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EFFECTS OF ETHINYL ESTRADIOL EXPOSURE ON REPRODUCTION IN AN ESTUARINE FISH TAUTOGLABRUS ADSPERSUS
Citation:
Mills, L J., R E. GutjahrGobell, D B. Horowitz, AND G Zaroogian. EFFECTS OF ETHINYL ESTRADIOL EXPOSURE ON REPRODUCTION IN AN ESTUARINE FISH TAUTOGLABRUS ADSPERSUS. Presented at New England Pharmacologist Meeting, Newport, RI, January 26-27, 2001.
Description:
Natural estrogen levels in women are routinely supplemented by potent pharmaceutical estrogens through use of birth control pills and hormone therapy. Excess estrogen is excreted by these women. Currently, about seventeen percent of women in the US use birth control pills and some 20 million women nationwide are receiving hormone therapy. While free estrogens are short-lived and do not bioaccumulate in the aquatic environment, they are constantly being renewed by release of sewage treatment effluent. Recent research at U. S. EP A's Atlantic Ecology Division indicates hormonal signals provided by such estrogens can disrupt normal reproduction in exposed fish. Our study investigated the impact of ethinyl estradiol (EE2), the human contraceptive, on reproductive success of cunner, Tautogolabrus adspersus. Reproductively active male and female fish were exposed in the .laboratory by subcutaneously implanting EE2 in a slow-release matrix. Treatments were control (matrix only) and three concentrations of EE2 (0.05, 0.5 and 2.5 mg/kg), Before and after exposures began, daily egg productivity, viability, and fertility were determined. During the two week exposure period, mean daily egg production in the high EE2 treatment was significantly lower than controls. In this treatment, gonadosomatic index (GSI) in females averaged 25% lower than control females, while mean GSI in males exhibited a 45% reduction compared to control males. Hepatosomatic index (HSI) in males treated with the high concentration of EE2 averaged more than twice the mean HSI of controls. The normal female protein vitellogenin, produced in the liver by estrogen stimulation, was found in plasma from males treated with EE2 and may account for the observed increase in HSI. These results show that exposure to EE2 can affect reproductive success in cunner in the laboratory and suggest estrogens in sewage effluent may impact the reproductive health of fish populations near such outfalls.