A recent study conducted by Texas A&M University-Corpus Christi, in collaboration with NOAA, revealed the presence of human drugsincluding the powerful opioid fentanylIn the blubber of bottlenose dolphins (Tursiops truncatus) living in the Gulf of Mexico.
The researchers have analyzed fat samples from 83 live and 6 dead dolphins, highlighting contamination from drugs such as sedatives, muscle relaxants and, in particular, fentanyl. This substance, well known for its devastating effects on humans, has been found in 18 live dolphins and all deceased ones.
Bottlenose dolphins are considered key bioindicators of the health of marine ecosystems, thanks to the ability of their lipid-rich blubber to accumulate contaminants. This peculiarity makes them precious tools for monitor the quality of the environment.
These substances can enter the human food chain via fish and shellfish
The study found that dolphins from high-risk areas, such as Redfish Bay, Laguna Madre and Mississippi Sound, show higher levels of pharmacological contamination. In particular, Mississippi dolphins represented 40% of the total detections, suggesting a problem rooted over time.
Fentanyl, an opioid 100 times more potent than morphine, binds easily to fats, accumulating over time. Its presence in dolphins could arise from waste water or industrial dischargesbut also from drug traffickingas suggested by a record seizure of liquid fentanyl in a county near one of the study sites. Among other identified drugs, some are lipophobic, i.e poorly soluble in fatsmaking their presence in adipose tissue even more surprising and indicative of widespread contamination.
Makayla Guinn, one of the researchers, called the findings “alarming”, underlining the need for further investigations to understand the long-term effects of these substances on marine mammals. Dara Orbach, lead author of the study, emphasized that chronic drug exposure poses a risk not only to dolphins, but also for human healthwhereas these substances can enter the food chain via fish and shellfish.
The research highlights the urgency of monitoring emerging contaminants in marine ecosystems, especially in areas characterized by intense anthropogenic activities. The goal is to assess the extent of the problem and develop strategies to mitigate the impact of pharmacological contamination on aquatic environments and the species that populate them.
