Prozac that finds its way into waterways could be wiping out fish’s personality, according to a new study out of Australia.
More than 250 million antidepressant prescriptions are filled in the US every year, including 20 million for Prozac, known generically as fluoxetine.
Traces of the drug typically get into the water when people go to the bathroom, since sewage treatment plants typically don’t filter them out.
Guppies exposed to levels of fluoxetine found in waterways near sewage plants exhibited ‘an enormous drop’ in variability, and all displaying similar behavioral traits.
‘For fish populations to thrive in the face of environmental change, members of a group need to behave differently from each other,’ they said.
‘If a fish makes the wrong decision and dies, some others will survive by taking different actions.’
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Researchers exposed guppies to levels of fluoxetine, known commercially as Prozac, that are similar to whats found in waterways near sewage plants
Because they’re so ubiquitous, antidepressants are the most-documented drugs contaminating waterways.
Numerous studies have examined the effects of antidepressants, specifically fluoxetine, on all kinds of wildlife, from shrimp to starlings.
But those findings are usually based on averages taken from all the members of a group, which could obscure subtle but important effects on individual animals.
To find out, Giovanni Polverino, a behavioral ecologist at the University of Western Australia in Perth, captured 3,600 guppies.
More than 250 million antidepressant prescriptions are filled in the US every year, including 20 million for Prozac, known generically as fluoxetine. Traces of the drug typically get into the water when people go to the bathroom, since sewage treatment plants typically don’t filter them out
Guppies are frequently used in scientific research because they’re small — usually less than two-and-a-half-inches — and they reproduce quickly.
Polverino’s team broke the guppies into three groups: One was left alone, one was exposed to levels of fluoxetine similar to what they’d encounter in the wild, and another given a dose similar to what’s found in waterways near sewage plants.
They then analyzed the fish’s behavior over a two year period.
Normally guppies have complex personalities and show a lot of variation—in aggressiveness,