The aim of the present study is to investigate the bioaccumulation and translocation of various heavy metals, notably copper, zinc, cadmium and lead, in the different plant organs of Trapa natans L. (the root, stem, and leaf) at nine sampling locations, as well as examining the variability in proline accumulation and chlorophyll content due to these heavy metals. Our analysis shows the existence of a statistically significant positive correlation (r = 0.75; p < 0.05) between the Zn content and the accumulation of proline in the root of the examined species. On the other hand, a statistically significant negative correlation was registered between the content of chlorophyll a and the concentration of Zn in the leaf (r = -0.68; p < 0.05). This indicates that Trapa natans L. can be used in biomonitoring Zn-polluted aquatic ecosystems using proline and chlorophyll as sensitive biomarkers.

Keywords: Trapa natans L.; chlorophyll; heavy metals; proline.