Exploring the chemical composition of water in the Kandalaksha Bay Svetlana Mazukhina 1 , Vladimir Masloboev 1 , Konstantin Chudnenko 2 , Vadim Khaitov 3 , Victoria Maksimova 1 , Natalia Belkina 4 1 Institute of North Industrial Ecology Problems, Kola Science Center, Apatity, Russian Federation (mazukhina@inep.ksc.ru, +7(81555)74964), 2 Vinogradov Institute of Geochemistry of SB RAS, Irkutsk, Russia (chud@igc.irk.ru), 3 The Kandalaksha Nature Reserve, Kandalaksha (polydora@rambler.ru), 4 Institute of Northern Water Problems Karelian Research Centre of RAS (bel110863@mail.ru) Abstract Oil films were noted at the head of the Kandalaksha Bay as far back as in 1971, as soon as the first stage of the oil tank farm had been commissioned (the autumn of 1970). In 1997-1998 there were accidental oil spills posing a real threat to the Kandalaksha Reserve biota. In May 2011, oil spills from the Belomorsk oil tank farm resulted in a local environmental emergency. In this work we have traced the evolution of polluted water by means of hydrogeochemical monitoring and reconstructing the chemical composition of surface and near-bottom water of the Kandalaksha Bay by using physical- chemical modeling (Selector software package, Chudnenko, 2010). The White Sea is an inland sea which average depth is 67 m with maximum of 350 m in the outer part of the Kandalaksha Bay and the Basin (central part of the sea). The basin of the White Sea is separated from the Barents Sea by the underwater threshold which depth is 20-40 m, what impedes water exchange with the Barents Sea (Gursky, 2003). The organic substance of petroleum origin is accumulated in the direction of water movement (Shvets, 1970). Research of Y. N. Gursky (1978) (Gursky, 2003) showed positive values of Eh in the bottom waters and on surface silts. Currently it seems necessary to carry out such studies particularly in the regions of accidents, waters and silts in the deep-water areas to determine the current state of the sea waters. Results Modeling of the chemical composition of near-bottom water (point 3) has revealed high contents of carbon dioxide, hydrogen disulphide, hydrocarbonates( ɇСɈ3 - ), and no oxygen (Eh<0). All this suggests a transformation of hydrocarbons that might have got to the sampling area in May 2011, or as the result of constant leakage of petroleum hydrocarbons from the oil tank farm. Sampling at point № 4 in 2013 has revealed petroleum hydrocarbons both in surface (0.09 mg/l) and near-bottom (0.1 mg/l) water. Both monitoring and modeling have demonstrated that hydrobionts on areas adjoining the oil tank farm are far from prospering. Monitoring should be accompanied by express analysis of oxidizing conditions in both the soil and near-bottom water. Picture 3. Varying concentrations of substances in surface water, points 3,4 Picture 4. Varying concentrations of substances in near-bottom water, points 3,4 Since the water contamination in the White Sea has lasted for decades, it is necessary to examine the near-bottom water, in particular in its deeper areas, to reveal the possible accumulation and destruction of organic substances at the sea floor. It is evident that an unbiased assessment of the environmental situation can be obtained by involving all kinds of information processing technologies. The surface and near-bottom water was sampled in the summer of 2012 and 2013 at the following points: № 3 (N 67.2.673, E 32.23.753); №4 (N 67.3.349, E 32.28.152); №5 (N 67.5.907, E 32.29.779), and № 6 (N 67.6.429, E 32.30.539). Materials & Method’s The monitored objects and sampling time were sensitive to both the effects of the White Sea water (high tide), fresh water, and water affected by human impact (the oil tank farm). In each of the selected points three samples were taken. Selection of waters was performed using dimensional plastic utensils. On the day of arrival of the samples to the laboratory water pH was measured using the potentiometric method without pre-filtering. Analysis was performed by methods of atomic absorption (flame) (Ca, Mg K, Na), and emissivity (Al, Fe, Zn, Mn, Cu, Ni) spectrometry, total P, P phosphates, Si using method of photo-colorimetry; anionic water composition comprising NO 3 - , SO 4 2- and Cl - using the method of ion-exchange chromatography. The next stage involved reconstructing of the sea water ion composition by modeling within the Al-B-Br-Ar-He-Ne-C-Ca-Cl-F-K-Mg-Mn-N-Na-P-S-Si-Sr-Cu- Zn-H-O-e system, where e is an electron. References ØGursky YU.N. Geochemistry of litho- and hydrosphere of inland seas. Volume 1. Study methods and processes of formation of the chemical composition of sludge sediments of the Black, Azov, Caspian, White and Baltic seas. M. GEOS. 2003. 332 P. ØKalinnikov V.T., Mazukhina S. I., Masloboev V.A., Chudnenko K.V., Maximova V.V. Peculiarities of interaction of “oil-water”inmarine and freshwaters, DAN. 2013, Vol. 449, №5,pp. 535-538 ØKhaitov V.M., Mazukhina S.I., Masloboev V.A., Maximova V.V. Spatial variation of hydrochemical indices in the shallow waters of the tops Kandalaksha Bay of the White sea in connection with the problem of high spatial heterogeneity of environment. Materials of IV all-Russian scientific conference with international participation «Environmental problems of the Northern regions and ways of their solving» part 2, p.p.61-63. ØChudnenko K.V. Thermodynamic modeling in Geochemistry: theory, algorithms, software, applications. Novosibirsk: Academic publishing house «GEO», 2010.- 287 P. ØLeonova G.A., Bobrov V.A. Geochemical role of plankton continental reservoirs of Siberia in the concentration and biosedimentation. Novosibirsk: Academic publishing house "GEO", 2012.-314 P. Picture 1. Sampling points, Kandalaksha Bay Analytical data (content of major ions -Na, Ca, Mg, and K) and results of computer modeling, the oxygen content, HCO 3 - (point 6, surface and bottom waters) are comparable with the chemical composition of waters from the White Sea. Analysis of the data (points 5,6) shows comparability of concentrations of Cu, Sr, Pb, Zn, Fe, and Mn. Moreover, concentrations of Cu, Zn, and Mn are considerably higher than those shown in the paper (Leonova, Bobrov, 2012), while the concentrations of Sr, Pb, Fe fairly close to the data of the cited work. At points 3 and 4 waters are more desalinated. Concentrations of all major ions (Na, Ca, Mg, and K) are significantly lower than at points 5 and 6, while concentrations of Cu, Sr, Zn, Fe, Mn are comparable. Picture 2. CJSC «Belomorskaya Neftebaza» 7,715 2,54 91,2 7,48 7,76 2,52 100 7,29 1 10 100 pH CO2 HCO3- O2 Sample №3 surface water, modeling Sample №4 surface water, modeling 7,65896 490 15,5 5,62 7,644 128 4,17 6,56 1 10 100 1000 pH HCO3- CO2 H2S* O2 Sample №3 near-bottom water, modeling Sample №4 near-bottom water, modeling O2(s.3) = 0 H2S(s.4) = 0