Channel Controlled Foraminiferal Distribution off Bakkhali, West Bengal, India

Sachin Kumar Tripathi, Resmi S., Satyendra Baraik, Debasis Sengupta, Amitava Lahiri


Study area is situated 8 km south of the Bakkhali Island, West Bengal of India and its subaqueous environment influenced by the fluvial processes such as Hooghly River in west and its distributary like Muri Ganga in the centre and Saptamukhi River in the east. To understand the submarine behavior of these channels and associated meiobenthos, total of 28 sediment samples have been studied in detail. The study reveal that a total of fifteen species of recent benthic foraminifera belonging to 13 genera under 11 families were present and their distribution mainly controlled by channel morphology and sediment character. Based on the distribution of these benthic foraminiferal species, two assemblages have been identified. First assemblage, observed within the Hooghly and Muri Ganga channel, where salinity is comparatively low and sediment is mainly dominated by silt and clay. The most dominating benthic foraminifers of this assemblage are Ammobaculites agglutinans, Cribrostomoides jeffreysii and Asterorotalia trispinosa. Whereas, second assemblage mainly comprise of A. trispinosa, Ammonia beccarii, Asterorotalia spp., Elphidium excavatum, Elphidium crispum and Ammonia tepida noticed over the sand bars and adjoining shallow area.
Keywords: channel morphology, Muri Ganga, Hooghly, sand bar


channel morphology, ;Muriganga; Hooghly; sand bar

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Albani, A. D., Favero, V. and Serandrei Barbero, R. 1991 The distribution and ecological significance of Recent Foraminifera in the Lagoon south of Venice. Revista Espanola de Micropaleontologia 23 (2), 129–143

Bianchi, T.S., 2013. Estuaries: where the river meets the sea. Nature Education knowledge 4 (4): 12.

Chakrabarti, A., 2005. Sedimentary structures of tidal flats: A journey from coast to inner estuarine region of eastern India, Journal of Earth System Science, 114 (3): 353–368.

Chaudhuri, A. B. and Choudhury, A.(1994). Mangroves of the Sundarbans, India. IUCN-Bangkok. Thailand. I, 1-247.

Debenay, J.P., Guillou, J.J., Redois, F., and Geslin, E., 2000. Distribution trends of foraminiferal assemblages in paralic environments: a base for using foraminifera as bioindicators, in Martin, R.E., ed., Environmental Micropaleontology: New York, Kluwer Academic/ Plenum Publishers, p. 39–67.

Folk R.L., 1966. Review of grain size parameters. Sedimentology, 6:73-93.

Gautam K.D., 2010.Environmetal status of Bakkhali beach, west Bengal, Geographical review of India, 72 (2):132-139.

Ghosh, B.K., 1966. Asteroralalia trispinosa (Thalamann), a spinose rotaliid foraminifera from Digha beach, Sourthern Bengal. Contribution from the Cushman Foundation for foraminiferal research, 17 (3), 104-108.

Ghosh, A., Biswas, S., and Barman, P., 2014. Marsh foraminiferal assemblages in relation to Vegetation in Sunderban, India. Journal of Geological Society of India, 84: 657-667.

Hameed, A., and Achyuthan, H., 2011. Benthic forminiferal assemblage from the estuary and tidal zones along the east coast of Tamilnadu, India: Deciphering Holocene Sea level changes, Journal of the Palaeontological Society of India 56 (2): 195-200.

Jayaraju, N., and Reddy, K.R., 1995. Foraminiferal ecosystem in relation to coastal and estuarine sediment of Kovalam-Tuticorin, South India, Journal of Geological Society of India, 46: 565-573.

Kathal, P.K., 2002. Distribution and ecology of recent foraminifera from littoral sediment of Eastern India, Journal of Geological Society of India, 60: 429-454.

Kraft, J.C., and Marqules, G., 1971. Sediment patterns physical characters of the water mass and foraminiferida distribution in the Indian River Bay, coastal Delaware: Southern eastern Geology.,12: 223-252.

Loeblich, A.R., and Tappan, H., 1988. Foraminiferal Genera and Their Classification. Van Nostrand Reinhold, New York, 715p.

Murray, J.W., 1991. Ecology and Paleoecology of Benthic Foraminifera: Longman Scientific and Technical, Essex: 397p

Murray, J.W., 2006. Ecology and application of benthic foraminifera. Cambridge University press, Cambridge: 426p.

Nigam, R., 1984. Living benthic foraminifera in a tidal environment: Gulf of Khambat (India), Marine Geology, 58 (3-4): 415-425.

Rao, T.V., and Rao, M.S., 1974. Recent Foraminifera of Suddagedda estuary, east coast of India” Micropaleontology: 398-419.

Reddy K.R., and Rao, R.J., 1984. Foraminifera- salinity relationship on the Pennar estuary, India”, Journal of Foraminiferal Research 14: 115-119.

Resmi, S., Tripathi, S.K., Chatterjee, A.K., Sengupta, D., Baraik, S., and Lahiri, A., 2017. Fresh water scarcity in central and eastern part of Indian Sunderban Delta Complex, The First International ASRO Geological Congress, Morocco, (ASRO- GS-2107): 71-72.

Ryan, J.J., 1969. A Sedimentological Study of Mobile Bay, Alabama. Florida State University Sedimentology Research Laboratory Contribution 30:109.

Sabyasachi, M., Choudhary, A., Naidu, T.Y., and Bandyopadhyay, S., 1996. A reconnaissance survey of recent benthic foraminifera from the mangrove Estuarine sector of Indian Sundarbans, Vidhyasagar university of Journal of Biological Science 2: 40-46.

Scott, D.B., Piper, D.J.W., and Panagos, A.G., 1979. Recent salt marsh and intertidal mud flat foraminifera from the western coast of Rivista Italiana di Paleontologia, 85: 243-266.

Sen Gupta, B. K., 1999, Foraminifera in marginal marine environments, in Sen Gupta, B. K. (ed.), Modern Foraminifera: Kluwer Academic Publishers, Dordrecht,. 141–159

Sen Gupta, D., Satyendra, B., Resmi S., Tripathi, S. K., Chatterjee, A. K., 2016. Seabed Mapping and study of shoreline changes and evaluation of Geomorphological parameters in the innershelf (0-10m water depth) off Western Sundarbans, unpublished report, Geological Survey of India.

Shepard, F.P., 1954. Nomenclature based on sand-silt-clay ratios: Journal of Sedimentary Petrology, 24: 151-158.

Susanta, K. C., Tridip, K. D., 2018. Relevance of Meiobenthic Research: Indian Perspectives. Examines Marine Biology Oceanography, 1 (4):1-5 DOI: 10.31031/EIMBO. 2018. 01.000523.

Tripathi, S. K., Resmi, S., Lahiri, A., Sengupta, D., and Baraik, S., 2017a. Submerging Susni Island of Sunderban Delta Complex: A Report, Indian Journal of Geosciences 71 (2): 405-412.

Tripathi, S. K., Resmi, S., Lahiri, A., Baraik, S., and Sengupta, D., 2017b. Substantial land subsidence and its impact on Kalinagar, Sundarban Delta, West Bengal, Indian Journal of Geosciences 71 (4): 589-598.

Tripathi, S.K., Sengupta, D., Sathikumar, R. Baraik, S., and Lahiri, A., 2018. Foraminiferal evidence of basin submergence in part of Sundarban mangrove delta, India, Arabian Journal of Geosciences 11: 639.