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Effects of soot deposition on particle dynamics and microbial processes in marine surface waters
Author(s) -
Mari Xavier,
Lefèvre Jérôme,
Torréton JeanPascal,
Bettarel Yvan,
Pringault Olivier,
RochelleNewall Emma,
Marchesiello Patrick,
Menkes Christophe,
Rodier Martine,
Migon Christophe,
Motegi Chiaki,
Weinbauer Markus G.,
Legendre Louis
Publication year - 2014
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1002/2014gb004878
Subject(s) - soot , biogeochemical cycle , deposition (geology) , environmental chemistry , particulates , seawater , aerosol , environmental science , ecosystem , pelagic zone , particle (ecology) , dissolved organic carbon , oceanography , chemistry , ecology , geology , biology , combustion , paleontology , organic chemistry , sediment
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 ~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.