According to a new study by Professor Charles Tyler of the University of Exeter in the United Kingdom, fish are becoming transgender as a result of chemicals found in oral contraceptives.
Tyler's study determined that approximately twenty percent of male freshwater fish became transgender as a result of chemicals being discharged down household drains.
“We are showing that some of these chemicals can have much wider health effects on fish than we expected,” Tyler explained. “Using specially created transgenic fish that allow us to see responses to these chemicals in the bodies of fish in real time, for example, we have shown that estrogens found in some plastics affect the valves in the heart.”
Tyler revealed that the male fish, after exposure to contraceptive pills, certain plastics, and cosmetics, took on more "feminized traits," which included a reduced sperm count and "less aggressive and competitive behavior."
“Other research has shown that many other chemicals that are discharged through sewage treatment works can affect fish, including antidepressant drugs that reduce the natural shyness of some fish species, including the way they react to predators,” Tyler added.
The findings of Tyler's study claimed that over 200 chemicals found in sewage treatment plants were directly correlated to "estrogen-like" effects.
Tyler is set to speak at the 50th Anniversary Symposium of the Fisheries Society in the British Isles at Exeter University from July 3 to July 7.