Dolphins in the Back Bay

Mumbai’s near-shore waters are known to harbour at least two cetaceans – the Indian Ocean humpback dolphin (Sousa plumbea) and the Indo-Pacific finless porpoise (Neophocaena phocaenoides), that inhabit shallow waters up to 25m deep. Anecdotal records and opportunistic sightings, along with documented strandings show that these two species are frequent and common along Mumbai’s shores.

Shore-based opportunistic surveys of the Back Bay area in 2018-2019 show that Indian ocean humpback dolphins (Sousa plumbea) use this area year around for a range of activities that include socialising and foraging. Throughout their species range, Sousa plumbea being a nearshore species has a habitat overlap with high human use areas, putting them at risk from anthropogenic activities and habitat degradation.

In this rapid survey, we studied waters between Haji Ali Bay and the Back Bay to confirm opportunistic reports. The project assessed the presence of Sousa plumbea over time and identified areas as dolphin hotspots that need monitoring. 

The outcomes of this preliminary work will provide the framework for the long term monitoring of the spatial distribution and habitat use of cetaceans along coastal Mumbai, including the identifying and mitigating of potential environmental and anthropogenic threats to the species and its habitat.