Depuration of anthropogenic particles by Pacific oysters (Crassostrea gigas): Feasibility and efficacy

Anthropogenic particles (APs) generated from both natural and synthetic materials are widespread in the aquatic environment and contaminate seafood products, including shellfish. Depuration, involving the placement of filter-feeding shellfish in clean water for a period of time, often several days, is used to reduce contaminant concentrations, but the practicality of its use by the shellfish industry for APs has not yet been examined. In the present study, cultured adult Pacific oysters (Crassostrea gigas) were depurated for 10 days in a facility with limited airflow and filtered seawater. On average, there was a 73 % reduction in oyster AP concentration after 5 days, but no further reduction at 10 days, potentially due to the difficulty in depurating some particles or to re-contamination from the experimental environment. Long-term feasibility for industry will depend on future guidelines for safe AP consumption levels and the practicality and financial feasibility of creating and running clean facilities.