The mean daily BSi rate strongly depends on the region:
* Coastal upwelling: 46 mmol.m.d
* Sub-arctic Pacific: 18 mmol.m.d
* Southern Ocean: 3&ndash;38 mmol.m.d
* mid-ocean gyres: 0.2&ndash;1.6 mmol.m.d
Likewise, the integrated annual BSi production strongly depends on the region:
* Coastal upwelling: 3 × 10 mol.yr
* Subarctic Pacific: 8 × 10 mol.yr
* Southern Ocean: 17&ndash;37 × 10 mol.yr
* mid-ocean gyres: 26 × 10 mol.yr
BSi production is controlled by:
* Dissolved silica availability, however, half saturation constant Kμ for silicon-limited growth is lower than Ks for silicon uptake.
* Light availability: There is no direct light requirement; silicon uptake at 2x depth of photosynthesis; silicon uptake continues at night but cells must be actively growing.
* Micronutrient availability.