Benthic foraminiferal response to estuarine environments-a case study from Cauvery river, Poombuhar, Tamil Nadu

摘要

The foraminiferal population in forty sediment samples collected from Cauvery river estuary, Poombuhar, were studied in detail to ascertain the influence of estuarine environments on them. The samples were collected from ten stations, once in threemonths during the four seasons of an year. 30 foramainiferal species belonging to 19 genera have been identified of which 7 are arenaceous agglutinated, 7 are calcareous porcelaneous and remaining 16 are calcarecous perforate forms. Population distribution of the three abundant species namely, Ammonia tepida, Florilus grateloupi and Quinqueloculina seminulum is discussed in relation to observed environmental factors like salinity, dissolved oxygen, temperature, depth, calcium carbonate, organic matter and sediment fines. The distribution and ecology of foraminifera reveals that the maximum living as well as total population are found to be high during March. Spatially, they are densely populated in the first three stations from the mouth of all collections.