Surface diatom community composition and species-specific contribution to carbon biomass, live and empty cell abundances over the Kerguelen region in the Southern Ocean (KEOPS 2 program), supplement to: Lasbleiz, Marine; Leblanc, Karine; Armand, Leanne K; Christaki, Urania; Georges, Clément; Obernosterer, Ingrid; Quéguiner, Bernard; King, Gary M (2016): Composition of diatom communities and their contribution to plankton biomass in the naturally iron-fertilized region of Kerguelen in the Southern Ocean. FEMS Microbiology Ecology, 92(11), fiw171

• Main Authors: Lasbleiz, Marine, Leblanc, Karine, Armand, Leanne K, Quéguiner, Bernard
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2016
• Subjects: Event label; Latitude of event; Longitude of event; Elevation of event; DATE/TIME; Bottle number; DEPTH, water; Radiation, photosynthetically active; Diatoms; Diatoms, biomass as carbon; Actinocyclus curvatulus; Asteromphalus hookeri; Asteromphalus hyalinus; Asteromphalus parvulus; Azpeitia tabularis; Chaetoceros spp.; Chaetoceros spp. resting spores; Chaetoceros aequatorialis; Chaetoceros atlanticus; Chaetoceros atlanticus var. neapolitanus; Chaetoceros bulbosus; Chaetoceros convolutus; Chaetoceros concavicornis; Chaetoceros criophilus; Chaetoceros decipiens; Chaetoceros dichaeta; Chaetoceros flexuosus; Chaetoceros mitra; Chaetoceros peruvianus; Chaetoceros radicans; Chaetoceros socialis; Corethron inerme; Corethron pennatum; Coscinodiscus sp.; Dactyliosolen antarcticus; Dactyliosolen tenuijunctus; Eucampia antarctica; Fragilariopsis kerguelensis; Fragilariopsis pseudonana; Fragilariopsis separanda; Guinardia cylindrus; Leptocylindrus danicus; Leptocylindrus mediterraneus; Membraneis sp.; Membraneis challengeri; Membraneis imposter; Navicula spp.; Nitzschia bicapitata; Nitzschia closterium; Nitzschia longissima; Odontella weissflogii; Paralia spp.; Plagiotropis spp.; Pleurosigma sp.; Proboscia alata; Proboscia inermis; Proboscia truncata; Pseudo-nitzschia spp.; Rhizosolenia antennata; Rhizosolenia chunii; Rhizosolenia crassa; Rhizosolenia pungens; Rhizosolenia simplex; Rhizosolenia styliformis; Rhizosolenia styliformis var. longispina; Thalassionema nitzschioides var. nitzschioides; Thalassionema nitzschioides var. parva; Thalassionema nitzschioides var. lanceolata; Thalassiosira spp.; Thalassiosira gracilis; Thalassiosira lentiginosa; Thalassiosira tumida; Thalassiothrix antarctica; Diatoms, centrales; Diatoms, pennales; Actinocyclus curvatulus, biomass as carbon; Asteromphalus hookeri, biomass as carbon; Asteromphalus hyalinus, biomass as carbon; Asteromphalus parvulus, biomass as carbon; Azpeitia tabularis, biomass as carbon; Chaetoceros spp., biomass as carbon; Chaetoceros spp. resting spores, biomass as carbon; Chaetoceros aequatoriale, biomass as carbon; Chaetoceros atlanticus, biomass as carbon; Chaetoceros atlanticus var. neapolitanus, biomass as carbon; Chaetoceros bulbosus, biomass as carbon; Chaetoceros convolutus, biomass as carbon; Chaetoceros concavicornis, biomass as carbon; Chaetoceros criophilus, biomass as carbon; Chaetoceros decipiens, biomass as carbon; Chaetoceros dichaeta, biomass as carbon; Chaetoceros flexuosus, biomass as carbon; Chaetoceros mitra, biomass as carbon; Chaetoceros peruvianus, biomass as carbon; Chaetoceros radicans, biomass as carbon; Chaetoceros socialis, biomass as carbon; Corethron inerme, biomass as carbon; Corethron pennatum, biomass as carbon; Coscinodiscus sp., biomass as carbon; Dactyliosolen antarcticus, biomass as carbon; Dactyliosolen tenuijunctus, biomass as carbon; Eucampia antarctica, biomass as carbon; Fragilariopsis kerguelensis, biomass as carbon; Fragilariopsis pseudonana, biomass as carbon; Fragilariopsis separanda, biomass as carbon; Guinardia cylindrus, biomass as carbon; Leptocylindrus danicus, biomass as carbon; Leptocylindrus mediterraneus, biomass as carbon; Membraneis sp., biomass as carbon; Membraneis challengeri, biomass as carbon; Membraneis imposter, biomass as carbon; Navicula spp., biomass as carbon; Nitzschia bicapitata, biomass as carbon; Nitzschia closterium, biomass as carbon; Nitzschia longissima, biomass as carbon; Odontella weissflogii, biomass as carbon; Paralia spp., biomass as carbon; Plagiotropis spp., biomass as carbon; Pleurosigma sp., biomass as carbon; Proboscia alata, biomass as carbon; Proboscia inermis, biomass as carbon; Proboscia truncata, biomass as carbon; Pseudo-nitzschia spp., biomass as carbon; Rhizosolenia antennata, biomass as carbon; Rhizosolenia chunii, biomass as carbon; Rhizosolenia crassa, biomass as carbon; Rhizosolenia pungens, biomass as carbon; Rhizosolenia simplex, biomass as carbon; Rhizosolenia styliformis, biomass as carbon; Rhizosolenia styliformis var. longispina, biomass as carbon; Thalassionema nitzschioides var. nitzschioides, biomass as carbon; Thalassionema nitzschioides var. parva, biomass as carbon; Thalassionema nitzschioides var. lanceolata, biomass as carbon; Thalassiosira spp., biomass as carbon; Thalassiosira gracilis, biomass as carbon; Thalassiosira lentiginosa, biomass as carbon; Thalassiosira tumida, biomass as carbon; Thalassiothrix antarctica, biomass as carbon; Diatoms, centrales, biomass as carbon; Diatoms, pennales indeterminata, biomass as carbon; Diatoms, pennales indeterminata; Chaetoceros aequatorialis, biomass as carbon; CTD/Rosette; Quantitative phytoplankton method Utermöhl, 1958; Biomass estimation after Cornet-Barthaux et al. 2007; MD188; Marion Dufresne 1995; Southern Ocean; Kerguelen; Mitra; LeBlanc; Cornet; Antarc*; Antarctica; antarcticus
• Online Access: https://dx.doi.org/10.1594/pangaea.860296; https://doi.pangaea.de/10.1594/PANGAEA.860296

In the naturally iron-fertilized surface waters of the northern Kerguelen Plateau region, the early spring diatom community composition and contribution to plankton carbon biomass were investigated and compared with the High Nutrient Low Chlorophyll (HNLC) surrounding waters (October-November 2011, KEOPS 2). The large iron-induced blooms were dominated by small diatom species belonging to the genera Chaetoceros (Hyalochaete) and Thalassiosira, which rapidly responded to the onset of favorable light-conditions in the meander of the Polar Front. In comparison, the iron-limited HNLC area was typically characterized by autotrophic nanoeukaryote-dominated communities and by larger and more heavily silicified diatom species (e.g. Fragilariopsis spp.). Our results support the hypothesis that diatoms are valuable vectors of carbon export to depth in naturally iron-fertilized systems of the Southern Ocean. Comparison with the diatom assemblage composition of a sediment trap deployed in the iron-fertilized area suggests that the dominant Chaetoceros (Hyalochaete) cells were less efficiently exported than the less abundant yet heavily silicified cells of Thalassionema nitzschioides and Fragilariopsis kerguelensis. Our observations emphasize the strong influence of species-specific diatom cell properties combined with trophic interactions on matter export efficiency, and illustrate the tight link between the specific composition of phytoplankton communities and the biogeochemical properties characterizing the study area. : Project: KErguelen Ocean and Plateau compared Study 2 (KEOPS2) (http://www.com.univ-mrs.fr/~queguiner/KEOPS_2.html)Seawater samples were collected from 12 L bottle CTD-rosette equipped with a Seabird SBE 911-plus CTD unit. Samples were taken at four to six depths relative to varying Photosynthetically Active Radiation. Diatom counts (live and empty cells) were made following the Utermöhl method (Hasle 1978). Specific diatom C biomass was assessed following the methodology of Cornet-Barthaux et al. (2007). The species-specific contribution to live cell abundance and to C biomass are then calculated from these results.