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| Cavagna, A. J.; Fripiat, F.; Elskens, M.; Mangion, P.; Chirurgien, L.; Closset, I.; Lasbleiz, M.; Florez-leiva, L.; Cardinal, D.; Leblanc, K.; Fernandez, C.; Lefevre, D.; Oriol, L.; Blain, S.; Queguiner, B.; Dehairs, F.. |
| Although the Southern Ocean is considered a high-nutrient, low-chlorophyll (HNLC) area, massive and recurrent blooms are observed over and downstream of the Kerguelen Plateau. This mosaic of blooms is triggered by a higher iron supply resulting from the interaction between the Antarctic Circumpolar Current and the local bathymetry. Net primary production, N uptake (NO3− and NH4+), and nitrification rates were measured at eight stations in austral spring 2011 (October–November) during the KEOPS 2 cruise in the Kerguelen Plateau area. Natural iron fertilization stimulated primary production, with mixed layer integrated net primary production and growth rates much higher in the fertilized areas (up to 315 mmol C m−2 d−1 and up to 0.31 d−1 respectively)... |
| Tipo: Text |
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| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00294/40561/39448.pdf |
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| Lasbleiz, M.; Leblanc, K.; Blain, S.; Ras, J.; Cornet-barthaux, V.; Nunige, S. Helias; Queguiner, B.. |
| The particulate matter distribution and phytoplankton community structure of the iron-fertilized Kerguelen region were investigated in early austral spring (October-November 2011) during the KEOPS2 cruise. The iron-fertilized region was characterized by a complex mesoscale circulation resulting in a patchy distribution of particulate matter. Integrated concentrations over 200 m ranged from 72.2 to 317.7 mg m(-2) for chlorophyll a 314 to 744 mmol m(-2) for biogenic silica (BSi), 1106 to 2268 mmol m(-2) for particulate organic carbon, 215 to 436 mmol m(-2) for particulate organic nitrogen, and 29.3 to 39.0 mmol m(-2) for particulate organic phosphorus. Three distinct high biomass areas were identified: the coastal waters of Kerguelen Islands, the easternmost... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40222/39345.pdf |
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| Closset, I.; Lasbleiz, M.; Leblanc, K.; Queguiner, B.; Cavagna, A. -j.; Elskens, M.; Navez, J.; Cardinal, D.. |
| A massive diatom bloom is observed each year in the surface waters of the naturally Fe-fertilized Kerguelen Plateau (Southern Ocean). We measured biogenic silica production and dissolution fluxes (rho Si and rho Diss, respectively) in the mixed layer in the vicinity of the Kerguelen Plateau during austral spring 2011 (KEOPS-2 cruise). We compare results from a high-nutrient low-chlorophyll reference station and stations with different degrees of iron enrichment and bloom conditions. Above the plateau biogenic rho Si are among the highest reported so far in the Southern Ocean (up to 47.9 mmol m(-2) d(-1)). Although significant (10.2 mmol m(-2) d(-1) on average), rho Diss were generally much lower than production rates. Uptake ratios (rho Si : rho C and rho... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00291/40220/39341.pdf |
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| Cavagna, A. J.; Fripiat, F.; Elskens, M.; Dehairs, F.; Mangion, P.; Chirurgien, L.; Closset, I.; Lasbleiz, M.; Flores–leiva, L.; Cardinal, D.; Leblanc, K.; Fernandez, C.; Lefèvre, D.; Oriol, L.; Blain, S.; Quéguiner, B.. |
| Although the Southern Ocean is considered a High Nutrient Low Chlorophyll area (HNLC), massive and recurrent blooms are observed over and downstream the Kerguelen Plateau. This mosaic of blooms is triggered by a higher iron supply resulting from the interaction between the Antarctic Circumpolar Current and the local bathymetry. Net primary production, N-uptake (NO3− and NH4+), and nitrification rates were measured at 8 stations in austral spring 2011 (October–November) during the KEOPS2 cruise in the Kerguelen area. Iron fertilization stimulates primary production, with integrated net primary production and growth rates much higher in the fertilized areas (up to 315 mmol C m−2 d−1 and up to 0.31 d−1, respectively) compared to the HNLC reference site (12... |
| Tipo: Text |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00294/40558/39445.pdf |
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