Skip to main content
U.S. flag

An official website of the United States government

Demasculinization of male fish by wastewater treatment plant effluent

January 1, 2011

Adult male fathead minnows (Pimephales promelas) were exposed to effluent from the City of Boulder, Colorado wastewater treatment plant (WWTP) under controlled conditions in the field to determine if the effluent induced reproductive disruption in fish. Gonadal intersex and other evidence of reproductive disruption were previously identified in white suckers (Catostomus commersoni) in Boulder Creek downstream from this WWTP effluent outfall. Fish were exposed within a mobile flow-through exposure laboratory in July 2005 and August 2006 to WWTP effluent (EFF), Boulder Creek water (REF), or mixtures of EFF and REF for up to 28 days. Primary (sperm abundance) and secondary (nuptial tubercles and dorsal fat pads) sex characteristics were demasculinized within 14 days of exposure to 50% and 100% EFF. Vitellogenin was maximally elevated in both 50% and 100% EFF treatments within 7 days and significantly elevated by 25% EFF within 14 days. The steroidal estrogens 17β-estradiol, estrone, estriol, and 17α-ethynylestradiol, as well as estrogenic alkylphenols and bisphenol A were identified within the EFF treatments and not in the REF treatment. These results support the hypothesis that the reproductive disruption observed in this watershed is due to endocrine-active chemicals in the WWTP effluent.

Publication Year 2011
Title Demasculinization of male fish by wastewater treatment plant effluent
DOI 10.1016/j.aquatox.2011.02.007
Authors A.M. Vajda, Larry B. Barber, James L. Gray, E.M. Lopez, A.M. Bolden, H.L. Schoenfuss, D.O. Norris
Publication Type Article
Publication Subtype Journal Article
Series Title Aquatic Toxicology
Index ID 70035024
Record Source USGS Publications Warehouse
USGS Organization National Water Quality Laboratory; Toxic Substances Hydrology Program; National Research Program - Central Branch