US shellfish test positive for opioids off Seattle coast

Researchers from the Washington State Department of Fish and Wildlife have discovered that mussels in the waters of Puget Sound, off the coast of Seattle, tested positive for opioids.

The scientists said the findings indicated that many Seattle residents were using oxycodone. The researchers were conducting a study of pollution in the waters off Seattle. They chose to use mussels to test the levels of pollution since mussels are filter-feeders, meaning they get nutrients by filtering water. When they do so, their tissues also store any pollutants in the water, making mussels a prime indicator of pollution.

The researchers seeded clean mussels in 18 areas of the Puget Sound, and removed them three months later for testing, Mussels from three of the locations tested positive for traces of oxycodone. While the levels were not great enough to get anyone high by consuming the mussels, the presence of opioids was concerning because it indicated that opioid use was becoming problematic in the area and that other species were being affected by the opioid epidemic.

The most likely source of the opioid mussel contamination was the discharge from the area’s wastewater treatment plant. Officials from the King County Wastewater Treatment Division said that while their plant can filter out many contaminants from wastewater, it does not attempt to filter out drugs.

Officials from the Department of Fish and Wildlife said that this was a one-off study, but they hoped to get extra funds to continue testing the state’s coastal waters.