Bioavailability of zinc in the sediment to the estuarine amphipod Grandidierella japonica

摘要

The utility of interstitial water concentrations of metals and simultaneously extracted metal s/acid-volatile sulfide differences (SEM-AVS) in two seasons were investigated to explain the biological availability of zinc in sediments to benthic organisms exposed in the laboratory. The amphipod Grandidierella japonica was exposed, in 10-day acute toxicity tests, to clean sediment spiked with zinc to obtain nominal treatments ranging from 0.25 to 74.4 mu mol g(-1) dry weight with respect to the molar difference between SEMZn and AVS. When the molar difference between SEMZn and AVS (i.e., SEM-AVS) was < 0 mu mol g(-1), the concentration of zinc in the sediment interstitial water was low and few adverse effects were observed for any of the biological endpoints measured. Conversely, when SEMZn-AVS exceeded 0 mu mol g(-1), the concentration of zinc in the interstitial water and amphipod mortality increased. These data compare favorably with observations made in short-term exposures and thus support the use of AVS as a normalization phase for predicting toxicity in metal-contaminated sediments in different season.