title: Phosphorous fractionation in mangrove sediments of Kerala, south west coast of India: the relative importance of inorganic and organic phosphorous fractions.
abstract: The study of phosphorous dynamics in mangrove ecosystems of the northern Kerala coast aims to delineate its relationships with other biogeochemical parameters. Our intension is to check the validity of the hypothesis that these mangrove ecosystems act as an efficient trap of organic phosphorous by acting as P sink. The dissolved inorganic phosphate displayed higher concentration in monsoon that could be correlated with higher P leaching from mangrove litter as well as terrigenous input during wet season. Fe(OOH)≈P was much higher in monsoon (235.23 to 557.70 μg g(-1)) and lower in pre-monsoon (36.50 to 154.97 μg g(-1)), and displayed significant contribution towards the inorganic sedimentary P fractions. In monsoon, adsorption of P on iron hydroxides is enhanced by fresh water conditions, but pre-monsoon is characterised by the reductive dissolution of iron oxy hydroxides and the subsequent efflux of P to water column. CaCO3≈Pinorg may be present as an inert fraction in the sediment matrix, and did not display any interrelationship with other geochemical parameters. The abundant total organic P (25 to 73 %) fractions, largely derived from P bound with humic/fulvic acid, played a major role in immobilising P and regulating its dynamics in the nearby estuarine and coastal environment.
authors.affiliation: Department of Chemical Oceanography, School of Marine Science, CUSAT, Cochin, Kerala, 682016, India. resmipmurali@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Resmi
authors.affiliation: Department of Chemical Oceanography, School of Marine Science, CUSAT, Cochin, Kerala, 682016, India.
authors.forename: M N
authors.initials: MN
authors.lastname: Manju
authors.affiliation: Regional Centre-Kochi, National Institute of Oceanography, Dr. Salim Ali Road, Kochi, 682018, India.
authors.forename: T R
authors.initials: TR
authors.lastname: Gireeshkumar
authors.affiliation: Chemical Examiners Laboratory, Thiruvanathapuram, Kerala, India.
authors.forename: C S
authors.initials: CS
authors.lastname: Ratheesh Kumar
authors.affiliation: Department of Chemical Oceanography, School of Marine Science, CUSAT, Cochin, Kerala, 682016, India.
authors.forename: M
authors.initials: M
authors.lastname: Movitha
authors.affiliation: Department of Chemical Oceanography, School of Marine Science, CUSAT, Cochin, Kerala, 682016, India.
authors.forename: K
authors.initials: K
authors.lastname: Shameem
authors.affiliation: Department of Chemical Oceanography, School of Marine Science, CUSAT, Cochin, Kerala, 682016, India.|Inter University Centre for Development of Marine Biotechnology, School of Marine Sciences, CUSAT, Cochin, Kerala, 682016, India.
authors.forename: N
authors.initials: N
authors.lastname: Chandramohanakumar
mesh_terms: D017753:Ecosystem; D004784:Environmental Monitoring; D005618:Fresh Water; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D007194:India; D007501:Iron / Q000737:chemistry; D010758:Phosphorus / Q000032:analysis / Q000737:chemistry*; D017553:Phosphorus Compounds / Q000032:analysis / Q000737:chemistry*; D012621:Seasons; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D053833:Wetlands
chemical_list: D017553:Phosphorus Compounds; D014874:Water Pollutants, Chemical; D010758:Phosphorus; D007501:Iron
keywords: India; Mangrove; Northern Kerala coast; Phosphorous fractionation