The drug was found in all 13 wild Brazilian sharpnose sharks tested, with a concentration as much as 100 times higher than previously reported for other aquatic creatures.
Sharks in waters off the coast of Brazil have tested positive for cocaine, scientists say.
Researchers have long suggested that sea life could be impacted by drugs dumped into the water by smugglers, with tonnes of cocaine found around Florida, South and Central America.
A study from the Oswaldo Cruz Foundation in Brazil has now found evidence sharks are in fact being affected by drugs polluting the ocean.
The scientists dissected 13 wild Brazilian sharpnose sharks that were bought from small fishing vessels, as the species spend their entire lives in coastal waters and were therefore most likely to be affected by pollution.
Muscle and liver tissue were then tested using a standard technique called liquid chromatography with tandem mass spectrometry – where molecules are separated in a liquid – to look for cocaine and benzoylecgonine, the main metabolite in the drug.