Determine of Mercury Levels in Various Tissues of Common coot (Fulica atra) and Common teal (Anas cerecca) Considering to the Age and Sex in the Fereydunkenar International Wetland

The aim of this study is to determine of mercury levels in various internal organs of the Fereydunkenar International Wetland’s birds for the first time and to determine the influence of this metal on their health.
This study has been done in the Fereydunkenar international wetland where is the most important wetland habitat of the central areas of Hyrcanian ecosystem. Fereydunkenar International Wetland with 5427 hectares area has located in the southern Caspian. This wetland also is the overwintering habitat of only surviving flock of Western Siberian Crane in Iran, every year attracts about one-third of overwintering birds species (150 species), that will migrate the northern geography latitudes to Iran. Bird samples were collected in autumn 2011.
Samples collected from tow species (Common coot: n = 15 and Common teal: n = 16). The birds were biometrics (total body length and weighing). Sex and age of birds was identified. Finally liver, kidney and breast muscle of each bird was completely separated from the body and were kept until beginning to analyze in temperature - 20 ° C. Then 0.2 g of each tissue (liver, kidney, and breast muscle) was transferred in 50 mL Teflon containers with lid and 5 ml of nitric was added to it. Then the samples were transferred to the microwave and temperature of microwave reached the 180° C temperature with a gentle slope during 40 minutes and maintained at this temperature for 20 minutes. Then, the temperature of the microwave was reduced with a gentle slope to cool the samples. After cooling, the solution was passed through filter paper to obtain a clear solution. Next, the clear solution obtained was increased with two time deionized water in the 50 mL volumetric flask. In this stage, Mercury concentration was measured in each sample by using atomic absorption tool, Perkin-Elmer model (AA 700) according to method of cold vapor technique.
Statistical analyses were carried out using SPSS ver. 18.0. Results have been expressed in µg/g-1 ww with SD.
The results showed, that the highest mercury levels were observed in the liver of both species (0.34±0.16 µg/g-1 ww in Common coot and 0.28±0.11 µg/g-1 ww in Common teal). After the liver, the amount of mercury in the kidneys of both species was higher (0.22±0.08 µg/g-1 ww in Common coot and 0.25±0.13 µg/g-1 ww in Common teal). There was a significant difference in mercury concentrations among different tissues (between liver with two other tissues), (P