Dolphins in Gulf Found Contaminated with Fentanyl
Recent research has detected fentanyl and other drugs in dozens of dolphins in the Gulf of Mexico, just months after cocaine was found in sharks off the coast of South America. This finding highlights the growing problem of pharmaceuticals infiltrating marine environments.
“Pharmaceuticals have emerged as micropollutants and are becoming a global concern, with their presence reported in freshwater ecosystems, rivers, and oceans worldwide,” says Dara Orbach, a mammologist at Texas A&M University-Corpus Christi (TAMU-CC).
Unexpected Discovery During Routine Tests
In 2020, TAMU-CC researchers conducting routine hormone level tests on common bottlenose dolphins (Tursiops truncatus) unexpectedly found traces of various pharmaceuticals in the cetaceans’ fat tissue.
Biologist Anya Ocampos and her team analyzed tissue samples from 89 dolphins, detecting fentanyl in 24 samples, including all six post-mortem dolphins. They also found sedatives like meprobamate and muscle relaxants like carisoprodol in the dolphins’ blubber.
Because dolphins do not drink seawater, these apex predators likely absorbed the chemicals through their diet or skin. Alarmingly, researchers collected some drug-contaminated samples from living dolphins as far back as 2013, suggesting that this issue has been ongoing.
Dolphins as Bioindicators of Marine Health
Orbach explains that researchers often use dolphins as bioindicators of ecosystem health in contamination research because their lipid-rich blubber stores contaminants and allows relatively non-invasive sampling in live animals.
One concerning case involved a dolphin found dead in Baffin Bay, South Texas, within a year of the largest liquid fentanyl drug bust in U.S. history in the adjacent county. Furthermore, 40% of the pharmaceutical detections came from dolphins in the Mississippi area, indicating that this is a long-standing issue in marine environments.
Researchers have found that more than a quarter of the world’s rivers contain pharmaceutical levels higher than what is considered safe for aquatic life, and these pollutants contribute to contamination in oceans.
Adding to an Overwhelming List of Stressors
Although the ecological impact of trace pharmaceuticals remains unclear, their presence adds to broader human-induced stressors like plastic pollution, chemical spills, and climate change. In 2021, Gulf of Mexico dolphins still faced health and reproductive issues from the 2010 BP Deepwater Horizon oil spill.
Chronic exposure to multiple environmental stressors weakens the immune systems of dolphins and whales, affecting their health, reproduction, and survival.
Researchers have not yet fully understood the chronic exposure to pharmaceuticals and their cumulative effects on marine mammals.
Their presence in three dolphin populations across the Gulf highlights the urgent need for large-scale studies to assess the extent and sources of this contamination,” urges Orbach.
Read the original article on: Science Alert
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