Overview
- A peer-reviewed study in Current Biology tracked 105 juvenile Atlantic salmon in Sweden using slow-release implants and acoustic tags.
- Fish exposed to benzoilecgonine, the main cocaine metabolite, swam up to 1.9 times farther per week and spread up to 12.3 kilometers more across the lake.
- The movement changes grew over the eight-week trial, pointing to lasting effects on space use in a natural ecosystem.
- Researchers reported no known risk to people who eat fish because exposures matched levels seen in waterways, the chemicals break down, and the study used fish below legal catch size.
- Scientists urged better wastewater treatment and wider monitoring as drug residues reach rivers through sewage, with the UN estimating 25 million people used cocaine in 2023.