| Assessing the Sensitivity of Different Life Stages for Sexual Disruption in Roach (Rutilus rutilus) Exposed to Effluents from Wastewater Treatment Works Katherine E. Liney,1 Susan Jobling,2 Jan A. Shears,1 Peter Simpson,3 and Charles R. Tyler1 1Environmental and Molecular Fish Biology Group, School of Biosciences, Hatherly Laboratories, Exeter, United Kingdom; 2Aquatic Ecotoxicology Research Group, Department of Biological Sciences, Brunel University, Middlesex, United Kingdom; 3Environment Agency, Waterlooville, United Kingdom Abstract
Surveys of U.K. rivers have shown a high incidence of sexual disruption in populations of wild roach (Rutilus rutilus) living downstream from wastewater treatment works (WwTW) , and the degree of intersex (gonads containing both male and female structural characteristics) has been correlated with the concentration of effluent in those rivers. In this study, we investigated feminized responses to two estrogenic WwTWs in roach exposed for periods during life stages of germ cell division (early life and the postspawning period) . Roach were exposed as embryos from fertilization up to 300 days posthatch (dph ; to include the period of gonadal sex differentiation) or as postspawning adult males, and including fish that had received previous estrogen exposure, for either 60 or 120 days when the annual event of germ cell proliferation occurs. Both effluents induced vitellogenin synthesis in both life stages studied, and the magnitude of the vitellogenic responses paralleled the effluent content of steroid estrogens. Feminization of the reproductive ducts occurred in male fish in a concentration-dependent manner when the exposure occurred during early life, but we found no effects on the reproductive ducts in adult males. Depuration studies (maintenance of fish in clean water after exposure to WwTW effluent) confirmed that the feminization of the reproductive duct was permanent. We found no evidence of ovotestis development in fish that had no previous estrogen exposure for any of the treatments. In wild adult roach that had previously received exposure to estrogen and were intersex, the degree of intersex increased during the study period, but this was not related to the immediate effluent exposure, suggesting a previously determined programming of ovotestis formation. Key words: differentiation, effluent, endocrine, fish, wastewater treatment works. Environ Health Perspect 113:1299-1307 (2005) . doi:10.1289/ehp.7921 available via http://dx.doi.org/ [Online 14 June 2005]
Address correspondence to K.E. Liney, Environmental and Molecular Fish Biology Group, School of Biosciences, Hatherly Laboratories, Prince of Wales Rd., Exeter, EX4 4PS, UK. Telephone: 44-1392-264389. Fax: 44-1392-263700. E-mail: k.e.liney@exeter.ac.uk We thank members of the Environmental and Molecular Fish Biology Research group at the University of Exeter, the Fish Physiology Research Group at Brunel University, Essex and Suffolk Water, and the Centre for Environment, Fisheries and Aquaculture Science (CEFAS ; Burnham on Crouch, UK) for help in maintaining the mesocosms and fish and support in sampling. P. Roberts at CEFAS carried out the analytical chemistry. We are especially grateful for the support and advice throughout this project from A. Henshaw and staff at Calverton Fish Farm, U.K. Environment Agency. This work was funded by UK Water Industry Research, the U.K. Environment Agency, and the Department for Environment, Food and Rural Affairs on a grant to C.R.T. and S.J. The authors declare they have no competing financial interests Received 12 January 2005 ; accepted 14 June 2005.
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