ABSTRACT

Detailed vertical profiles of dissolved Ag in the Bering Sea, the central North and South Pacific and the Southern Ocean have been present here. These profiles are comparable to our previous report in the western North Pacific, the Okhotsk Sea and the Japan Sea (Zhang et al., 2001). There is a systematic enrichment of Ag concentrations in the deep waters (North Atlantic < South Atlantic < South Pacific < North Pacific), which is parallel with the distributions of dissolved Si and consistent with the route of the global ocean circulation. In the surface waters, the latitudinal distributions of both Ag and Si showed higher concentrations at higher latitude, suggesting that Ag in the oceanic surface waters are supplied from the deep water by upwelling and vertical mixing similar to that of Si. However, the Ag/Si ratios in surface waters are significantly higher than those in deep waters. Neither anthropogenic nor natural input from the atmosphere can play an important role for the elevated Ag/Si ratios in the surface waters. It is assumed that the elevated Ag/Si ratios in the surface waters are due to the difference in the biological uptake between the two elements.