Cr AND Zn DISTRIBUTION IN SEDIMENT FROM THE SEMI-ENCLOSED KASTELA BAY, THE ADRIATIC SEA (CROATIA)

This paper presents the results of the distribution of granulometric composition, organic matter, carbonate, chromium (Cr) and zinc (Zn) contents in the samples from the first 10 cm of sediment sample, collected in December, 2007, at three stations in the Kastela Bay (eastern Adriatic Sea). The relationship between determined parameters in the sediment was established using the regression analysis. As a result of the surrounding flysch deposit weathering, clay particles prevail in the sediment. Average values of organic matter content for the three stations were in the range from 5.31 to 9.63%, while carbonate content values were from 34.7 to 87.6%. As for the trace metals, Zn is accumulated with carbonate-rich fine-grained sediment, while Cr is associated with samples with the highest (up to 20 %) coarse-grained particles content. The average value for Zn content was 82.68 mg kg super(-1) and for Cr 42.13 mg kg super(-1). The purpose of this study is to identify expected changes of trace metals accumulation and sediment characteristics following the changes in anthropogenic influence, which decreased in the last 15 years. The content of chromium and zinc are lower, in comparison to the results of earlier investigations, but it is still present in sediment, which leads to the conclusion that their origin is mostly natural.