SPATIAL DISTRIBUTION OF COASTAL ECOLOGICAL PROVINCES OF MANGROVE, CORAL REEF AND SEAGRASS WITHIN THE EXCLUSIVE ECONOMIC ZONE OF THE INDIAN OCEAN RIM COUNTRIES: A REVIEW

Coastal ecosystems play a crucial role in carbon sequestration, coastal protection, fisheries support, and marine biodiversity conservation in the Indian Ocean Rim(IOR) countries. In this study, globally consistent datasets were used to assess the spatial distribution of mangroves, coral reefs, and seagrass meadows across IOR countries at the basin scale. The Global Mangrove Watch (GMW) was used for Mangrove distribution, UNEP-WCMC: Global Distribution of Seagrasses was used to retrieve seagrass data, and coral reef distribution from UNEP-WCMC’s global warm-water coral reef dataset. Quantification of Ecosystem areas was made to enable cross-country comparison within national coastal waters and Exclusive Economic Zones (EEZs).Mangroves have dominant coverage in Malaysia, Myanmar, Bangladesh, India, and Madagascar, contributing ~15–20% of the mapped coastal ecosystems, driven by monsoon climate, deltaic sediment supply, and sheltered estuarine settings. Mangroves are among the most carbon-dense ecosystems, providing effective shoreline stabilization and land–sea ecological connectivity, although spatially limited.Mangroves deliver high carbon density and coastal resilience, coral reefs maximize biodiversity per unit area, and seagrasses dominate spatial extent and carbon sequestration. Overall, the analysis shows strong functional complementarity among IOR coastal ecosystems.