PARENT SESSION

(WE8/6) Estrogenic effects in the European Chub (Leuciscus cephalus) in laboratory, bypass and field exposure scenarios.

Grillitsch, Britta¹, Gemeiner, Manfred¹, Miller, Ingrid¹, Moestl, Erich¹, Schabuss, Michael¹, Schober, Ursula, Tschulenk, Waltraud¹, Walter, Ingrid¹, ¹ University of Veterinary Medicine, Vienna, Vienna, Austria

ABSTRACT- European Chub (Leuciscus cephalus; Cyprinidae; mean total body length = 11.6 cm, CV = 0.13; mean body mass = 14 g, CV = 0.42) were analyzed for estrogenic effects under three exposure scenarios: (i) standard single compound tests in the laboratory with five estrogenic test substances (17alpha-ethinylestradiol, 17beta-estradiol, bisphenol A, Marlophen NP3, 4-nonylphenol technical grade; three weeks duration of exposure in all tests); (ii) on-site effluent bypass experiments (two reference sewage treatment plants; three weeks duration of exposure); (iii) field exposure in three rivers receiving effluents from municipal sewage treatment plants (three sampling locations at three sampling seasons each). For the indication of estrogenic effects, fish were analyzed for mass and histomorphology of the gonads (sex of germ cells and stage of gonadal maturity; HE-staining), and plasma levels of the egg precursor protein vitellogenin (anti-L. cephalus-vitellogenin enzyme-immuno-assay). The study design using young L. cephalus proved to be practicable and sensitive through the three exposure scenarios which reflect increasing levels of complexity. Data are evaluated for the tradeoff between power, magnitude of effect , sample size and variability.

Key words: estrogenic effects, endocrine modulators, fish, power analysis