Scientific publications

This paper summarizes the results of studies of anaerobic processes (specifically sulfate reduction) in the sediments of two interconnected small boreal lakes in the Arkhangelsk Region. One of these lakes is anthropogenically impacted, while the other is essentially in its natural state. It is noted that the distribution of reactive iron in the water and sediments indicates that reducing conditions occur even in the top layers of Lake Nizhneye’s sediments as a result of anoxic conditions developing in the hypolimnion. The significant content of organic matter in the pelitic silts of the studied water bodies does not limit the sulfate reduction process, leading to the accumulation of reduced sulfur compounds – derivatives of bacterial hydrogen sulfide – in the sediments. A comparative analysis of the quantitative parameters of the sulfate reduction process (concentrations of reduced sulfur compounds, organic carbon, and reactive iron) showed that the content and ratio of reduced sulfur forms in Lakes Verkhneye and Nizhneye can serve as a marker of anthropogenic impact on the water body. Based on the obtained data, the environmental situation in Lake Nizhneye can be assessed as unfavorable, while the situation in Lake Verkhneye, which is hydrographically connected to the former, is generally favorable.