Researchers have found cocaine, caffeine, and common painkillers in sharks living off Eleuthera Island in the Bahamas.
The findings, published in ScienceDirect, were based on blood samples taken from 85 sharks in the area. According to the study, 28 sharks from three different species tested positive for caffeine, anti-inflammatory drugs, or other substances, while some carried more than one drug in their system.
Caffeine was the most commonly detected substance, followed by acetaminophen and diclofenac. Scientists also found cocaine in some of the sharks, adding to growing evidence that pharmaceutical and narcotic contamination is making its way into marine life.
The study is being described as the first to report caffeine and acetaminophen in any shark species, and the first to detect diclofenac and cocaine in sharks from the Bahamas. Unlike earlier research that relied on muscle and liver tissue, this study used blood samples, which are considered a better indicator of recent exposure.
Researchers believe the contamination is likely linked to sewage discharge and human waste in waters used for tourism, boating, and diving.
Scientists say the bigger concern is not whether the sharks become more aggressive, but what long-term exposure to these substances could do to their health. Early signs suggest the drugs may be affecting biological functions and increasing stress as the animals try to process the chemicals in their bodies.
Source: ScienceDirect