Measurement and Comparison of Mercury Concentration in Different Length Groups of Common Carp Muscle Tissue from the Shadegan Wetland

Due to the ecological importance of the Shadegan wetland as a valuable international wetland and some studies reporting high mercury concentration in its water and bird's tissues, this study was done to measure and compare the concentration of accumulated mercury in different length groups of common carp muscle tissue and to determine the correlation of mercury concentration with morphological parameters such as standard length, total length and total weight.
In this cross-sectional study, 41 common carp fish were randomly captured in summer 2011 from the Shadegan wetland, and they were classified into three groups based on their lengths. Samples were prepared from their muscle tissues and mercury concentration was determined by Advanced Mercury Analyzer. The relation between mercury concentration in the samples and demographic characteristics was determined by Pearson’s Correlation Coefficient.
Mean (±Standard deviation) mercury concentration in groups of A, B and C were respectively 0.337±0.15, 0.556±0.21 and 0.798±0.19 µg gr-1 of dry weight basis. Comparison of mercury concentrations of muscle tissues among the three groups showed statistically significant difference (P=0.001); so that, mercury concentration was increased with increase of weight and length.
Mercury concentration in fish weighing more than 500 grams were higher than the limit allowed by WHO and EPA, it is necessary to be more careful about consuming this fish.