Data from: Molecular underpinnings and biogeochemical consequences of enhanced diatom growth in a warming Southern Ocean

We found that nitrate uptake and primary productivity were elevated at increased temperature in the absence of iron addition, and were even greater at high temperature with added iron. Pseudo-nitzschia became more abundant under increased temperature without added iron, while Fragilariopsis required additional iron to benefit from warming. We attribute the apparent advantage Pseudo-nitzschia shows under warming to upregulation of iron-conserving photosynthetic processes, utilization of iron-economic nitrogen assimilation mechanisms, and increased iron uptake and storage.

These data identify important molecular and physiological differences between dominant diatom groups and add to the growing evidence for the increasingly important role of Pseudo-nitzschia in warming SO ecosystems. This study also suggests that temperature-driven shifts in SO phytoplankton assemblages may increase utilization of the vast pool of excess nutrients in iron-limited SO surface waters, and thereby influence global nutrient distributions and carbon cycle.