Determination of quantity and investigation of BASF of heavy metals (Ni & V) in Anodonta cygnea and sediments in Anzali Lagoon

Anzali Lagoon is an international lagoon in North of Iran. It has specific ecosystem characteristics and is a suitable environment for aquatic animals and molluscs, therefore environmental monitoring is very important in this lagoon. On the other hands in recent year'sattention to heavy metals increased. Entry of industrial sewage into aquatic environments and with consideration to bioaccumulation of heavy metals in food chain, the utilization of the polluted aquatic animals by human can bring about irrevocable hazards. The present research aimed to assess Ni, V levels, as oil pollution index, in surface sediments and bivalves (Anodonta cygnea) in 2 stations (Mahrozeh and Selkeh). Samples were collected during 2 different periods of the year, dry and rain seasons, (June & September 2009). Heavy metal (Ni, V) concentrations were determined by Atomic Absorption in Anodonta cygnea and the sediments in Anzali Lagoon. The vanadium concentration in bivalve and sediment was ND (not detected)- 0.3243 µg/g and 2.1796 -306.9603 µg/g respectively. Nickel concentration in bivalve and sediment was 0.0231-1.3351 µg/g, 0.4949-19.5326 µg/g respectively. These amounts in Anzali Lagoon were lower than those of Ni and V in aquatic ecosystems in other countries, and are not in the effect range low (ERL). Besides, the average Vanadium amount is much lower than the sediments in the similar spots, and since ERL and effect range medium (ERM) are not defined for Vanadium, there is no room for judgment. Bioaccumulation sediment factor (BASF) was low for Ni, V (