Heavy metals and ¹³⁷Cs levels in macrophytes and temporal distribution in sediments – application for estuarine environment status assessment (Vistula Lagoon – southern Baltic)

The paper presents the first data on the concentrations of heavy metals (Cd, Pb, Zn, Cu, Ni, Cr, Mn) and ¹³⁷Cs and their contamination ratios (CR) in the most abundant species of macrophytes in the Vistula Lagoon. No significant differences in the concentrations of heavy metals and ¹³⁷Cs between macrophyte taxa or the influence of rivers flowing into the Vistula Lagoon on heavy metal concentrations in the area were found. The concentrations of heavy metals in macrophyte taxa varied in the following ranges: Cd – 0.1–0.7 mg kg⁻¹ d.w.; Pb – 0.5–5.0 mg kg^-1 d.w.; Zn – 29–390 mg kg^-1 d.w.; Cu – 2.5–8.3 mg kg^-1 d.w.; Ni – 0.4–6.8 mg kg⁻¹ d.w.; Cr – 0.5–2.8 mg kg⁻¹ d.w.; Mn – 380–8500 mg kg⁻¹ d.w. Since the 1990s, a decline or stable state of heavy metal concentrations in bottom sediments has been observed, reflecting changes in the environment of the Vistula Lagoon. The linear sedimentation rate in the Vistula Lagoon was 3.3 mm y⁻¹. The results presented in the paper can serve as a baseline for assessing changes in the environmental status of the Vistula Lagoon, which may occur as a result of future investments, including building a new navigable canal through the Vistula Spit.