Swine farm wastewater discharge causes masculinization of western mosquitofish (Gambusia affinis).

Swine farm wastewater discharge causes masculinization of western mosquitofish (Gambusia affinis). Environ Int. 2018 Dec 05;123:132-140 Authors: Huang GY, Liang YQ, Liu YS, Shi WJ, Liu SS, Hu LX, Xie L, Ying GG Abstract Natural and synthetic steroid hormones have been detected in swine farm wastewaters (SFWs) and receiving waters. However, little is known on their potential endocrine disrupting effects on fish population in receiving rivers. Here we investigated the concentrations of androgens and estrogens in the SFWs and the receiving waters. In addition, the endocrine disrupting effects of SFWs on wild western mosquitofish (Gambusia affinis) were also analyzed by assessing the sex ratio, secondary sex characteristics and transcriptional expression of genes related to the endocrine system. Chemical analysis showed the maximum concentration of total androgens reached 1375.7 ng L-1 in the SFWs and 1020.8 ng L-1 in receiving river waters. A total of 3552 adult G. affinis were collected from the Lianhe River (Guangdong, China), which was heavily impacted by SFWs, before and after the Ban of Swine Farming (BSF) in the river basin. The results showed the presence of male-biased G. affinis populations and masculinized anal fins and hemal spines of females at all contaminated sites prior to BSF. In addition, the transcription of vitellogenin (vtg) was inhibited by SFWs by 99.9% in the females from one sampling site. In contrast, th...
Source: Environment International - Category: Environmental Health Authors: Tags: Environ Int Source Type: research