‘Cocaine shark’: In a worrisome incident, sea creatures test positive for drugs

As per Brazilian scientists, a total of 13 sharks tested positive for cocaine. Ten among them were females, and three were males.

From deforestation to rampant pollution, humankind's actions are chipping away at the delicate balance of ecosystems. Brazilian scientists noticed one such disturbing instance and published a research paper. The study is about 13 sharks that tested positive for cocaine.

The scientists are unsure about the source of the cocaine but claim that it was introduced to the sharks in their natural habitat. (Unsplash/geerald)

The study, titled, “‘Cocaine Shark’: First report on cocaine and benzoylecgonine detection in sharks,” was published in the journal Science of the Total Environment.

As per the study, the drugs were probably introduced into the marine ecosystem by drainage from illicit cocaine labs or from “excrement of drug users, via untreated sewage.” It suggests that the sharks could also have eaten the bales of cocaine dumped or lost in the water. However, the scientists are still unsure about the source.

How is this impacting marine life?

“Sharks and rays play crucial roles in marine ecosystems as predators, shaping marine trophic chains, and are recognised as sentinel species for environmental contamination. Additionally, they represent a valuable protein source and are extensively consumed worldwide. However, this consumption has encouraged even more commercial fishing activities, leading to significant population declines across various regions,” explains the study.

About the sharks that tested positive for drugs

The sharks that tested positive for drugs were Brazilian Sharpnose sharks or Rhizoprionodon lalandii. Among the 13, three were males and 10 were females. The sea creatures were captured off the coast of Rio de Janeiro, south-eastern Brazil, specifically in the Recreio dos Bandeirantes in 2011. Over the years, the researchers collected various data for individual sharks, including length, weight, sex, pregnancy status, condition factor, and life stage, before publishing the study.

Five of the ten female sharks were pregnant. Of the remaining five, only one was an adult, and the others were juveniles. None of the male sharks were adults; they were all categorised as juveniles.

The study indicates that the sharks were introduced to the drugs in their natural habitat.