When I first read this research paper, I was hopeful that the adverse affects of contraceptives waste found in water would actually turn out to be useful to Koi Keepers as a future way to prevent or control spawning in Koi ponds.  While it is clear that exposure to low doses of contraceptive waste does affect fish, the findings showed it was limited to subsequent generations.  This may not ever be applicable for Koi keepers, but perhaps suggests that there is hope for future research regarding contraception and Koi!  Full article after the break...

WOMEN who take the contraceptive pill aren’t the only ones not reproducing. Fish are affected too.

A recent study by the US Geological Survey, published in the Journal of Scientific Reports, found fish who were exposed to “estrogenic chemicals” in a lab experiment had a “significant reduction in the fertilisation rate in offspring” and a “reduction of embryo survival in offspring.”

Scientists exposed fish to either BPA or EE2 for one week during embryonic development, while subsequent generations were never exposed.

EE2 is a hormone found in oral contraceptive and up to 68 per cent of it is excreted by the person taking it. BPA is also a chemical used to produce plastic.

“These adverse outcomes may have negative impacts on populations of fish inhabiting contaminated aquatic environments,” the study says.

“If those trends continued, the potential for declines in overall population numbers might be expected in future generations,” a scientist from the US Geological Survey and assistant research professor at University of Missouri, Ramji Bhandari, told The Washington Post.

“These adverse outcomes, if shown in natural populations, could have negative impacts on fish inhabiting contaminated aquatic environments.”

news.com.au

Reference:

Welshons, W. V., Nagel, S. C. & vom Saal, F. S. Large effects from small exposures. III. Endocrine mechanisms mediating effects of bisphenol A at levels of human exposure. Endocrinology 147, S56–69 (2006).