Sharks test positive for cocaine and caffiene in Bahamas study

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A recent study found that sharks in the Bahamas have traces of drugs like cocaine and caffeine, as well as common pain relievers, in their systems. This indicates a problem with pollution in the ocean around the islands.

A recent study led by biologist Natascha Wosnick at the Federal University of Paraná revealed that nearly a third of sharks living near Eleuthera Island have traces of drugs commonly used by humans in their blood. The findings were published online in the journal Environmental Pollution on February 20, 2026, after scientists analyzed samples from 85 sharks.

This research reinforces the increasing evidence that pollution from human sources – like sewage and illegal drug operations – is harming ocean life.

Substances like caffeine and painkillers found in Bahamian sharks

Scientists found various substances inside the sharks, like caffeine, common pain relievers such as acetaminophen and diclofenac, and even cocaine in one shark.

The research focused on several shark species, including Caribbean reef, nurse, and lemon sharks. Scientists discovered caffeine in these sharks – a first for any shark globally. They also found traces of acetaminophen for the first time ever in sharks, and detected cocaine and diclofenac in Bahamian sharks, which hadn’t been reported before.

Researchers believe these pollutants probably get into the ocean from sources like sewage and wastewater. In popular tourist spots, divers and general human activity can also add to the problem. Surprisingly, cocaine sometimes enters the water from lost or thrown-away drug shipments.

The research found that sharks containing these substances exhibited metabolic shifts, such as changes in triglycerides, urea, and lactate—indicators of stress. Although it hasn’t been directly observed how these substances affect shark behavior, studies on other fish suggest that stimulants like caffeine could influence their energy and willingness to take risks.

A 2024 study by the same researchers revealed even more cocaine in sharks near Rio de Janeiro – in fact, every shark they tested had the drug in its system. This finding sparked worries about the ongoing effects of this exposure on ocean creatures and people who eat seafood.

While scientists are still studying the lasting impact on marine life, this research shows that pollution created by humans is affecting even the top predators in the ocean.

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2026-03-22 17:48