W. Halicki, M. Kochańska, S. Kirpotin

QUALITY ASSESSMENT OF SELECTED SURFACE WATERS OF THE ARCTIC TUNDRA OF WESTERN SIBERIA IN THE CONTEXT OF CLIMATE CHANGE

This chapter presents the results of research on selected terrestrial surface waters in the arctic tundra of Western Siberia conducted during spring of 2013, fall of 2014, and winter of 2015. The assessment of parameters studied demonstrates a strong influence of climate change on the water quality of Western Siberia.

Various effects of environmental changes noted in many parts of the world are the result of both climate change and human activity. The aquatic environment plays a significant role in these changes due to its high sensitivity. Because of the importance of water for the existence of human beings, animals, and plants, it is important to understand the mechanisms affecting water resources. Changes in terrestrial surface water quality are most visible in the Arctic, where surface waters have the most natural character. Arctic terrestrial water systems have not undergone modifications to their morphology nor are they impacted by anthropogenic pollution; thus, any changes observed in these systems are associated with changes in climatic conditions. Although many variables shape the climate, temperature is the most easily observed factor. This study looked at multiple aquatic variables during spring, fall, and winter. Analyses of pH showed large differences between the measurements made in autumn and spring. Increased ambient temperatures, which increase average seasonal temperatures in surface waters, affect the biological activity of organisms inhabiting the waters of this area. This effect is demonstrated by biochemical oxygen demand. The BOD5 results obtained in the range of 5, 4 – 5, 7 mgO2/dm3, and the average oxygen saturation in the amount of 137% with presence of phytoplankton and zooplankton, suggests primary productivity is a greater source of organic matter than mineralization. Progressive climate warming is likely to enhance the increasingly changing water parameters. Despite complete lack of anthropogenic pollution in surface waters of the studied area, there is excessive concentration of organic matter, as evident by the results of chemical oxygen demand (COD) and total organic carbon (TOC) analyses. As many as in 80% of cases, the concentration of tested parameters bore the hallmarks of excessive concentration. Due to the low impact of human factors, progressive climate change can be the only justification at the moment. These changes are accompanied by mineralization of peat and release of nutrients contained therein. Despite the release of nitrogen compounds during mineralization of peat, a frequent process in this part of Siberia, the concentration in the tested waters was at a minimum level, as a result of favorable conditions for denitrification of nitrogen in the benthic zone. The concentration of phosphates in the tested waters is much higher, especially in lakes, where it causes intense blooms of phytoplankton. Climate warming has a strong impact on water catchments of the boggy arctic parts of Western Siberia. The progressive increase in the fertility of waters in this area will lead to an increasing amount of organic matter and phosphorus discharged from this region to the Arctic Ocean.