From caffeine to cocaine, sharks are carrying many surprising substances in their blood.
A disturbing new study has revealed that the pristine waters of the Bahamas are far from isolated from human activity, as researchers discovered pharmaceutical and illicit drugs flowing through the blood of local sharks.
Out of 85 sharks tested near Eleuthera Island, nearly one-third tested positive for human-made substances. While caffeine was the most common contaminant, everyday painkillers and anti-inflammatory medications like ibuprofen, acetaminophen, and diclofenac were also highly prevalent. Most shocking was the detection of cocaine in the blood of a juvenile lemon shark, suggesting recent, direct exposure to discarded or lost drug trafficking cargo.
The pathway for these contaminants is primarily coastal tourism and outdated wastewater infrastructure, where untreated human waste and runoff flow directly into delicate marine habitats.
Beyond the novelty of finding ‘cocaine sharks’ in real life, scientists are deeply concerned about the physiological consequences.
The affected sharks showed altered metabolic markers linked to stress and energy consumption, which previous research indicates can severely disrupt their feeding habits, natural movements, and survival instincts.
The findings are a stark warning that our chemical footprint extends far beyond plastic pollution, quietly contaminating even the ocean’s most vital apex predators.
source: Wosnick, N., Agudelo, M. A. H., Deolindo, C. T. P., Hoff, R., Oliveira, L. V. A., Cardena, P. A. B., Leite, R. D., & Charvet, P. (2026). Drugs in paradise: caffeine, cocaine, and painkillers detected in sharks from The Bahamas. Environmental Pollution, 396, 127818.
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