Spatial distribution of labile and total forms of copper and zinc in sediments from the Port of Gdansk

Sediment cores were collected from a number of sites in the Port of Gdansk in 1997 and 1998. The samples were segregated by depth then dried, homogenised and sieved into four grain size fractions (>2.00 mm, 2.00 - 0.063 mm, 0.063 - 0.032 mm, and 0.032 mm) Small-grained sand with a low admixture of silt predominated in all samples, whilst the amount of organic matter and water varied between samples. The 2.00 - 0.063 mm size fraction was the most abundant; and also showed the highest accumulation of trace metals. In the >2.00 mm size fraction the mean concentration of labile forms of copper was 9.06 mg kg^-1 DW, while the concentration of total forms was 12.73 mg kg^-1 DW. The mean concentrations of labile and total forms of zinc in this fraction were 31.79 and 46.27 mg kg^-1 DW, respectively. The widest ranges of concentrations for both labile and total forms of the metals were found in the near-surface sediment layers (0-20 cm). Sediments collected from highly industrialized locations contained the highest concentrations of metals.