A study by the University of Washington reveals that the largest ocean nitrogen fixation takes place in the Pacific Ocean and not in the Atlantic. This news has annulled the assumption of several years.
In the last decade it had been recognized that most of the nitrogen settled in the Atlantic Ocean, which is the one that receives most of the iron from the earth. Iron is one of the components of nitrogase, an enzyme that causes living things to fix nitrogen. Based on this, they considered that the iron of the oceans was the main limiting factor of nitrogen fixation.
By refining nitrogen, the microorganisms capable of doing so turn nitrogen into useful for living beings, since most of the nitrogen is unused by living beings. There are also living beings that perform an anti-fixation process, that is, that make the fixed nitrogen unusable, in the process called denitrification.
In the Pacific Ocean the nitrification is very high and the iron collection of the land is very low. Since most nitrogen is fixed in the Pacific Ocean, the conclusion is that denitrification is the cause of the growth of nitrogen-fixing microorganisms, not water iron. In fact, denitrification produces a lack of nitrogen and, under these conditions, nitrogen fixers are more competitive than microorganisms unable to fix nitrogen.