Professor Charles Tyler, reproductive physiologist and environmental biologist at the University of Exeter (United Kingdom), has found that chemicals from contraceptive pills and other household cleaning products are causing fresh-water male fish to develop female parts and even to lay eggs.
Tyler’s research has shown that oestrogen and other chemicals being washed down the drain are causing male fish to reduce “sperm quality and display less aggressive and competitive behaviour, usually associated with attracting females of the species, which make them less likely to breed successfully,” reported Exeter in a press release.
Tyler presented his research on July 3 in a keynote address at 50th Anniversary Symposium of the Fisheries Society in the British Isles, held at Exeter University. His lecture was titled “The Feminisation of Nature – an Unnatural History.”
In the lecture, he laid out data on the Roach fish in particular, and how estrogens are causing some males to develop ovaries and become an “intersex.”