Distribution of selected trace metals in coastal surface sediments from the middle and south Adriatic

Abstract

The environmental conditions along the well-indented Croatian coast change over a short distance. The same applies to the concentration of various pollutants in the marine environment. In addition, numerous islands, which are located in front of the mainland in several lines, create numerous channels and passages. This limits the exchange of water masses between the inner shore and off shore areas. The aim of the present work was to determine the levels of cadmium, lead, copper and zinc in coastal surface sediments at five stations located in the inner shore waters, and at one station located off shore, considered as a reference station. The comparison of the obtained results for the inner shore stations with the reference station showed that the station located at a river mouth in the vicinity of a former metallurgical complex and a phosphate ores and fertilizer terminal is significantly contaminated by Cd, Cu, Pb and Zn. At other inner shore stations a slight increase of lead was recorded, as the result of anthropogenic inputs. The increase of copper concentration at one inner shore station, which is under the impact of open waters, is most probably the result of the weathering of source rocks. The granulometric composition of the sediment indicated that allochtonous fine coarse particles settle down in the inner shore waters, which leads to the conclusion that the majority of terrigenous inputs would remain in the inner shore areas.