Photosynthetic characteristics of Trichodesmium in the southwest Pacific Ocean: importance and significance

Masotti, Ítalo; Ruiz‐Pino, Diana; Bouteiller, Aubert Le

doi:10.3354/meps338047

Cited by 25 publications

(15 citation statements)

References 44 publications

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“…Low filament densities characterized the end of the bloom season in April 1998 when Trichodesmium contribution to biomass was reduced (Dupouy et al, 2000;Campbell et al, 2006) (Dupouy et al, 2004b(Dupouy et al, , 2008, the light beam attenuation was high (0.1 m −1 ), and a maximal Trichodesmium contribution to Chl-a of 50-70 % coincident with a high density of 5000 filaments.L −1 was observed with maximal biomass of 1.9 and 14 mg m −3 for Chl-a and phycoerythrin, respectively. Densities were similar to those measured during February 2003 in Diapalis 07 (Tenório, 2006;Neveux et al, 2006;Masotti et al, 2007). The determination of biomass in surface slicks is challenging and requires a specific thin-layer surface sampler.…”

Section: Field Observationsmentioning

confidence: 72%

An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific

et al. 2011

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Abstract. Trichodesmium, a major colonial cyanobacterial nitrogen fixer, forms large blooms in NO 3 -depleted tropical oceans and enhances CO 2 sequestration by the ocean due to its ability to fix dissolved dinitrogen. Thus, its importance in C and N cycles requires better estimates of its distribution at basin to global scales. However, existing algorithms to detect them from satellite have not yet been successful in the South Western Tropical Pacific (SP). Here, a novel algorithm (TRICHOdesmium SATellite) based on radiance anomaly spectra (RAS) observed in SeaWiFS imagery, is used to detect Trichodesmium during the austral summertime in the SP (5 • S-25 • S 160 • E-170 • W). Selected pixels are characterized by a restricted range of parameters quantifying RAS spectra (e.g. slope, intercept, curvature). The fraction of valid (noncloudy) pixels identified as Trichodesmium surface blooms in the region is low (between 0.01 and 0.2 %

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Section: Field Observationsmentioning

confidence: 72%

An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific

et al. 2011

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“…(Dupouy et al, 1988(Dupouy et al, , 2008Masotti et al, 2007;Rodier and Le Borgne, 2010) and diazotrophic picocyanobacteria (Biegala and Raimbault, 2008) but also non-diazotrophic picocyanobacteria such as Synechococcus spp. and Prochlorococcus spp.…”

Section: Introductionmentioning

confidence: 99%

Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (south-west Pacific)

et al. 2016

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Abstract. In the framework of the VAHINE project, we investigated the spectral characteristics and the variability of dissolved and particulate chromophoric materials throughout a 23-day mesocosm experiment conducted in the south-west Pacific at the mouth of the New Caledonian coral lagoon (22 • 29.073 S-166 • 26.905 E) from 13 January to 4 February 2013. Samples were collected in a mesocosm fertilized with phosphate at depths of 1, 6 and 12 m and in the surrounding waters. Light absorption coefficients of chromophoric dissolved organic matter (CDOM) [a g (λ)] and particulate matter [a p (λ)] were determined using a point-source integrating-cavity absorption meter (PSICAM), while fluorescent DOM (FDOM) components were determined from excitation-emission matrices (EEMs) combined with parallel factor analysis (PARAFAC). The evolutions of a g (λ) and a p (λ) in the mesocosm were similar to those of total chlorophyll a concentration, Synechococcus spp. and picoeukaryote abundances, bacterial production, particulate organic nitrogen and total organic carbon concentrations, with roughly a decrease from the beginning of the experiment to days 9-10, and an increase from days 9-10 to the end of the experiment. In the surrounding waters, the same trend was observed but the increase was much less pronounced, emphasizing the effect of the phosphate fertilization on the mesocosm's plankton community. Correlations suggested that both Synechococcus cyanobacteria and heterotrophic bacteria were strongly involved in the production of CDOM and absorption of particulate matter. The increase in phytoplankton biomass during the second part of the experiment led to a higher contribution of particulate material in the absorption budget at 442 nm. The three FDOM components identified (tryptophan-, tyrosine-and ultraviolet C (UVC) humic-like fluorophores) did not follow the evolution of CDOM and particulate matter, suggesting they were driven by different production/degradation processes. Finally, the results of this work support the idea there is indirect coupling between the dynamics of N 2 fixation and that of chromophoric material via the stimulation of Synechococcus bloom.

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“…These oligotrophy and temperature relationships to diazotroph abundance are probably tightly intertwined with other significant regulating factors [ Karl et al , 2002; Langlois et al , 2005; LaRoche and Breitbarth , 2005; Langlois et al , 2008], including light harvesting, availability of phosphorus and iron, and top‐down controls. Culture experiments show Trichodesmium and unicellular diazotrophs to be adapted to high light environments [ Carpenter and Roenneberg , 1995; LaRoche and Breitbarth , 2005; Masotti et al , 2007; Goebel et al , 2008]. In addition, phosphorus has been noted to limit diazotrophs in the North Atlantic Ocean [ Wu et al , 2000; Sanudo‐Wilhelmy et al , 2001; Mills et al , 2004].…”

Section: Introductionmentioning

confidence: 99%

Biogeographical controls on the marine nitrogen fixers

Monteiro

Dutkiewicz

Follows

2011

Global Biogeochem. Cycles

112

128

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[1] We interpret the environmental controls on the global ocean diazotroph biogeography in the context of a three-dimensional global model with a self-organizing phytoplankton community. As is observed, the model's total diazotroph population is distributed over most of the oligotrophic warm subtropical and tropical waters, with the exception of the southeastern Pacific Ocean. This biogeography broadly follows temperature and light constraints which are often used in both field-based and model studies to explain the distribution of diazotrophs. However, the model suggests that diazotroph habitat is not directly controlled by temperature and light, but is restricted to the ocean regions with low fixed nitrogen and sufficient dissolved iron and phosphate concentrations. We interpret this regulation by iron and phosphate using resource competition theory which provides an excellent qualitative and quantitative framework.

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Photosynthetic characteristics of Trichodesmium in the southwest Pacific Ocean: importance and significance

Cited by 25 publications

References 44 publications

An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific

An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific

Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (south-west Pacific)

Biogeographical controls on the marine nitrogen fixers

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Photosynthetic characteristics of Trichodesmium in the southwest Pacific Ocean: importance and significance

Cited by 25 publications

References 44 publications

An algorithm for detecting &lt;i&gt;Trichodesmium&lt;/i&gt; surface blooms in the South Western Tropical Pacific

An algorithm for detecting &lt;i&gt;Trichodesmium&lt;/i&gt; surface blooms in the South Western Tropical Pacific

Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (south-west Pacific)

Biogeographical controls on the marine nitrogen fixers

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An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific

An algorithm for detecting <i>Trichodesmium</i> surface blooms in the South Western Tropical Pacific