What gas is the most common in the ocean? What is DON? How does phosphor occur? Who are often iron limited? What are macro and micronutrients?

Nitrogen is most common as gas in the oceon (ca 90%) but only cyanobakterie kan use it this way. We call everything below what we can filter disolved organic nitrogen (DON) so even small cells fit in this category Phosphor occors as phosphate or dissovled organic phosphuros. Iron is also very important in phytoplankton cells. Nitrogen, phosphor and silicon are called macronutrients because they occur in large amounts in the oceon. Micronutrients: < 0,05% of biomass in the cell: Fe, Mg, Zn etc