A recent study published in Current Biology investigates the effects of cocaine and its metabolite, benzoylecgonine, on juvenile Atlantic salmon in Lake Vätern, Sweden. The research revealed that fish exposed to benzoylecgonine swam up to 1.9 times farther per week and dispersed up to 12.3 kilometers farther than their unexposed counterparts. This exposure occurs as cocaine and its metabolites enter wastewater systems, which are not designed to fully eliminate these compounds before they are released into rivers and lakes. The study emphasizes that cocaine is now one of the most detected illicit drugs in aquatic environments globally, with average concentrations of about 105 nanograms per liter for cocaine and 257 nanograms per liter for benzoylecgonine. The findings raise concerns about the ecological impact of drug contamination, as altered fish behavior can affect feeding, predator avoidance, and overall survival. Notably, benzoylecgonine was found to have a more significant impact on fish behavior than cocaine itself, suggesting that environmental assessments may overlook the risks posed by metabolites. This research highlights the need for further investigation into the broader effects of human-derived chemicals on aquatic ecosystems.