Brazilian Waters Infested with ‘Cocaine Sharks,’ Scientists Say

For years, researchers have explored the ecological threat of drug smuggling on marine life. It’s no shock that drug-polluted waters negatively affect its inhabitants, what with the literal tons of cocaine sometimes found floating in the ocean.

To determine the presence of cocaine in sharks, marine biologists tested 13 wild Brazilian sharpnose sharks near Rio de Janeiro. They specifically looked for cocaine and benzoylecgonine, the primary metabolite of the drug. As it turned out, all 13 showed evidence of cocaine in their system—mostly in their muscle tissues. 

Not only that, the concentration of cocaine was 100 times higher than had been previously observed in other aquatic creatures, likely because this species spends all of its life in coastal waters.

The study is ​​from an organization affiliated with Brazil’s Ministry of Health and published in the Science of the Total Environment. Though the scientists identified cocaine in sharpnose sharks, they didn’t measure its actual impact on the creatures. In other words, it’s unclear how the drug might actually affect the sharks’ behavior. 

Speaking to the BBC, biology professor Alex Ford, who has researched the impact of drugs—and the chemicals they produce—on marine life, shed some light on the issue. 

"If you give [animals] antidepressants that were designed to affect human behavior, they affect the behavior of these organisms too," he said. "They will swim differently, they'll behave differently, and they'll behave with each other differently. We've got to take this seriously because there are chemicals harming our wildlife now, which we banned 30 years ago and they're still having effects now."

Experts believe the concentration of drugs in coastal waters could be from illegal labs, lost packages in the course of trafficking, or, in fact, primarily from the urine and excrement of drug users. 

It’s a stark reminder that our actions on land—including, apparently, pissing while on coke—can have profound and unforeseen effects on the delicate balance of life around the world.