Contraceptives and antidepressants can reduce fish reaction times and reproductive rates.
Scientists have known for years that human medications, from anti-inflammatories to the hormones in birth-control pills, are ending up in waterways and affecting fish and other aquatic organisms. But researchers are only beginning to compile the many effects that those drugs seem to be having. And it isn't good news for the fish.
One such drug, fluoxetine, is the active ingredient in the antidepressant Prozac. Like some other pharmaceuticals, fluoxetine is excreted in the urine of people taking it, and reaches lakes and waterways through sewage-treatment plants that are unequipped to remove it.
When fluoxetine concentrations are increased yet again, fathead reproduction completely halts. "The males start killing the females," she said.
At the same symposium, Dan Rearick, an aquatic toxicologist from St Cloud State University in Minnesota, reported that a chemical found in birth-control pills, 17-β-estradiol, reduced the ability of fathead minnow larvae to elude predators