This study reports the first confirmed presence of Heritiera littoralis in the Rivière des Créoles, Mauritius, challenging previous assumptions that only Rhizophora mucronata and Bruguiera gymnorhiza were mangrove species in the country. This discovery is crucial for understanding the history, adaptation, and vulnerability of Mauritian mangrove ecosystems to climate change. When comparing mangrove forests of the same estuary type, it is found that forest structure and soil properties (e.g., bulk density, EC, and total organic matter content) are influenced by physical stress. The presence of a nearby lagoon attenuates wave attack, leading to more mature mangroves with lower density and higher DBH. Heritiera littoralis in the study site is growing in intertidal zones mixed with Rhizophora mucronata, despite its physiological vulnerability to high salinity. Mangrove habitat widths in the study sites are notably narrow, measuring only 25 meters wide. Furthermore, its habitat is threatened by the invasion of terrestrial trees such as Pongamia pinnata (PP).　Given the limited inland migration space for mangroves due to rising sea levels, integrated coastal planning and land-use policies are essential to ensure natural adaptation space for mangrove ecosystems and enhance climate resilience in the face of climate change.