The Invasion of the Zombie Guppies

You have to love this story, even if you don’t understand it. And I will not claim to understand it.

Here it is. It’s all about Prozac. Millions of people consume millions of prescriptions of Prozac. As you know, it is an extremely popular anti-depressant. Now, as the drug passes through patients’ digestive systems, it gets expelled into the water system through urination. Nothing in the human body breaks down the chemical. Thus, our waterways-- the ones our environmental activists are whining about all the time-- are becoming filled with Prozac. 

Now, I am sure you are concerned about how this impacts fish. You were worried about all the industrial solvents and poisons that are saturating our water supplies. Now, we have one more-- and it is doing damage to fish. 

Researchers in Australia are studying the issue. The Daily Mail reports:

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.

The studies involve guppies. They are easier to study and less visible than polar bears. So, how much damage is being done to the guppy population. Apparently, the answer is-- a lot. In particular, it is changing the way the guppies behave. Instead of having different guppies exhibiting different behavior patterns, the presence of fluoxetine causes the guppies all to adopt the same behavior. This is maladaptive because it makes it impossible for better-behaved guppies to survive and to pass on their genes.

As the researchers put it, the guppies are becoming zombies:

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. 

Normally guppies have complex personalities and show a lot of variation—in aggressiveness, anxiety and even in their levels of bravery and self-control.

According to a 2017 report in the journal Functional Ecology, the fish exhibit a variety of strategies for coping with stressful or unfamiliar situations.

And the control groups did exhibit diverse behaviors, researchers found, with some darting about and others acting more 'lazy,' according to Science Magazine.

The fish treated with high levels of fluoxetine, though, had very little differentiation in their behavior. 

The story continues:

That drone-like behavior could be a killer: Fish, like humans, learn by example—if one makes a wrong move and dies, other fish will try a different tactic and survive. 

'Unfortunately, we found that such behavioral diversity is eroded in fish populations exposed to fluoxetine, and might place large groups of fish at an increased risk of perishing in a changing and increasingly polluted world.'

The uniform behavior maintained throughout numerous generations of guppies, dispelling the idea that behavioral changes caused by fluoxetine could fade as animals get used to it..

'Most studies often focus on the impact of short-term exposure,' said co-author Bob Wong, 'even though many drugs can be highly persistent in the environment and affect animals over long periods of time.'

This is not the first study of the impact of fluoxetine on fish:

Fluoxetine has been associated with a variety of behavioral changes in fish: A 2019 study from Melbourne's Monash University found high levels of the drug disrupted the foraging habits of female Gambusia holbrooki, a species of freshwater mosquitofish, and made them eat less.

Males, meanwhile, spent more time trying to mate.

A 2014 study from the University of Wisconsin-Milwaukee found that male fathead minnows administered Prozac became aggressive, anti-social and sometimes even homicidal.

The minnows, which are common to Midwest waterways, were given fluoxetine in the same concentration as found in wastewater.

The fish's usually-elaborate reproductive habits evaporated with males becoming aggressive — hiding, hunting and sometimes killing females— and females producing fewer eggs.

The technology exists to allow plants to test for pharmaceuticals in their wastewater and waters downstream - but most don't.

The Environmental Protection Agency considers pharmaceuticals an 'emerging concern,' and agrees prescription drugs may pose risks to wildlife and humans, but there are no federal regulations in place yet.

How come our environmentalist zealots do not call for the banning of Prozac? If I had to guess, I think that they would be discombobulated if they went off their meds. They think of themselves as purer than pure, they refuse to touch plastic bags, and they are polluting the environment and killing of the guppy population.