A study has found that sharks near the Bahamas are testing positive for painkillers, caffeine, and cocaine. Known as pharmaceutical pollution, this occurs when drugs enter the water through waste dumping, researchers say.
Marine scientists from the Federal University of Parana discovered this while studying sharks off Eleuthera Island in the Bahamas. The scientists tested 85 sharks swimming in waters about four miles offshore. They found that around 30 tested positive for traces of caffeine, painkillers, multiple over-the-counter drugs, and even cocaine.
“What makes this study notable is not just the detection of pharmaceuticals and cocaine in nearshore sharks, but the associated shifts in metabolic markers,” Tracy Fanara, an oceanographer at the University of Florida in Gainesville, who was not involved with the study, told Science News. Fanara previously helped produce the documentary Cocaine Sharks, which aired during Discovery’s Shark Week in 2023.
“This represents the first report concerning contaminants of emerging concern (CEC) and potentially associated physiological responses in sharks from The Bahamas, pointing to the urgent need to address marine pollution in ecosystems often perceived as pristine,” the researchers wrote in their report published in the journal Environmental Pollution.
In 2024, a study found that every Brazilian sharpnose shark that was dissected had the presence of cocaine. 92 percent of muscle samples and 23 percent of liver samples also tested positive for benzoylecgonine – the main cocaine metabolite.
How do so many drugs end up in the ocean?
The researchers noted that drugs likely enter water from people “peeing and dumping sewage,” but other factors exist.
In 2023, New Zealand authorities reported over 3.5 tons of cocaine floating in the Pacific Ocean. That same year in Italy, authorities found 1,600 packets of cocaine worth $450 million floating in a raft off Sicily.
And, in the aforementioned documentary that aired during Shark Week, scientists studied how cocaine that has washed up on Florida beaches has affected the shark population.