Hong Kong: Wonders never cease

Abstract

The physical characteristics, and concentrations of major and trace metals, in 6 m long sediment cores from five marine locations in Hong Kong have been determined. Core chronologies have been reconciled with dredging, construction, and other anthropogenic activities taking place since 1900. Sedimentation rates varied by an order of magnitude, from the more open harbour environments to enclosed ones. The most critical pollutant in the cores, copper, had normalized enrichment factors between 2.8 and 312 at the five sites, and surficial concentrations >6 g kg−1 in the upper sediment of the Typhoon Shelter sampling site. Whereas the Cu, Ni and Cr pollution largely dates from the post-industrial period, Zn and Pb pollution have a longer history from the construction, maintenance and anchorage of ships. Individual trace metal fluxes varied from one location to another by factors >1500, and the magnitudes in the Typhoon Shelter were generally greater than values at other polluted harbour environments.