The effect of bioturbation by polychaete Perinereis aibuhitensis on release and distribution of buried hydrocarbon pollutants in coastal muddy sediment

As a headdown deposit feeder, polychaete Perinereis aibuhitensis may transport particles from the deep sediment layers to the surface enhancing sediment resuspension, which influences the fate of sediment-associated pollutants. The impact of P. aibuhitensis on the remobilization of buried hydrocarbons was investigated through a 30 day laboratory microcosm experiment with hydrocarbon spiked sediment buried in different layers. The bioturbation of P. aibuhitensis enhanced sediment resuspension by approximately fourfold suspended particulate matters (SPM) and twofold dissolved organic carbon (DOC) in bioturbation (BI) microcosms (added P. aibuhitensis) than control (CL) microcosms (without P. aibuhitensis). The release of buried hydrocarbons were also enhanced with significantly higher hydrocarbon concentrations in BI microcosms than CL and blank (BK) microcosms (without spiked hydrocarbons). The presence of P. aibuhitensis led to the transport of buried spiked hydrocarbons in sediment and enhanced the loss of buried hydrocarbons.