Summary
Metals at contaminated sites in Antarctica rarely occur in isolation, but rather occur in complex mixtures with a number of contaminants. Despite this, the majority of previous ecotoxicological studies on Antarctic marine biota have investigated the toxicity of single metals only. Information on the effects of metal mixtures is required in order to make realistic management decisions regarding the potential risk and the remediation of contaminated sites. In this study, the effects of individual and combined metals including copper, cadmium and zinc on the survival of Antarctic benthic harpacticoid copepods were determined in 10 day toxicity tests. The toxicity of each metal increased when combined with an additional metal as indicated by lower LC50 values for metal mixtures: Cu=14?g/L and Cu(+Cd)=5?g/L (Test 2); Cd=370 ?g/L and Cd(+Cu)=29?g/L (Test 2); Zn=140?g/L and Zn(+Cd)=160 ?g/L . The addition of cadmium to the copper concentration series was most noticeable at copper concentrations of 10 ?g Cu/L and 22 ?g Cu/L. In the higher concentrations of 44?g Cu/L and 85?g Cu/L, 100% mortality was reached by day 7 and day 5 respectively with the added metal cadmium. Results from this work suggest that metal combinations as they are found in the environment, are likely to have a greater impact on copepod survival than single metals do.