ORGANOCHLORINES IN THE WATER AND BIOTA OF LAKE BAIKAL, SIBERIA

Organochlorine contaminants were measured in water, fish, and Baikal seal from Lake Baikal, Siberia. Organochlorine levels in water were comparable to those reported from the upper Great Lakes, with the exception of chlordanes, which were a factor of 2 lower. Dissolved toxaphene and SIGMADDT (sum of 4,4'-DDE, 4,4'-DDD, 2,4'-DDT, and 4,4'-DDT) averaged 64 +/- 37 pg/L and 87 +/- 37 pg/L, respectively. Total polychlorinated biphenyl (SIGMAPCB) concentrations in biota ranged from 1.2 to 26 mg/kg of lipid in the omul (an endemic salmonid) and the Baikal seal, respectively. Tetra- and pentachlorobiphenyl congeners accounted for a greater proportion of SIGMAEPCB in omul and hexa-, hepta-, and octachlorobiphenyl congeners in pelagic sculpins and seal. Toxaphene concentrations in biota ranged from 1.1 to 2.3 mg/kg of lipid in sculpin and seal, respectively. A linear relationship was observed between the log bioconcentration factor and log octanol-water partition coefficient with slopes ranging from 0.47 +/- 0.08 for the omul to 0.88 +/- 0.11 for seal (r2 = 0.45 and 0.62, respectively).