Science Suggests We’re Making Fish Homicidal Through Antidepressants We Flush Into the Water

By Reynard Loki, AlterNet’s environment, food and animal rights editor. Follow him on Twitter @reynardloki. Email him at Originally published at Alternet

New research has found that human antidepressant medications are accumulating in the brains of fish in the Great Lakes region. Earlier research indicates the drugs could be making fish antisocial and unnaturally aggressive.

The scientists behind the recent study, from Ramkhamhaeng University and Khon Kaen University, both in Thailand, and the State University of New York at Buffalo, looked at fish living in the Niagara River, which connects Lake Erie and Lake Ontario via Niagara Falls.

“The continuous release of pharmaceuticals and personal care products (PPCPs) into freshwater systems impacts the health of aquatic organisms,” they concluded, adding that the cause was “direct exposure” to the discharge from wastewater treatment plants.

Approximately 70 percent of consumed pharmaceuticals are excreted in urine, and subsequently aren’t filtered out by municipal sewage systems, which primarily focus on removing disease-causing bacteria and solids like human excrement. So Prozac and other medications end up in the river, leaving fish and other wildlife exposed to a host of foreign chemicals.

Largemouth Bass is one of the 10 species of Great Lakes fish found with human antidepressants in their brains. (image: Rostislav Stefanek/Shutterstock)

In addition to various pharmaceuticals, the researchers found ingredients from personal care products in the bodies of all 10 species of fish they studied. This disturbing discovery could have significant impacts not just on the species impacted, but up and down the food chain—and entire ecosystems.

Unnatural-Born Killers

One impact is on the behavior of the fish. “When fish swim in waters tainted with antidepressant drugs, they become anxious, antisocial and sometimes even homicidal,” writes Brian Bienkowski of Environmental Health News, who notes that pharmaceuticals “can alter genes responsible for building fish brains.”

A 2014 study conducted by researchers from the University of Wisconsin-Milwaukee and published in the journal Aquatic Toxicology found that antidepressants cause changes in the hormone levels of fish, “indicating significant neuroendocrine changes.”

They warned that even low concentrations of fluoxetine—more commonly known by the trade name Prozac—which has been found in many freshwater ecosystems, can “significantly impact mating behavior, specifically nest building and defending in male fish,” such as the fathead minnow, a native North American fish species.

They found that when male minnows were exposed to Prozac, they ignored females and spent more time hiding under a tile, which resulted in lower reproductive rates. In addition, they took longer in capturing prey and also became aggressive; in some cases, even killing females. Exposed females were also impacted by producing fewer eggs.

Adding to the concern is the fact that the fish behavior was altered even with low doses of the drug. “At high doses, we expect brain changes,” said Rebecca Klaper, a professor of freshwater sciences at the University of Wisconsin-Milwaukee and co-author of the 2014 study. “But we saw the gene expression changes and then behavioral changes at doses that we consider environmentally relevant.”

Antidepressants like Prozac are the most commonly prescribed medications in the U.S., with around 250 million prescriptions filled every year. (image: callumrc/Shutterstock)

Dr. Diana Aga, a chemistry professor at SUNY Buffalo and lead researcher of the Great Lakes study, said she and her colleagues detected antidepressants in all 10 species studied: smallmouth bass, largemouth bass, rudd, rock bass, white bass, white perch, walleye, bowfin, steelhead and yellow perch. The highest drug concentration—400 nanograms of norsertraline per gram of brain tissue—was found in rock bass. Norsertraline is produced in the body by sertraline, the active ingredient in Zoloft.

The major pollutants they found were the antidepressants Celexa, Paxil, Zoloft, Effexor and Wellbutrin. Also found in high concentrations were metabolites of fluoxetine (Prozac) and sertraline (Zoloft), as well as diphenhydramine, an antihistamine commonly found in over-the-counter flu and cold medications.

With Every Toilet Flush, More Harm to Wildlife 

The more pharmaceuticals we dump into waterways, the worse it gets, as many of these chemicals are bioaccumulative, meaning that the fish and other aquatic wildlife absorb the chemicals at a rate faster than their bodies can break it down or excrete it.

“These active ingredients from antidepressants, which are coming out from wastewater treatment plants, are accumulating in fish brains,” said Dr. Aga. “It is a threat to biodiversity, and we should be very concerned.”

Since wastewater treatment plants do not filter out these drugs, she said, “wildlife is exposed to all of these chemicals. Fish are receiving this cocktail of drugs 24 hours a day.” In the Great Lakes fish, the “highest bioaccumulation was found in the brain, followed by liver, muscle and gonads.”

The high concentrations are connected to the sheer amount of antidepressants Americans take. As Bienkowski notes, “about 250 million prescriptions are filled every year. And they also are the highest-documented drugs contaminating waterways.”

Dr. Randolph Singh, one of the co-authors of the Great Lakes study, said such human-caused, synthetic alterations to fish brains have the potential to disturb the harmony of biodiversity that maintains ecosystem stability. Most people don’t eat fish brains, so the antidepressants found in them would likely not pose a human health hazard, but he warned, “The risk that the drugs pose to biodiversity is real, and scientists are just beginning to understand what the consequences might be.”

The researchers said wastewater treatment plants must address these drugs to keep them out of the environment. “These plants are focused on removing nitrogen, phosphorus and dissolved organic carbon,” Dr. Aga said. “But there are so many other chemicals that are not prioritized that impact our environment.”

Biochar to the Rescue?

Other research indicates that biochar—a cheap porous charcoal material converted from agricultural waste that is a precursor to activated carbon—can be used to remove pharmaceuticals from urine. Biochar made from activated coconut carbon, bamboo and southern yellow pine has been shown to have the highest pharmaceutical removal properties.

Dr. Treavor Boyer, an associate professor in the School of Sustainable Engineering and the Built Environment at Arizona State University, and Avni Solanki, a Ph.D. candidate in Environmental Engineering Sciences at the University of Florida, have studied biochar to see if it could work as a viable method for removing pharmaceuticals from urine in order to reuse it as a fertilizer. The results are promising.

“We wanted to look at a low-cost material that all countries could use [for wastewater management], whether developed or developing,” said Solanki. They said they were also pleased “to see that something this cheap with such a low environmental footprint could actually be applied for pharmaceutical removal and nutrient recovery.”

“There is also some work on urine-diversion from the toilet,” Dr. Aga told AlterNet. She noted the work of the Rich Earth Institute, a nonprofit supporting sustainable agriculture by working to turn human urine into fertilizer.

Until municipal wastewater treatment plants start filtering out pharmaceuticals, people who want to remove pharmaceuticals from their urine might be able to do so using a DIY biochar filter. Of course, we could also stop taking so many antidepressants. But that’s another story.

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  1. visitor

    What happens then to the chemicals-soaked biochar? Does it end up in massive landfills eventually leaching the noxious molecules into the ground?

    More generally, the accumulation of those news are increasingly pushing me to think that we are doomed in the short to medium term. The immense variety and scale of assaults against the environment, the sheer rapacity of human beings, and the absence of any serious large-scale, systematic action to counter the obvious environmental devastation (the only, much-touted one, was to protect the ozone-layer, and even there lobbies repeatedly attempt to knowingly let ozone-destroying chemicals be approved — because profits) are completely disheartening.

    1. PlutoniumKun

      Biochar is very biologically stable and usually holds on to the compounds within it very effectively. Its been studied by archaeologists (biochar was frequently used by early farmers as a soil improver) and its closely related to activated carbon, which is usually landfilled after its use for industrial emission scrubbing, without any significant leaching problem. The molecular structure of carbon acts almost like a one way sponge, soaking up other molecules and not letting them out.

      While its likely that biochar filters used in treatment plants would be landfilled, it would also be an excellent agricultural product if it was proven not to leach excessive amounts of undesirable compounds. Its a very good soil improver and week suppressant. It is also an excellent way of removing CO2 from the atmosphere.

      If there is such a thing as a low tech environmental wonderproduct, biochar is it.

      1. johnnygl

        Building on PK’s good comment, carbon, as an element, is really good at bonding to other elements and even breaking down compounds to create new ones. This is why we see carbon come in so many forms and combinations.

        The old greening the desert video with geoff lawton included a bit about how using lots of mulch consisting of organic matter helped to desalinate the soil, even in a harsh environment like the jordan valley.

        Carbon can be a really useful tool for humanity if we put it to work for us, instead of creating problems with it.

      2. Lynn

        If toxins do not leach out of the biochar this could be a very good solution. Biochar is an excellent medium for soil microbes. Biochar is condo’s for soil microbes as it creates the perfect mix of air space, moisture and surface space for soil microbes to flourish. That is why farmers use it for enriching the soil.

    2. joe defiant

      Have you read Endgame Vol. 1 The Problem of Civilization by Derrick Jensen? Great book about how civilization (urban cities and suburbs mostly) itself is the problem and all these single issue solutions that dance around that issue are just going to make the eventual collapse much worse. It’s a book everyone should read.

  2. ambrit

    Most municipal wastewater systems treat and dump, sending the effluent directly into bodies of water. Some newer wastewater systems are now exploring the use of marshland as a tertiary treatment method. This doesn’t ‘solve’ the problem outright, but could significantly reduce complex chemical discharge to bodies of water.
    Here’s the EPAs version:
    Yet another of those unmet infrastructure needs. There is so much that needs to be done. Anyone who seriously argues that there are no community projects ready to go needs to be confined for ‘observation’ in a psychiatric facility. (Now there’s another unmet community need.)

    1. johnnygl

      With all the roofs and asphalt in the usa these days, there’s so much surface run off that it seems there’s a lot more marshlands being created than might otherwise exist.

      If we’re going to do this as a society, we might as well go further and make these new wetlands work for us to solve other problems we create. It seems like an obvious opportunity that is being wasted. Unfortunately, environmental pollution is a low priority in our society.

  3. Anti-Schmoo

    Prozac/Zoloft nation; whom the gods wish to destroy, they first make mad…
    Not to be too cryptic here; but the U.S.’s most serious failing is in the mental health of the nation.
    The exemplar would be the sitting president; nothing more needs be said, yes?

      1. joe defiant

        The majority of high ranking politicians and business elite score high on the psychopath test. “Snakes in Suits” is a book about the corporate psycopaths running the world. “I Am Fishhead” is a good documentary about this as well.

        Talking about Donald Trump as if he is an outlier is problematic and the large effort being undertaken to point this out mostly points to a desire for the return to normal of the Bushes and Clintons running things who have both been responsible for more needless deaths and destruction in their first year than Trump has.

        1. Vatch

          Talking about Donald Trump as if he is an outlier is problematic

          The book discusses a number of psychological disorders besides psychopathic personality disorder. Trump has displayed clear symptoms of extreme malignant narcissism. He may also be in the early stages of dementia. Yes, George W. Bush and the Clintons are terrible, but Trump really is an outlier.

          The majority of high ranking politicians and business elite score high on the psychopath test.

          I don’t think it’s the majority. I recall that Robert Hare has estimated that about 1% of the population consists of psychopaths, and about 4% of senior business executives and politicians are psychopaths. Martha Stout estimates that about 4% of the total population is sociopathic (I consider that a synonym for “psychopathic”). She might estimate that 10% to 20% of executives are sociopaths, but that’s a guess on my part. It’s a continuum, and many people display some of the symptoms, but not enough symptoms to be definitively declared a psychopath or sociopath. A lot of business executives are simply greedy, or they may reluctantly do some of the things that a psychopath would do because that seems to be a route to success.

  4. The Rev Kev

    I was looking at Google for a story about how these chemicals are also altering the sexes of fish here is Oz but when I put in the search term fish sex change pollution there turned out to be a whole slew of these stories in both the UK as well as the US. This is starting to get creepy. Apparently the cause is birth control pills whose hormones cannot be properly filtered out of the water so yet another factor in the pollution of fish.

    1. ef

      I just did a search on Google, Duckduckgo, and using “fish sex change pollution” and found very much the same stories in both the US and UK. You’re right, this does sound creepy.
      So take the antidepressants flushed down the toilet from a local high school and have them non-filtered back into the water supply of the local water supply and we’re all set.

  5. Darn

    Sounds like the episode of Red Dwarf where a fish committed suicide by closing its own gills after exposure to the ink of the despair squid.

    1. Mel

      I wondered whether that was the right word .. you mean they’re actually up and killing people? But I had seen the movie Snakehead, which was Jaws built to 1:10 scale. Instead of the ocean, there was a lake in cottage country. Instead of a Great White Shark, there were these fresh-water fish with nasty teeth. The scientific back-story was very similar to this one. It was an OK movie. I wouldn’t dis-recommend it.

  6. Wade Riddick

    “When fish swim in waters tainted with antidepressant drugs, they become anxious, antisocial and sometimes even homicidal”

    Yeah. Just like us.

    Should we ask to treat the fish better than us or treat us better than the fish? I’m torn.

    Since nutritional deficiencies in fish oil intake (DHA and EPA) can cause depression, doesn’t that mean that because our diets aren’t swimming in enough fish food, we’re taking antidepressants that the fish are then swimming around in themselves?

    I can’t keep up. Help.

    (Donald Trump. #2 cause of homicidal fish and gaining fast!)

  7. Steve H.

    To repeat a quote from Iberall: “…(T)he biological system- including man- is not run by the central nervous system but by the endocrine system.”

    I was peripherally involved in work on endocrine dispruptors in fish about a decade ago. An aspect of ‘Limits to Growth’ which was weirdly prescient was that the pollution predictions were general enough to cover aspects which were little known at the time. Global warming and biological disruptions like those described in this article may be the most serious.

    1. wilroncanada

      Reports from about five years ago were tracking the increases in caffeine in ocean waters off both the northeast and northwest coasts, particularly Oregon and Washington.

  8. John

    Intersex fish are ubiquitous in the upper reaches of the Potomac River basin. For a long time. But no one talks about it much. Most likely caused by endocrine disruptors. Just another sign of late stage empire going down. Gonna be a lot of chaos coming down the road. It’s a good thing everybody is watching Walking Dead to get ready.

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