Geochemistry of the Kola River, northwestern Russia

Abstract: The Kola River in the northern part of the Kola Peninsula, northwestern Russia, flows into the Barents Sea via the Kola Bay. The river is vital for the reproduction of salmon and an important source of drinking water for more than 500,000 people in Murmansk and the surrounding municipalities. To evaluate the environmental status of the Kola River water, extensive sampling of water (the dissolved (ƒ¬0.22 ƒÝm) and suspended (ƒ®0.22 ƒÝm) phases) and aquatic mosses (Fontinalis spp.) was performed on thirteen sites along the Kola River and its tributaries during 2001 and 2002. Major (Ca, K, Mg, Na, S, Si, HCO3 and Cl) and trace (Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sr, Ti, and Zn) elements, total and particulate organic carbon (TOC and POC), N and P were analyzed. For aquatic bryophytes, the analyzed metals were Al, As, Ba, Cu, Cd, Co, Fe, Mn, Mo, Pb, Zn and Ni. The levels of major nutrients (P and N), as well of major and trace elements in the Kola River water, with the exception of Na, Cl, Cu, Zn and Ni, were close to natural baseline levels. Comparison with the boreal pristine Kalix River, northern Sweden, shows that, except for Na, Cl, Cu, Zn and Ni, which exceed the concentrations in the Kalix River by as much as 2-3 times, the levels of other major and trace elements are close to or even below the levels in the Kalix River. The water chemistry and the aquatic bryophyte results show a similar picture of pollution status in the Kola River, indicating relatively low contamination in the river. The Kola River shows elevated levels of Cu and Ni both in water and in the aquatic bryophytes compared with the Swedish reference data. Comparison with the unpolluted River Tenojoki, Finland, reveals elevation of Al, Cd, Cu, Co, Ni and Zn concentrations in the aquatic bryophytes in the Kola River. Spatial variations in concentrations of Fe, Al, Co, Pb and Zn in bryophytes show a general trend of increase downstream the watercourse. Aquatic bryophytes and water quality close to the upstream mine areas show elevated concentrations of As, Cu, Mn, Mo and Ni, while values in the middle part of the river are near background levels. The concentrations of As and Cu in the aquatic bryophytes mostly reflect the dissolved phase of the metal in water, while the concentrations of Ba and Co mainly reflect the suspended phase. Fe, Al, Mn, Mo, Ni, Pb and Zn in mosses reflect both the dissolved and the suspended phases of these metals in water. The results demonstrate that pollutants from the two major sources: the open-pit iron mine and ore concentration plant in Olenegorsk in the upper part of the basin and the Varlamov, the Medveziy and the Zemlanoy Creeks, draining the area of large agricultural enterprises in the lower part of the watershed, influence the water quality of the Kola River.