A Texas A&M University research project has found traces of fentanyl in dead dolphins from the Gulf of Mexico. But researchers fear the dolphins that are affected by the deadly drug just may be scratching the surface.

Drug smugglers using open waterways to move products may be affecting the health of sea life in the Gulf of Mexico

Of 89 dolphins tested in the Gulf of Mexico, 30 contained some form of pharmaceutical—and 18 had fentanyl in their blubber.

For there to be drugs in a dolphin means that the drugs are either in the water, or they’re in the prey that they’re consuming,” a researcher told a Texas news outlet.

The team found fentanyl, as well as the drugs carisoprodol and meprobamate, both used pharmaceutically for pain relief, in 30 of the 89 dolphins they studied, which were recovered from sites in Texas and Mississippi.

The opioid fentanyl has made its presence known in an unexpected place — the blubber of dolphins in the Gulf of Mexico. In a concerning study, researchers detected fentanyl in 27% of analyzed dolphins,