Story perspectives

Cocaine Metabolite Boosts Salmon Migration 1.9×, Outpaces Parent Drug

4/24/2026

Summary

Story summary

The study found benzoylecgonine, cocaine’s main metabolite, increased salmon movement more than cocaine.
Researchers implanted 105 juvenile Atlantic salmon with cocaine, benzoylecgonine or control devices and tracked them in Lake Vättern, Sweden.
Benzoylecgonine-exposed fish swam up to 1.9 times farther per week and dispersed up to 12.3 km farther than controls.
Eight-week telemetry confirmed realistic chemical levels persisted in brains, highlighting wastewater-treatment gaps and ecosystem effects but no human consumer risk.

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Story summary

The study found benzoylecgonine, cocaine’s main metabolite, increased salmon movement more than cocaine.
Researchers implanted 105 juvenile Atlantic salmon with cocaine, benzoylecgonine or control devices and tracked them in Lake Vättern, Sweden.
Benzoylecgonine-exposed fish swam up to 1.9 times farther per week and dispersed up to 12.3 km farther than controls.
Eight-week telemetry confirmed realistic chemical levels persisted in brains, highlighting wastewater-treatment gaps and ecosystem effects but no human consumer risk.