Accumulation of copper, nickel, lead and zinc by snail, Lunella coronatus and pearl oyster, Pinctada radiata from the Kuwait coast before and after the gulf war oil spill

This study investigated the contribution of the 1991 oil spill to heavy metal contamination in the marine environment of the Gulf in Kuwait by analyzing moleskin organisms (gastropod snail, Lunella coronatus and bivalve Pearl oyster, Pinctada radiata) for their heavy metal contents before and after the spill. Concentrations of copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) were determined in the soft tissue of both snail and oyster samples from three coastal stations during 1990 and 1994. In the 1990 samples, the metal concentrations in snail and oysters from different sampling stations were between 0.35 and 0.67; 0.11 and 2.29 μg/g for Cu, 1.50 and 4.50; 0.47 and 1.33 μg/g for Ni, 0.16 and 2.98; 0.44 and 0.69 μg/g for Pb and 19.94 and 54.79; 247.20 and 1204.40 μg/g for Zn, respectively. In the 1994 samples, the metal concentrations were between 11.24 and 55.00; 28.90 and 168.43 μg/g for Cu, 15.33 and 16.96; 0.08 and 1.54 μg/g for Ni, 0.37 and 0.57 μg/g; 0.07 and 0.44 μg/g for Pb and 28.86 and 486.61; 17.75 and 575.00 μg/g for Zn respectively. The 1994 samples have significantly higher mean concentrations of Cu, Ni and Zn than the 1990 samples, except Pb in the 1994 samples, which showed a slightly lower mean concentration. The difference in patterns of metal occurrence and the significant increase in the Cu, Ni, and Zn concentrations in the 1994 snail and oyster samples were due to a contribution from the 1991 Gulf War oil spill.