Trace metals in the Antarctic soft-shelled clam Laternula elliptica : implications for metal pollution from Antarctic research stations

Abstract

The concentrations of Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in several soft-tissue types of the Antarctic soft-shelled clam, Laternula elliptica, which had been collected from Rothera Research Station, Adelaide Island, Antarctic Peninsula. Concentrations of Mn, Ni, Cr and Pb were significantly higher in the kidney than in any other soft tissue and highest concentrations of Cu were observed in the digestive gland. In general, the total tissue concentrations of heavy metals in L. elliptica were considered to be at baseline levels, except for Cu in organisms near the end of the runway. Copper concentrations were an order of magnitude greater (357 µg/g dry weight) than baseline levels, suggesting anthropogenic contamination or an unidentified natural source. However, there was no indication of anthropogenic metal contamination occurring close to the sewage outfall at Rothera, which is a significant metal source. The results indicate that L. elliptica is a useful long-term biomonitor of heavy metal contamination in Antarctic coastal waters.