INTERACTIONS OF SILVER, CADMIUM, AND COPPER ACCUMULATION IN GREEN MUSSELS (PERNA VIRIDIS)

摘要

Metal interaction is vital for assessing the use of aquatic organisms in monitoring metal contamination. The present study examined the interactions between Ag and Cd accumulation and between Ag and Cu accumulation in the green mussel (Perna viridis). Accumulation of Ag and Cd in the whole tissue of green mussels exposed to 5 μg/L of Ag and 20 μg/L of Cd for two weeks was independent; however, interaction was observed at the subcellular level. Approximately 25% of Ag shifted from the insoluble fraction (IF) to the metallothionein-like protein in the presence of Cd, which probably resulted from the competition of Cd on IF in the Ag-Cd coexposure. On the other hand, coexposure of the mussels to Ag (5 μg/L) and Cu (30 μg/L) for two weeks increased the Ag and Cu concentrations in the tissue synergistically (two- to fivefold), but Ag and Cu subcellular distributions were similar in the coexposed and the singly exposed mussels. Exposure to Ag alone increased the dietary uptake of Ag by 30%, but the effect was reduced in the presence of Cd. No interaction, however, was observed between uptake rates of metals from the dissolved phase. To conclude, a significant interaction was observed for total Ag and Cu accumulation, but not for total Ag and Cd accumulation, in the mussels. Metal interaction is more likely to be observed at the subcellular level than at the whole-tissue level.