Mangroves are the only woody, facultative halophytes that grow at the ecotone between land and sea. Effective stress management is crucial for mangrove plant survival in the saline environment, leading to distinctive adaptations among species. The study aimed to examine the variation in leaf lamina characteristics of Rhizophora mucronata Lam., focusing on its saline thriving and the impact of water pollution and salinity on the foliar characteristics of species at selected sites in northern Kerala districts. R. mucronata plants with similar heights and diameters were chosen from each study site, and their mature leaves from the third node were taken away for foliar examination. The laminar characteristics of R. mucronata vary spatially and are influenced by salinity and water quality. Significant foliar modifications such as low density of stomata, thick waxy cuticles, corky warts, thick water storage tissue/ hypodermis, and thick lamina were developed by R. mucronata to adapt to the high saline and polluted environment. Water analysis revealed that the conserved sites are less polluted than others. Water quality parameters like turbidity, NTU, colour, Hazen, total Coliforms, CFU/100ml, and total dissolved solids (TDS), mg/l were lower at the conserved sites. Compared to less polluted and conserved sites, R. mucronata distributed in more saline and polluted sites exhibit low leaf chlorophyll content in mg/g tissue, which indicates high salinity and water pollution impact the photosynthesis and productivity of Rhizophora. Therefore, immediate conservation measures must be implemented to conserve these polluted mangrove habitats.