Researchers found cocaine in all samples of shrimp tested in a rural area of eastern England, with ketamine also widespread.

Looking at some freshwater shrimp on a riverbank in the sleepy English countryside, one probably wouldn’t reckon those creatures are high. Very high.
But in fact, what scientists discovered in them get would keep a rock band on tour happy.
To be precise, they found notable levels of cocaine, ketamine, valium, xanax, tramadol, and other pharmaceuticals in the bodies of freshwater shrimp and their habitat in Suffolk, UK (along with traces of numerous pesticides now banned in the EU).
Reporting in the journal Environment International, scientists from King’s College London analyzed Gammarus pulex freshwater shrimp along with levels of micropollutants in surface water samples from 15 different sites across the county of Suffolk in East England. They were surprised to see trace levels of at least 67 different contaminant compounds. They most frequently detected the presence of cocaine: the substance was found in every single shrimp from all 15 sites.

“Such regular occurrence of illicit drugs in wildlife was surprising,” Dr Leon Barron, a forensic scientist at King’s College, said in a statement.
“We might expect to see these in urban areas such as London, but not in smaller and more rural catchments.”
You wonder what’s to come downstream.
Sources: 1, 2, 3