Modern benthic foraminiferal assemblages from the world’s largest deltaic mangrove ecosystem, the Sundarbans

• Published in: Marine biodiversity Vol. 46; no. 2; pp. 421 - 431
• Main Authors: Sen, Areen, Ghosh, Moumita, Khanderao, Pradnya, Das, Sunit Kumar, Chowdhury, Debmalya Roy, Sarkar, Pankaj Kumar, Saha, Ratul, Bhadury, Punyasloke
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2016; Springer Nature B.V
• Subjects: Animal Systematics/Taxonomy/Biogeography; Benthos; Biodiversity; Biomedical and Life Sciences; Foraminifera; Forests; Freshwater & Marine Ecology; Genera; Habitats; Intrusion; Life Sciences; Mangrove swamps; Mangroves; Organic carbon; Original Paper; Plant Systematics/Taxonomy/Biogeography; River ecology; Saline intrusion; Salinity; Salinity effects; Saltwater intrusion; Sea level; Sea level changes; Seawater; Sediment; Sediment composition; Sediment texture; Sediments; Total organic carbon; Bangladesh; Sundarbans; Bay of Bengal; Japan; India; Canonical correspondence analysis (CCA); Mangrove; Benthic foraminifera; Total organic carbon (TOC); Indian Sundarbans; Sea level; Sediment texture
• ISSN: 1867-1616; 1867-1624
• DOI: 10.1007/s12526-015-0383-z

The Sundarbans is the world’s largest contiguous mangrove ecosystem. Recent changes in the region have been reported due to a rise in relative sea level along with increased salinity intrusion. Intertidal benthic foraminifera are widely used as indicators of relative sea level change. The taxonomic diversity of foraminifera in the Sundarbans remains relatively understudied due to the remoteness of this ecoregion. The present study documented modern intertidal benthic foraminiferal assemblages across eight sites from previously unexplored eastern parts of the Indian Sundarbans. We also analyzed sediment texture from the study sites, which is essential for sea level reconstructions. Our study recorded an assemblage dominated by agglutinated genera that are characteristic of mangroves globally. However, we also recorded calcareous genera characteristic of higher-salinity zones, indicating saline intrusion further upstream in the region. In total, we recorded 15 species, representing ten different foraminiferal families. Total organic carbon (TOC) content and sediment composition showed variation across the studied sites. Canonical correspondence analysis (CCA) of the biological and environmental data confirmed its usefulness for understanding shifts in hydrological conditions across this region.