Assessing pollution in the Kola River, northwestern Russia, using metal concentrations in water and bryophytes

Intensive Cu-Ni and Fe mining and smelting in northwestern Russia constitutes a potential risk of pollution in the Kola River. We assessed the degree of pollution along the Kola River by means of overall water quality evaluation and analyses of metals in water samples (dissolved and particulate fractions) and aquatic mosses. The observed pollutant levels were compared with those in unpolluted reference rivers. The results indicate relatively low overall contamination in the Kola River, although Cu and Ni levels are elevated relative to the reference data. Furthermore, PCA ordination models identified clear metal concentration patterns along the river. Al, Cd, Co, Fe, Pb and Zn exhibited an almost continuous increase from the headwaters to the river mouth, whereas As, Ba, Cu, Mn, Mo and Ni showed their highest concentrations in the headwaters, close to the mining areas, relatively low concentrations in the middle parts of the river and elevated concentrations at the river mouth. Bryophyte analysis appeared to be a more sensitive tool for metal pollution assessment than metal concentrations in water.