Could this not have been simply an instinct to find cleaner waters? I'm surprised they didn't add another control group which injected something unpleasant that could be naturally found in an area, but would be undesirable - ammonia, some sort of acid, or something along those lines.

I learned recently about “Vin Mariani” a wine from the 1860s that was fortified with coca leaves and contained 6mg per liquid ounce of the wine; except for the bottles sold in USA where it was 7.2mg per ounce, because there were other patent medicines that had cocaine in them and the manufacturer added a bit more to be competitive in the market.

The Pope of the time loved the stuff and awarded the company a Vatican medal for it.

And just like that, smoked Salmon became popular again :)

BTW, did you knew municipalities can easily measure fluctuations in drug usage by testing the sewage water? In fact, sometimes they can see clear differences between different parts of the city.

Shine on you crazy salmon

Cocaine bear, cocaine shark, cocaine… salmon?

We’re looking at you, Vancouver.

If that is not one good argument to start producing cocaine locally, then I don't know!

Save the fish.