Pb. Dorn et al., ASSESSING THE EFFECTS OF A C-14-15 LINEAR ALCOHOL ETHOXYLATE SURFACTANT IN STREAM MESOCOSMS, Ecotoxicology and environmental safety, 34(2), 1996, pp. 196-204
Fish, benthic macroinvertebrate, and plant responses to 30-day exposur
es of C-14-15 linear alcohol ethoxylate surfactant with an average of
7 mol of ethylene oxide (LAE) were measured in flowthrough stream meso
cosms. Replicate stream mesocosms were treated in two experiments with
concentrations of LAE ranging from 80 to 550 mu g/liter. Macroinverte
brates were relatively insensitive with the exception of Simuliidae de
nsity which was significantly affected at 160 mu g/liter. Fathead minn
ow (Pimephales promelas R.) reproduction was significantly reduced at
> 280 mu g/liter and larval survival decreased significantly at 330 mu
g/liter. Growth and mortality of bluegill sunfish (Lepomis macrochiru
s L.) were not affected at the highest exposure concentration of 330 m
u g/liter in the first experiment. No ecologically significant effects
were observed for vascular aquatic plants or periphyton. The laborato
ry and stream mesocosm results were similar with NOECs ranging between
80 and 550 mu g/liter surfactant. The study provided data for an impr
oved risk assessment of this nonionic surfactant, by reducing the unce
rtainty associated with extrapolation from laboratory data. (C) 1996 A
cademic Press, Inc.