Dissolved oxygen measurement photosynthesis

Redox mediators provide an alternative to dissolved oxygen measurements for monitoring of respiration or photosynthesis. The mechanism is based on the reducing activity of metabolising biological whole cells ... 

The dissolved oxygen data follow depth trends that are nearly a mirror image of the nutrients. The OMZ lies at depths slightly above the core of the AAIW. Why is the OMZ located at these depths To answer this question, oceanographers use the vertical concentration profiles of O2, nutrients, and TDIC to assess the relative rates of aerobic respiration and photosynthesis as a function of depth. (The TDIC concentration is used as a measure of how much CO2 has been taken up from or released into the water.)... 

For your further interest, these relations between the luminescent intensity and the pressure are also applicable to liquid flows by replacing the pressure with the dissolved oxygen (DO) concentration. Matsuda et al. [7] measured the unsteady DO concentration distribution by PSP. Mamyama et al. [8] evaluated the photosynthesis of single Synechocystis sp. PCC 6803 by measuring the DO concentration by using pressure-sensitive channel chip (PSCC) [9]. 

As shown in Fig. 10-13, there is also a flux of O2 produced during net photosynthesis from the ocean to the atmosphere and an export flux of particulate and dissolved organic matter out of the euphotic zone. For a steady-state system, new production should equal the flux of O2 to the atmosphere and the export of organic carbon (Eppley and Peterson, 1979) (when all are expressed in the same units, e.g., moles of carbon). Such an ideal state probably rarely exists because the euphotic zone is a dynamic place. Unfortunately, there have been no studies where all three fluxes were measured at the same time. Part of the difficulty is that each flux needs to be integrated over different time scales. The oxygen flux approach has been applied in the subarctic north Pacific (Emerson et al, 1991) and subtropical Pacific (Emerson et al, 1995, 1997) and Atlantic (Jenkins and Goldman, 1985). The organic carbon export approach has... 

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