PT14 Toxicity of Mixtures
Exhibit Hall
8:00 AM - Tuesday
(PT217) Intersex and reproductive disruption in white suckers (Catostomus commersoni) downstream of Colorado wastewater treatment plants.
Vajda, A.1, Lopez, E.1, Woodling, J.1, 2, Maldonado, T.1, Norris, D.1, 1 University of Colorado, Boulder, USA2 Colorado Division of Wildlife, USA
ABSTRACT- The objective of this study was to determine if gonadal intersex or other forms of reproductive disruption found in fishes throughout Europe, are also present in Colorado waters. White suckers were collected downstream of the effluent of wastewater treatment plants (WWTP) and at reference sites on the South Platte River and Boulder Creek in spring (April) and fall (October). Gonadal morphology was examined using standard histological techniques. Intersex fish were collected downstream of WWTP effluent in both streams. The male to female ratio was skewed toward females downstream of WWTP effluent on Boulder Creek and the South Platte River. Ninety-three percent (n=60) of the white suckers collected downstream of the Boulder WWTP were female compared to 45% upstream (n=33). Only female (n=17) or intersex (n=4) white suckers were collected in the South Platte River downstream of the WWTP. Abnormalities in gross gonadal morphology, smaller ovaries, less developed oocytes and increased follicular asynchrony were noted in female white suckers downstream of the Boulder Creek WWTP. We also found vitellogenin in the plasma of males from downstream sites. The reproductive potential of native fishes may be compromised in stream reaches of western states where large volumes of treated wastewater are discharged into relatively small-sized streams.
Key words: wastewater effluent, endocrine disruption, intersex , fish reproduction