Bioindication of mercury pollution of the Amur River during the ice-covered period

Abstract

The results of the layer-by-layer research of a river ice cores by using spectral and microbiological methods were presented. The impact of the mercury on sulfate-reducing bacteria activity from different layers of ice that had been sampled in March 2016 in the lower Amur River in Khabarovsk city was found. It was found that mercury concentration range of 0.0005-0.001 mg/l stimulated the sulfate-reducing bacteria activity, which were into the ice throughout the study area of the Amur River. To a large extent, this effect was typical for the ice that was sampled in the right bank of the Amur River near Khabarovsk city, where mercury pollution of the aquatic environment had been detected repeatedly. The activity of biogeochemical processes into the ice determined by high concentrations of organic substances, by the pollution of the aquatic environment with mercury during the ice cover formation, and by the abundance of cultivated heterotrophic and sulfate-reducing bacteria. During the ice drift and ice melting, the secondary pollution with toxic substances of various genesis of the aquatic environment occurs, which can have a negative impact on a hydrobionts.