Diversity of macrophytes and differences in the contents of metals between macrophyte species in alpine Lake Bohinj (Slovenia)

Alpine Lake Bohinj is the largest natural lake in Slovenia. It is located in the Triglav National Park, which provides protection and limits activities in its catchment area. In the present study, we determined the aquatic macrophyte richness in Lake Bohinj and the trace metal content of Cu, Pb, Cr, Cd, Co, Mn, Fe, Zn, Hg, and Ni in macrophyte and sediment samples. Samples of Myriophyllum spicatum and Chara spp., and sediment were collected on five sampling plots chosen according to the highest plants diversity and sediment accessibility. The following species were found in the littoral of the lake: M. spicatum, Potamogeton alpinus, P. crispus, P. filiformis, P. lucens, P. perfoliatus, P. pusillus, Ranunculus circinatus, Phragmites australis, Chara aspera and C. delicatula. The most diverse genus in Lake Bohinj was Potamogeton and the most abundant species was M. spicatum, which was in accordance with previous studies. The content of most elements (Cd, Co, Cu, Hg, Mn, Ni, and Zn) and bioconcentration factors (BCFs) were higher in M. spicatum than in stoneworts. Bioconcentration of elements from sediments to plants was high in M. spicatum (BCF ˃1 for Cd, Co, Mn and Zn), confirming the suitability of this species in the phytoremediation of sediments of polluted water bodies.