Metal (Cu, Cr, Cd, Pb) levels in muscle tissue of Laternulla elliptica from Potter Cove, Antarctica

MARQUEZ M.; VODOPIVEZ C.; CASAUX R.; CURTOSI A.; GESINO A.; SIK E.

Simposio; VII SCAR International Biology Symposium; 2001

The main objectives of this study were to determine the baseline of  copper (Cu), chromium (Cr), cadmium (Cd) an lead (Pb) concentrations in muscle tissue of the bivalve Laternula elliptica from Potter Cove, Antarctica, to estimate the potential impact of metallic pollutants in this remote area, as well as to evaluate the possibility of using this species as  a future food resource for fisheries. Laternula elliptica is a benthic filter feeder which is widely distributed around Antarctica and their growth and populational parameters are well known. Considering that the muscle tissue constitutes a large fraction of the body mass of L. elliptica, and that is the only portion susceptible to be used for human consumption, its potential metal accumulation should be considered. During the 1996/97  summer season, 31 specimens of this Antarctic bivalve were collected by SCUBA diving at Potter Cove, King George Island, South Shetland Islands. The content of trace metals (Cu, Cr, Cd and Pb) in the muscle tissue (edible portion) of individuals from 4 different size groups (ranged from 4-5.9, 6-7.9, 8-9.9, 10-12 cm shell length) was determined. Trace metals were quantified by Graphite Furnace Atomic Absorption Spectrometry (GFAAS) using pyrolitic tubes. The Pb (0.28-0.30-0.55-0.31 µg*g-1 dry weight, mean values for different groups) and Cd (1.16-1.46-1.57-3.47 µg*g-1 dry weight) values obtained in the present study were lower than those reported for L. elliptica at Maxwell Bay, also at King George Island, and for other common Antarctic bivalve such as Adamussium colbecki at the East Antarctica. The Cu muscle values (14.11-18.25-39.60-29.00 µg*g-1 dry weight) observed were similar than those reported for A. colbecki at East Antarctica but markedly lower than the reported for L. elliptica at Maxwell Bay. The Cr values (1.30-5.89-2.64-1.57 µg*g-1 dry weight) observed at Potter Cove were slightly higher than the observed for the same species at Maxwell Bay. These results are discussed in relation to the availability of these metals in the environment. The levels of Cu, Cd and Pb tended to increase with the size of the specimens analysed whereas Cr did not evidence any trend.. According to the Cd levels, which are higher than the maximum limit allowed for human consumption,  the ingestion of the flesh of L. elliptica may have potential risk to human health.