Inventorization of spatial patterns and reassessment of benthic foraminiferal assemblages from mangrove ecosystems of Bay of Bengal

Mangrove ecosystems across the northeast coastal Bay of Bengal are highly productive yet increasingly showing vulnerability to climate change. This study presents a comprehensive inventory of benthic foraminifera from the Indian Sundarbans mangrove and the Budhabalanga estuary along with surrounding mangroves by integrating published records with new observations. Calcareous taxa Ammonia spp., porcelaneous taxa Quinqueloculina seminulum , along with the agglutinated taxon Entzia macrescens , show widespread distribution across the study areas. A species–site occurrence matrix was developed to reassess regional benthic foraminiferal assemblages and establish an updated baseline for future ecological monitoring. Bray–Curtis clustering revealed strong similarity among sites in Sundarbans, whereas the Budhabalanga estuary exhibited distinct assemblage, highlighting differences in community composition between the two mangrove systems. The agreement between literature and present observations supports the persistence of key taxa, while updated records refine the regional inventory. The dominance of Ammonia spp., Quinqueloculina seminulum and Entzia macrescens highlights their adaptability to salinity fluctuations, organic enrichment and hypoxic conditions typical of mangrove systems. Overall, this study provides a robust baseline dataset for assessing environmental change driven by changing climate and supports future ecological monitoring as well as conservation strategies in mangrove-dominated coastal ecosystems.