Distributions of Polycyclic Aromatic Hydrocarbons and Fecal Sterols in Sediment from Gamak Bay and Their Impact on Benthic Community

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and fecal sterols were determined in the sediment from Gamak Bay in Korea, to investigate their distributions and impacts on benthic environment. Concentrations of 16 PAHs and 8 fecal sterols in Gamak Bay sediments ranged from 130 to 2,100 ng/g dry weight (mean 400 ng/g dry weight), and from 740 to 9,500 ng/g dry weight (mean 2,900 ng/g dry weight), respectively. Concentrations of coprostanol (Cop), which has been used as indicator of domestic pollution, ranged from 12 to 600 ng/g dry weight. Concentrations of PAHs and Cop in the sediment from Gamak Bay were similar to or lower than those reported for industrialized bays of Korea and other countries. No correlation between the levels of PAHs and fecal sterols was found in sediment from Gamak Bay, suggesting the differences of source and behavior for these chemicals in coastal environment. Diagnostic ratios and profiles of PAHs in Gamak Bay sediment showed a strong pyrolytic origin with a slight petrogenic contamination. The Cop/(Cop+cholestanol) and Cop/cholesterol showed that the organic pollution in Gamak Bay was attributed to biogenic source rather than sewage pollution. Spearman correlation analyses and non-parametric multidimensional scaling (MDS) technique showed that distribution of fecal sterols was associated with benthic community structure in sediment from Gamak Bay.