Development of a Marine Sediment Pollution Index.

To facilitate translation of the state of marine sediment quality for public information, a pollution index was developed from the results of a routine monitoring program. Principal component analysis (PCA) of 24 variables at 64 monitoring stations from 1987 to 1997 was carried out to identify the most important parameters that were applied in the index formulation. Of the 24 variables, six (Cr, Cu, Ni, chemical oxygen demand, Zn, Mn) were selected on the basis of their high PCA loadings. The derived Marine Sediment Pollution Index, rating from 0 to 100, reflected the general trend in the monitoring areas. The index was also found to have a significant negative correlation (P < 0.05) with the benthic species diversity and toxicity of the sediment, indicating its usefulness in reflecting marine sediment quality. The application of PCA to identify important variables from a monitoring program would reduce sampling resources, as parameters that did not show significant spatial or temporal variations could be analyzed in a lesser frequency than those that were identified to be more important from the results of PCA.