Trace elements in the river waters of the coast of the Tatar Strait (eastern macroslope of the northern Sikhote-Alin)

Abstract

The river basins of the northern Sikhote-Alin are unique, since most of the rivers are spawning for Pacific salmon, and the eastern slope of the Sikhote-Alin is a promising area for the construction of fish hatcheries. At the same time, in recent years, the anthropogenic impact on the territory has been increasing, mainly in the mouth areas of many small rivers flowing into the Tatar Strait. In 2010–2017 hydrochemical studies of the surface waters of the coast of the Tatar Strait were carried out. On the basis of the obtained results, a characteristic of the microelement composition of river and lake waters in the zone of mixing with sea water is given. Analysis of the data obtained by inductively coupled plasma mass spectrometry on an ICP-MS Agilent 7500cx instrument made it possible to estimate the content of trace elements in the water of coastal rivers. The regional factors of the formation of the microelement composition of river waters, determined by the geological features of the catchment structure, are revealed. The elevated geochemical background determines the high concentrations of Cu, Zn, in some cases Cd, Co, Ni, As, Mn in river water. The influence of geochemical features and landscape structure of river catchments on the spatial variation and temporal variability of concentrations is shown. The influence of thermal springs and outflows of formation and fissure groundwater on the increase in the concentrations of individual elements V, Mo, Ba in the rivers of the Botchi and Koppi interfluve was noted. The thermal waters of the Tumninskoe geothermal field with a high content of As, Fe, Mn, Mo, and Cr caused a local increase in the As content in water bodies in the lower reaches of the Tumnin River. Interannual seasonal differences in the runoff of microelements depending on the degree of moisture in the catchment area were noted. Taking into account that the chemical composition of the rivers along the coast of the Tatar Strait is formed mainly in a remote and underdeveloped territory and is determined by natural processes, the obtained concentration values can be considered background.