Context-Odisha Forest Department officials, wildlife experts and researchers on Sunday sighted 146 endangered Irrawaddy dolphins in Chilika Lake, which boasts of the highest single lagoon population of the aquatic mammal in the world

• The dolphin census was simultaneously taken up in Chilika and off Odisha coast. The Chilika Development Authority (CDA) is elated that the direct sighting of 146 dolphins meant that its population in the lake would stabilise well above 150. According to last year’s census, the Irrawaddy dolphin population in Chilika was 151
• The direct sighting of 146 dolphins only corroborates the estimate of the CDA, which does counting of dolphins round the year using hydrophones.
• The mass demolition of prawn gheris in the recent years and regular cautions for responsible tourism seem to have resulted in maintaining the quality of the habitat for the endangered species and stabilisation of their population
• While 113 dolphins were sighted in Chilika last year, 162 were spotted in 2018 and 123 in 2017.

Irrawaddy dolphins:

• Scientific name: Orcaella brevirostris.

• Habitats: Lakes, Rivers, Estuaries, and Coasts.

• Regions: Coastal areas in South and Southeast Asia, and in three rivers namely the Irrawaddy (Myanmar), the Mahakam (Indonesian Borneo) and the Mekong.

• Population: The total population of these animals in the world is estimated to be less than 7,500. Of these, the highest 6,400 was reported from Bangladesh. The population in Chilika is considered to be the highest single lagoonal population.

• Threat: Dolphins had been under stress in Chilika due to unregulated boating by tourists as well as illegal prawn enclosures.

• IUCN Status: Endangered

• Features: Dolphins have a bulging forehead, short beak, and 12-19 teeth on each side of both jaws. They pop out their head out of the water to breathe, followed by its back; the tail is rarely seen.

Chilika lake

• It is Asia’s largest brackish water lagoon.
• It is the largest coastal lagoon in India and the second largest coastal lagoon in the world
• It lies in Odisha state on the eastern coast of India, at the mouth of the Daya River flowing into the Bay of Bengal.
• Because of its rich bio-diversity and socio-economic importance, Chilika was designated as a Ramsar site in 1981 to afford better protection.
• It was first waterbody in Indian to be designated as wetland of international importance under the Ramsar Convention.
• It is the largest wintering ground for migratory birds on the Indian sub- continent.
• It was put under Montreux Record (record for such sites where there has been or likely to be adverse ecological change due to manmade activities), but was later removed from it due to conservation efforts