『Abstract
　Phosphorus (P) species concentrations in 0-2 cm surface sediment layer were investigated monthly from November 2001 to December 2002 at the bay, channel and open sea stations in the middle Adriatic. Modified SEDEX method was used for inorganic phosphorus species determination [P in biogenic (P-FD), authigenic (P-AUT), detrital apatite (P-DET) and P adsorbed on to iron oxides and hydroxides (P-Fe)], and organic phosphorus (P-ORG). P-FD, P-AUT and P-DET concentration ranges (1.5-5.4, 0-2.7 and 0.4-3.4 μmol g^-1, respectively) were similar at all stations, and showed no obvious common trend of seasonal changes. P-Fe ranged from 1.9 to 11.9 μmol g^-1 with the highest values at bay station and higher seasonal oscillations than other inorganic P forms. P-ORG ranged from 0.3 to 18.7 μmol g^-1 with higher concentrations at stations of fine-sized sediments and showed increased concentrations in warm part of the year at all stations. Correlation between concentrations of P-Fe in the surface sediment layer and orthophosphate sediment-water interface concentration gradients at bay and channel stations indicated to P-Fe importance in the orthophosphate benthic flux. For the bay station, linkage between sediment P-ORG and chlorophyll a concentrations, primary production and microzooplankton abundance was established, indicating a 1 month delay of sediment response to production fluctuations in the water column.

Keywords: Sediment; Phosphorus species; SEDEX method; Adriatic Sea』

Introduction
Materials and methods
　Study area
　Sampling and analytical determinations
Results and discussion
　Orthophosphate (HPO4^2-) concentration in the sediment pore water
　Biogenic (P-FD), authigenic (P-AUT) and detrital (P-DET) apatite phosphorus species concentrations in the sediment
　Iron-bound phosphorus species (P-Fe) concentrations in the sediment
　Organic P species (P-ORG) concentrations in sediments
Conclusions
References

※抽出法は、SEDEX法を改良したもの。