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Lignin biomarkers as tracers of mercury sources in lakes water column

Ouellet, Jean-François and Lucotte, Marc and Teisserenc, Roman and Paquet, Serge and Canuel, René Lignin biomarkers as tracers of mercury sources in lakes water column. (2009) Biogeochemistry, vol. 94 (n°5). pp. 123-140. ISSN 0168-2563

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Official URL: http://dx.doi.org/10.1007/s10533-009-9314-z

Abstract

This study presents the role of specific terrigenous organic compounds as important vectors of mercury (Hg) transported from watersheds to lakes of the Canadian boreal forest. In order to differentiate the autochthonous from the allochthonous organic matter (OM), lignin derived biomarker signatures [Lambda, S/V, C/V, P/(V ? S), 3,5-Bd/V and (Ad/Al)v] were used. Since lignin is exclusively produced by terrigenous plants, this approach can give a non equivocal picture of the watershed inputs to the lakes. Moreover, it allows a characterization of the source of OM and its state of degradation. The water column of six lakes from the Canadian Shield was sampled monthly between June and September 2005. Lake total dissolved Hg concentrations and Lambda were positively correlated, meaning that Hg and ligneous inputs are linked (dissolved OM r2 = 0.62, p\0.0001; particulate OM r2 = 0.76, p\0.0001). Ratios of P/(V ? S) and 3,5-Bd/V from both dissolved OM and particulate OM of the water column suggest an inverse relationship between the progressive state of pedogenesis and maturation of the OM in soil before entering the lake, and the Hg concentrations in the water column. No relation was found between Hg levels in the lakes and the watershed flora composition—angiosperm versus gymnosperm or woody versus non-woody compounds. This study has significant implications for watershed management of ecosystems since limiting fresh terrestrial OM inputs should reduce Hg inputs to the aquatic systems. This is particularly the case for largescale land-use impacts, such as deforestation, agriculture and urbanization, associated to large quantities of soil OM being transferred to aquatic systems.

Item Type:Article
Additional Information:Thanks to Springer editor. The definitive version is available at http://www.springerlink.com/content/6g261h1508373732/
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Other partners > Concordia University (CANADA)
Other partners > Institut National de la Recherche Scientifique - INRS (CANADA)
Other partners > Université de Montréal - UdeM (CANADA)
Other partners > Université du Québec à Montréal - UQAM (CANADA)
Other partners > Collaborative Mercury Research Network - COMERN (CANADA)
Other partners > Université McGill (CANADA)
Other partners > Université de Laval (CANADA)
Other partners > Université du Québec à Chicoutimi - UQAC (CANADA)
Other partners > Université du Québec à Rimouski - UQAR (CANADA)
Laboratory name:
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Deposited By: Nadia Kelmouss
Deposited On:23 Oct 2012 09:50

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