Sharks Off Brazil Coast Test Positive for Cocaine

Fins and Highs: Brazil’s Sharks Swimming in Drug-Infested Waters

Underwater View of Swimming Sharks

In a shocking discovery, sharks off the coast of Brazil have tested positive for cocaine. This startling revelation sheds light on the extent of drug pollution in the country’s marine ecosystems, raising concerns about the well-being of these apex predators and the broader impact it has on the delicate balance of coastal environments.

The Research

View of the Ipanema Beach, Rio de Janeiro, Brazil
View of the Ipanema Beach, Rio de Janeiro, Brazil | Credit: Vinícius Vieira ft/Pexels

Marine biologists with the Oswaldo Cruz Foundation tested 13 Brazilian sharpnose sharks taken from the shores near Rio de Janeiro, which all tested for high levels of cocaine. 12 out of the 13 also tested positive for benzoylecgonine, which is cocaine’s primary metabolite.

The highest concentrations of cocaine were found in the sharks’ muscle tissue, but traces of the drug were also found in their livers with concentrations as much as 100 times higher than those found in other marine animals.

This is the first-ever study to find the presence of cocaine in sharks.

How Did This Become Possible?

While it’s not clear how exactly the sharks ingested the cocaine, the scientists believe that the drug enters the animal’s system through the waters via the illegal drug labs in the area, where the drug is manufactured or through the excrement of drug users.

Researchers also noted that packs of cocaine lost or dumped by traffickers at sea could also be a source, but this is much less likely.

The Effect on Sharks and Humans

In an interview with Science magazine, Sara Novais, a marine eco-toxicologist at the Marine and Environmental Sciences Centre of the Polytechnic University of Leiria, said the findings are “very important and potentially worrying”.

While additional research is necessary to determine whether cocaine is changing the behavior of the sharks, a previous study has found that drugs were likely to have similar effects on animals as they do on humans, according to BBC News.

A shark underwater
A shark underwater | Credit: Cliff Simon/Pexels

It’s also worth noting that while all female sharks in the study were pregnant, the consequences of cocaine exposure for the fetuses are currently unknown.

As for how this poses a threat to humans, marine biologist Tom “The Blowfish” Hird said that cocaine-ingested sharks are more of a danger to themselves than to people.

“If cocaine made sharks hyper and didn’t put them to sleep, my personal belief would be that it would make them much more skittish,” said Hird, according to Fox News. “And the loud noises, things like divers in the water splashing, — all that kind of stuff — it’s actually going to drive them away because it’s going to act as a deterrent.”

Sources: BBC News, Fox News