Carbonate System Characteristics of the Sevastopol Bay Waters in 2009 – 2015

Abstract

A 20% increase of the carbon dioxide concentration in the atmosphere during the last century and a dramatic increase in nutrient load to marine systems due to human activity have resulted in pronounced carbon cycle transformation in coastal areas. The results of the inorganic part of the carbon cycle and its transformation in the Sevastopol Bay (the Black Sea) are presented in this study. The bay is semi-enclosed coastal area that has been under heavy anthropogenic pressure over the last century. Here we present data on dynamics of the inorganic part of the carbon cycle from 2009 – 2015. Values of pH and total alkalinity were obtained analytically, whereas CO₂, HCO₃^-, CO₃^2- concentrations and pCO₂ values were calculated. Dissolved inorganic carbon and its partitioning into CO₂, HCO₃^-, CO₃^2- demonstrate the state of the carbon cycle and its evolution. Our results show a negligible upward trend of dissolved inorganic carbon concentration (~ 1%), which may indicate the ability of the bay ecosystem to the "self-healing". However, carbon dioxide partial pressure significant growth in the bottom and surface layers of the bay (up to 23%) indicates negative changes, resulting to the carbon cycle transformation. Moreover, currently the Sevastopol bay waters are in a state of invasion, but, according to the calculations, there is a downward trend of the atmospheric carbon dioxide flow, and it is possible that the invasion can be replaced by evasion in 2018.

Keywords

carbon cycle, carbonate system, carbon dioxide partial pressure, ocean-atmosphere gas exchange, the Sevastopol Bay (the Black Sea).

DOI: 10.22449/1573-160X-2016-3-36-46

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