POTENTIALLY TOXIC ELEMENTS IN LOWLAND GREAT MORAVA RIVER – BIOINDICATION WITH BLEAK (ALBURNUS ALBURNUS)

The utilization of fish bioindicators has become of crucial importance for ecosystem contamination assessment. Bleak (Alburnus alburnus) is a widely distributed epipelagic fish species characterized as very active with fast metabolism which can lead to a high accumulation of pollutants in tissues. Bleak is easy to sample, identify in the field by morphological characteristics, and easy to work within the laboratory. This study deals with the bleak sensitivity in detecting the pressure of the potentially toxic elements (PTEs) in the large lowland Great Morava River. The Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sn, and Zn were estimated in whole body composite (wbc) of bleak. The study was conducted at Great Morava River, near the city of Paraćin in Serbia. The highest concentrations of essential elements Zn and Fe were detected. The most toxic elements As and Hg were below detection limits. The metal pollution index (MPI) was 0.39. In large lowland rivers, point sources of pollution such as municipal wastewaters of smaller settlements usually have only local impact due to high dilution by the main watercourse. Since bleak is a site-specific species, results in this study indicated that this stretch of the Great Morava River is slightly affected by PTEs. None of the elements above the maximum permitted concentrations (MPC) in fish meat for use in the human diet, prescribed by the Official Gazette and European Commission Regulation, were not recorded.