Vertical Distributions of Cadmium,Copper,Nickel and Zinc in the Western Philippine Sea and a Comparison with Data from Other Parts of the Pacific Ocean

The concentration profiles of Cd, Cu, Ni and Zn in a water column in the western Philippine Sea (located at 124 degree 00'E, 21 degree 45'E) were investigated. All four elements showed surface-low and deep-high distribution pattern. The maximum concentrations found between 0-2000 m were 0.97, 2.6, 9.3 and 7.7 nM for Cd, Cu, Ni and Zn respectively. The distributions can be further classified into different types according to their relationships with nutrients. Cadmium was strongly correlated to nitrate and phosphate, whereas nickel and zinc were related to silicate. The concentration of copper increased linearly with depth, but it correlated poorly with either phosphate, nitrate or silicate. A comparison between the present data set and those reported for the northeast Pacific Ocean indicates that those elements follow similar distribution patterns across the Pacific Basin, with a decreasing, trend on the maximum concentrations in the deep water form the east to the west.