Scientists have discovered fentanyl and other drugs in several dolphins from the Gulf of Mexico, raising alarm about the potential implications for ocean health.
The research began in September 2020 when marine biologists, on a routine survey of the dolphin population, encountered a deceased dolphin floating in the water. Dara Orbach, an assistant professor at Texas A&M University-Corpus Christi’s marine biology program and co-author of the study, noted that they recognized the dolphin had recently died, prompting them to tow it back to campus for further examination.
Years later, when graduate student Makayla Guinn needed tissue samples for research on hormones, the team retrieved blubber from the deceased dolphin. They then collaborated with biochemist Hussain Abdulla to perform an untargeted analysis of the tissue to identify chemical compounds present. According to Christiana Wittmaack, a toxicologist and co-author of the study, this method involves using specialized instruments to detect unknown chemicals in the samples.
Although the initial goal was to study hormones, the analysis yielded thousands of compounds. To their astonishment, the researchers found traces of fentanyl, a muscle relaxant, and a sedative in the samples. Undergraduate student Anya Ocampos further analyzed 89 dolphin samples, 83 of which were collected from live dolphins in Laguna Madre, a shallow lagoon near Corpus Christi Bay. Fentanyl was the most prevalent drug found, appearing in 24 of the samples.
Significantly, all dead samples tested positive for at least one drug, including historic samples collected from the Mississippi Sound in 2013, indicating that these contaminants may have been present in the Gulf’s waters for an extended period. Orbach explained that dolphins do not drink water but obtain hydration from their prey, suggesting that the marine animals they consume likely also carry these contaminants.
“This may be a widespread and longstanding issue that hasn’t been adequately addressed,” she remarked.
The sources of these drugs and contaminants could be varied, including dermal contact, water pollution, and possibly drugs discarded overboard. Orbach mentioned the proximity to the Mexican border, agricultural runoff, and human wastewater as potential contributors, noting that the dolphin found in 2020 was near Robstown County, where the largest liquid fentanyl drug bust in U.S. history occurred in 2023.
“We need to monitor this situation over time to ensure that fentanyl concentrations do not increase,” Wittmaack cautioned. According to Orbach, there have been no prior studies analyzing the long-term effects of pharmaceuticals on marine mammals.
While the amounts detected were low, this water pollution reflects a growing series of stressors faced by marine animals.
“These animals are exposed to constant noise pollution, vessel traffic, dredging, algal blooms, oil spills, and chemical spills,” Orbach stated. “As more factors are added, the animals become increasingly vulnerable, eventually reaching a point where they cannot adequately respond.”
Credit: ABC News
