Sharks off waters in Brazil test positive for cocaine
Sign up now: Get ST's newsletters delivered to your inbox
Follow topic:
Thirteen Brazilian Sharpnose sharks found off the waters in Brazil tested positive for cocaine, according to research published in the Science Of The Total Environment on July 15.
According to Britain’s Sky News, this is the first time the presence of cocaine in sharks has been reported in any study.
Test samples as recorded in the research showed drug concentrations 100 times higher than previous cases in other aquatic creatures.
Cocaine levels were about three times higher in the muscle tissue of the sharks than in their livers, and higher concentrations of the drugs were found in females as compared to males, the study found.
The findings are “very important and worrying”, said marine ecotoxicologist Sara Novais, reported the Science academic journal.
She added that more research is needed to determine if the sharks, or humans who eat them, are harmed by the exposure.
It is unclear if the drugs impact the sharks’ behaviour, said Dr Enrico Saggioro, who participated in the research, told Science.
“This may be the case, as cocaine targets the brain, and hyperactive and erratic behaviour has been noted in other animals. It’s a possibility and further studies are required,” he added.
This is not the first time the drug has been detected in marine wildlife.
Cocaine and ecstasy were among the drugs found in crabs, oysters and seaweed found in waters around the United Kingdom, reported Reuters in June.
Cocaine can be toxic to molluscs, crustaceans and bony fish, reported Science. Studies have also shown that the drug can cause various signs of damage in zebrafish embryos, such as DNA fragmentation and cell death.
