Abstract: To evaluate the nutrient value and estimate the mercury concentration and fatty acids composition in the cultured fishes of Wujiangdu Reservoir, we randomly collected 120 samples of 10 dominant fish species. The concentrations of THg, MeHg and polyunsaturated fatty acids (n6/n3 PUFA) and DHA and EPA (speciation of fatty acids) in fishes were analyzed. The results showed that the concentration of THg in cultured fishes varied from 3.50 to 185.05 ng·g^-1, with an average value of 23.90 ng·g^-1. The concentration of MeHg varied from 0.16 to 49.09ng·g^-1, with an average value of 7.78 ng·g^-1. The concentrations of THg in cultured fishes were low, and did not exceed the limit of provisions of China’s edible standards of contaminants in aquatic products. Furthermore, the content of EPA + DHA in n3 PUFA, the essential fatty acids to human body, was the highest in crucian carp, and the lowest in carnivorous catfish. After analyzing the ratio of n6/n3 PUFA of samples, we found that the fishes enriched with n6 PUFA as well as EPA and DHA. In conclusion,Parabramis pekinensis, Hypophthalmichthys molitrix, Ctenopharynodon idellus, Mylopharyngodon piceus, and Tinca tinca are fishes with higher concentration of EPA and DHA and lower concentration of MeHg, being better dietary for human health.

Key words: peatland, sexual regeneration, fire, smoke, spore bank