Accumulation of lead, cadmium, copper and nickel by pearl oyster, Pinctada radiata, from Kuwait marine environment

Concentrations of cadmium (Cd), copper (Cu), lead (Pb) and nickel (Ni) were determined in the soft tissue of the oyster Pinctada radiata from three coastal stations during March–June 1990 and March–June 1992. In the 1990 samples, mean metal concentrations in oysters from different sampling stations varied between 0.77 and 1.93 μg g−1 for Cd, 0.38 and 2.29 μg g−1 for Cu, 0.44 and 0.64 μg g−1 for Pb and 0.96 and 1.33 μg g−1 for Ni. In the 1992 samples, the mean concentrations varied between 1.85 and 3.16 μg g−1, 1.01 and 1.18 μg g−1, 10.68 and 18.66 μg g−1, and 0.94 and 1.33 μg g−1 for Cd, Cu, Pb and Ni, respectively. The 1992 samples appeared to have significantly ( p < 0.01 by Studentsʹ t-test) higher mean concentrations of Pb, Cd and Cu than the 1990 samples, except Cu in the 1992 samples, from one station which showed a significantly (p < 0.01 by Studentsʹ t-test) lower mean concentration. The difference in patterns of metal occurrence and the significant increase in the Pb, Cd and Cu mean concentrations in the 1992 oyster samples may be due to a contribution from the 1991 Gulf War oil spill.