M4 AM Endocrine Disruption in Fish
Monday, 14 November 2005: 8:00 AM - 11:40 AM in Ballroom 4

(VID-1117-830276) Sexual Abnormalities in Southern Coastal California Coastal Flatfish Near Municipal Wastewater Outfalls.

Vidal , D. E.¹, Bay , S. M.¹, Gully , J.², Hagstrom , R.^{1, 3}, Irwin , M.⁴, Kelley, K. M.³, Montagne , D. ², Reyes , J. ³, Schlenk , D.⁴, ¹ Southern California Coastal Water Research Project, Westminster, CA, USA² Los Angeles County Sanitation District, Whittier, CA, USA³ California State University at Long Beach, Long Beach, CA, USA⁴ University of California at Riverside, Riverside, CA, USA

ABSTRACT- Intersex is a condition that is now frequently encountered in fish living in areas near wastewater outfalls. The occurrence of intersex has been linked with exposures to endocrine-disrupting compounds present in the environment, which mimic the actions of the female sex hormone 17--oestradiol. When affected by estrogenic endocrine disruptor compounds male fish develop oocytes in the testicular tissue. The purpose of this study was to evaluate histological gonadal sections of English sole (Parophrys vetulus) and hornyhead turbot (Pleuronichthys verticalis) to determine the presence of intersex as part of an endocrine disruption survey in southern Califonia (USA) costal flatfish. Gonadal tissue was also used to determine the stage of gonad maturity and other abnormalities such as female atresia, which may be the result of endocrine disruptors in fish. Although the number of fish examined per site was not very large, testis-ova formations were found in some male English sole and hornyhead turbot near outfalls. Fish affected by intersex also showed evidence of elevated production of vitellogenin (an egg yolk precursor) and estradiol. An increase in oocyte atresia was also found in female fish of both species collected in suspected contaminated areas. These partial results warranted the planning of a more complete and rigorous study to further investigate and assess endocrine disruption in flatfish near Southern California municipal wastewaters.

Key words: Marine Fish, Endocrine Disruption, Intersex, Municipal Wastewaters