L.M. Kondratyeva,
Institute of Water and Ecology Problems FEB RAS, Khabarovsk, Russia


The research results of correlation between the level of water, bottom sediments and ice pollution and the bioaccumulation of toxicants in fish are presented. According to monitoring data benzene derivatives and volatile chlorine-containing substances accumulated in bottom sediments, ice and hydrobionts constitute main risk factors in the river freezing period. Maximal concentrations of methylbenzene were registered after the ice break in the bottom sediments at the right bank lowers the Sungari juncture. In summer time different compositions of benzene derivatives (ethylbenzene, xylene and toluene) remained in fish of this river passage. The Sungari River also discharged stable polycyclic aromatic hydrocarbons. The dominant substance stretching up to the water-inlet in Khabarovsk was benzо(b)fluoranthene. Moreover, spectral methods, chromatography and chomatomass spectrometry of benzene derivatives revealed different pollutants accumulated in the bottom sediments and fish. Phthalate, naphthalene, highly toxic anisole and benzothyozole, as well as fluorine and phosphorus - containing pesticides of a new generation were identified in fish.
Response reactions of the Amur hydrobionts much depend on the total impact of toxic substances regularly discharged from the Sungari (chlorophenols, polycyclic aromatic hydrocarbons, trace metal ions). Ecological risks for Amur hydrobionts caused by the technogenic accident in the Sungari Basin (November, 2005) are enhanced by the additional effect of the regular chronic pollution of the Amur River in recent years. Various classes of toxic substances, revealed in all components of the Amur ecosystem threaten fish resource regeneration and population health in the region.