Epsilon Archive for Student Projects

Abstract

17α-ethinylestradiol (EE2), found in pharmaceuticals is regularly consumed and secreted mainly
from women. Consequently, a significant level of this endocrine disrupting chemical is cont inuously
discharged into the aquatic environment. EE2 is the most potent known estrogen discharged,
it can bioaccumulate in animals and persist in nature relatively long. Laboratory research
indicates decreased population growth in fish exposed to EE2 and this may consequently
change the time of fecundity, bias the sex ratio and decrease the survival rate in young fish. In
this laboratory experiment the growth (length and weight) of roach was analyzed. Roach was
exposed to different concentrations of EE2 (0 ng/l (control), 0.5 ng/l, 5.0 ng/l and 50.0 ng/l) for 75
days in their egg, larvae and juvenile phase. In the final result the mortality was higher among
the estrogen treated roach. The weight and length was significantly increased among the estrogen
treated roach (50.0 ng/l), but the condition factor was higher for the control. The high
growth rate indicates a physiological response caused by the higher food supply among EE2
treated roach. The high mortality among the smallest EE2 treated roach probably influenced
the final composition of EE2 treated roach, which were significantly larger. This is enhanced by
the lower condition factor among the estrogen treated roach, which may indicate a depressed
health due to EE2.