engleski

ECOTOXIC TRACE METALS IN WATERS OF PROTECTED NATURAL AREAS IN CROATIA

Protected natural areas, particularly National parks, are very sensitive systems because of their substantial uniqueness which should be preserved in their original form. Two Croatian National parks were included in our study. “ Krka” National park is positioned on the east coast of Adriatic middle section near town of Šibenik with aquatic environment mainly consisted of fresh water, while its south border is estuary. “ Mljet” National park lies on the island of Mljet in Croatian south Adriatic, and its aquatic environment is generally saline. Elevated trace metals concentration levels in such vulnerable systems could be an indicator for possible anthropogenic influence and potential risk in natural environment. Therefore, it is very important to assess actual ecotoxic trace metals concentration levels. Systematic survey (periodic, field/laboratory) is necessary to distinguish elevated trace metals concentrations naturally present in aquatic environment from the anthropogenic influence. Spatial and temporal distribution of five ecotoxic trace metals (Cd, Cu, Pb, Zn and Hg) in waters of Croatian “ Krka” and “ Mljet” National parks was studied. Trace metals abundances are presented as dissolved (filtered) and total concentrations (non-filtered). Concentrations were measured by differential pulse anodic stripping voltammetry, while total mercury was measured by cold vapour atomic absorption spectrometry. Very low metals concentrations in waters of Krka River in “ Krka” N.P. were determined. Due to such concentrations these waters are classified in 1st class (waters without anthropogenic influence), according to Croatian water classification directive (NN 77/98). Higher concentrations in bottom water than in upper water samples of both saline lakes in “ Mljet” N.P. were detected.

TRACE METALS; WATER; PROTECTED NATURAL AREAS

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