Distribution of Trace Bioelements in the Subarctic North Pacific Ocean and the Bering Sea (the R/V Hakuho Maru Cruise KH-97-2)

Abstract

⋅Trace bioelements, ⋅Mn, ⋅Fe, ⋅Co, ⋅Ni, ⋅Cu, ⋅Zn, ⋅subarctic North Pacific, concentrations for Ni and Zn in the Bering Sea were also 1.3-2 times higher than in the North Pacific. The profiles for Co and Cu were examined in the subarctic North Pacific, and results obtained were consistent with previous reports. There was a sig- nificant correlation between the concentrations of Co and Mn except for surface mixed layer. The profiles for total adsorbable Mn were similar to the reported profiles for total dissolvable Mn. The deep water concentration of Mn in the Bering Sea was also 4 times higher than in the North Pacific. Iron and zinc were depleted in surface water of the subarctic North Pacific. The relationship between these trace elements and nutrients suggests that these elements could be a limiting factor of phytoplankton productivity. In the Bering Sea, surface water contained ~0.3 nM of Fe. The Zn con- centration, which was less than the detection limit in surface water, increased at shal- lower depths (~30 m) compared with the subarctic North Pacific. These results imply a higher flux of Fe and Zn to surface water in the Bering Sea. This in turn may cause the ecosystem in the Bering Sea characterized by a dominance of diatoms and high regenerated production.