Range: 5-12 %
||Mangan, N. M., Flamholz, A., Hood, R. D., Milo, R., and Savage, D. F. (2016). pH determines the energetic efficiency of the cyanobacterial CO2 concentrating mechanism. Proc. Natl. Acad. Sci. U. S. A. 113, E5354–E5362.PubMed ID27551079
||Estimate based on primary measurements, see comments below.
||SI, p33: "About 45% of the global net primary photosynthetic productivity (NPP) is due to photosynthesis in the oceans, where cyanobacteria are major contributors to NPP. By contrast, nearly all of the NPP on land is due to macroscopic plants (refs 63, 64). Some previous reviews and papers attribute up to 25% of global NPP to the cyanobacteria (refs 5, 63) based on the assessment that 50% of oceanic carbon fixation is due to cyanobacteria. Tracing these references it seems that the 50% number is drawn from two studies of Prochlorococcus in the equatorial Pacific (refs 65, 66). These values are likely artificially high because they focus on one of the regions of the world’s oceans where Prochlorococcus is most abundant (as shown in Figure 3 of (ref 67)). Based on a review of the recent literature, [investigators] conclude that a number closer to 10% is more accurate. Some have estimated the cyanobacterial contribution as 10% of oceanic NPP (ref 68) or 25% (ref 67). As carbon fixation is estimated to be ~45% of total NPP, cyanobacteria contribute 5-12% of global NPP."