Timing of exposure to a pulp and paper effluent influences the manifestation of reproductive effects in rainbow trout.

摘要: Rainbow trout were exposed to a secondary treated, thermomechanical/bleached kraft pulp and paper effluent in 12,000-L, flow-through exposure tanks at an environmental research facility located mill Kawerau, New Zealand. Trout (age, 2+ years) obtained from local hatchery either upstream river water or nominal concentration of 12% (v/v) diluted water. Three treatment groups used: Effluent that started approximately three months before gonadal growth (eight-month total exposure), halfway through development (two-month reference alone for the duration experiment. sacrificed just spawning; exposure, growth, reproductive endpoints assessed during termination Reduction was observed both sexes eight-month group relative group. No differences condition factor liver size treatment. Females also had significantly lower ovary weight. The two-month showed no somatic indices. Estradiol testosterone reduced blood samples taken by four into experiment as compared Steroid vitellogenin levels individual female this correlated with gonadosomatic indices (GSI) measured GSI not strongly consistently pregnenolone, nor any treatment-related pregnenolone observed, indicating steroid hormone reductions likely related cholesterol side-chain cleavage. Male significant induction I 1-ketotestosterone (only examined), but did result testes development. Thus, study has shown impact on physiology appeared be hormonally mediated. Furthermore, effect could only manifest when initiated start gonad