Meeting Abstract

74.1  Wednesday, Jan. 6  Reproductive disruption of fishes by endocrine-active wastewater effluent BOLDEN, A.M.*; VAJDA, A.M.; BARBER, L.B.; SCHOENFUSS, H; NORRIS, D.O.; University of Colorado, Boulder; University of Colorado, Denver; U.S. Geological Survey; St. Cloud St. University; University of Colorado, Boulder alan.vajda@ucdenver.edu

We investigated the impact of a wastewater treatment plant (WWTP) effluent on fish reproduction. This effluent is known to contain endocrine-active compounds including alkylphenols, reproductive steroids, and pharmaceutical contraceptives. Previously, we identified female biased sex ratios, gonadal intersex, asynchronous ovarian development, and other forms of reproductive disruption in feral white suckers (Catostomus commersoni) collected downstream of WWTP effluent but not at reference sites. To investigate the putative link between reproductive disruption observed in feral fish and wastewater effluent, we conducted on-site exposure experiments in 2005 and 2006 using a mobile flow-through laboratory. In these experiments, adult male fathead minnows (Pimephales promelas) were exposed to either WWTP effluent, reference water from Boulder Creek upstream of the wastewater plant, or mixtures of reference water and WWTP effluent. Exposure to diluted wastewater treatment plant effluent significantly elevated vitellogenin and suppressed primary and secondary sex characters. In 2008, we conducted similar on-site experiments to determine effects of an engineering upgrade (change from trickling filter to activated sludge) on the estrogenicity of the effluent. We report a physiological assessment of changes that have occurred in the endocrine activity (estrogenicity) of the WWTP effluent.