Bioaccumulation of mercury in aquatic and terrestrial birds in Isfahan province

Mercury is a toxic heavy metal and is stable in the environment which can enter the living organisms through various ways. Bioaccumulation of mercury in birds has several impacts including nephron toxicity, kidney lesions and can lead to bird death. In the current studybioaccumulation of mercury was investigated in kidney, liver and tail feathers of 40 birds collected at three sites in Isfahan province belonging to three bird orders: Charadriiformes, Passeriformes and Columbiformes. Mercury level in tail feather, liver and kidney of aquatic birds averaged at about 4290, 3056 and 2704 ppb respectively and significantly (p < 0.05) higher than the mercury amount in the same organs (770, 816 and 519 ppb) of terrestrial species. In aquatic birds, tail feather with the average amount of 4290 ppb and in non aquatic birds, liver with the average of 816.64 ppb showed the highest amount of mercury. Charadriiformes had significantly (p = 0.0001) higher amount of mercury in their organs compared to the other two orders. Among the bird's families, Sternidae and Laridae showed significantly higher amount of mercury in their organs. The results can be an indicative of mercury presence in the Zayandehroud River, therefore it is necessary to monitor and manage heavy metals in the river.