Publication Abstract

Exposure of juvenile roach (Rutilus rutilus) to treated sewage effluent induces dose-dependent and persistent disruption in gonadal duct development.

Exposure of juvenile roach (Rutilusrutilus) to treated sewage effluent induces dose-dependent and persistent disruption ingonadal duct development

T.P. Rodgers-Gray, S. Jobling, C.A. Kelly, S. Morris, G. Brighty, M.J. Waldock, J.P.Sumpter and C.R. Tyler

Wild roach (Rutilusrutilus) have been found with intersex gonads in rivers throughout the UnitedKingdom. The incidence of intersexuality is strongly correlated with discharges ofestrogenic treated sewage effluent into those rivers, and this has led to the hypothesisthat estrogenic chemicals in effluents are feminizing wild male fish. In this study,early-life stage roach (50 days post hatch, dph) were exposed for 150 days to a gradedconcentration (0%, 12.5%, 25%, 50%, and 100%) of treated sewage (primarily domestic)effluent to examine the effects of exposure on sexual differentiation and development.Measurement of steroid estrogens and alkylphenolic chemicals in the effluent and aresulting dose-dependent induction of vitellogenin (VTG; a female-specific,estrogen-dependent plasma protein) confirmed that the fish had been exposed and respondedto estrogen in the effluent. Exposure to treated sewage effluent induced feminization ofthe reproductive ducts in male roach in a dose-dependent manner (in full-strengtheffluent, 100% of the fish had feminized ducts), indicating that the disruption of thegonad ducts seen in wild roach is the result of exposure to treated sewage effluentsduring early-life stages. There were no effects of treated sewage effluent exposure ongerm cell development; therefore, no oocytes occurred in the testes of the feminized maleroach. Subsequent, depuration of the effluent exposed fish in clean water for 150 daysresulted in a reduction in plasma VTG but no alteration of the feminized ducts, indicatingthat the effect of the treated sewage effluent on reproductive duct development waspermanent. The causality of oocytes in the testes of wild male roach therefore remains tohe elucidated.

Reference:

T.P. Rodgers-Gray, S. Jobling, C.A. Kelly, S. Morris, G. Brighty, M.J. Waldock, J.P.Sumpter and C.R. Tyler, 2000. Exposure of juvenile roach (Rutilus rutilus) to treatedsewage effluent induces dose-dependent and persistent disruption in gonadal ductdevelopment. Environmental Science and Technology, 35(3): 462-470.

T.P. Rodgers-Gray, S. Jobling, C.A. Kelly*, S. Morris*, G. Brighty, M.J. Waldock*, J.P. Sumpter and C.R. Tyler

Environmental Science and Technology, 35(3): 462-470