Evaluation of Ark clam (Barbatia helblingii) as Biomonitor Agent for PAHs Contamination in Coastal Area of Bushehr

Polycyclic aromatic hydrocarbons (PAHs) are a major group of organic contaminants which are consisted of two or more benzene rings. Many of these compounds are potentially toxic and many studies have been carried out to investigate their toxicity in PAHs exposed people. The Bushehr coastal area is very important place for oil exploration, exploitation and transportation in north Persian Gulf. In addition it is influenced by industrial and municipal effluents as well. Since oil sector activities are the major sources of PAHs input in to the Bushehr marine environment, PAHs contamination of water and aquatic organisms in the area is an expected issue. In order to study the extent of PAHs contamination in seawater and Ark clam (Barbatia helblingii) and to evaluate of the clam as biomonitor agent for PAHs compounds in the area, seawater and clams were sampled from intertidal zone of 5 different stations along Bushehr coasts. After digestion and extraction of PAHs by organic solvents, their PAHs contents were analyzed using HPLC. Result showed that tPAHs concentration in seawater taken from Rafael, Sheghab, Abshirinkon, Industrial zone and Helyleh stations was 31.03 µg/l, 20.85 µg/l, 4.04 µg/l, 17.58 µg/l and 12.29 µg/l respectively. Concentration of tPAHs in soft tissue of B.helblingii from the same stations was 634.75 ng/g, 476.66 ng/g, 129.54 ng/g, 452.47 ng/g and 414.96 ng/g (dw) respectively. A significant difference was found between tPAHs concentrations in both seawater and clam samples collected from different stations. Among the studied stations the maximum PAHs level was found in Rafael while the lowest PAHs level was found in Abshirinkon. A significant linear correlation was found between PAHs concentrations in seawater and its level in clam’s soft tissues (P<0.05), suggesting that ark clam (B.helblingii) is a good biomonitor agent for study PAHs contamination in the area.