NATIONWIDE一 A new study has found bait might not be the only thing getting fish hooked in our waterways. A recent laboratory study found methamphetamine pollution in waterways could be affecting fish and could lead to an alteration in their natural behavior.
Methamphetamine can and has worked its way through wastewater treatment facilities and sewage systems all over the world where it contaminates rivers and streams, with concentrations of the drugs ranging from a few nanograms to dozens of micrograms per liter of water, according to reports in the journals Chemosphere and Water.
Pavel Horký, from the Czech University of Life Sciences in Prague, led a team in researching the effects of methamphetamine-laced water on brown trout and published the findings in the July issue of the Journal of Experimental Biology.
“Our results suggest that emission of illicit drugs into freshwater ecosystems causes addiction in fish and modifies habitat preferences with unexpected adverse consequences of relevance at the individual and population levels,” the researchers wrote in the published study.
For the study, researchers isolated trout in a large tank of water laced with methamphetamine for eight weeks to simulate the effects of persistent drug exposure that might occur in a polluted river. A separate group of trout were kept in a tank with clean water for the same period. The fish were then transferred to a new tank with fresh water and every other day transferred to a tank with two stream choices, fresh water and water laced with meth. The researchers found in the first four days after the tank swap, the meth-exposed fish showed a stronger preference for drugged water when compared with the fish who started out in the clean water tank. This difference waned the more time the exposed fish spent in the drug-free tank.
The study’s authors discovered during the withdrawal period, the trout exposed to methamphetamine moved less, which they interpreted as a sign of stress or anxiety, the usual signs of drug withdrawal in humans. They also took samples of the fishes’ brain tissue and screened them for both methamphetamine and amphetamine, a metabolic byproduct of the drug. They found “there were differences in concentration of amphetamine and methamphetamine that were shown to be related to changes in behavior.”
The authors said these results suggest brown trout could become addicted to trace amounts of methamphetamine in rivers, which could lead to the fish looking for a fix by gathering near places where contaminated water is discharged and result in problems with their feeding, breeding, and eventually, survival.