Fishing with Rod Discussion Forum
Fishing in British Columbia => General Discussion => Topic started by: RalphH on April 22, 2026, 10:28:35 AM
-
It's kind of known that the drugs that people use, both legal (ie by Rx) and illegal have downstream effects both on people and the environment.
A recent rather unusual study out of Sweden investigated the effects of cocaine use on wild salmon particularly the effect of benzoylecgonine, the primary metabolite of cocaine on wild Atlantic salmon in a Swedish Lake and found a number of negative effects. One of the most startling was salmon so exposed swam more than twice as much distance over the study period as unexposed subjects.
The article also cites other studies that show that "tests on freshwater shrimp in rivers in Suffolk found traces of dozens of different drugs, including cocaine, methamphetamine, antidepressants, anxiolytics for anxiety and antipsychotics, but the researchers did not draw any conclusions about their potential to cause harm".
https://www.theguardian.com/science/2026/apr/20/cocaine-pollution-may-disrupt-behaviour-of-salmon-study-suggests?shem=dsdf,sharefoc,agadiscoversdl,,sh/x/discover/m1/4
Link to the Study:
https://www.cell.com/current-biology/fulltext/S0960-9822(26)00315-5
"Summary
Cocaine and its metabolites are increasingly being detected in aquatic environments worldwide. While previous research has demonstrated that these substances can affect brain function and behavior in wildlife, this research has exclusively been conducted under artificial laboratory conditions. How cocaine pollution affects animal behavior in the wild is, thus, unknown. Here, we combine slow-release chemical implants with acoustic telemetry tracking to reveal how environmentally realistic levels of cocaine and its main metabolite, benzoylecgonine, affect the movement of Atlantic salmon (Salmo salar) smolts in a large natural lake (Lake Vättern, Sweden). Benzoylecgonine exposure increased weekly movement rates of fish in the wild, with exposed fish swimming up to ∼1.9 times farther per week relative to controls. In addition, benzoylecgonine-exposed fish dispersed up to ∼12.3 km farther than control conspecifics. These results indicate that cocaine-derived pollutants can alter fish spatial ecology, potentially influencing habitat use, trophic interactions, and population-level dispersal patterns in natural ecosystems."
-
Wolf of Vedder