Effects of contaminants in the Antarctic environment -: potential of the gammarid amphipod crustacean Paramorea walkeri as a biological indicator for Antarctic ecosystems based on toxicity and bioaccumulation of copper and cadmium

This study provides information on LC(50) toxicity tests and bioaccumulation of heavy metals in the nearshore Antarctic gammarid, Paramorea walkeri. The 4 day LC(50) values were 970 mu g/l for copper and 670 mu g/l for cadmium. Net uptake rates and bioconcentration factors of these elements were determined under laboratory conditions. After 12 days of exposure to 30 mu g/l, the net uptake rates were 5.2 and 0.78 mu g/g per day and the bioconcentration factors mere 2080 and 311 for copper and cadmium, respectively. The body concentrations of copper were significantly correlated with the concentrations of this element in the water. Accumulation of copper and cadmium continued for the entire exposure suggesting that heavy metals concentrations were not regulated to constant concentrations in the body. Using literature data about two compartments (water-animal) first-order kinetic models, a very good agreement was found between body concentrations observed after exposure and model predicted. Exposure of P. walkeri to mixtures of copper and cadmium showed that accumulation of these elements can be assessed by addition of results obtained from single exposure, with only a small degree of uncertainty. The study provides information on the sensitivity of one Antarctic species towards contaminants, and the results were compared with data of similar species from lower latitudes. An important finding is that sensitivity to toxic chemicals and toxicokinetic parameters in the species investigated are comparable with those of non-polar species. The characteristics of bioaccumulation demonstrate that P. walkeri is a circumpolar species with the potential to be a standard biological indicator for use in monitoring programmes of Antarctic nearshore ecosystems. The use of model prediction provide further support to utilise these organisms for biomonitoring. (C) 2000 Elsevier Science B.V. All rights reserved.