Abstract: The temporal and spatial distributions of mercury in river water in the Changbai Mountain area were studied. Total mercury and methylmercury were measured in water samples collected in both low flow period and flood period from Changbai Mountain forest area. The results show that total mercury concentrations varied from 2.0 to 20 ng·L^-1 and were higher in low flow period than those in flood period due to local coal combustion for domestic heating in winter. Methylmercury concentrations ranged from 0.12 to 0.55 ng·L^-1 and were almost comparable between the different periods. Mercury concentrations were decreased with increase of altitude. The influence of the Songhua River in which several rivers flow into was evident, dissolved mercury decreased and particulate mercury increased with river inflow. Compared to other forest rivers worldwide, methylmercury concentrations were relatively lower, however, total mercury concentrations were higher. The estimated output of THg and MeHg to downstream in study area was 33 kg·a^-1 and 200 g·a^-1 respectively, which further increase the downstream loads of mercury.

Key words: Tai Lake, Egretta garzetta, Pollutants, Bioindicator, Breeding success