Determination of Toxic Chemical Contents in the Black Sea Marine Water , Sediment and Biota //// Определяне съдържанието на токсични химични елементи в системата вода-седимент- биота
[EN] Heavy metals in marine systems are a global problem, since continuous exposure of marine organisms to their low concentrations may result in bioaccumulation, and subsequent transfer to man through the food web (Mendil et al, 2005). Heavy metals in the marine environment may originate from either natural or anthropogenic sources. Although trace metals are normal constituents of the marine environment, and some of them are essential to marine organisms, all metals are toxic above some threshold level (Kljakovic´- Gašpic´ et al, 2010). The Black Sea is the world’s largest natural anoxic water basin below 180m in depth. It is a closed sea with a very high degree of isolation from the world’s oceans, but it receives freshwater inputs from some of the largest rivers in Europe; the Danube, the Dniester, and the Dnieper (Stoichev et al., 2007). For this reason, Black Sea is considered one of the most polluted seas in the world, and the increasing concentration of nutrients in recent years have led to a higher degree of eutrophication. There are limited data about heavy metals pollution of the Bulgarian Black Sea coast for the last twenty years (Görür et al., 2012). Therefore, the aim of this study were to determine the kinetically labile forms of As and Hg in the system water-sediment. To investigate the content and to trace the dynamics of the total concentration of ten toxic and essential elements (As, Cd, Cr, Cu, Fe, Hg, Ni, Zn, Pb and Mn) in Black and freshwater fish species, and to assess the safety of these fish species as food sources. A study for the total concentration of toxic and essential elements in the edible tissue of various Black Sea and freshwater fish covering the period 2010-2015 was conducted. .
toxic, heavy metals, essential elements, Black sea, sediment, biota, Химия / Chemistry
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