Scavenging differentiates the distribution of cadmium, nickel, zinc and copper in the North Pacific Ocean

The North Pacific Ocean is located at an end point of thermohaline circulation, where the Pacific Deep Water (PDW) is formed internally with contributions of the Lower Circumpolar Water and the North Pacific Intermediate Water. Zheng and co-authors (2021, see reference below) observed sectional distributions of cadmium (Cd), nickel (Ni), zinc (Zn), and copper (Cu) in the North Pacific Ocean during three GEOTRACES related cruises. Although Cd shows a high correlation with PO4 throughout the distributions, Ni, Zn, and Cu show considerable deviations from the correlation with PO4. Based on the analysis of the mole ratios of dissolved metal (dM) to phosphate (dM/PO4) and the enrichment factor of dM, EF(dM) = (dM/dAl)seawater/(M/Al)upper crust, they propose that scavenging influences the distribution of these recycled-type metals in the stagnant PDW. They conclude that, among the four metals, Cu is the most affected by scavenging, while Cd is the least affected, and scavenging plays a significant role on Ni and Zn.

Figure: Left panels: full-depth sectional distributions of dCd, dNi, and dCu from KH-05-2 (along 160°W, 10°S–54°N). Right panels: plots of dM/PO4 vs. apparent oxygen utilization (AOU) at depths > 800 m of the three cruises. AOU is a measure of the age of deep water. The point color indicates depth. Click here to view the image larger.

Reference:

Zheng, L., Minami, T., Takano, S., Ho, T.-Y., & Sohrin, Y. (2021). Sectional distribution patterns of Cd, Ni, Zn, and Cu in the North Pacific Ocean: Relationships to nutrients and importance of scavenging. Global Biogeochemical Cycles, 35, e2020GB006558. https://doi.org/10.1029/2020GB006558

Latest highlights

Science Highlights

Icebergs as sources of trace metals to the ocean: which impact?

Earth’s Ice Sheets are known to release significant quantities of lithogenic particles into the ocean every year, but how does this material affect trace metal availability in the ocean?

18.10.2021

Science Highlights

Microbial trace metal trafficking on marine particles

This study provides evidence for the processing of nine particulate trace metals in multiple manners by diverse microbial communities.

28.09.2021

Science Highlights

Volcanic emissions in the Southern Ocean: an efficient and unexpected source of iron for this remote area

This study suggests that volcanic emission can represent a significant source of bioavailable Fe to open ocean anaemic ecosystems.

20.09.2021

Science Highlights

Surprisingly heavy silicon isotopes in the surface and deep Arctic Ocean

Brzezinski and his colleagues report on a comprehensive study of the Arctic Ocean silicic acid concentrations and silicon isotopic composition…

14.09.2021

Rechercher