Sharks Test Positive for Cocaine and Painkillers in Caribbean Waters
Researchers have made a startling discovery in the Caribbean, finding traces of cocaine, caffeine, and painkillers in sharks prowling the waters around the Bahamas. The study, published in Environmental Pollution, marks the first detection of cocaine and diclofenac in sharks native to the Bahamas, and the first global detection of caffeine and acetaminophen in any shark species.
Contaminated Marine Life
Eighty-five sharks were captured for the study, primarily near remote Eleuthera Island and an inactive fish farm popular with divers. Of these, 28 exhibited detectable levels of cocaine, caffeine, acetaminophen, or diclofenac. The affected species included Caribbean Reef Sharks, Atlantic Nurse Sharks, and Lemon Sharks, with Blacktip Sharks and Tiger Sharks also examined.
Natascha Wosnick, a biologist at the Federal University of Paraná in Brazil and one of the study's scientists, explained to Science News that the contamination likely stems from human activity. "It's mostly because people are going there, peeing in the water and dumping their sewage in the water," she said.
Health Impacts on Sharks
The research revealed concerning changes in metabolic markers in sharks with contaminated blood. Some showed altered levels of triglycerides, urea, and lactate. Diclofenac, an active ingredient in Voltaren, has been linked to kidney disease in animals, while cocaine and caffeine are associated with hyperglycemia and lactate accumulation.
Wosnick noted that a young Lemon Shark testing positive for cocaine was likely exposed shortly before the study, as drugs persist longer in muscle tissue than in blood. She suggested the shark might have ingested a packet containing cocaine residues, stating, "They bite things to investigate and end up exposed."
Broader Pollution Concerns
This study highlights emerging pollution risks in seemingly pristine ecosystems. Wosnick pointed out that chemical pollution is often overlooked in the Bahamas, where concerns typically focus on oil spills and plastic waste. In the Environmental Pollution study, researchers emphasized that pharmaceuticals and illicit drugs are increasingly recognized as contaminants of emerging concern in marine environments, especially in areas with rapid urbanization and tourism-driven development.
Wosnick has previously detected cocaine and rare earth minerals in sharks off the coast of Rio de Janeiro, with higher cocaine levels in that study, possibly due to testing muscle tissue rather than blood. The findings underscore the urgent need to address chemical pollution to protect marine life and ecosystems.
