The effects of a C12-13 linear alcohol ethoxylate surfactant on periphyton, macrophytes, invertebrates and fish in stream mesocosms

摘要: The ecological effects of a C12–13 linear alcohol ethoxylate (LAE) were studied in stream mesocosms. surfactant has an average distribution six and one-half ethylene oxide groups per mole alcohol. Responses periphyton, macrophytes, invertebrates, fish examined used to estimate mesocosm-predicted no-observable-effect concentration (NOEC). mesocosm experiment consisted 2-week period natural colonization, 30-d treatment period, post-treatment period. Four concentrations duplicate streams along with two untreated control streams. Surfactant delivered the no apparent loss during 17-min transit time. structural integrity was also maintained observed differences between head, middle, or tail sections individual Average measured LAE for replicate 0.32, 0.88, 1.99, 5.15 mg/L. Periphyton Myriophyllum aquaticum did not show significant effects. no-observed-effect (NOEC) all periphyton M. parameters mg/L, highest tested. Statistically on Simuliidae, Copepoda, Cladocera densities exposure concentrations. Thus, lowest-observed-effect (LOEC) invertebrate 0.32 Drifting invertebrates effects; however, increased numbers drifted 5.15-mg/L compared controls. LC50 farm-raised University-cultured fathead minnows similar at 1.27 survival NOEC LOEC both populations 0.88 mg/L 1.99 respectively. There reproduction minnow. Fathead minnow reproductive behavior feeding most susceptible Bluegill sunfish responded similarly as No sublethal juvenile bluegill growth this study. For primarily regulatory purposes, “mesocosm NOEC” 0.28 derived use risk assessment.