Antidepressant drugs flushed into waterways worldwide are altering shrimp behavior and making them easier prey.
Scientists exposed shrimp to the antidepressant fluoxetine, the key ingredient in the drugs Prozac and Sarafem, at levels detected in average sewage-treatment waste. Shrimp normally gravitate toward dark corners, but when exposed to fluoxetine, they became five times more likely to swim toward a bright region of water. This makes them more likely to be eaten by a predator.
According to National Geographic:
“The fluoxetine likely makes shrimp's nerves more sensitive to serotonin, a brain chemical known to alter moods and sleep patterns ... animals other than shrimp likely suffer from these high doses of fluoxetine”.