DISTRIBUTION PATTERNS OF DIFFERENT FORMS OF PHOSPHORUS IN SOME SURFICIAL SEDIMENTS OF THE BALTIC SEA

Abstract

The lateral distribution patterns of different forms of phosphorus (P) in some Baltic Sea sediments were investigated by a sequential extraction procedure. The distribution and amount are mainly related to redox state, grain size, organic content and the chemical characteristics of the sediments. Recalculation from mol P per dry weight (d.w.) to mol P per unit area indicates that coarse sediments typical of transportation bottoms contain more total P than the finer sediments found in accumulation areas. This is applicable for almost all extracted P fractions. The extraction procedure shows that HCl-extractable P, often referred to as apatite-P, is the dominating fraction of almost all sediment types. Oxidized fine-grained sediments of the near-shore area and the archipelago are enriched in the hydrogen sulfide (H2S) extractable P fraction.