The recent news indicates a rise in the dolphin population along the coast of Odisha and surrounding water bodies. However, contrary to the overall surge, there has been a noted decrease in the number of Irrawaddy dolphins in Chilika Lake. A study reveals six dolphin species– Irrawaddy, bottlenose, humpback, striped, finless, and spinner dolphins– have been recorded in the region.
About Different Dolphin Species
Irrawaddy Dolphins
Frequently found in coastal areas in South and Southeast Asia, Irrawaddy Dolphins are also known to live in three rivers: the Ayeyarwady (Myanmar), the Mahakam (Indonesian Borneo), and the Mekong. The segment of the Mekong River between Cambodia and Lao PDR is inhabited by this breed. Classified as ‘Endangered’ on the IUCN Red List, these dolphins are also listed under Appendix I of CITES and Schedule I of the Wildlife Protection Act, 1972.
Indo-Pacific Bottlenose Dolphins
The shallow coastal waters of the Indian Ocean, Southeast Asia, and Australia serve as the habitat for Indo-Pacific Bottlenose Dolphins. As per the IUCN Red List, these dolphins fall under the category of ‘Near Threatened’ and are included in Appendix II of CITES.
Indian Ocean Humpback Dolphins
The Indian Ocean Humpback Dolphin inhabits the Indian Ocean, ranging from South Africa to India. They are listed as ‘Endangered’ on the IUCN Red List, registered under Appendix I of CITES and Schedule I of the Wildlife Protection Act, 1972.
Striped Dolphins
Living in temperate or tropical, off-shore waters, Striped Dolphins are widely found in the North and South Atlantic Oceans, including the Mediterranean and Gulf of Mexico, the Indian Ocean, and the Pacific Ocean. They fall under the ‘Least Concern’ category on the IUCN Red List and are part of Appendix II of CITES.
Finless Dolphins
Originating from salt water niches along the coast of the Indo-Pacific Ocean, Finless Dolphins have unfortunately been classified as ‘Critically Endangered’ on the IUCN Red List and are mentioned in Appendix I of CITES.
Spinner Dolphins
Spinner Dolphins, known for their acrobatic displays, inhabit off-shore tropical waters worldwide. The conservation status is ‘Least Concern’ on the IUCN Red List and they are enlisted in Appendix II of CITES.
About Chilika Lake
Recognized as Asia’s largest and the world’s second-largest lagoon, Chilika Lake is situated on the east coast of India within the state of Odisha. It covers an expansive area of over 1,100 square kilometers and spreads across Puri, Khurda, and Ganjam districts of Odisha. Famous for Irrawaddy dolphins often seen off Satapada Island, it is also the largest wintering ground for migratory birds on the Indian subcontinent and houses numerous threatened species of plants and animals.
In 1981, Chilika Lake was deemed the first Indian wetland of international significance under the Ramsar Convention. A major highlight of the lake is the Nalabana Island (Forest of Reeds) which was declared a bird sanctuary in 1987.
UPSC Civil Services Examination Queries
A significant query from the UPSC Civil Services Examination (2019) focused on matching specific wildlife to their natural habitats. For instance, Blue-finned Mahseer was matched with Cauvery River, Irrawaddy Dolphin with Chambal River, and Rusty-spotted Cat with Eastern Ghats. Among all the given pairs, only the Blue-finned Mahseer and the Rusty-spotted Cat were correctly matched to their respective habitats.
