Table 1.
HNLC Region Project | Year | Dominant phytoplankton within bloom | Initial Chl a (μg L−1) | Peak Chl a (μg L−1) | Refs. |
Equatorial Pacific | |||||
IronEx-I | 1933 | Synechococcus red-fluorescing picoplankton autotrophic dinoflagellates | 0.24 | >0.65 | 37, 38 |
IronEx-II | 1995 | Pseudonitzschia spp. (Initially reported as Nitzschia) | 0.15–0.20 | <4.0 | 6, 7, 39 |
Northwest Pacific | |||||
SEEDS-I | 2001 | Chaetoceros debilis | 0.8–0.9 | 21.8 | 40, 41 |
SEEDS-II | 2004 | Pseudonitzschia spp., Neodenticula semina | 0.80 | 2.48 | 42 |
Northeast Pacific | |||||
SERIES | 2002 | Pseudonitzschia spp., Neodenticula semina, Chaetoceros spp. | 0.27–0.43 | 6.30 | 43, 44 |
PAPA-SEEDS | 2006 | Pseudonitzschia turgidula | 0.2–0.3 | – | Present study |
Southern Ocean | |||||
SOIREE (Australian polar waters) | 1999 | Fragillariopsis kerguelensis, Rhizosolenia spp., Pseudonitzschia sp. | 0.25 | 3.0 | 8, 45 |
EisenEx (Atlantic polar waters) | 2000 | Pseudonitzschia lineola | 0.48–0.56 | 2.80 | 9, 15 |
SOFeX – North (Pacific subpolar waters) | 2002 | Pseudonitzschia spp. | 0.26 | 2.60 | 10, 11 |
SOFeX – South (Pacific polar waters) | 2002 | Fragillariopsis spp., Corethron spp., Chaetoceros spp., Rhizosolenia spp. | 0.20 | 4.0 | 10, 11 |
EIFEX (Atlantic subpolar waters) | 2004 | Chaetoceros spp., Fragilariopsis kerguelensis, Pseudonitzschia spp., large single-celled diatoms | 0.54 | 2.85 | 46, 47 |
SAGE (Pacific subpolar Si-depleted coastal waters) | 2004 | – | ~0.6–0.4 | 1.3 > 0.7 | 2, 48 |
The present, deck-board Fe-enrichment experiment was compared with previous open-ocean mesoscale Fe enrichment experiments conducted in HNLC regions of the Equatorial and North Pacific Oceans, and Southern Oceans with respect to initial and peak biomass [as chlorophyll a (Chl a)], and the dominant phytoplankton species or genera that increased in response to alleviation of in situ Fe-deficient conditions.