Influence of ciliated protozoa and heterotrophic nanoflagellates on the fate of primary production in the northeast Atlantic Ocean

Karayanni, Hera; Christaki, Urania; Denis, Michel; Moutin, Thierry

doi:10.1029/2004jc002602

Cited by 41 publications

(37 citation statements)

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“…Virtually all studies of microbial dynamics during the North Atlantic spring bloom have identified microzooplankton as active and important grazers (Burkill et al 1993, Verity et al 1993b, Gifford et al 1995, consuming much of the daily primary production (StelfoxWiddicombe et al 2000, Fileman & Leakey 2005, Karayanni et al 2005. The microzooplankton community is typically dominated by aloricate ciliates (Verity et al 1993b, Stoecker et al 1994, Fileman & Leakey 2005 and, less frequently, by heterotrophic dinoflagellates and tintinnids (Verity et al 1993a, Stelfox-Widdicombe et al 2000.…”

Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Rose¹,

Feng²,

Gobler³

et al. 2009

Mar. Ecol. Prog. Ser.

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The North Atlantic spring bloom is one of the largest annually occurring phytoplankton blooms in the world ocean. The present study investigated the potential effects of climate change variables (temperature and pCO 2 ) on trophic dynamics during the bloom using a shipboard continuous culture system. The treatments examined were (1) 12°C and 390 ppm CO 2 (ambient), (2) 12°C and 690 ppm CO 2 (high pCO 2 ), (3) 16°C and 390 ppm CO 2 (high temperature), and (4) 16 °C and 690 ppm CO 2 (greenhouse). Individually, increasing temperature and pCO 2 initially resulted in significantly higher total microzooplankton abundance and grazing rates over the ambient treatment mid-experiment, with significantly greater increases still in the greenhouse treatment. By the end of the experiment, microzooplankton abundance was highest in the 2 low temperature treatments, which were dominated by small taxa, while the larger ciliate Strombidium sp. numerically dominated the high-temperature treatment. Microzooplankton community composition was dominated by small taxa in the greenhouse treatment, but total abundance declined significantly by the end after peaking mid-experiment. This decrease occurred concurrently with the growth of a potentially unpalatable phytoplankton assemblage dominated by coccolithophores. Our results suggest that indirect effects on microzooplankton community structure from changes in phytoplankton community composition as a result of changing temperature or pCO 2 were likely more important than direct effects on microzooplankton physiology. Similar changes in trophic dynamics and whole plankton community composition may also be important for future climate-driven changes in the North Atlantic spring bloom assemblage.KEY WORDS: Microzooplankton · Herbivory · Temperature · pCO 2 · North Atlantic spring bloom · Climate change Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 388: [27][28][29][30][31][32][33][34][35][36][37][38][39][40] 2009 also be an important food source for mesozooplankton and, as such, can contribute to carbon transfer to higher trophic levels (Sherr et al. 1986, Atkinson 1996, Schnetzer & Caron 2005.The annually occurring and spatially extensive spring bloom of phytoplankton in the North Atlantic Ocean has been extensively studied since the early days of oceanography (e.g. Sverdrup 1953). The US Joint Global Ocean Flux Study (JGOFS;Ducklow & Harris 1993), US Marine Light Mixed Layer research initiative (MLML;Plueddemann et al. 1995), UK Biogeochemical Ocean Flux Study (BOFS;Savidge et al. 1992), UK Plankton Reactivity in the Marine Environment program (PRIME; Savidge & Williams 2001), and French 'Programme Océan Multidisciplinaire Méso Echelle' (POMME; Memery et al. 2005) have all been large-scale efforts to combine physical, chemical, biological, and modeling approaches to understand ecosystem dynamics throughout the stages of the bloom. This phytoplankton bloom is initiated by a reduction in mixed layer depth and is typified by an i...

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Section: Resale or Republication Not Permitted Without Written Consenmentioning

confidence: 99%

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Rose¹,

Feng²,

Gobler³

et al. 2009

Mar. Ecol. Prog. Ser.

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“…The factors 49, 250, 671, 2100 and 3498 fg C cell −1 were used to convert Prochlorococcus, Synechococcus, picoeukaryotes, nanocyanobacteria and nanoeukaryotes, respectively (Cailliau et al, 1996;Kana and Glibert, 1987;Campbell and Yentsch, 1989;Karayanni et al, 2005).…”

Section: Flow Cytometry (Fcm) and Carbon Biomassmentioning

confidence: 99%

Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions

Girault

Arakawa²,

Barani³

et al. 2013

Biogeosciences

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The distribution of ultraphytoplankton was investigated in the western North Pacific Subtropical Gyre (NPSG) during La Niña, a cold phase of El Niño Southern Oscillation (ENSO). Observations were conducted in a north-south transect (33.6–13.25° N) along the 141.5° E meridian in order to study the ultraplankton assemblages in various oligotrophic conditions. Analyses were performed at the single cell level by analytical flow cytometry. Five ultraphytoplankton groups (Prochlorococcus, Synechococcus, picoeukaryotes, nanoeukaryotes and nanocyanobacteria-like) defined by their optical properties were enumerated in three different areas visited during the cruise: the Kuroshio region, the subtropical Pacific gyre and a transition zone between the subtropical Pacific gyre and the Warm pool. Prochlorococcus outnumbered the other photoautotrophs in all the investigated areas. However, in terms of carbon biomass, an increase in the relative contribution of Synechococcus, picoeukaryotes and nanoeukaryotes was observed from the centre of the subtropical gyre to the Kuroshio area. In the Kuroshio region, a peak of abundance of nanoeukaryotes observed at the surface suggested an increase in nutrients likely due to the vicinity of a cold cyclonic eddy. In contrast, in the salinity front along the isohaline 35 and anticyclonic eddy located around 22.83° N, the mainly constant distribution of Prochlorococcus from the surface down to 150 m characterised the dominance by these microorganisms in high salinity and temperature zone. Results suggested that the distribution of nanocyanobacteria-like is also closely linked to the salinity front rather than low phosphate concentration. The maximum abundance of ultraphytoplankton was located above the SubTropical Counter Current (STCC) at depths > 100 m where higher nutrient concentrations were measured. Finally, comparison of the ultraphytoplankton concentrations during El Niño (from the literature) and La Niña (this study) conditions seems to demonstrate that La Niña conditions lead to higher concentrations of Synechococcus in the Subtropical gyre and a lower abundance of Synechococcus in the Kuroshio region. Our results suggest that the west part of NPSG is a complex area, where different water masses, salinity fronts and eddies lead to a heterogeneous distribution of ultraphytoplankton assemblages in the upper layer of the water column

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“…Tintinnid ciliates are characterized by the possession of a tube or vase-shaped shell or lorica into which the ciliate cell can contract. They are generally a minority component of the microzooplankton, representing 5-10% of ciliate numbers (e.g., Dolan and Marassé, 1995) but occasionally dominate the microzooplankton (Karayanni et al, 2005). Tintinnids, as loricate choreotrich ciliates, are considered a monophyletic group in traditional ciliate classification schemes (Lynn and Small, 2000) and based on results of molecular work (e.g., Agatha and Strüder-Kypke, 2007;Agatha et al, 2005;Snoeyenbos-West et al, 2002).…”

Section: Introductionmentioning

confidence: 99%

The "neutral" community structure of planktonic herbivores, tintinnid ciliates of the microzooplankton, across the SE Tropical Pacific Ocean

2007

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Abstract.We assessed the community characteristics of a group of planktonic herbivores across a species-rich area, the SE Pacific Ocean. A series of 22 stations between the Marquise Islands (7 • S 142 • W) and the coast of Chile (35 • S 73 • W) was sampled during the BIOSOPE cruise in 2004. We examined the relationships between taxonomic diversity, morphological diversity, patterns of tintinnid species assemblage, and phytoplankton abundance. Tintinnid community characteristics were estimated from large volume (20-60 l) discrete depth sampling and phytoplankton were characterized based on HPLC pigment signatures. Across the transect, average water column concentrations of tintinnids ranged from 2-40 cells l −1 or 8-40 ng C l −1 , and were positively related to chlorophyll a concentrations which varied between 0.07-2 µg l −1 . Large numbers of tintinnid taxa were found, 18-41 species per station, yielding a total of 149 species. Among stations, morphological and taxonomic diversity metrics co-varied but were not significantly related to phytoplankton diversity estimated using a pigment-based size-diversity metric. Taxonomic diversity of tintinnids, as H' or Fishers' alpha, was inversely related to chlorophyll concentration and positively to the depth of the chlorophyll maximum layer. Species abundance distributions were compared to geometric, log-series and log-normal distributions. For most stations, the observed distribution most closely matched log-series, coherent with the neutral theory of random colonization from a large species pool. Occurrence rates of species were correlated with average abundance rather than specific characteristics of biomass or lorica oral diameter (mouth) size. Among stations, species richness was corCorrespondence to: J. Dolan (dolan@obs-vlfr.fr) related with both the variety of mouth sizes (lorica oral diameters) as well as numbers of species per mouth size, also consistent with random colonization.

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Influence of ciliated protozoa and heterotrophic nanoflagellates on the fate of primary production in the northeast Atlantic Ocean

Cited by 41 publications

References 54 publications

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions

The "neutral" community structure of planktonic herbivores, tintinnid ciliates of the microzooplankton, across the SE Tropical Pacific Ocean

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Influence of ciliated protozoa and heterotrophic nanoflagellates on the fate of primary production in the northeast Atlantic Ocean

Cited by 41 publications

References 54 publications

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Effects of increased pCO2 and temperature on the North Atlantic spring bloom. II. Microzooplankton abundance and grazing

Distribution of ultraphytoplankton in the western part of the North Pacific subtropical gyre during a strong La Niña condition: relationship with the hydrological conditions

The &quot;neutral&quot; community structure of planktonic herbivores, tintinnid ciliates of the microzooplankton, across the SE Tropical Pacific Ocean

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Resources

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The "neutral" community structure of planktonic herbivores, tintinnid ciliates of the microzooplankton, across the SE Tropical Pacific Ocean