Usually, when we think of human behaviors that affect aquatic life like trout, littering and oil spills come to mind. While these activities are detrimental, there are much more dangerous conditions our waterways face that are much harder to see.
Recently, a research team from the Czech University of Life Sciences in Prague studied the effect of methamphetamine on brown trout. While the most obvious source of the drug in waterways comes from dumping materials, methamphetamine makes it to fish populations through human excrement as well.
Although wastewater treatment facilities are able to filter the majority of impurities, the study stated that the plants are not equipped to filter residual levels of drugs.
Behavioral ecologist, Pavel Horky, headed the team, collecting a specimen of 40 brown trout from freshwater rivers. The team placed the school of fish in a tank of water contaminated with methamphetamine. For eight weeks, the research team monitored the trout’s behavior before moving them to a tank full of clean water. A separate tank held a control group of an additional 40 fish.
Brown Trout Become Dependent on Drug
Every other day, Horky and his team checked the experimental group for signs of methamphetamine withdrawal. In order to do so, researchers gave the fish the choice between clean and contaminated water. After spending roughly two months in water with methamphetamine, the experimental group became dependent on the drug.
Within the four days of their transfer to a clean tank, the trout chose the meth-contaminated water. This indicated to Horky’s team that when in clean water, the trout experienced withdrawal.
In humans, methamphetamine causes increased wakefulness and physical activity. However, the Czech University researchers observed that the fish addicted to meth were less active than the control group. Further, while meth remains in a person for up to 48 hours, researchers found the drug in trout up to 10 days following exposure.
Researchers Find Other Drugs May Cause Problems As Well
Beyond methamphetamine, other, even legal drugs can potentially damage trout and other aquatic populations.
“Fish are sensitive to adverse effects of many neurologically active drugs from alcohol to cocaine and can develop drug addiction related to the dopamine reward pathway in a similar manner as humans,” Horky told CNN.
That means prescription drugs, too, pose a threat in our waterways. Antidepressants and anxiety medication, like venlafaxine or fluoxetine, can be just as dangerous as illegal drugs to aquatic life.
“Current research from teams around the world undoubtedly shows their adverse impact on ecosystems, which in turn can influence humans,” Horky continued.
Although essential for many people, this may mean that wastewater plants need to rethink filtration and treatment.
For now, though, we’ll just have to find comfort in the fact that knowing the problem is half the battle.