WASHINGTON, DC (CBSDC) – Drugs that treat anxiety in people may alter the behavior of fish when the chemicals are flushed into rivers.
Researchers found that European perch that were exposed to tiny concentrations of a drug became less sociable, ate more, and became adventurous. They say these changes in behavior can have unexpected ecological impacts on the fish population.
Scientists at Umea University in Sweden screened rivers when they found oxazepam, a drug that treats anxiety, piling up in fish.
Tomas Brodin led a team on the study that monitored how the behavior was impacted by small quantities of the drug.
“Normally, perch are shy and hunt in schools,” Brodin told The Guardian. “This is a known strategy for survival and growth. But those who swim in oxazepam became considerably bolder.”
Jonatan Klaminder, an ecologist at Umea University and one of the authors of the study, felt that the effect of the drug on fish was similar to its effect on people.
“What the drug does is remove some of the fear that the very small fish experience,” Klaminder told The Guardian.
Scientists believe that this change in behavior can have evolutionary consequences. They feel that fish with these behaviors are more adventurous and more likely to be eaten by larger fish.
Researchers say the solution is to improve sewage treatment plants that will capture the drugs and reduce the contamination of water systems.
The study was published in a recent edition of Science after being announced at a meeting of the American Association for the Advancement of Science.