Population responses of the freshwater amphipod gammarus pulex (L.) to an environmental estrogen, 17α-ethinylestradiol

摘要

The effects of the environmental estrogen 17-ethinylestradiol(EE) on mixed populations of 90 individual Gammarus pules were examined following a l00-d exposure in a flow-through system. Counts of total animal numbers revealed that, in all treatment groups, population size dramatically increased due to recruitment, with neonate and juvenile gammarids the most abundant. At concentrations of 1 and 10 g/L EE, the recorded mean population sizes of 385 and 411, respectively, were significantly greater (p=0.018) than the control(169). Mean population sizes in the solvent control(257) and 100 ng/L EE treatment (267) were not significantly different(P > 0.05) from the control.