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Review
. 2002 Mar;68(3):1015-24.
doi: 10.1128/AEM.68.3.1015-1024.2002.

Nitrogen cycling in the ocean: new perspectives on processes and paradigms

Jonathan P Zehr  1 , Bess B Ward
Affiliations
Review

Nitrogen cycling in the ocean: new perspectives on processes and paradigms

Jonathan P Zehr et al. Appl Environ Microbiol. 2002 Mar.
No abstract available

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Figures

FIG. 1.
FIG. 1.
Conceptual diagram of major features of the nitrogen cycle in coastal shelf and upwelling (I), OMZs (II), surface waters of the open ocean (III), and deep water (IV). PON, particulate organic nitrogen. Dashed lines indicate transformations involving multiple steps. Pathways: A, DIN assimilation; B, ammonium regeneration; C, nitrogen fixation; D, nitrate diffusion/advection from deep water; E, nitrification; F, nitrification; G, denitrification.
FIG. 2.
FIG. 2.
Diagrams of classical and present views of the N cycle in the surface waters of oligotrophic oceans. The composition of the dissolved N pool is shown with approximate relative concentrations of inorganic and organic constituents indicated by the size of the box. Dashed lines indicate transformations and processes included in the newer view of nitrogen cycling. (A) Some phytoplankton use simple organic compounds as a source of nitrogen. (B) There are multiple species of phytoplankton (cyanobacteria) in the open ocean that fix N2. (C) Bacteria can compete for nitrate and ammonium. (D) Bacteria can excrete urea and can also be a source of high-molecular-weight DON. (E). Some oceanic bacterioplankton appear to fix N2.
See this image and copyright information in PMC

References

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