Potential cobalt limitation of vitamin B12 synthesis in the North Atlantic Ocean

• Published in: Global Biogeochemical Cycles
• Main Authors: Panzeca, C., Beck, Aaron J., Leblanc, K., Taylor, G. T., Hutchins, D. A., Sañudo-Wilhelmy, S. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU (American Geophysical Union) 2008
• Subjects: North Atlantic
• Online Access: https://oceanrep.geomar.de/id/eprint/39825/; https://oceanrep.geomar.de/id/eprint/39825/1/Panzeca.pdf; https://doi.org/10.1029/2007GB003124

[1] While recent studies have confirmed the ecological importance of vitamin B12, it is unclear whether the production of this vitamin could be limited by dissolved Co, a trace metal required for B12 biosynthesis, but found at only subnanomolar concentrations in the open ocean. Herein, we demonstrate that the spatial distribution of dissolved B12 (range: 0.13–5 pmol L−1) in the North Atlantic Ocean follows the abundance of total dissolved Co (range: 15–81 pmol L−1). Similar patterns were observed for bacterial productivity (range: 20–103 pmol 3H leucine L−1 hr−1) and algal biomass (range: 0.4–3.9 μg L−1). In contrast, vitamin B1 concentrations (range: 0.7–30 pM) were decoupled from both Co and B12 concentrations. Cobalt amendment experiments carried out in low-dissolved Co waters (∼20 pmol L−1) enhanced B12 production two-fold over unamended controls. This study provides evidence that B12 synthesis could be limited by the availability of Co in some regions of the world ocean.