HEAVY METAL CONTENT AND ELEMENT COMPOSITION OF ALBURNOIDES BIPUNKTATUS BLOCH IN ISKAR RIVER, BULGARIA

I. Petrov, D. Rozdina, E. Nikolova, R. Marinova, G. Raikova-Petrova, S. Ilieva

Abstract: Altogether 28 specimens of Alburnoides bipunctatus from the middle stream of Iskar River were studied to determine the element composition, distribution and deposition of heavy metals in tissues and organs of the species. An x-ray fluorescent analysis was used. Twenty one out of the 32 surveyed elements were found. The highest concentration of elements was found in the fins, gill caps and gills. The level of Pb, Zn, Cd and Cu in certain tissues and organs is higher than the maximum allowed concentrations for the same metals. The highest levels of Cd were found in the muscles (4 mg.kg–1) and internal organs (3 mg.kg–1) of 3–4 years old fish. The highest level of Zn was established in the fins and gill caps of 3–4 years old specimens (147 mg.kg–1) while the lowest rates were found in the gills of 1–2 year olds (71 mg.kg–1). The lead was accumulated mainly in the muscles (12 mg.kg–1 in 1–2 years old and 15 mg.kg–1in 3–4 years old). The highest levels of Cu were found in the internal organs of 3–4 year olds (17 mg.kg–1), and lowest in gills and muscles of 1–2 years old (2 mg.kg–1). Heavy metals accumulation is age dependent and increases with the fish age. A. bipunctatus is ”macro-concentrator” in relation to heavy metals in whole
body, since bio-accumulation coefficient is higher than 2 (from 146 for cadmium to 1603 for zinc).

Keywords: Alburnoides bipunktatus; bioaccumulation; heavy metals; Iskar River

Date published: 2017-09-29