Mumbai On the eve of World Environment Day, the state forest department’s Mangrove Foundation announced its decision to conduct the first-ever dolphin population estimation across coastal waters of the Mumbai Metropolitan Region.
A recent pilot study by the Coastal Conservation Foundation (CCF) in South Mumbai’s Backbay area resulted in 27 sightings of Indian Ocean humpback dolphins, prompting the state to conduct a detailed study across the entire 150-kilometre MMR coast.
Dolphins are an endangered cetacean species and are protected under Schedule I of the Wildlife Protection Act, 1972. The largest group encountered during CCF’s pilot study in Mumbai comprised six individuals. The study was conducted between Haji Ali Bay and Raj Bhavan and within the Back Bay, between April 14 and May 11, 2022. Approximately 15 sightings from these were of groups that included juveniles and sub-adults.
“While dolphins in this area have been documented and photographed before, this study gave us an opportunity to understand how they react to both environmental and human-induced factors in the area. Through this pilot study, it’s too early to know how many dolphins there are, and how this area is being used by juveniles, sub-adults and adults regularly,” said Shaunak Modi, founder, CCF.
Modi’s team also gathered environmental data such as the depth, temperature, salinity, turbidity and tidal flow; and anthropogenic data such as the presence of fishing activity, every time a pod or individual dolphin was sighted. Photographs of fins were taken whenever possible to use towards building a fin catalogue that could serve as the basis for future long-term population studies.
Virendra Tiwari, the additional principal chief conservator of forests (mangrove cell), said, “There have been stray sightings of dolphins reported along the Mumbai coast all the way from Manori, Versova creek areas to Nariman Point, Marine Drive, and going towards Alibaug for quite some time now. However, no such dedicated population estimation or analysis of their habitat usage has been carried out prior to this. The study will begin post-monsoon across MMR. These dolphins are also biological indicators and their behaviour and the environmental conditions they are surviving in will also reveal more details on climate impacts that they are exposed to and the interventions we can build.”