New research proves that 'gender-bending' chemicals, which leach from human products into rivers and oceans, can have a significant impact on the ability of fish to breed. The study has important implications for understanding the impacts of these chemicals.
Endocrine-disrupting chemicals (EDCs) affect hormones. They are found in products ranging from contraceptive drugs to liquid detergents.
They have been seeping into rivers through the sewage system for decades and alter the biology of fish, changing male fish to make them more female.
"Until now, there has been no solid evidence to show the long-term impact of this effect on fish in the wild -- but the new research focusing on wild roach in two UK rivers (Bourne and Arun) has provided new evidence
... It was found that intersex fish -- those that had their sexuality compromised by EDCs and which contain both male (sperm) and female (eggs) sex cells -- had their reproductive performance reduced by up to 76 percent."