title: Elemental composition, distribution and control of biogenic silica in the anthropogenically disturbed and pristine zone inter-tidal sediments of Indian Sundarbans mangrove-estuarine complex.
abstract: Spatial distribution and interrelationship among organic nutrients - silica and carbon - and various lithogenic elements were investigated in the surficial sediments of Matla estuary and Core Zone of Indian Sundarbans Reserve Forest using spatial analysis and multivariate statistics. Biogenic silica (BSi), an important parameter for coastal biogeochemisry, was measured using Si-time alkaline leaching method. BSi concentration ranged from 0.01% to 0.85% with higher concentrations in upstream region of Matla estuary and attenuated values towards the bay, seemingly due to changes in hydrodynamics and land use conditions. Spatial distribution of BSi did not exhibit significant correlation with sediment parameters of organic carbon (OC), elemental composition and clay content. However, it showed significant contrasting trends with total phosphorus (TP) and total silica of human influenced Matla estuary sediments as well as the dissolved silica (DSi) of its surface waters. Anthropogenic influence on sediment geochemistry is discernable with the presence of higher concentrations of organic and inorganic elements in Matla estuary than in Core Zone sediments. Spatial variation trends are often challenging to interpret due to multiple sources of input, varying energy and salinity conditions and constant physical, chemical and biological alterations occurring in the environment. Nonetheless, it is certain that anthropogenic activities have a substantial influence on biogeochemical processes of Sundarbans mangrove-estuarine complex and potentially the coastal ocean.
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
authors.forename: Shreya
authors.initials: S
authors.lastname: Dhame
authors.affiliation: School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India; Department of Environmental Science, Central University of Rajasthan, Kishangarh, Ajmer, 305817, Rajasthan, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Kumar
authors.affiliation: Department of Environmental Science, Central University of Rajasthan, Kishangarh, Ajmer, 305817, Rajasthan, India. Electronic address: alrjnu@gmail.com.
authors.forename: A L
authors.initials: AL
authors.lastname: Ramanathan
authors.affiliation: Department of Environmental Science, University of Calcutta, Ballygunge Campus, Kolkata, India.
authors.forename: Punarbasu
authors.initials: P
authors.lastname: Chaudhari
mesh_terms: D002244:Carbon / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods; D063366:Estuaries; D019015:Geologic Sediments / Q000032:analysis* / Q000737:chemistry; D007194:India; D008670:Metals / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D012822:Silicon Dioxide / Q000032:analysis*; D062206:Spatial Analysis; D014874:Water Pollutants, Chemical / Q000032:analysis; D053833:Wetlands
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D002244:Carbon; D012822:Silicon Dioxide
keywords: Biogenic silica; Organic carbon; Sediment geochemistry; Sundarbans mangroves; Total phosphorus