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Is Water Pollution Making All Fish Female?


Water pollution from everyday chemicals is causing fish to switch gender from male to female, reports Spanish scientists.

First noted in Basque Country (the region between northeastern Spain and southwestern France) estuaries in 2007-2008 were seeing fish show traits of feminization. Researchers out of the University of Basque Country have now found feminization of fish in seven other estuaries in the area.

According to the research, which was recently published in the journal of Science of the Total Environment and in the journal Marine Environmental Research, chemicals are making their way through water treatment plants or getting into the waterways via industrial activity and large-scale farming operations.

"[E]ndocrine-disrupting chemical pollutants acting as estrogens, the primary female sex hormones, are seeping into the waters and causing immature eggs to develop in male fish," reports NBCNews. "These chemicals are found in relatively modern products such as plasticizers, pesticides, contraceptive pills, fragrances and detergents."

According to NBC, Miren P. Cajaraville, director of the research team, said in a statement that clear biological indicators of fish feminization are evident "in each of the places studied we have measured which pollutants have appeared recently and their respective concentrations, and we have confirmed the correlation existing between the presence of the pollutants and the feminization phenomenon."

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From the Organic Authority Files

A 2012 study in Washington's Puget Sound found similar cases of fish feminization of English sole. Estrogens and chemicals in the water were also suspected as the cause.

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