Where do marine organisms in the tropical oceans get the nitrogen they need to grow?
In the process, the study also may help to explain how tons of carbon dioxide disappears into the ocean every day, slowing the progress of global warming. Nitrogen is a building block of life and an essential nutrient for phytoplankton and other aquatic life. Biologists have long known that as dead organic matter decomposes in the depths of the ocean; nitrogen breaks free and drifts upward. The problem is that not nearly enough nitrogen rises up to nourish all of the teeming life near the surface. In a paper chosen for a commentary in the current issue of Nature, a team led by biological oceanographer Douglas Capone of the USC College of Letters, Arts and Sciences confirms that certain aquatic microorganisms draw huge amounts of nitrogen from the air. Previous estimates suggested that nitrogen fixation from the atmosphere played only a very minor role in the oceans. The term “fixation” describes the process by which nitrogen, an inert gas, is transformed into usable chemical forms such
