A phytoplankton class-specific primary production model applied to the Kerguelen Islands region (Southern Ocean)

Uitz, Julia; Claustre, Hervé; Griffiths, F. Brian; Ras, Joséphine; Garcia, Nicole; Sandroni, Valérie

doi:10.1016/j.dsr.2008.11.006

Cited by 108 publications

(91 citation statements)

References 77 publications

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“…Pigments were identified and quantified using the EMPOWER software provided by Waters. Three pigment-based phytoplankton size classes (micro-, nano-, and picophytoplankton) were estimated following the method of Uitz et al (2009), which has been tested for the Southern Ocean waters. Microphytoplankton corresponded to phytoplankton with size 420 μm, nanophytoplankton between 2 and 20 μm, and picophytoplankton between 0.2 and 2 μm.…”

Section: Pigments In Sediment Trapsmentioning

confidence: 99%

High particulate organic carbon export during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean

Roca‐Martí

Puigcorbé

Iversen

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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a b s t r a c tCarbon fixation by phytoplankton plays a key role in the uptake of atmospheric CO 2 in the Southern Ocean. Yet, it still remains unclear how efficiently the particulate organic carbon (POC) is exported and transferred from ocean surface waters to depth during phytoplankton blooms. In addition, little is known about the processes that control the flux attenuation within the upper twilight zone. Here, we present results of downward POC and particulate organic nitrogen fluxes during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean in summer 2012. We used thorium-234 ( 234 Th) as a particle tracer in combination with drifting sediment traps (ST). Their simultaneous use evidenced a sustained high export rate of 234 Th at 100 m depth in the weeks prior to and during the sampling period. The entire study area, of approximately 8000 km 2 , showed similar vertical export fluxes in spite of the heterogeneity in phytoplankton standing stocks and productivity, indicating a decoupling between production and export. The POC fluxes at 100 m were high, averaging 26 715 mmol C m À 2 d À 1 , although the strength of the biological pump was generally low. Only o 20% of the daily primary production reached 100 m, presumably due to an active recycling of carbon and nutrients. Pigment analyses indicated that direct sinking of diatoms likely caused the high POC transfer efficiencies ( $ 60%) observed between 100 and 300 m, although faecal pellets and transport of POC linked to zooplankton vertical migration might have also contributed to downward fluxes.

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Section: Pigments In Sediment Trapsmentioning

confidence: 99%

High particulate organic carbon export during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean

Roca‐Martí

Puigcorbé

Iversen

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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“…0 -butanoyloxyfucoxanthin (But-fuco), alloxanthin (Allo), zeaxanthin (Zea), and monovinyl chlorophyll-b (MVChl-b, divinyl chlorophyll-b was not detected in the samples) were the seven pigments chosen as diagnostic pigments (DP) representing specific phytoplankton taxa and grouped into one of the three size classes in the following equations (Uitz et al, 2009)…”

Section: Nutrientsmentioning

confidence: 99%

“…In addition, the contribution (%) of three pigment-based phytoplankton size classes (micro-, nano-, and picophytoplankton) to total phytoplankton biomass was estimated following the method of Uitz et al (2009). Microphytoplankton (micro) correspond to phytoplankton with size 4 20 μm, nanophytoplankton (nano) between 2 and 20 μm, and picophytoplankton (pico) between 0.2 and 2 μm.…”

Section: Nutrientsmentioning

confidence: 99%

Importance of deep mixing and silicic acid in regulating phytoplankton biomass and community in the iron-limited Antarctic Polar Front region in summer

Cheah

Soppa

Wiegmann

et al. 2017

Deep Sea Research Part II: Topical Studies in Oceanography

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a b s t r a c tPhytoplankton community structure and their physiological response in the vicinity of the Antarctic Polar Front (APF; 44°S to 53°S, centred at 10°E) were investigated as part of the ANT-XXVIII/3 Eddy-Pump cruise conducted in austral summer 2012. Our results show that under iron-limited ð o 0:3 μmol m À 3 Þ conditions, high total chlorophyll-a (TChl-a) concentrations ð 40:6 mg m À 3 Þ can be observed at stations with deep mixed layer ð 4 60 mÞ across the APF. In contrast, light was excessive at stations with shallower mixed layer and phytoplankton were producing higher amounts of photoprotective pigments, diadinoxanthin (DD) and diatoxanthin (DT), at the expense of TChl-a, resulting in higher ratios of (DD þDT)/ TChl-a. North of the APF, significantly lower silicic acid (Si(OH) 4 ) concentrations ð o 2 mmol m À 3 Þ lead to the domination of nanophytoplankton consisting mostly of haptophytes, which produced higher ratios of (DD þDT)/TChl-a under relatively low irradiance conditions. The Si(OH) 4 replete ð 4 5 mmol m À 3 Þ region south of the APF, on the contrary, was dominated by microphytoplankton (diatoms and dinoflagellates) with lower ratios of (DD þDT)/TChl-a, despite having been exposed to higher levels of irradiance. The significant correlation between nanophytoplankton and (DD þDT)/TChl-a indicates that differences in taxon-specific response to light are also influencing TChl-a concentration in the APF during summer. Our results reveal that provided mixing is deep and Si(OH) 4 is replete, TChl-a concentrations higher than 0:6 mg m À 3 are achievable in the iron-limited APF waters during summer.

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“…Remotely sensed [48,49] as well as in situ optical observations [50] offer an appealing framework for this task. The prominent role of stirring of large-scale niches on planktonic diversity further supports the possibility of estimating hotspots of diversity from optical niche heterogeneity, as proposed by [5].…”

mentioning

confidence: 99%

The dynamical landscape of marine phytoplankton diversity

Lévy

Jahn

Dutkiewicz

et al. 2015

J. R. Soc. Interface.

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Observations suggest that the landscape of marine phytoplankton assemblage might be strongly heterogeneous at the dynamical mesoscale and submesoscale (10-100 km, days to months), with potential consequences in terms of global diversity and carbon export. But these variations are not well documented as synoptic taxonomic data are difficult to acquire. Here, we examine how phytoplankton assemblage and diversity vary between mesoscale eddies and submesoscale fronts. We use a multi-phytoplankton numerical model embedded in a mesoscale flow representative of the North Atlantic. Our model results suggest that the mesoscale flow dynamically distorts the niches predefined by environmental contrasts at the basin scale and that the phytoplankton diversity landscape varies over temporal and spatial scales that are one order of magnitude smaller than those of the basin-scale environmental conditions. We find that any assemblage and any level of diversity can occur in eddies and fronts. However, on a statistical level, the results suggest a tendency for larger diversity and more fast-growing types at fronts, where nutrient supplies are larger and where populations of adjacent water masses are constantly brought into contact; and lower diversity in the core of eddies, where water masses are kept isolated long enough to enable competitive exclusion.

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A phytoplankton class-specific primary production model applied to the Kerguelen Islands region (Southern Ocean)

Cited by 108 publications

References 77 publications

High particulate organic carbon export during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean

High particulate organic carbon export during the decline of a vast diatom bloom in the Atlantic sector of the Southern Ocean

Importance of deep mixing and silicic acid in regulating phytoplankton biomass and community in the iron-limited Antarctic Polar Front region in summer

The dynamical landscape of marine phytoplankton diversity

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