Cadmium distribution in sediment and the lugworm Arenicola marina in a low concentration exposure experiment.

Abstract

In the central and southern North Sea, and in the Dutch coastal zone, total cadmium (Cd) concentrations in water are 0.02 {+-} 0.01 {mu}g/L and 0.06 {+-} 0.02 {mu}g/L, respectively Cadmium in the estuarine waters of the Dutch Wadden Sea varied from 0.3 {+-} 0.01 {mu}g/L in the western part to 0.08 {+-} 0.03 {mu}g/L in the eastern part. In whole sediment, the Cd background concentration for the Wadden Sea is 0.5 {+-} 0.01 {mu}g/g dry weight (dw), whereas the reference concentration is 0.08 {+-} 0.02 {mu}g/g dw. The concentrations of total-Cd in surface bulk sediments (0-2 cm) of the central North Sea (Oyster Grounds), and of intertidal mud-flats in the western Wadden Sea varied from 0.05 to 0.15 {mu}g/g dw and from 0.13 to 0.46 {mu}g dw, respectively (calculated from Kahn et al. 1992). These concentration ranges match the reference Cd concentration for Wadden Sea whole sediment (0.5 {+-} 0.01) {mu}g/g dw. Cadmium concentrations in surface sediments of the Dutch coastal zone and estuaries are only slightly elevated compared to the 0.2 {mu}g/g dw, considered as the background concentrations in pristine areas, but well below the level of 10 {mu}g/g dw at heavily contaminated sites. This laboratory study reportsmore » on the distribution of cadmium in the sediment column, and the uptake in the blood/coelomic fluid, intestine and body-wall of lugworms at low cadmium concentration exposure. The aim was to determine possible interaction between the vertical distribution of sediment-bound cadmium and the bioturbating activity of lugworms. 14 refs., 3 figs., 2 tabs.« less