Sharks swimming off the coast of Eleuthera Island in The Bahamas have tested positive for cocaine, caffeine, and common painkillers, according to a new study published in the Science Direct journal. The research, conducted by a team from the Federal University of Paraná, Brazil, examined 85 sharks in waters approximately four miles offshore and revealed the presence of these substances in a significant portion of the sampled animals.
Around 30 sharks exhibited traces of caffeine and painkillers, including acetaminophen and diclofenac – active ingredients in anti-inflammatory drugs. One shark specifically tested positive for cocaine. The study, titled “Drugs in paradise: caffeine, cocaine, and painkillers detected in sharks from The Bahamas,” marks the first documented instance of caffeine and acetaminophen found in any shark species globally, and the first report of diclofenac and cocaine in sharks from The Bahamas, researchers stated.
Natascha Wosnick, a biologist with the Federal University of Paraná, suggested a likely source for the contamination. “The waters where the sharks were swimming were close to fish farms where divers would operate and near to sewage outflow pipes,” she told ScienceNews. Wosnick believes the sharks ingest the substances while investigating their environment, stating, “they bite things to investigate and end up exposed.” She expressed concern over the high proportion of positive results, noting the remote location of the island.
The study similarly observed metabolic changes in the sharks exposed to the substances. Sharks with caffeine in their systems displayed increased movement and reactivity, mirroring the effects observed in humans. Tracy Fanara, an oceanographer at the University of Florida in Gainesville, highlighted the significance of these metabolic shifts, telling ScienceNews, “What makes this study notable is not just the detection of pharmaceuticals and cocaine in nearshore sharks, but the associated shifts in metabolic markers.”
The Bahamas, a Commonwealth realm with King Charles III as its head of state, is a popular tourist destination. The findings raise concerns about the potential for human-generated pollution to impact marine ecosystems, even in seemingly pristine environments. The research team did not immediately offer recommendations for remediation or further study.
