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Organic carbon, mercury and climate change: towards a better understanding of biotic contamination in the Canadian Arctic

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dc.contributor.supervisor Wang, Feiyue (Environment & Geography) Stern, Gary (Environment & Geography) en
dc.contributor.author Carrie, Jesse D.
dc.date.accessioned 2010-04-08T20:04:18Z
dc.date.available 2010-04-08T20:04:18Z
dc.date.issued 2010-04-08T20:04:18Z
dc.identifier.citation Carrie, J., Sanei, H., Goodarzi, F., Stern, G., Wang, F. (2009) Characterization of organic matter in surface sediments of the Mackenzie River Basin, Canada, International Journal of Coal Geology 77:416-423. en
dc.identifier.citation Carrie, J., Stern, G., Sanei, H., Macdonald, R., Outridge, P., Wang, F. (2010) Increasing contaminant burdens in an Arctic fish, burbot (lota lota), in a warming climate, Environmental Science & Technology 44: 316-322. en
dc.identifier.uri http://hdl.handle.net/1993/3923
dc.description.abstract Mercury (Hg) is a known neurotoxin that is often found in concentrations exceeding safe consumption guidelines in aquatic biota. This is evident in northern Canada, where northerners consume significant amounts of animals such as beluga, seals and burbot. In the Mackenzie River Basin, recent increases in Hg concentration in many of these animals over the past 25 years have been observed. The warming climate, and with it, the changing carbon cycle, are hypothesised in this thesis to play a role in the increases. Within the context of the two major zones (mountainous and peatland), with distinct geomorphology, hydrology and geology, traditional fossil fuel exploration methods (Rock-Eval pyrolysis, organic petrography) have been employed in a novel manner on recent sediments to qualify and quantify the OM and several geochemical analyses have been used to determine the geochemical sources of Hg. The mountainous zone is composed mostly of refractory OM, from forest fire char and heavily reworked OM. It also contains, and fluxes, most of the Hg, which derives from oxidative weathering and erosion of widespread sulfide minerals. However, Hg from this zone is in chemical forms of limited bioavailability. The peatland zone has a greater proportion of labile OM, with higher concentrations of DOC and algal-derived OM. Lake-fed tributaries in this zone contain even higher proportions of labile OM. At one of these sites, the sediment core record shows that Hg has been increasingly associated with labile OM over time, due to increasing primary productivity accelerated by climate change, and is resulting in an increase in scavenged Hg. The temporal trend in algal-bound Hg in the sediment record matches very well with the temporal trend of Hg in burbot sampled from the area, providing one of the first and strongest lines of evidence for the climatic impact on Hg bioaccumulation in Arctic ecosystems. en
dc.format.extent 50548251 bytes
dc.format.mimetype application/pdf
dc.language.iso en_US
dc.subject mercury en
dc.subject Mackenzie River en
dc.subject Arctic en
dc.subject organic matter en
dc.subject burbot en
dc.subject climate change en
dc.title Organic carbon, mercury and climate change: towards a better understanding of biotic contamination in the Canadian Arctic en
dc.degree.discipline Environment and Geography en
dc.contributor.examiningcommittee Papakyriakou, Tim (Environment & Geography) Macdonald, Robie (Environment & Geography) Halden, Norman (Geological Science) Gobeil, Charles (Institut National de Recherche Scientifique) en
dc.degree.level Doctor of Philosophy (Ph.D.) en
dc.description.note May 2010 en


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