A recent pilot study conducted in south Mumbai’s Backbay region has confirmed 27 sightings of Indian Ocean humpback dolphins, a development that has prompted the Maharashtra government to launch a detailed population study of marine mammals along the Mumbai coastline.

In what came as something to cheer for nature lovers on the eve of the World Environment Day, the Maharashtra State Mangrove Cell announced on Saturday that it would launch first-of-its-kind detailed population estimation study of dolphins along the coastline of the Mumbai Metropolitan Region (MMR).

The announcement follows the outcome of a preliminary research exercise carried out by the Coastal Conservation Foundation (CCF), which was sanctioned by the Maharashtra State Mangrove Foundation, determined the population and habitat usage of Indian Ocean humpback dolphins in the Backbay region of south Mumbai. The study confirmed 27 sightings of dolphins of which the largest group comprised six individuals.

After the  detailed census of marine mammals along the MMR coastline, Mumbaikars will have a clarity about the number of Dolphins along the 150 km-long Mumbai coastline.   

Dolphins are endangered cetacean species, protected under Schedule I of the Wildlife Protection Act, 1972.

Mumbai’s waters are known to harbour at least two cetaceans - the Indian Ocean humpback dolphin (Sousa plumbea) and the Indo-Pacific finless porpoise (Neophocaena phocaenoides), as per anecdotal sightings and documented stranding.

Indian Ocean humpback dolphins reside in groups of up to twelve individuals, however, this number varies greatly. Sciaenid fish, cephalopods, and crustaceans make up their food. The species is listed as Globally Endangered by the International Union for Conservation of Nature (IUCN).

Cetaceans such as dolphins that live in close proximity to coastal development and its ramifications have a high death rate owing to anthropogenic disturbances such as fishing entanglement, pollution, habitat degradation, and noise pollution.