engleski

Vertical distribution of phosphorus species and iron in sediment at the open sea stations in the Middle Adriatic region

Sedimentary phosphorus species concentrations were examined in cores (0-10 cm) from 5 locations in the open Middle Adriatic in June 2002. Measurements included organic phosphorus (OP) and inorganic P species: P in biogenic apatite (P-FD), P adsorbed onto iron-oxy/hydroxides (P-Fe), P in authigenic apatite (P-AUT), and P in detrital apatite (P-DET). Total iron (Fe-TOT) and Fe-oxyhydroxides (Fe(III)OOH) concentrations were also determined as well as granulometric composition, organic matter (OM), organic carbon (C-ORG), and carbonate content (CA). Sediment pore water measurements included redox-potential (EH) and orthophosphate concentration. All relevant data were subject of correlation, Cluster and PC analysis. Cluster analysis indicated that granulometric composition and carbonate content is the leading factor of distinction between the stations. PCA revealed that fine fraction of sediments has a key role in vertical distribution of Fe-TOT and P-ORG. Linkage among the P-AUT, P-DET and C-ORG is resulting from the river input influence, while association between OM, P-Fe, Eh and OP arises from internal complex processes in sedimentary P cycle.

phosphorus ; sediment ; iron ; Adriatic Sea

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