Copper and lead uptake by aquatic macrophytes in eastern Connecticut, U.S.A.

Copper and lead concentrations of submersed, floating-leaved and emergent macrophytes in three interconnected rivers subjected to different amounts of human influence were compared. Concentrations were highest downstream from a printed circuit factory and near urban areas. Lowest concentrations occurred in rural areas. Pontederia cordata L., an emergent species, had lower copper concentrations than Potamogeton epihydrus Raf. and other floating-leaved and submersed macrophytes, but differences among growth forms were small or negligible for lead. Concentrations of both elements were much higher in Pontederia rhizomes and roots than in shoots, especially in polluted areas. Copper concentrations of Pontederia seemed to depend primarily on concentrations in the sediments, whereas copper concentrations of Potamogeton and other floating-leaved and submersed species appeared more indicative of water quality. The lead concentrations of Pontederia seemed to be controlled primarily by uptake from sediments and atmospheric inputs. Differences in lead concentrations of Potamogeton were small among rivers, indicating that foliar absorption and acropetal translocation of lead from roots is low.