Manganese biogeochemistry in the Southern Ocean ...

• Main Author: Latour, PMA
• Format: Thesis
• Language: unknown
• Published: University Of Tasmania 2023
• Subjects: Southern Ocean; Antarc*; Antarctica
• Online Access: https://dx.doi.org/10.25959/23246414; https://figshare.utas.edu.au/articles/thesis/Manganese_biogeochemistry_in_the_Southern_Ocean/23246414

Manganese (Mn) is a redox-active metal essential for most life on Earth. In photosynthetic microalgae (phytoplankton), Mn is used in the oxygen evolving complex of photosystem II, and in the superoxide dismutase enzyme to detoxify reactive oxygen species. Thus, phytoplankton have a strict Mn requirement for growth. In the Southern Ocean, the largest High-Nutrient Low-Chlorophyll (HNLC) region, phytoplankton growth is strongly limited by the micronutrient iron (Fe), but recent evidence shows Mn can (co-)limit phytoplankton growth in both coastal and open ocean regions. These results conflict with earlier studies that found Mn levels in Southern Ocean waters were sufficient to support phytoplankton growth. Hence, there is a need to constrain the distribution of Mn in Southern Ocean waters, to describe its sources and sinks and to identify potential regions of limitation. Here, we aim to tackle this problem by firstly describing Mn distribution along a meridional transect between Tasmania and Antarctica. ...