FENTRESS, J. F.; BART, H. L., Jr.; CHEEK, A. O.: Endocrine effects of paper mill effluent in longear sunfish

Endocrine disrupting compounds are exogenous agents that interfere with the normal functioning of the endocrine system. Paper mill effluent is believed to contain endocrine disrupting compounds that affect sex steroid and protein levels, as well as reproductive behavior in several species of fish. To determine the effects of paper mill effluent on longear sunfish, Lepomis megalotis, living in the Pearl River, Washington Parish, LA, fish were collected by electroshocking from November 2000-November 2001. Plasma levels of testosterone (T), 11-ketotestosteron (11-KT), 17b-estradiol (E₂), and vitellogenin (VTG) were measured in all samples by ELISA. Blood was obtained via caudal puncture. A total of four sites were sampled, two above and two below the outfall from the paper mill. Differences in hormone and protein levels were analyzed by 2 way ANOVA with time and site as main effects. There was no difference in male or female VTG levels between sites, however a periodicity in VTG levels was observed. VTG levels were low from November-February and high from April-September. No difference in T levels was observed between sites or sexes. Based on the data collected there is no apparent feminization of longear sunfish located downstream of the paper mill effluent.