Seasonal heavy metal accumulations in the bivalve Barbatia decussate and their relationships with water quality and the metal-induced biochemical biomarkers

Seasonal tissue concentrations of heavy metals, antioxidant enzymes, immunological components, and water quality parameters were investigated during 1 year in the ark clam, Barbatia decussate , from the coast of Lengeh port, located in the north of the Persian Gulf, Iran. The tissue accumulation of the heavy metals (Cd, Pb, Hg) significantly increased accumulations in late autumn and winter ( P 0.01). Seasonal changes were also observed in metal-induced biochemical components. In this regard, the malondialdehyde (MDA) levels and the activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) elevated throughout spring and summer and then declined during autumn and winter ( P < 0.01). Phagocytosis activity significantly decreased from December to February and then increased from March to September ( P