Chemical Structure of Pelagic Redox Interfaces Observation and M
Over the last few decades many studies have focused on the oxygen depletion of coastal and oceanic waters. An understanding of the processes involved is fundamental to assess the effects of global and climatic changes and to support an ecosystem approach
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Abstract Analysis of the vertical distributions of the ratios between C, S, Si, N, and P revealed the layers with significant systematic differences from the theoretical Redfield and Richards values. These anomalies can testify to the presence of such processes as denitrification/anammox and the processes of the “phosphate dipole” formation. Based on the ratios to Si, which concentrations do not change under the redox conditions variability, we estimated numerically the other elements deficiencies and the rates of the processes that form these deficiencies. The calculated rates of denitrification/anammox (0.012–0.046 mM per day) correspond well to the present observations data. The calculated possible rates of the processes controlling the shallower phosphate minimum formation equal to 0.008–0.032 mM per day, and the rates of the deeper phosphate minimum formation are in the range of 0.006–0.024 mM per day. The Ct/St ratio showed that bacterial sulfate reduction was the only significant process in the anaerobic mineralization of organic matter in the anoxic zone of the Black Sea that lead to a constant stoichiometric C/S ratio close to the theoretical one of 2. Keywords Black Sea, Hydrogen sulfide, Nutrients, Redfield ratio, Redox layer, Richards ratio
M.V. Chelysheva and E.L. Vinogradova P.P. Shirshov Institute of Oceanology, RAS, Moscow, Russia E.V. Yakushev (*) Norwegian Institute for Water Research, Gaustadalleen 21, 0349 Oslo, Norway Southern Branch of P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Okeanologiya, Gelendzhik-7, 353470 Krasnodarsky Kray, Russia e-mail: [email protected] V.K. Chasovnikov Southern Branch of P.P. Shirshov Institute of Oceanology, Russian Academy of Sciences, Okeanologiya, Gelendzhik-7, 353470 Krasnodarsky Kray, Russia E.V. Yakushev (ed.), Chemical Structure of Pelagic Redox Interfaces: Observation and Modeling, Hdb Env Chem (2013) 22: 13–26, DOI 10.1007/698_2011_119, # Springer-Verlag Berlin Heidelberg 2011, Published online: 20 October 2011
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Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Materials and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Results and Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1 Introduction The Black Sea is the largest meromictic basin in the world. The presence of oxic layer
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