Noteworthy news has just surfaced from the recent Dolphin Census in Chilika lake: 146 Irrawaddy dolphins have been directly spotted! The identity of these aquatic creatures was confirmed by leveraging a unique underwater sound-monitoring apparatus known as a hydrophone.
The Census and Hydrophone Technique
The Dolphin Census employed a hydrophone monitoring technique to count the number of Irrawaddy dolphins in Chilika lake. A hydrophone is a specialized microphone engineered for the distinct purpose of recording or tuning into underwater sounds. Its enhanced sensitivity to the acoustics of the aquatic world allows researchers to track and identify different species of water-dwelling creatures like the Irrawaddy Dolphins.
Meet the Irrawaddy Dolphins
Irrawaddy dolphins (Orcaella brevirostris) predominantly inhabit the coastal waters of South and Southeast Asia. Notably, they are also found in three rivers: the Irrawaddy (Myanmar), the Mahakam (Indonesian Borneo), and the Mekong (China). According to the International Union for Conservation of Nature (IUCN) Red List, the Irrawaddy dolphins are classified as ‘Endangered.’ Globally, their population is estimated to be fewer than 7,500, with Bangladesh hosting more than 6,000 of these aquatic mammals. In terms of their distribution within Chilika, it is deemed the highest single lagoon population.
| Species | Status | Global Population |
|---|---|---|
| Irrawaddy Dolphins | Endangered | Less than 7,500 |
The Role of Chilika Lake
Chilika Lake, Asia’s largest and the world’s second-largest lagoon situated on India’s east coast in Odisha, plays an essential role as a haven for these dolphins. A sand strip separates this massive lake from the imposing Bay of Bengal. The lake distinguishes itself as the prime wintering ground for migratory birds on the Indian subcontinent. Besides hosting abundant bird life, it also shelters several species of threatened plants and animals.
In 1981, the Ramsar Convention designated Chilika Lake as the first Indian wetland of international importance. The main attraction at Chilika is without a doubt the Irrawaddy dolphins, frequently spotted around Satpada Island. In addition, the expansive Nalabana Island, spanning about 16 sq km within the lagoon, was declared a bird sanctuary in 1987. Lastly, the revered Kalijai Temple graces one of the islands in Chilika Lake, adding a touch of cultural significance to the natural abundance.
