Assessing the Sensitivity of Different Life Stages for Sexual Disruption in Roach ( Rutilus rutilus ) Exposed to Effluents from Wastewater Treatment Works

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.

2, 4-Dichloro-6-nitrophenol, a photonitration product of 2, 4-dichlorophenol, caused anti-androgenic potency in Chinese rare minnows (Gobiocypris rarus)

“…Regarding the sex steroid levels, the endocrine system in males and juvenile fish was more affected than that in females. Similar observations concerning differential life stage sensitivity have been reported in other studies (Duffy et al, 2014;Liney et al, 2005). Moreover, antiandrogenic effects may be provoked by inhibition of testosterone synthesis.…”

Reduced embryonic survival in rainbow trout resulting from paternal exposure to the environmental estrogen 17α-ethynylestradiol during late sexual maturation

“…These contaminants are widely distributed in aquatic environments and are identified through both direct chemical detection in surface waters as well as their known biological impacts in North America (Kolpin et al 2002, Goksoyr 2006, Woodling et al 2006, South America (Orrego et al 2006), Europe (Jobling et al 1998, Liney et al 2005, and Asia (Hashimoto et al 2000). The effects of environmental estrogens are primarily mediated by either their binding to or interference with estrogen receptors.…”

“…Sewage treatment plant effluent, the most frequent source of environmental estrogen contamination, can be directly released into adjacent surface waters. Documented reports of fishes in these waters with both physiological and developmental problems have been observed (Hashimoto et al 2000, Jobling et al 2003, Liney et al 2005, Rempel et al 2006. Sewage effluents may contain many environmental estrogens, but of particular concern is EE 2 .…”

Aerobic and Anaerobic Transformations in Estrogens and Nutrients in Swine Manure: Environmental Consequences

“…A serious concern regarding pig CAFO is that manure, despite being rich in nutrients, also contains high concentrations of estrogens that, even at low doses, have been proven to have long-term adverse health effects in humans and aquatic/wild animals [5,6]. The ecological hazard posed by steroidal hormones resulting from swine production is not clearly known.…”