Endocrine disruption in patagonian trout exposed to sewage effluents.

GUERREÑO, MARIANA; LUQUET, C. M.; LO NOSTRO, F. L.; CASTIÑEIRA, L; MAGGESE, M. C.; GENOVESE, G

Hilton Riverside, New Orleans, Louisiana, USA

Congreso; SETAC North America 30th Annual Meeting; 2009

SETAC

The Lake Lacar, of glacial origin, ends in a relatively shallow bay of San Martín de los Andes (Patagonia, Argentina), a city which has demographically increased in the last few years. The Pocahullo River, the main affluent of the lake, crosses this city receiving both untreated domiciliary effluents and the discharge of the main sewage treatment plant of the city. Sewage effluents normally cause endocrine disruption in wild animals, evidenced by biomarkers such as the induction of female proteins, sex reversal, and reproductive impairment. We compared the effect of acute and chronic exposure of adult male Oncorhynchus mykiss (Teleostei, Salmoniformes) to Pocahullo River with control fish from unpolluted upstream areas (Centro de Ecología Aplicada del Neuquén). Surface mucus, blood, and organ samples were obtained for Western blots and histological analysis, respectively. Liver and gonad sections were stained with haematoxylineosin and further analysed under light microscopy. Marked alterations in the morphology of both organs were only detected in male exposed fish. These alterations included liver hyperplasia, euchromatic and basophilic hepatocytes, and abnormal spermatogenesis. We detected vitellogenin immunoreactive bands between 90-140 KDa in plasma from male fish submitted to chronic exposure. Such bands could not be detected in controls and fish exposed during 10 days to Pocahullo River, though hepatosomatic and gonadosomatic indices in exposed fish were augmented and reduced, respectively. This is the first report of xenoestrogenicity in a Patagonian fresh water salmonid fish. This work was supported by UBACyT X620, PICT2005 34417 and, CONICET PIP 6244.