Biologists testing mussels in the waters around Seattle as part of the Puget Sound Mussel Monitoring Program found oxycodone in mussel tissue for the first time, along with antibiotics, antidepressants, chemotherapy drugs, and heart medications. “We have found evidence that these chemicals are in our nearshore marine waters and are being taken up by marine biota living there,” said Washington Department of Fish & Wildlife biologist Jennifer Lanksbury. She also tested juvenile Chinook salmon in Puget Sound estuaries and found similar results, with the fish being exposed to multiple human medications and other products. The mussels tested were not wild mussels but clean mussels the researchers had transplanted from an aquaculture farm on Whidbey Island to locations near the port of Seattle and the Bremerton shipyard.“Our results do not directly represent contaminants in wild mussels, and they are restricted only to the areas in Puget Sound that we tested,” cautions Lanksbury. She says oxycodone and other human medications likely came from treated wastewater from local sewage treatment plants, stormwater runoff carrying untreated sewage from cities or towns, or even leaking septic tanks in more rural areas. Because marine organisms are being exposed to more than one medication at a time, Lanksbury is concerned that there could be synergistic or multiplicative effects, but she stresses that further testing is needed.