Evaluation of Ni, Pb and V concentrations in egg contents and Eggshell of Sterna bengalensis and Dromas ardeola in Khourmousa Islands, Persian Gulf

Nowadays, it has been revealed that biomonitoring can be the optimal method for evaluating metal levels and their bio-availability. Birds are ideal for monitoring metal pollution due to being in high trophic levels and their high sensitivity to toxic substances.
The levels of nickel, lead, and vanadium were evaluated in egg contents and eggshell of Dromas ardeola (n=14), and Sterna bengalensis (n=13), breeding in the northwestern Persian Gulf.
Findings: Levels of Ni, Pb and V (µg/kg dry weight) in the eggshell of Sterna bengalensis were found to be 51±16, 293±89, 82±5 respectively, and also the level of these metals (µg/kg dry weight) in egg contents of this species were found to be 47±8, 374±134, 96±7 respectively. Levels of Ni, Pb and V (µg/kg dry weight) in the eggshell of Dromas ardeola were found to be 46±18, 228±43, 73±12 respectively, and also the level of these metals (µg/kg dry weight) in egg contents of this species were found to be 36±8, 244±43, 95±3 respectively.
The results showed that Sterna bengalensis, because of feeding from the higher levels of the food chain, has a greater potential for bioaccumulation of metals as compared to Dromas ardeola, and can be used as a biological indicator.