Estrogenicity and intersex in juvenile rainbow trout (Oncorhynchus mykiss) exposed to Pine/Eucalyptus pulp and paper production effluent in Chile

CHIANG, G.; BARRA, R.; DÍAZ JARAMILLO, M.; RIVAS, M.; BAHAMONDE, P.; MUNKITTRICK, K.R.

AQUATIC TOXICOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2015 vol. 164 p. 126 - 134

0166-445X

Pulp and paper mill effluents (PPMEs) have been shown to increase gonad size, cause early maturation, and disrupt hormone functions in native and non-native Chilean fish. In this study, we assessed repro- ductive (plasma vitellogenin; VTG, gonad development) and metabolic (ethoxyresorufin-O-deethylase activity; EROD) end points, relative liver size (LSI) and condition factor (K) of juvenile female and male rainbow trout exposed to effluents. Unlike previous studies, which have focus either on the specific effects of effluent on fish in laboratory exposures or biotic population statuses downstream of discharge sites, we simultaneously assessed the impacts of PPMES on trout using two approaches: (1) laboratory exposures of tertiary treated PPME produced from processing Eucalyptus globulus or Pinus radiata; and (2) in situ bioassay downstream of the combined discharge of the same pulp mill. Despite an increase in the average gonadosomatic index (GSI) in exposed fish, no statistical differences in gonad size between exposed and unexposed individuals was detected. However, both female and male fish exposed to effluents showed significantly higher concentrations of plasma VTG, so more in fish exposed to Eucalyptus-based efflu- ent when compared to Pinus PPME. In addition, male fish showed intersex characteristics in all exposure assays (Eucaliptus and Pinus) and, despite the low concentration of effluent in the river (