Diversity of Recent Benthic Foraminifera and its Environmental Condition of Selected Estuaries in Tamil Nadu, India

Micropaleontological investigation has been carried out, for the first time to study the systematic of recent Benthic Foraminifera from the southeast coast flowing river estuaries Cauvery, Athankarai and Thamirabarani, Tamil Nadu, India. Totally 16 sediment samples were collected during December 2018. Benthic foraminiferal species, belonging to 14 species, 7 families and 5 Sub-orders are identified. Among this Miliolida (>75%) occupies the dominant place followed by Rotaliida (<25%). The higher species are observed in the rivermouth area particularly in the Cauvery estuary sample (365 species of Ammonia beccarii). The following species are abundantly distributed in this region namely Ammonia beccarii, Quinqueloculina and Miliolinella subrotunda. The abundance of species in the river mouth may be due to the mixing of marine and nearshore environment.