Freshwater Contamination Might Be Getting Trout Hooked On Drugs

Most people would not consider drug use as affecting the environment but it may be more far-reaching than most people realize.

For humans, taking drugs is a choice, albeit a bad one in some cases. What most people don’t think about is the fact that some of those drugs are released when we use the restroom.

Those drugs ultimately end up in the environment, regardless of whether they are prescription medications or illegal drugs.


Our wastewater systems are frequently contaminated with those medications, and it ends up in freshwaters, such as streams and rivers.

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According to at least one study, antidepressants are having an effect on crayfish, causing them to ignore some of their natural cautious behavior and that puts them at risk from predators.

Photo: Wikimedia Commons

Another study, published in the Journal of Experimental Biology, looked into how recreational drug usage by humans was affecting one particular type of freshwater fish, the brown trout.

In order to look into the matter, they put brown trout in a tank that was spiked with high levels of methamphetamines. They tried to match what was seen in freshwater rivers and then the trout were put in the tanks for eight weeks to acclimate.

After being in the tanks for eight weeks, the trout were removed in order to see if they had any withdrawal to the drugs that were in the water. In order to do so, researchers gave them an opportunity to either go into a fresh body of water or one that was contaminated. The trial continued for 10 days.

Photo: flickr/U.S. Department of Agriculture

The researchers felt that the fish would try to get back into the water that was drugged if they were experiencing withdrawal. It seems as if the fish were certainly hooked on methamphetamines because, during the first four days after they were moved to an uncontaminated tank, they were less active than others who were kept in a fresh tank.

They also found that the drug lasted for up to 10 days in the brains of the trout, something that may have contributed to a long length of withdrawal symptoms.

Photo: flickr/U.S. Department of Agriculture

According to Eureka Alert!, a researcher from the Czech Republic University of life sciences said: “Whether illicit drugs alter fish behaviour at levels increasingly observed in surface water bodies was unclear.”

He went on to say, however, that the addition of wild fish to methamphetamine and other drugs would represent yet another example of pressure being placed on those species in urban environments.

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