Myriophyllum spicatum and Najas marina as Bioindicators of Trace Element Contamination in Lakes

ABSTRACT

The value of Myriophyllum spicatum and Najas marina as indicators for contamination by certain trace elements was studied in two artificial lakes (Velenjsko jezero and Družmirsko jezero, Slovenia). The lakes lie in the vicinity of the Šoštanj Thermal Power Plant and are the result of mining activity. The concentrations of heavy metals (Cd, Cu, Pb, Zn, Cr) and As were determined in sediment, water samples, and shoots of macrophytes. The sediment of Družmirsko jezero contained significantly higher concentrations of trace elements Cu, Pb, and Cr than that of Velenjsko jezero. The concentrations of trace elements in shoots of M. spicatum were higher than those in shoots of N. marina in indicating their concentrations in lake sediments. While the concentration of Pb was significantly higher in the tissues of both species from Družmirsko jezero, the difference in Cr sediment loading between the two lakes was indicated only in shoots of M. spicatum. The concentrations of Cu in shoots of the two species did not reflect the differences in the concentration of Cu in the lake sediments.