Ecosystems, Aquatic ecosystems, eutrophication, Algae, Fresh water, Inland water environment, Toxicity, Herbicides, Phytoplankton, Selectivity, Blooms, Natural products, Scenedesmus obliquus, Scenedesmus, Algicides, Algal blooms, Biological poisons, Lead compounds, Chlorella, Alkaloids, Bioassays, Aniline