TEXAS — A team from Texas A&M Corpus Christi discovered human pharmaceuticals in dolphins inhabiting the Gulf of Mexico.

The study, “Pharmaceuticals in the Blubber of Live Free-Swimming Common Bottlenose Dolphins,” found that pharmaceuticals were detected in 30 out of 89 dolphin blubber samples, comprising 83 samples from live dolphins and six from deceased ones. Fentanyl was found in 18 out of 30 positive tests.

Researchers chose dolphins from three Gulf of Mexico locations—Texas’ Redfish Bay and Laguna Madre, plus Mississippi Sound samples collected in 2013. 

Dolphins living in high-risk areas (oil spills, boat traffic, algal blooms) had more pharmaceutical pollution in their tissue samples.

“Pharmaceutical drugs are therapeutic substances used in human and veterinary medicine to diagnose, treat, cure or prevent disease,” said Dr. Dara Orbach, assistant professor of marine biology at Texas A&M Corpus Christi and principal investigator on the study. “Furthermore, pharmaceuticals have become emerging micropollutants and are a growing global concern as their presence has been reported in freshwater ecosystems, rivers and oceans worldwide.”  

Orbach also pointed out that, in contaminant research, dolphins’ lipid-rich blubber makes them valuable bioindicators of ecosystem health because it stores contaminants.

While the long-term impact of pharmaceuticals on marine mammals remains unclear, Orbach highlights the need for extensive research, given their presence in three Gulf of Mexico dolphin populations.

Fentanyl, a powerful synthetic opioid, serves as a treatment for severe pain and is sometimes used during surgery. According to the DEA, a dose of two milligrams of fentanyl may be lethal, influenced by factors such as body size, tolerance and prior exposure. 

U.S. overdose deaths are primarily caused by synthetic opioids like fentanyl, according to the CDC.