Dissolved inorganic remineralization

Deviations from the Redfield-Richards ratio can also be caused by remineralization that proceeds by processes other than aerobic respiration. As shown in Figure 10.6, water samples obtained from depths where denitrification has occurred have lower dissolved inorganic nitrogen concentrations ([NOj ] + [NOH) than would be predicted from their AOU. During denitrification, nitrate is first reduced to nitrite and then to N2,... 

Ono, S., Ennyu, A., Najjar, R. G., and Bates, N. R. (2001). Shallow remineralization in the Sargasso Sea estimated from seasonal variations in oxygen, dissolved inorganic carbon and nitrate. Deep Sea Res. 1/48, 1567-1582. 

This equation describes the ratios with which inorganic nutrients dissolved in seawater are converted by photosynthesis into the biomass of "average marine plankton" and oxygen gas 02. The opposite of this reaction is respiration, or the remineralization process by which organic matter is enzymatically oxidized back to inorganic nutrients and water. The atomic ratios (stoichiometry) of this reaction were established by... 

The impact of anthropogenic nutrient emissions in the coastal zone is heightened by its chemical speciation. Pollutant nitrogen and phosphorus are delivered to the coastal waters primarily in inorganic form, whereas most of the natural riverine dissolved nitrogen and phosphorus are components of organic compounds, i.e., DON and DOE Thus, the pollutant nutrients are delivered to the coastal waters in a chemical form that can be directly assimilated by coastal plankton, whereas the organically bound (natural) forms must first be remineralized. 

In the ocean interior, the ratio of fixed inorganic nitrogen (in the form of N03 ) to PO4 in the dissolved phase is remarkably close to the ratios of the two elements in living plankton. Hence, it seemed reasonable to assume that the ratio of the two elements in the dissolved phase was the result of the sinking and subsequent remineralization... 

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