Changing perspectives in marine nitrogen fixation

• Published in: Science
• Main Authors: Zehr, Jonathan P., Capone, Douglas G.
• Other Authors: National Science Foundation, Simons Foundation
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 2020
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1126/science.aay9514; https://syndication.highwire.org/content/doi/10.1126/science.aay9514; https://www.science.org/doi/pdf/10.1126/science.aay9514

Changing views and a changing ocean As a component of many biomolecules, nitrogen is a crucial element for life, especially in nutrient-poor environs such as the open ocean. Atmospheric dinitrogen gas (N 2 ) is abundant but must be fixed by reduction to ammonia, a process limited to certain organisms and environments. Zehr and Capone review changes in our understanding of what marine microorganisms are fixing N 2 , where they live, and what environmental features influence their activity. N 2 fixation is more widely distributed than previously thought, and we still have much to learn about the physiology and regulation involved. We now have better estimates of global- and basin-scale inputs and outputs, but questions remain as to whether the oceanic N cycle is balanced. New tools are enabling better understanding of ocean N 2 fixation despite disruptive consequences from human activities, including ocean acidification and warming. Science , this issue p. eaay9514