1503 / 2024-09-27 20:19:57

Assessment of ecological health status of Sundarbans mangrove of the Bay of Bengal using benthic foraminifera biofacies

mangrove,benthic foraminifera,ecological health

The northeast coastal Bay of Bengal in South Asia is interspersed with several coastal biotopes influenced by the Ganga-Brahmaputra-Meghna delta, among others, and contributes to the sustainable blue economy locally and regionally. Over the last decade, anthropogenic climate

change, including relative rise in sea level, coastal erosions, depressions, reduced freshwater flow and altered riverine course, has become a primary driver toward changing ecosystem conditions in the Sundarbans. The present study investigated the seasonal and spatial extent of

benthic foraminiferal community across the Sundarbans to identify degraded mangrove patches. Extensive sampling of the significantly different Sundarbans microhabitats highlighted the overwhelming abundance of calcareous taxa Ammonia spp., Quinqueloculina spp. as well as

lower number of agglutinated taxa Entzia macrescens (found exclusively in mangrove forest). The overwhelming abundance of calcareous taxa indicated that the mixing of freshwater with saline water has decreased in recent years. The falling flushing rate can have biological consequences on mangrove vegetation structure and physiology. The infrequent occurrence of Entzia macrescens indicated the degraded mangrove patch, as these taxa are particularly sensitive to mangrove vegetation. Thus, the benthic foraminifera dataset helped towards mapping of severely impacted sites with deteriorating ecological health status and for undertaking future ecological restoration activities to ensure the resilience of Sundarbans mangrove.