Because of Estrogen, Canadian Fish Are Too 'Confused' to Mate

The Hormone is Blamed for the 'Feminization' of Male Fish

The Gazette, an online Canadian journal, reports that fish in Canadian rivers and lakes are so full of estrogen that they are too confused to mate. The estrogen comes from two sources -- natural estrogen from women and synthetic estrogen from the Pill -- and is introduced into the rivers and lakes through sewage systems.

Fish scientist, Karen Kidd, a biology professor at New Brunswick University, experimented by dripping estrogen, in small amounts over several years, into a lake in Northwestern Ontario, in an effort to reproduce the effects of female urine being introduced into the lake through a town's sewage. She found that "This constant hormone bath made male minnows produce eggs in unnatural, part-female sex organs," according to the Gazette. After she ended the experiment and allowed the lake to return to its pre-experiment condition, the minnows "almost completely disappeared for several years," she said.

The introduction of estrogen into the eco-system holds the potential for a disastrous impact on the fish population in Canada and on the Canadian fishing industry. Researchers have found alarming data about the effects of estrogen on salmon. Other large fish, such as trout or pike, might also be in danger if they are exposed to estrogen for a long enough period. Kidd, in the Gazette article, noted that even small concentrations of estrogen can "decimate" fish populations. Those levels are already present in some Canadian rivers, she added.

The first reports of so-called "feminized" fish came in 1990. Observers found that male fish, near sewage plants, were exhibiting female behavior-producing eggs-and female organs. Kidd is quoted by the Gazette, "A lot of follow-up studies showed it was the natural estrogen that women excrete and then the synthetic estrogens in birth control pills that were the main causes of feminization in male fish." She added that the Pill is one of the most heavily prescribed pharmaceuticals in the world.