Data/hora: 09/06/2024 05:26:35

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France
Título: | Evolution of dissolved and particulate chromophoric materials during the VAHINE mesocosm experiment in the New Caledonian coral lagoon (south-west Pacific)
Autores: | Tedetti, Marc; Marie, Lauriane; Roettgers, Ruediger; Rodier, Martine; Van Wambeke, France; Helias, Sandra; Caffin, Mathieu; Cornet-barthaux, Veronique; Dupouy, Cecile.
Data: | 2016
Ano: | 2016
Resumo: | 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 degrees 29.073 S-166 degrees 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 12m and in the surrounding waters. Light absorption coefficients of chromophoric dissolved organic matter (CDOM) [a(g) (lambda)] and particulate matter [a(p) (lambda)] 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) (lambda) and a(p) (lambda) 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.
Tipo: | Text
Idioma: | Inglês

Identificador:

https://archimer.ifremer.fr/doc/00348/45893/45572.pdf

DOI:10.5194/bg-13-3283-2016

https://archimer.ifremer.fr/doc/00348/45893/

Editor: | Copernicus Gesellschaft Mbh
Formato: | application/pdf
Fonte: | Biogeosciences (1726-4170) (Copernicus Gesellschaft Mbh), 2016 , Vol. 13 , N. 11 , P. 3283-3303

Fonte:

Author(s) 2016. This work is distributed under the Creative Commons Attribution 3.0 License.

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