Native Olympia oysters in Oregon’s Netarts and Coos bays are loaded with pharmaceuticals and chemicals, including pain relievers, antibiotics, mercury and pesticides, says a study by Portland State University researchers, the Oregon Department of Fish and Wildlife, U.S. Geological Survey and Oregon Department of Environmental Quality.
The chemical contamination discovered fell within acceptable levels set by state health officials, but the impact on the broader ecosystem and on human health is not widely understood, says The Oregonian.
“In addition to potential human health risks, the pollutants may affect the growth and reproduction of the oysters themselves,” said Elise Granek, an associate professor of environmental sciences at PSU. She emphasized that the importance of the study goes beyond one species of oysters, “since oysters play important ecological roles of filtering water and providing habitat for other estuarine and marine species like juvenile salmon.”
The chemicals would have flowed into the bays through groundwater runoff or wastewater. Mercury could have arrived through polluted air. Officials chose not to issue a warning to consumers in response to the study, noting that you would have to eat tens of thousands of pounds of oysters to amass a single dose worth of pharmaceuticals.
Olympia oysters are protected from wild harvesting due to low populations, but are commercially farmed. Researchers suspect that the other native oyster species in Oregon, the Pacific oyster, may have the same level of contamination.