Assessment of sediment quality in Jinhae and Gwangyang bays

Abstract

Marine environment is the ultimate sink for land based anthropogenic pollutants. After the adsorption to the suspended particles, the contaminants sink and stay remained at the sediment for a long time. Benthic organisms will eventually uptake and bioaccumulate these contaminants, and then they are biomagnified through the food web. In order to assess the contamination status and identify the priority substances in two special management areas in the South coast of Korea such as Masan Bay and Gwangyang Bay, intensive surface sediment sampling was conducted and organic and inorganic contaminants were quantitatively determined. Additionally, sediment toxicity test was conducted with benthic amphipod as well. The spatial distribution of contaminants clearly revealed the fact that sewage treatment plant outfall and industrial waste output from the inner bay are major pollution sources. The overall trend in sediment contamination decreased except for PBDE, one of emerging contaminants, in Masan Bay. In order to assess the pollution status of this bay in an integrative way, sediment quality index (SQI) was derived from the chemical data. The SQI was calculated using two functions viz. ‘scope’ (the number of variables that do not meet guideline objective) and ‘amplitude’ (the magnitude by which variables exceed guideline objective) based on sediment quality guideline (SQG) values from Canada, uptake and bioaccumulate these contaminants, and then they are biomagnified through the food web. In order to assess the contamination status and identify the priority substances in two special management areas in the South coast of Korea such as Masan Bay and Gwangyang Bay, intensive surface sediment sampling was conducted and organic and inorganic contaminants were quantitatively determined. Additionally, sediment toxicity test was conducted with benthic amphipod as well. The spatial distribution of contaminants clearly revealed the fact that sewage treatment plant outfall a