Resumen de Changes in Shoreline and Its Impact on Mangrove Structure in Selected Islands of Sundarbans, Northeast Coast of India

S. Sreelekshmi, S. Bijoy Nandan, M. Harikrishnan

• Climate change impacts, along with anthropogenic interventions, result in rapid land dynamics in terms of erosion and accretion, as well as changes in species diversity and structure, particularly in vulnerable ecosystems like river deltas. In response, the study attempted to analyze the land transformation of selected islands of Sundarbans, the world’s largest delta, during the 1942–2017 period using topographic maps and satellite images as well as estimated the structural parameters of mangroves using the quadrat method. The fndings of the study in Indian Sundarbans revealed a very dynamic shoreline ensuing in the erosion of mangrove habitats, while some areas exhibited accretion. Overall, the islands of central Sundarbans were expanding due to accretion while the western Sundarbans were eroding, however, erosion was found to be higher than accretion in the Sundarbans islands on average. The structural analysis revealed a higher structural development of mangroves in central Sundarbans than in the western sector. However, a higher salinity was also recorded in central Sundarbans compared to western Sundarbans attributed to the low density of native and freshwater-loving species like Heritiera fomes and Nypa fruticans. The study found that rising sea levels, coupled with other natural and human interventions, impacted the shoreline and salinity profle and thereby the species diversity and structure of Sundarbans mangroves, and advocates mangrove restoration and proper management of freshwater resources for the conservation of this vulnerable and sensitive ecosystem.