.
• Rajasthan government built temporary shelters for birds near the Lake before the 2020 winter season.

Production of Salt

Known for brine/salt production, with one of the largest salt manufacturing units in India.

Other Nearby Places

• Shakambari Devi temple.
• Sambhar Wildlife Sanctuary.

PRACTICE QUESTION

Q.Consider the following statements about Avian Botulism:

1. It is caused by a neurotoxin produced by Clostridium botulinum which affects birds' nervous systems.
2. It affects aquatic bird species leading to paralysis and potentially death.
3. The toxin is transmitted through direct contact with infected birds.
4. Avian botulism outbreaks are commonly linked to high temperatures and low water levels in wetlands.

Which of the statements given above are correct?

(a) 1, 2, and 4 only

(b) 1, 3, and 4 only

(c) 2, 3, and 4 only

(d) 1, 2, 3, and 4

Answer: a

Explanation:

Statement 1 is correct: Avian botulism is caused by a neurotoxin produced by the bacterium Clostridium botulinum, which affects the nervous systems of birds, leading to paralysis and death in severe cases.

Statement 2 is correct: This disease primarily affects aquatic bird species, as the toxin is found in aquatic environments where birds feed, leading to paralysis and potentially death due to the toxic effect of the botulinum toxin.

Statement 3 is incorrect: The toxin is not transmitted through direct contact with infected birds. Rather, birds ingest the toxin by consuming contaminated food, such as decaying fish or invertebrates infected with the bacterium, found in water bodies or wetlands.

Statement 4 is correct: Avian botulism outbreaks are commonly associated with environmental conditions such as high temperatures and low water levels in wetlands, which create favorable conditions for the growth of Clostridium botulinum spores and the production of the botulinum toxin.