A Study on the Concentration of Polycyclic Aromatic Hydrocarbons and the Detection of Oil in Subtidal Seafloor Sediments at the Wu Yi San Oil Spill Site

Wu Yi San, a 164,000-ton Singaporean class tanker, broke an oil pipeline when entering the crude oil pier in Nakpo-dong, Korea, on January 31, 2014, causing crude oil and oil mixture spills of 483.9 kl and 32–131 kl, respectively. Following the spill, polycyclic aromatic hydrocarbons (PAHs) were used to detect residual oil in the accident area. This investigation used subtidal sediments from the accident site, and oil was detected using concentration, PAH inflow route, and alkylated PAHs. The highest concentration was observed at the collision site one month after the accident; ∑16 PAHs decreased and remained at pre-accident levels, whereas ∑alkyl PAHs decreased considerably four months after the accident, and subsequently remained constant. When the double ratios of spilled oil and that reported in this study were compared, the results did not show similar patterns. PAH levels before the accident may be restored.