Biogenic-to-lithogenic handoff of particulate Zn affects the Zn cycle in the Southern Ocean

• 成果类型: Article
• 署名作者: Duan, J.; Cloete, R.; Loock, J. C.; Lanzirotti, A.; Newville, M.; Martinez-Garcia, A.; Sigman, D. M.; Lam, P. J.; Roychoudhury, A. N.; Myneni, S. C. B.
• 署名单位: Princeton University; Stellenbosch University; University of Chicago; Max Planck Society; University of California System; University of California Santa Cruz
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-13242
• DOI: 10.1126/science.adh8199
• 发表日期: 2024-06-14
• 页码: 1235-1240
• 关键词: x-ray; biogeochemical cycles; trace-metals; zinc; speciation; atlantic; diatom; iron; complexation; limitation

摘要

Zinc (Zn) is vital to marine organisms. Its active uptake by phytoplankton results in a substantial depletion of dissolved Zn, and Zn bound to particulate organic matter replenishes dissolved Zn in the ocean through remineralization. However, we found that particulate Zn changes from Zn bound to phosphoryls in cells to recalcitrant inorganic pools that include biogenic silica, clays, and iron, manganese, and aluminum oxides in the Southern Ocean water column. The abundances of inorganic pools increase with depth and are the only phases preserved in sediments. Changes in the particulate-Zn speciation influence Zn bioavailability and explain the decoupling of Zn and phosphorus and the correlation of Zn and silicon in the water column. These findings reveal a new dimension to the ocean Zn cycle, implicating an underappreciated role of inorganic Zn particles and their impact on biological productivity.