Effects of copper sulfate on Typha latifolia seed germination and early seedling growth in aqueous and sediment exposures

The vascular macrophyte Typha latifolia Linnaeus (common cattail) may be a sentinel for evaluating potential phytotoxicity to rooted aquatic macrophytes in aquatic systems. To further evaluate the potential utility of this species, T. latifolia seed germination, shoot growth, and root elongation were measured in 7-day aqueous exposures using mean measured aqueous copper concentrations of 10.0, 23, 41, 62, 174, and 402 mug Cu/L, which were greater than or equal to 62% of nominal concentrations. Seed germination and seedling shoot growth were not significantly affected by any of these copper concentrations as compared to controls. Mean measured no-observed-effect-concentration (NOEC) and lowest-observed-effect-concentration (LOEC) for root elongation were 18.6 mug Cu/L and 35.0 mug Cu/L, respectively. Seven-day sediment tests were conducted by amending uncontaminated sediments with copper sulfate to mean measured concentrations of 7.9. 17.1, 21.0, 51.2, 89.5, and 173.5 mg Cu/kg, which were greater than or equal to 84% of nominal concentrations. Seed germination was not significantly different from controls. Mean measured NOEC and LOEC values for seedling shoot growth were 89.5 mg Cu/kg and 173.5 mg Cu/kg, respectively, and mean measured NOEC and LOEC values for root growth were 14.0 mg Cu/kg and 19.7 mg Cu/kg, respectively. These results demonstrate that T. latifolia early seedling growth can be utilized for assessing aqueous and sediment toxicity of copper.