Coastal lagoons are a highly unique productive ecosystem, biologically conserving units located onshore in thickly populated areas from tropics to artic. Each lagoon and coastal wetlands along east coast vary in their characteristics seasonally and geo especially. Many lagoons are under threat in countries like India, Brazil, Australia, Sri-Lanka due to hydrological, anthropogenic, geologic, pedologic and climatologic anomalies since the last 40-50 years. Further, the uncertainties of geologic, seismic and ENSO activities in the east coast of India is continuously shifting the strand laine keeping pace with sea level rise indicating loss of coastal wetlands and lagoons. Studies on deformation of lagoons and anthropogenic activities near or in the edge of the barrier islands with SLR shall change the TI?s behavior and accompanying ecology. Basin and ecosystem management is essential to combat the future exacerbation of lagoons along the east coast of India in the altering scenario of RSLR, temperature induced increased evapotranspiration, longshore drift and the paucity of sediment inflow to deltas. Present study envisages about lagoons, its classification, a comparative study of major lagoons along the east coast of India in changing CC, SLR and seismic activities as ESS unit. The causes, effects and ameliorating measures to combat 21st-century natural and anthropogenic scenario of lagoons are analysed.