Fish on Prozac: Anxious, Anti-Social and Aggressive
By Brian Bienkowski
When fish swim in waters tainted with antidepressant drugs, they become anxious, anti-social and sometimes even homicidal.
New research has found that the pharmaceuticals, which are frequently showing up in U.S. streams, can alter genes responsible for building fish brains and controlling their behavior.
Antidepressants are the most commonly prescribed medications in the U.S.; about 250 million prescriptions are filled every year. And they also are the highest-documented drugs contaminating waterways, which has experts worried about fish. Traces of the drugs typically get into streams when people excrete them, then sewage treatment plants discharge the effluent.
Exposure to fluoxetine, known by the trade name Prozac, had a bizarre effect on male fathead minnows, according to new, unpublished research by scientists at the University of Wisconsin-Milwaukee.
Male minnows exposed to a small dose of the drug in laboratories ignored females. They spent more time under a tile, so their reproduction decreased and they took more time capturing prey, according to Rebecca Klaper, a professor of freshwater sciences who spoke about her findings at a Society of Environmental Toxicology and Chemistry conference last fall. Klaper said the doses of Prozac added to the fishes’ water were “very low concentrations,” one part per billion, which is found in some wastewater discharged into streams.
When the dose was increased, but still at levels found in some wastewater, females produced fewer eggs and males became aggressive, killing females in some cases, Klaper said at the conference.
The drugs seem to cause these behavioral problems by scrambling how genes in the fish brains are expressed, or turned on and off. The minnows were exposed when they were a couple of months old and still developing.
There appeared to be architectural changes to the young minnows’ brains, Klaper said at the toxicology conference. Growth of the axons, which are long nerve fibers that transmit information to the body, was disrupted.
The new findings build on Klaper’s previous research, which tested minnows with the gene changes to see how well they avoided predators. They swam longer distances and made more directional changes, which suggests that the drugs induced anxiety.
The drugs used in the study were among the most common in sewage: Prozac, Effexor and Tegretol. The researchers tested each drug alone and in combination.
“At high doses we expect brain changes,” Klaper said. “But we saw the gene expression changes and then behavioral changes at doses that we consider environmentally relevant.”
However, there is too little evidence to know whether pharmaceuticals are having any impacts on fish populations in the wild, said Bryan Brooks, an environmental science professor at Baylor University who has extensively studied pharmaceuticals in streams and fish.
Any changes in reproduction, eating and avoiding prey can have devastating impacts for fish populations, Klaper said.
The most vulnerable fish populations are those downstream of sewage treatment plants, where prescription drugs consistently show up in higher levels than in other waterways. It’s only within the past decade that technology has allowed plants to test for the chemicals in their wastewater and in waters downstream, though most still don’t, said Steve Carr, supervisor of the chemistry research group at the Los Angeles County Sanitation Districts.
One of the antidepressants tested in the fish—Tegretol—comes into the treatment plants and goes out at near constant levels, said Eric Nelson, a senior chemist with the Los Angeles County Sanitation Districts.
That means the county’s treatment technology does not seem to have any effect on the drug. It comes in and leaves in a very tight range, about 150 to 400 parts per trillion, Nelson said.
Nelson said the two other drugs tested on the fish—Prozac and Effexor—are discharged in effluent at even lower levels: between about 20 and 30 parts per trillion. In comparison, the levels that altered behavior of the lab fish were 50 times higher.
When monitoring an Iowa and a Colorado stream, the U.S. Geological Survey found most drugs at levels similar to Los Angeles County’s. However, these low levels could still find their way into fish brains, according to their 2010 study.
Researchers found elevated levels of pharmaceuticals in the stream water two to six miles from the sewage treatment plants. But the chemicals at the highest levels in the water were not the ones most prevalent in the fish brains.
“The fish downstream of the wastewater treatment had elevated concentrations of two antidepressants … Zoloft and Prozac,” said Edward Furlong, a research chemist at the U.S. Geological Survey based in Boulder, CO. “And these were relatively low in water compared to others.”
Even if the levels released into streams seem low, they are constant, which is problematic, Brooks said.
“The drugs may not be classically persistent like PCBs [Polychlorinated biphenyl],” Brooks said. “But they’re pseudo-persistent. The [continuous] exposure of organisms in a stream is equivalent to a chemical that is persistent.”
Some drugs bioaccumulate, or build up, in rainbow trout, according to Brooks’ research. Also, rainbow trout exposed to sewage effluent have pharmaceuticals in their blood at levels as high as those that affect the brains of people, according to research in Sweden.
Brooks said the likelihood of bioaccumulation for pharmaceuticals is high. “People have to take these drugs for weeks before they start having effects. They slowly bioaccumulate in your system,” which suggests bioaccumulation potential in fish, too, said Brooks.
Changes to the brain can affect all kinds of things in fish, Klaper said. And since humans have a similar brain gene structure, the findings raise questions about whether traces of these drugs in drinking water might harm human health.
The U.S. Environmental Protection Agency (EPA) considers pharmaceuticals an “emerging concern,” and has concluded that the chemicals may pose risks to wildlife and humans. There are currently no federal regulations of the compounds in waste or drinking water. However, 12 pharmaceuticals are currently on the EPA’s Contaminant Candidate List, which are chemicals that may require regulation under the Safe Drinking Water Act.
Studies have consistently found prescription drugs in drinking water at parts-per-trillion levels. U.S. Geological Survey scientists sampled 74 waterways used for drinking water in 25 states in 2008 and found 53 had one or more of the three dozen pharmaceuticals they were testing for in their water. Forty percent of the pharmaceuticals were found at one or more of the sites.
Fifty-four active pharmaceutical ingredients and 10 metabolites have been detected in treated U.S. drinking water, according to a 2010 EPA review.
But health officials say the levels found in some drinking water are too low to cause harm.
According to a 2012 World Health Organization report, the “trace quantities of pharmaceuticals in drinking water are very unlikely to pose risks to human health.” The report said that the amount found in drinking water is usually 1,000 times lower than doses expected to have an effect on a person.
But Klaper said that in light of the gene changes in fish brains, officials may need to rethink what is considered safe.
“Fish do not metabolize drugs like we do,” Klaper said. “Even if environmental doses aren’t thought to be much for a human, fish could still have significant accumulation, and, it appears, changes in their brain’s gene expression.”
Visit EcoWatch’s BIODIVERSITY page for more related news on this topic.
This week marks the official start of fall, but longer nights and colder days can make it harder to spend time outdoors. Luckily, there are several inspiring environmental films that can be streamed at home.
1. Kiss the Ground<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="ccc5f0c92a5603e68aec39e56b0db02a"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/K3-V1j-zMZw?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: Netflix</strong></p><p><strong>Premiere Date: Sept. 22</strong></p><p>Between <a href="https://www.ecowatch.com/wildfires-california-washington-oregon-photos-2647585008.html" target="_self">wildfires devastating the U.S. West Coast</a> and <a href="https://www.ecowatch.com/tropical-storm-beta-landfall-2647760268.html" target="_self">storms battering the Gulf</a>, the impacts of the <a href="https://www.ecowatch.com/climate-change/" target="_self">climate crisis</a> can feel overwhelming right now. <em><a href="https://kissthegroundmovie.com/" rel="noopener noreferrer" target="_blank">Kiss the Ground</a> </em>offers an alternative to all of the bad news by focusing on solutions.</p><p>The film, directed by Josh and Rebecca Tickell and narrated by Woody Harrelson, explains how we can heal the Earth through "regenerative agriculture," farming practices that draw carbon dioxide from the atmosphere and into soil as a way to restore soil health, which in turn boosts ecosystems and food supplies.</p><p>"<em>Kiss the Ground </em>shows how feasible it is to make these changes at a grassroots level immediately and make a truly substantive impact with low cost and easy to implement solutions," Executive Producer RJ Jain said in an email. "This is why I got involved."</p>
2. Public Trust: The Fight for America's Public Lands<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="5338f7a2931e356910026e5fd76fac56"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/jsKMTAaj_wQ?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: YouTube</strong></p><p><strong>Premiere Date: Sept. 25, 2 p.m. EDT </strong></p><p>This <a href="https://www.patagonia.com/films/public-trust/" target="_blank">award-winning documentary</a> tells the stories of Indigenous activists, journalists, whistleblowers and historians working to protect America's <a href="https://www.ecowatch.com/tag/public-lands" target="_self">public lands</a>. The film focuses on three political struggles: the shrinking of <a href="https://www.ecowatch.com/tag/bears-ears" target="_self">Bears Ears</a> National Monument in Utah, the mining of Boundary Waters Wilderness in Minnesota and the opening of the <a href="https://www.ecowatch.com/tag/Arctic-National-Wildlife-Refuge" target="_self">Arctic National Wildlife Refuge</a> to fossil fuel exploration.</p><p><em>Public Trust</em> was directed by David Garrett Byars and produced by Jeremy Rubingh. Patagonia Films, Patagonia founder Yvon Chouinard and actor Robert Redford are executive producers. It will be <a href="https://www.youtube.com/watch?v=OGjnIG7puzY" rel="noopener noreferrer" target="_blank">released</a> on YouTube in time for <a href="https://www.ecowatch.com/national-public-lands-day-2640656776.html" target="_self">National Public Lands Day</a>.</p><p>"Our country is fortunate to have millions of acres of public lands, including National Parks, Monuments, Wildlife Refuges and Wilderness set aside for future generations," Redford said. "Sadly, these lands that belong to you and me are under unprecedented threats from the greed of big corporations, eager to weaken restrictions in the pursuit of profits. Many of our current politicians are also to blame. <em>Public Trust</em> tells the story of citizens who are fighting back. It's a much-needed wake-up call for all of us who want to preserve our unique and wild cultural heritage."</p>
3. David Attenborough: A Life on Our Planet<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="156438a30836a765d7a92982545fc334"><iframe lazy-loadable="true" src="https://www.youtube.com/embed/B_OFZvAd05Y?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p><strong>Streaming On: Netflix</strong></p><p><strong>Premiere Date: Oct. 4</strong></p><p>Beloved nature broadcaster <a href="https://www.ecowatch.com/tag/David-Attenborough" target="_self">David Attenborough</a> has spent his career introducing viewers to the wonders of our planet. In recent years, his footage of albatrosses swallowing <a href="https://www.ecowatch.com/tag/plastics" target="_self">plastic</a> in <em>Blue Planet II</em> has been credited with <a href="https://www.ecowatch.com/2018-fighting-plastic-waste-2624606566.html" target="_self">helping to ramp up</a> the global fight against plastic pollution. Now, in this <a href="https://www.wwf.org.uk/" rel="noopener noreferrer" target="_blank">World Wildlife Fund</a> (WWF)-produced <a href="https://www.attenborough.film/" rel="noopener noreferrer" target="_blank">documentary</a>, he reflects on the defining moments of his career and the devastating changes he has witnessed.</p><p><em>David Attenborough: A Life on Our Planet,</em> which was also produced by Silverback Films and directed by Alastair Fothergill, Jonnie Hughes and Keith Scholey, features an intimate conversation between Attenborough and Sir Michael Palin as the broadcaster reflects on his life and a career that took him to every continent on Earth. In addition to streaming on Netflix, the movie will be available in select theaters starting Sept. 28.</p><p>"For decades, David has brought the natural world to the homes of audiences worldwide, but there has never been a more significant moment for him to share his own story and reflections," WWF executive producer Colin Butfield said in a <a href="https://www.wwf.org.uk/updates/david-attenborough-life-our-planet" target="_blank">statement</a>. "This film coincides with a monumental year for environmental action as world leaders make critical decisions on nature and climate. It sends a powerful message from the most inspiring and celebrated naturalist of our time."</p>
- Sir David Attenborough Set to Present BBC Documentary on ... ›
- 7 of the Best New Documentaries About Global Warming - EcoWatch ›
- Movies to Watch This Earth Day: EcoWatch Staff Picks - EcoWatch ›
EcoWatch Daily Newsletter
The world's largest online retailer is making it slightly easier for customer to make eco-conscious choices.
- Employees Are Fighting for Climate Change at Work - EcoWatch ›
- Amazon's Carbon Footprint Rises 15% as Company Invests $2 ... ›
- Jeff Bezos Pledges $10 Billion to Fight the Climate Crisis - EcoWatch ›
- Budweiser Re-Labels As Climate-Friendly Beer - EcoWatch ›
The Trump administration's Environmental Protection Agency (EPA) released a risk assessment for toxic pesticide chlorpyrifos Tuesday that downplayed its effects on children's brains and may be the first indication of how the administration's "secret science" policy could impact public health.
- Democratic Bill Banning Toxic Pesticides Applauded as 'Much ... ›
- Trump EPA Won't Regulate Toxic Drinking Water Chemical That ... ›
- California, Nation's Top User of Chlorpyrifos, Announces Ban on ... ›
- Wheeler's EPA Keeps Brain-Damaging Chlorpyrifos in Food ›
- Entire Pesticide Class Must Be Banned to Save Children's Health ... ›
By Maria Trimarchi and Sarah Gleim
If all the glaciers and ice caps on the planet melted, global sea level would rise by about 230 feet. That amount of water would flood nearly every coastal city around the world [source: U.S. Geological Survey]. Rising temperatures, melting arctic ice, drought, desertification and other catastrophic effects of climate change are not examples of future troubles — they are reality today. Climate change isn't just about the environment; its effects touch every part of our lives, from the stability of our governments and economies to our health and where we live.
<p>Why environmental refugees flee their homes is a complicated mixture of environmental degradation and desperate socioeconomic conditions. People leave their homes when their livelihoods and safety are jeopardized. What effects of climate change put them in jeopardy? Climate change triggers, among other problems, desertification and drought, <a href="https://science.howstuffworks.com/environmental/green-science/deforestation.htm" target="_blank">deforestation</a>, land degradation, rising sea levels, <a href="https://science.howstuffworks.com/nature/natural-disasters/flood.htm" target="_blank">floods</a>, more frequent and more extreme storms, <a href="https://science.howstuffworks.com/nature/natural-disasters/earthquake.htm" target="_blank">earthquakes</a>, <a href="https://science.howstuffworks.com/nature/natural-disasters/volcano.htm" target="_blank">volcanoes</a>, food insecurity and famine.</p><p>The September <a href="http://visionofhumanity.org/app/uploads/2020/09/ETR_2020_web-1.pdf" target="_blank">2020 Ecological Threat Register Report</a>, by the Institute for Economics & Peace, predicts the hardest hit populations will be:</p><ul><li>Sub-Saharan Africa, South Asia, the Middle East and North Africa</li><li>Afghanistan, Syria, Iraq, Chad, India and Pakistan (which are among the world's least peaceful countries)</li><li>Pakistan, Ethiopia and Iran are most at risk for mass displacements</li><li>Haiti faces the highest risk of all countries in Central America and the Caribbean</li><li>India and China will be among countries experiencing high or extreme water stress</li></ul>
- Think Today's Refugee Crisis is Bad? Climate Change Will Make it a ... ›
- Climate Change Forces 20 Million People to Flee Each Year, Oxfam ... ›
- Meet the World's First Climate Refugees - EcoWatch ›
In his latest documentary, My Octopus Teacher, free diver and filmmaker Craig Foster tells a unique story about his friendship and bond with an octopus in a kelp forest in Cape Town, South Africa. It's been labeled "the love story that we need right now" by The Cut.
- You're Not So Different From an Octopus: Rethinking Our ... ›
- 'Eating Animals' Drives Home Where Our Food Really Comes From ... ›