Abstract: Soil samples were collected from the northern slope of Changbai Mountain in April and September 2009 to study the concentration and distribution of total mercury (THg) and methyl mercury (MeHg) in the soils under boreal forests at different altitudes. The THg and MeHg concentrations in the soil profiles ranged from 0.08-0.73 mg·kg^-1 and 0.05-0.56 μg·kg^-1, and the stocks were 97 kg·km^-2 and 128 g·km^-2, respectively, being higher than the background value of Jilin Province. Surface soil layer (0-10 cm) commonly had the highest MeHg concentration. There existed definite seasonal and spatial variations in the distribution of soil Hg. The gaseous Hg from wet and dry atmospheric depositions was the primary source of soil Hg in the study region.

Key words: Paralytic shellfish toxins, Red tides, HPLC, Mouse bioassay