UTTAR PRADESH JOURNAL OF ZOOLOGY

While the Indian Ocean is home to a diverse assemblage of marine mammals, there is a marked paucity of data concerning cetacean ecology and conservation in the region. This review analyzes current knowledge of species richness, distribution and conservation status of marine mammals in the Indian Ocean, particularly climate change vulnerability and management considerations. Based on systematic synthesis of more than 80 publications (2000-2025) from major databases, this review identifies key patterns, vulnerabilities, and research gaps. The Indo-Pacific represents a global hot-spot for threatened coastal cetaceans. The Indian Ocean humpback dolphin (Sousa plumbea) is one of the most threatened species with small geographic distribution and dependence on coastal localities. Climate change has emerged as the most devastating threat, fuelled by rapid warming of the Indian Ocean that currently has the highest rate of oceanic warming on a global scale. The projections indicate that by 2050, on-going marine heat wave conditions will establish with severe impacts on the ecosystem services and fishery productivity. Over 70% of marine mammal populations exhibit high sensitivity to climate impacts (e.g., modified prey distribution, habitat alteration, physiological stress). Such pressures are exacerbated by fisheries by catch, rising vessel traffic and acoustic pollution. Priorities for action include the implementation of climate-proof marine spatial planning, living protected areas, improved by catch measures in the fisheries sector and strengthened regional cooperation. Urgent policy action is needed to halt these declines and ensure long-term conservation of marine mammals in the Indian Ocean.