Accumulation of selected metals pollution in aquatic ecosystems in the Smeda river (Czech republic).

OBJECTIVES: Biomonitoring of some slelected heavy metals in the Smeda river (Czech Republic) was carried out during 2015-2016 to assess the extent of environmental pollution. Attempts were also made to map the intensity of bioaccumulation in brown trout which was used as an indicator species. Monitoring of the environmental pollution of the Smeda river was carried in 2016.

DESIGN: Concentrations of some heavy metals i.e. Mercury (Hg), Lead (Pb), Cadmium (Cd) and Cobalt (Co) were quantified in the fish muscles. Correlations (Pearsons, 2-tailed) among selected metals with some morphometric parameters (standard length and total weight) in brown trout (Salmo trutta fario) were also examined.

RESULTS: Results showed a significant positive correlation between concentrations of Hg, Pb (group-I) and Pb, Cd (group-II) with the muscles and age of fishes (p<0.05). The groups of heavy metals i.e. group-I (Hg and Pb) and group-II (Pb and Cd) were purposively synthesized for better inference of the data since Pb formed significant (p<0.05) but distinct positive correlations with Hg and Cd. The contents of the analyzed metals in brown trout muscles were low Hg 0.06-0.5; Pb 0.01-0.3; Cd 0.01-0.04 and Co 0.01-0.03 mg.kg-1 wet weight basis and did not exceed the values of limits admissible in the Codex Alimentarius for safe human consumption except in the case of Hg which is little vulnerable to reach critical limit.

CONCLUSIONS: The contents of the analyzed metals in Brown trout muscles were lower at monitoring sites and did not exceed the values of limits admissible in the Czech Republic. Potential ecological risk analysis of toxic metals concentrations in sediments suggested only two sites (2 and 3) with elevated values that posed a midlle environmental risks. Strict periodical monitoring of Hg levels in the selected stretches of the River Smeda is recommended.