Table 2.
Contribution of small phytoplankton to CO2-fixation on and off iron-fertilized areas of the Southern Ocean.
| Study area (experiment name) | Type of Fe-fertilization | Small phytoplankton size (µm) | HNLC (%) | Fe-fertilized (%) | Month | Method | Source |
|---|---|---|---|---|---|---|---|
| Crozet (CROZEX) | Natural Fe | <20 | 66 | 53 | November - January | Size-fractionation | [83] |
| Kerguelen (KEOPS1) | Natural Fe | <10 | 68 | 10–20 | February | Size-fractionation | [12] |
| Amundsen Sea | Natural Fe | <5 | 51 | 15 | January | Size-fractionation | [84] |
| South Georgia | Natural Fe | <12 | >60 | <20 | January | Size-fractionation | [85] |
| South of Australia (SOIREE) | Artificial | <20 | >60 | Decrease to <40 during the experiment | February | Size-fractionation | [86] |
| Atlantic sector of the so (EISENEX) | Artificial | <20 | 70–90 | Decrease to <50 during the experiment | November | Size-fractionation | [87] |
| Kerguelen (MOBYDICK) | Natural Fe | <20 | 43–70 | 41–61 | March | NanoSIMS | This study |
During artificial fertilization studies, the initial contribution of small phytoplankton corresponds to the HNLC value. This contribution decreased throughout the fertilization experiments as the contribution of larger phytoplankton increased.