ABSTRACT
Macrophytes are known as good indicators of heavy metal contamination in aquatic ecosystems and they act as biological filters by accumulating heavy metals from surrounding environments. Concentrations of heavy metals such as Hg, Cd, Co, Cu, Mo, Ni, Pb, Tl and Zn were measured in 13 selected macrophytes and water samples from the mouth of four main rivers of the Lake Sevan basin (Armenia), namely, Gavaraget, Argichi, Makenis and Masrik. Myriophyllum spicatum L. showed the highest accumulation of total heavy metals. Potamogeton perfoliatus L., Ranunculus rionii (Lagger.), and Veronica anagallis-aquatica L. also showed high potential for heavy metal accumulation. Range in concentrations (µg/l; ppb) of Co (<0.5 ppb), Cd (<0.5 ppb), Hg (<0.3 ppb), and Tl (<0.1 ppb) in water samples were similar from all the sites. Occurrence of heavy metals was much higher in macrophytes and water from the Gavaraget and Masrik rivers than that from the Argichi and Makenis rivers, probably due to discharge of sewage into the river Gavaraget and industrial wastewaters into the river Masrik. Concentrations of heavy metals in these macrophytes were far higher than in their respective water column. This indicates their bioaccumulation capacity and role in biogeochemical cycles of heavy metals.
