Abstract
This paper describes the vertical profiles of dissolved bioactive trace metals such as Fe, Cd, Cu, Ni, Zn and Co in the Western Tropical Pacific Ocean. The behavior and profile of bioactive trace metals were classified into three types. 1) Nutrient type behavior and profile (Cd, Ni). 2) Extremely high concentration at the surface with the concentration decreasing linearly from 10m to the bottom (Cu, Zn), 3) Distribution and behavior are different at each sampling station (Fe, Co). Significant correlations were observed between Cd, Ni and nutrient concentrations. The average concentrations of Cd, Cu, Zn, Ni and Co below 2000m in the Western Tropical Pacific were lower than those in the North Pacific Ocean. The origin of the air mass above 1500m at four stations was off shore. The air mass above 1500m at only one station passed through the New Britain Island. Thus, the dissolved Cu and Zn at the surface might be supplied from materials other than these of terrigenous origin.
