Nitrogen and phosphorus are two such elements. They are crucial to the operation of the Bay's life support system. Nitrogen is a major component of all organisms, primarily as a key ingredient in protein. When an organism dies, bacteria breaks down proteins into amino acids. Bacteria then remove the carbon, converting the acids into ammonia.
Plants are able to use ammonia as a source of nitrogen.
In the presence of oxygen, bacteria can convert ammonia to nitrite and nitrate, also good sources of nitrogen. Under low oxygen conditions, some bacteria convert nitrate to gaseous nitrogen which is unavailable to most aquatic organisms. However, in tidal freshwater, some blue-green algae are able to use gaseous nitrogen directly. Phosphorus is another element essential to plant growth. During decomposition and in the presence of oxygen, bacteria convert organic phosphorus to phosphate.