Beta males explained?

The discovery raises some tough questions. Scientists don’t know whether the growing number of feminized fish could hinder reproduction enough to disturb the rest of the ecosystem or even drive bass into extinction. Even scarier, the culprit is still unknown. The prime suspect? Our toilets. Previous research indicates that wastewater treatment plants flush endocrine-disruptive compounds (EDCs), including pharmaceuticals, pesticides and hormones, into rivers. Even minuscule amounts of EDCs can trigger powerful hormonal shifts that deform male fishes’ reproductive organs. During a seven-year study, for instance, scientists added parts-per-trillion amounts—the levels emitted by treatment plants—of the synthetic estrogen used in birth-control pills to a closed lake. The resulting sex changes collapsed the entire fish population…

Hinck is now investigating the mechanisms that could be transforming the fish, but we’re just beginning to learn what this means for those of us with opposable thumbs, many of whom drink water from these rivers. The same compounds can interfere with the human endocrine system, but there are no regulations for controlling hormones in drinking water.