Experimental Lakes study finds damage from birth control pills
Addition of synthethic hormone causes minnow population to crash
A new study shows the surprising damage that birth control pills can do to freshwater ecosystems.
The study was conducted at the Experimental Lakes Area near Kenora, with the findings published in the most recent issue of a prestigious British science journal.
To find out, researchers added small amounts of synthetic estrogen to a lake to reflect what comes downstream from a wastewater plant. Two interesting components emerged, according to Rennie.
Scientists found that among the fathead minnow population, males started to produce eggs and their behaviour changed. The fish couldn't reproduce for almost five years after the addition of the estrogen to the lake.
Rennie said he was surprised by the extent of the impact. "I don't think anyone predicted there would be a total recruitment failure for the fathead minnows, that they would stop reproducing entirely. That's a pretty dramatic effect."
The bigger issue for Rennie was the impact on the whole ecosystem. "The loss of the minnows caused a ripple effect including a decline in the lake trout population."
As for what can be done about the impact of estrogen in water systems, Rennie said technologies are being developed to remove the components at treatment plants. However, there is a much larger question, he added. "It's about how to deal with the hormones, yes, but also about all pharmaceuticals at the waste treatment stage."