Mumbai: Is marine life vanishing amid city's rapid transformation?

The area around the rocky outcrop off Chowpatty where the Chhatrapati Shivaji Maharaj Memorial is to be built has undergone alarming ecological changes over less than a decade according to a recent biodiversity survey The researchers suspect a combination of humandriven and natural causes including coastal development and climate change are primarily to blamePseudopterogorgia fredericki or the Indian Sea plume a species common along Mumbairsquos rocky shores PicsPradip PatadeView this post on InstagramA post shared by midday middayindiaLocated 107 to 15 nautical miles or 19 to 27 km off Chowpatty the site was once a thriving underwater habitat rich with corals gorgonians nudibranchs gastropods and reef fishes In the last week of May marine biologist Dr Ramvilas Ghosh and Pradip Patade cofounder of Marine Life of Mumbai and director of the Coastal Conservation Foundation CCF visited the proposed memorial site during low tide and conducted a twohourlong survey Following the visit both experts revealed ecological changes that point to the possible local extinction of key marine speciesThe experts told midday that several sessile immobile colonial organisms have vanished entirely from the site which is an offshore extension of the rocky coastal ecosystem of South Mumbai ldquoThe disappearance of gorgonians especially Menella indica and Echinogorgia sp is not just a loss of individual species it signals a collapse in the ecological balance of the entire systemrdquo said Dr Ghosh whose conservation efforts are supported by the Mohammed Bin Zayed Species Conservation FundWhat are gorgoniansGorgonians also called sea whips or sea fans are a type of marine invertebrate commonly known as octocorals and are found along the coast of Mumbai in intertidal and subtidal zones which are coastal ecosystems that lie between the high and low tide marksGenus Echinogorgia commonly known as spiny sea fans at the spot where the proposed Chhatrapati Shivaji Maharaj Memorial is slated to be builtThe survey also formed part of CCFrsquos citizen science project Marine Life of Mumbai led by Patade From April to May 2025 the duo conducted surveys across several key sites from Geeta Nagar in Colaba the stretch from Nepean Road to Haji Ali and Carter Road in Bandra West covering significant portions of Back Bay and South MumbaiThree speciesIn December 2018 a similar survey recorded the presence of three gorgonian species Pseudopterogorgia fredericki a species common along Mumbairsquos rocky shores Menella indica first described from Back Bay in 1870 and Echinogorgia sp a more elusive inhabitant These species were previously abundant in specific microhabitats for instance Echinogorgia dominated the exposed rocky surfaces while Menella indica and P fredericki preferred the waveflanked edges ldquoMenella indica holds historical significance Its earliest recorded presence from the Indian coastline dates back nearly 150 years That we can no longer spot it in its type locality is deeply concerningrdquo said Dr GhoshThe spot off Chowpatty where the proposed Chhatrapati Shivaji Maharaj Memorial is slated to be builtSince its first description the true identity and extent of Menella indicarsquos distribution remains unknown as the species is not reported outside the type locality place where a specimen is found Patade who has been documenting regional marine life through the citizen science platform iNaturalist also confirmed the absence of these species in recent observations ldquoI was deeply disappointed and shocked to see the marine life nearly vanish especially the gorgonians which once thrived here in healthy large coloniesrdquo said PatadeGiven that gorgonians are slowgrowing and sessile their abrupt disappearance is unlikely to be a result of seasonal variation The researchers suspect a humandriven and natural causes including coastal development ongoing reclamation projects sedimentation and climate change could be the primary reason behind the declineThe proximity of the site to the proposed Shivaji Memorial raises concerns about the potential ecological impact of largescale infrastructure development in sensitive marine zones However the team does not entirely rule out the possibility that these species may have migrated to deeper less disturbed waters a hypothesis that calls for more extensive underwater exploration and monitoringUnexpected coloniserOne of the most striking discoveries during the latest survey was the noticeable colonisation of Carijoa sp commonly known as snowflake coral Though its invasive status remains debated its aggressive spread and ability to outcompete native species are welldocumented ldquoWersquore seeing early signs of Carijoa engaging in space and resource competition Without consistent monitoring this could further disrupt the faunal composition of what little remains in this fragile habitatrdquo said PatadeExperts also pointed out that as Mumbairsquos coastline continues to undergo rapid transformation the findings serve as a reminder of the delicate balance between development and conservation They also feel that there is an urgent need for sustained marine biodiversity assessments protective policy frameworks and deeper public engagement in safeguarding the cityrsquos underwater heritage