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 macrophyt es in aquatic systems. To further evaluate the potential utility of this sp ecies, T. latifolia seed germination, shoot growth, and root elongation wer e measured in 7-day aqueous exposures using mean measured aqueous copper co ncentrations 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 seedl ing shoot growth were not significantly affected by any of these copper con centrations as compared to controls. Mean measured no-observed-effect-conce ntration (NOEC) and lowest-observed-effect-concentration (LOEC) for root el ongation were 18.6 mug Cu/L and 35.0 mug Cu/L, respectively. Seven-day sedi ment 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 concent rations. Seed germination was not significantly different from controls. Me an 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.