Distribution of heavy metals in the meat, gills and liver of common bream (Abramis brama L.) caught from Zninskie Duze Lake (in Poland)

The aim of this work was to compare the concentrations of Pb, Cd and Co in the meat, gills and liver of common bream (Abramis brama L.) caught from Żnińskie Duże Lake. Analyses were carried out on 20 individual fish caught in autumn, in the natural environment. Measurements of the mass of the fish body (BW) and body length (Lc) were taken on the each specimen. Muscle samples were taken from the large side muscle of the fish body above the lateral line. Pb, Cd and Co concentrations were determined on an atomic absorption spectrometer Solaar 939 QZ. Significance of differences in the average content of metals was calculated by one-way analysis of variance (ANOVA). Analyses of the variance indicated that the mean value of Pb was highest in gills (0.880 mg kg-1 dry weight) and lowest in the liver (0.068 mg kg-1 dry weight). The same results were observed for Co, and those values were 2.391 and 0.357 mg kg-1 dry weight, respectively. The highest mean concentration of Cd was determined in the liver (0.143 mg kg-1 dry weight). There were statistically significant differences in the content of all analyzed metals between the muscle, gills and liver (at p ≤ 0.05). Analyses indicated that the mean concentrations of Pb, Cd and Co were detected in the following order: Co > Pb > Cd (in the meat and gills) and Co > Cd > Pb (in the liver). Co and Pb accumulated in the large amounts in the gills (gills > meat > liver). Cd concentrations detected decreased in the following order: liver > meat > gills. Results of the principal component analysis (PCA) substantiated very good separation of the three analyzed tissues in respect of their metal content, which confirms the results obtained from the analysis of variance.