Dolphin population in Odisha's Chilika Lake rises to 156

After emerging as the favourite destination of migratory birds, the Chilika lake in Odisha has also turned out to be a safe haven for rare Irrawaddy dolphins.

This came to the light after the Chilika Development Authority (CDA) conducted an annual survey on the biodiversity of the lagoon, which is the largest lake along the east coast of India. The population of dolphins has increased to 156 in 2020 against 150 in 2019, an official said.

The Irrawaddy dolphin is the flagship species inhabiting the Chilika Lake. The CDA in a statement said that the present distribution range of this species is only in Asia, from Chilika to Indonesia. Irrawaddy dolphins in India are protected under the Wildlife (Protection) Act 1972, ClTES (Appendix-l) and IUCN Red List.

The CDA has initiated many conservation measures for the protection and conservation of Irrawaddy dolphins in the past in close coordination with the Wildlife Wing of state Forest Department, CDA chief executive Susanta Nanda said.

He said that in the past there had been survey and identification of dolphin habitat in the lake for proper management, dolphin watching protocol was formulated, sensitization training of tourist boat operators was conducted, widening and deepening of Magarmukha channel was undertaken for free movement of dolphin from outer channel to the main lake.

The annual population estimation survey of Irrawaddy dolphin has been conducted by CDA since 2003. The annual survey conducted on January 15, 2021, by "Transact Survey Method", followed worldwide for population of aquatic mammals.

Each survey team was equipped with binoculars, GPS, Range finder and data recording sheets.

The movement has been facilitated by clearing of gherries (illegal embankments) at places. One significant population of dolphin is now observed in southern sector, by moving from other sectors, the official said.

A total of 18 teams had conducted the annual count of the dolphin population for around six hours. While 10 teams of experts conducted the counting in Balugaon area and 8 teams were engaged for the counting in Satapada area, he said, adding that restriction on the visit of the tourists to the lake was also imposed during the counting period.

A bird census conducted on January 5, 2021 also revealed that a total of 12,42,000 individuals of 105 water bird species and 26,405 individuals of 76 wetland dependent species, were counted from the entire lagoon.

"This year, more birds are found in Central and Southern sectors of Chilika. An increase in the population of open water preferring diving ducks was noticed during the current season, particularly in the prawn gherries evicted areas clearly indicating the beneficial impact of eviction for migratory birds," Nanda said.

The bird survey also brought to light the number of waderer have increased across the lake compared to the census date. Lesser Flamingo, Ferruginous Pochard and common Shelduck were encountered after a long gap, Nanda said.

During the Flora and Fauna Monitoring of Chilika Lake on January 15, 2021, five species of seagrasses were reported. Seagrass species such as Holodule uninervis, Holodule pinifolia, Halophila ovalis, Halophila ovata and Halophila beccarii were recorded during the survey, he said.

This occurs over an area of 155 sq km, an increase from 152 sq km of last year. Chilika now has 22 per cent of India's seagrass area, the official said.