Characteristics of total petroleum hydrocarbon contamination in sediments in the Yangtze Estuary and adjacent sea areas

Abstract

The spatial and temporal distribution characteristics of total petroleum hydrocarbon contamination in sediments in the Yangtze Estuary and adjacent sea areas were studied according to survey and monitoring data during the wet seasons of 2011–2016. The influencing mechanism was also analyzed. The average total petroleum hydrocarbon content was 176.25 mg/kg. This result indicated the absence of total petroleum hydrocarbon contamination in the sediments. With regard to spatial distribution, the total petroleum hydrocarbon content in the sediments decreased gradually from the coastal areas to the offshore areas. The spatial distribution of total petroleum hydrocarbon in the studied sea area can be divided into four sea areas, as supported by both multidimensional scaling index analysis and analysis of similarities. Sediments in the largest coastal turbidity zone presented the highest total petroleum hydrocarbon content, followed by those in coastal areas and mud areas successively. The total petroleum hydrocarbon content in offshore areas was low throughout the year.