Accumulation of Copper and Zinc in the Yellow Water Lily, Nuphar variegatum: Relationships to Metal Partitioning in the Adjacent Lake Sediments

Abstract

Relationships between the partitioning of Cu and Zn in lake sediments and their availability to the yellow water lily, Nuphar variegatum, were examined downstream from a major Cu/Zn mining and smelting complex in Northwestern Quebec, Canada. At each of 13 sampling sites, five N. variegatum individuals were collected, separated into stem and rhizome portions, and analyzed for total Cu and Zn. At the same sites, sediment cores were collected at the base of each plant; the 0- to 2-cm stratum was extruded, wet sieved (850 μm), and subjected to a sequential leaching procedure to determine the partitioning of Cu and Zn among various operationally defined geochemical fractions. Statistical analysis suggested that a significant portion of the Cu burden in N. variegatum was probably derived from the sediments, whereas the Zn content of the plant originated largely in the water column. The concentrations of Cu in the fractions most readily extracted from the sediment were the best indicators of Cu bioavailability in the sediment; normalization of these concentrations with respect to the Fe content of the sediment improved the relationship with [Curhizome], suggesting that Fe may play a protective role in regulating Cu bioavailability.