Abstract:

Three Gorges Reservoir has captured the public attention for its impacts on ecological environment and ecological safety.The effect of mercury reactivity on fish mercury content after impoundment of the reservoir is concerned by whole society.Mercury concentrations in eight fish species collected in eight tributaries of the Yangtze River in Three Gorges Reservoir Area in 2011 were determined.The average concentration of mercury in the fish in wet weight was 564 μg/kg, ranged from 305 to 1096 μg/kg.Ten years after the first impoundment of Three Gorges Reservoir,the mercury concentration of fish in Three Gorges Reservoir Area has not obviously increased,comparing with the data before impoundment.However slight difference in mercury concentrations among the fish species was found.The mercury concentration of fish increased with its trophic level.Accumulation of mercury in fish was found along the food chain.It is notable that the benthic fish species had higher mercury concentration than other species,which indicates that the mercury reactivity in bottom strata is a potential risk in environment