TY - JOUR
T1 - Bacterial response to dust pulses in the western Mediterranean
T2 - Implications for carbon cycling in the oligotropic ocean
AU - Pulido-Villena, Elvira
AU - Wagener, Thibaut
AU - Guieu, Cécile
PY - 2008/3
Y1 - 2008/3
N2 - The bacterial response to dust pulses was investigated in the Mediterranean Sea through a combined field and experimental study. During the stratification period, characterized by a nutrient-starved mixed layer isolated from the depth, a Saharan dust event (2.6 g m-2) induced a 1.5-fold increase in bacterial abundance (BA) and a 2-fold increase in bacterial respiration (BR). Experimental dust additions (equivalent to fluxes of 5 and 20 g m-2) to bacteria natural assemblages also stimulated BA (between 2- and 4-fold increases) and BR (between 1.5- and 3-fold increases). Pooling the in situ and expenmental data, linear relationships were obtained between dust concentration and BA (r2 = 0.86; p < 0.01) and BR (r2 = 0.89; p < 0.001). The dust-induced bacterial bloom resulted in a C mineralization of 0.5 g m-2, which may represent up to 70% of bloavailable DOC annually exported to the depth in the Mediterranean. These results demonstrate that heterotrophic: bacteria may play a much larger role in the connections between dust and the ocean carbon cycle than previously recognized and highlight the need for a more accurate understanding of how dust pulses may affect C export in the oligotrophic ocean.
AB - The bacterial response to dust pulses was investigated in the Mediterranean Sea through a combined field and experimental study. During the stratification period, characterized by a nutrient-starved mixed layer isolated from the depth, a Saharan dust event (2.6 g m-2) induced a 1.5-fold increase in bacterial abundance (BA) and a 2-fold increase in bacterial respiration (BR). Experimental dust additions (equivalent to fluxes of 5 and 20 g m-2) to bacteria natural assemblages also stimulated BA (between 2- and 4-fold increases) and BR (between 1.5- and 3-fold increases). Pooling the in situ and expenmental data, linear relationships were obtained between dust concentration and BA (r2 = 0.86; p < 0.01) and BR (r2 = 0.89; p < 0.001). The dust-induced bacterial bloom resulted in a C mineralization of 0.5 g m-2, which may represent up to 70% of bloavailable DOC annually exported to the depth in the Mediterranean. These results demonstrate that heterotrophic: bacteria may play a much larger role in the connections between dust and the ocean carbon cycle than previously recognized and highlight the need for a more accurate understanding of how dust pulses may affect C export in the oligotrophic ocean.
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U2 - 10.1029/2007GB003091
DO - 10.1029/2007GB003091
M3 - Article
AN - SCOPUS:45449102293
SN - 0886-6236
VL - 22
JO - Global Biogeochemical Cycles
JF - Global Biogeochemical Cycles
IS - 1
M1 - GB1020
ER -