Behavior of Mn in the western north pacific

The determination of dissolved Mn in sea water was carried out using a Chelex 100 resin and graphite furnace atomic absorption spectrophotometer. The nearshore surface layer waters off the Straits of Kii had the highest Mn concentration of 6.40 n mol kg⁻¹ at these stations. Mn concentration of intermediate and deep water off the Straits of Kii ranged between 0.18 and 1.42 n mol kg⁻¹. Mn concentration in deep and bottom waters at the Mariana Trough were between 0.71 and 2.48 n mol kg⁻¹. Sharp increases of Mn concentration near the bottoms were observed at two stations near the hydrothermal vents of the central ridge of the Mariana Trough.