Effects of soot deposition on particle dynamics and microbial processes in marine surface waters

Type : ACL
Nature : Production scientifique
Au bénéfice du Laboratoire : Oui
Statut de publication : Publié
Année de publication : 2014
Auteurs (13) : MARI Xavier LEFÈVRE J TORRÉTON J-p BETTAREL Y PRINGAULT O ROCHELLE-NEWALL Emma,j MARCHESIELLO P MENKES C RODIER Martine MIGON Christophe MOTEGI Chiaki WEINBAUER Markus,g LEGENDRE Louis
Revue scientifique : Global Biogeochemical Cycles
Volume : 28
Fascicule : 7
Pages : 662-678
DOI : 10.1002/2014gb004878
URL : http://onlinelibrary.wiley.com/doi/10.1002/2014gb004878/abstract
Abstract : Large amounts of soot are continuously deposited on the global ocean. Even though significant concentrations of soot particles are found in marine waters, the effects of these aerosols on ocean ecosystems are currently unknown. Using a combination of in situ and experimental data, and results from an atmospheric transport model, we show that the deposition of soot particles from an oil-fired power plant impacted biogeochemical properties and the functioning of the pelagic ecosystem in tropical oligotrophic oceanic waters off New Caledonia. Deposition was followed by a major increase in the volume concentration of suspended particles, a change in the particle size spectra that resulted from a stimulation of aggregation processes, a 5% decrease in the concentration of dissolved organic carbon (DOC), a decreases of 33 and 23% in viral and free bacterial abundances, respectively, and a factor similar to 2 increase in the activity of particle-attached bacteria suggesting that soot introduced in the system favored bacterial growth. These patterns were confirmed by experiments with natural seawater conducted with both soot aerosols collected in the study area and standard diesel soot. The data suggest a strong impact of soot deposition on ocean surface particles, DOC, and microbial processes, at least near emission hot spots.
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Commentaire : Times Cited: 0 Pringault, Olivier/A-7399-2008 0
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Citation :
Mari X, Lefèvre J, Torréton J-P, Bettarel Y, Pringault O, Rochelle-Newall EJ, Marchesiello P, Menkes C, Rodier M, Migon C, Motegi C, Weinbauer MG, Legendre L (2014) Effects of soot deposition on particle dynamics and microbial processes in marine surface waters. Global Biogeochem Cy 28: 662-678 | doi: 10.1002/2014gb004878