Raised plasma vitellogenin in male wild brown trout (Salmo trutta) near a wastewater treatment plant in Ireland.

Ovotestis (intersex) and raised plasma vitellogenin in male fish are widely employed biomarkers of estrogen contamination in the aquatic environment. In the present study, these biomarkers were used to determine whether Irish rivers contain estrogenic chemicals at levels capable of affecting the reproductive health and success of exposed fish populations. A number of aquatic ecosystems were investigated (the rivers Liffey, Lee, and Bandon and the Killarney lakes).