Integrated assessment of sediment contamination by anthropogenic pollutants in a semi-enclosed bay in Korea

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 bottom sediment for a long time. Benthic biota will eventually pickup these residues and biomagnify through the food web. In order to assess the contamination status and identify the priority substances in Masan Bay, intensive sediment sampling was conducted and organic and inorganic contaminants were analyzed. Additionally, benthic amphipod toxicity test was conducted 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. After the implementation of ‘Total Pollution Loads Management System (TPLMS)’ to this bay in 2008, the overall trend in sediment contamination decreased except for PBDE. In order to assess the pollution status of this bay in an integrative way, sediment quality index (SQI) was prepared 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, USA and Australia/New Zealand. The overall status of this bay is ‘fair’ or ‘good’. Among th