Production bactérienne et structure du réseau alimentaire microbien dans le fleuve Mackenzie et l'océan Arctique côtier

Authors: Vallières, Catherine
Advisor: Vincent, Warwick F.
Abstract: Globally significant quantities of organic carbon are stored in northern permafrost soils, but little is known about how this carbon is processed by microbial communities once it enters rivers and is transported to the coastal Arctic Ocean. As part of the Arctic River-Delta Experiment (ARDEX), we measured environmental and microbiological variables along a 300 km transect across the Mackenzie River and coastal Beaufort Sea in July-August 2004 to investigate the river and estuarine gradients in microbial community structure and activity, and to evaluate the influence of UV exposure and carbon supply on bacterial processes in these ecosystems. Microbial community structure changed along the transect and the contribution of particle-attached bacteria was significantly higher in riverine and transition zone stations. Experimental results showed that bacterial metabolism was carbon limited in the Mackenzie River. Photodegradation increased organic carbon biolability in the Mackenzie River and decreased it in the Beaufort Sea.
Document Type: Mémoire de maîtrise
Issue Date: 2007
Open Access Date: 13 April 2018
Grantor: Université Laval
Collection:Thèses et mémoires

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