Simin Khojasteh Noshari - Department of Fisheries, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran
Javid Namin Imanpour - Corresponding author: Department of Fisheries, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran
Mohammad Forouhar Vajargah - Department of Fisheries, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Iran
Mehdi Bibak - Department of Fisheries and Marine Sciences, Persian Gulf Research Institute, Persian Gulf University, Bushehr, Iran

Background: Wetlands are among the most important ecosystems and areas of life that are ecologically and economically important in the world and susceptible for heavy metal contamination. The elements in water and sediment may be easily and in large quantities available to animals in aquatic ecosystems. This study aimed to investigate the level of heavy metal contamination in Anodonta cygnea. Methods: Anodonta cygnea sampling was carried out in the summer ۲۰۲۳. A total of ۳۵ specimens were collected randomly by fishing net. Following the laboratory analyses, the concentration of aluminum (Al), arsenic (As), copper (Cu), cobalt (Co), cadmium (Cd), iron (Fe), manganese (Mn), magnesium (mg), lead (Pb), nickel (Ni), tin, vanadium (V) and zinc (Zn) were determined by ICP-OES. Results: Target hazard quotient (THQ) values of Mn were above ۱. The pi index showed that A. cygnea is slightly contaminated by Pb. Analyses of the metal accumulation showed that A. cygnea bivalve was moderately contaminated by Zn and severely contaminated by As. The results showed no significant relationship between the total weight of the organism and concentration of Al, Fe, and Ni. Conclusion: Aquatic organisms, including bivalves, do not possess an advanced excretory system, therefore the excretion of metabolites and pollutants is a is a slow process. once the concentration of heavy metals in the aquatic environment increases, they become easily available to aquatic organisms and enter the biological system. In this study, the absorption rate of metals was higher than its excretion or removal by the excretory system which results in their accumulation in various tissues and organs of the organism.

Environmental pollutants, Wetlands, Metals