Vertical Distribution of Phosphorous Fractions and Bioavailability of the Nutrient in the Southern Indian Ocean

Abstract The study evaluated concentration, vertical distribution, and bioavailability of phosphorus fractions in the Indian Ocean core sediments. Sediment samples were collected from two sites during January–February 2010 using gravity corer. Phosphorus sediments analyzed by a modified sequential extraction procedure (SEDEX). profile revealed silt clay as dominant grain size both cores. enriched levels organic carbon observed due to adsorption on fine grained Loosely bound P was most fraction, its higher concentration increased productivity subsequent inputs biogenic components. Detritus marine organisms lower oxygen concentrations (depleted E h values) enhanced production authigenic P. iron fraction at specific depths attributed nature Fe minerals present within Decreased level phosphate mineralization. presence Detrital P, diagenetically stable form might be Himalayan, peninsular Indian, Sri Lankan regions. throughout cores suggesting dissolution fish debris. Estimated bioavailable phosphorous (BAP) ranged 82.2 98.7% Core I 90.21 92.98% II, fact that major portion hence alterations environmental conditions can release BAP water column resulting nutrient enrichment. Graphical