Award: OCE-1233155

We observed a large input of dissolved Fe, Mn and Zn from deep sea hydrothermal vents of the East Pacific Rise to the deep Pacific Ocean as shown by the coincidence of dissolved Fe, Mn and excess Zn cocnentrations with the mantle derived helium-3 along a 4000 km transect from the East Pacific Rise westward (Fig. 1). Much of the hydrothermal dissolved Fe input is via the supply of 300 kDa-0.2 micron size macro colloids from the hydrothermal vents (Fig. 2). There is a limited influence of hydrothermal activities on dissolved Cd and Cu distribution in the deep sea. However, there is a deficit of dissolved Cd relative to phosphate at 200-400 m depth range as shown by negative Cd* that appears to result from the subduction of Cd deplete water from the Polar Front Zone, and a colloidal Cu signal in the water column that may result from Cu complexation by colloidal organic ligands. This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content. Last Modified: 09/11/2016 Submitted by: Jingfeng Wu