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Etude du transfert du mercure et du méthylmercure dans les écosystèmes lacustres alpins

Abstract : Mercury (Hg), a toxic element for all life forms, is present in all environmental compartments. However, its biogeochemical cycle has been poorly studied in high-altitudes areas, particularly in the French Alps. This work presents the results of our study dedicated to the understanding of mercury dynamics in the French Alps lakes. The transfer of mercury species between different reservoirs such as snow (catchments), lake water and fishes was investigated during several field campaign conducted on four different lakes of the Massif de Belledone. Total mercury and methylmercury measurements in surface snow samples collected throughout the season suggest that anthropogenic Hg sources of the Grenoble area influence the chemical composition of the snowpacks. We also show that upon snowmelt, mercury and methylmercury are released to the lake water. However, a large proportion of Hg species seem to be rapidly drained out off the lake by an important renewal of water. Specific characteristics of the catchment areas also explain the low methylmercury content of lakes water. The low Hg content measured in fish could be attributed to a short residence time of mercury species in the lake. Finally, using a decision support tool (WARMF), we show that the physical and chemical properties of the lake and the catchments area could have a greater influence on Hg methylation and Hg levels in fish than the atmospheric Hg deposition.
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https://tel.archives-ouvertes.fr/tel-00553704
Contributor : Nicolas Marusczak <>
Submitted on : Thursday, January 13, 2011 - 5:09:39 PM
Last modification on : Friday, October 23, 2020 - 10:42:05 AM
Long-term archiving on: : Saturday, December 3, 2016 - 1:47:23 AM

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  • HAL Id : tel-00553704, version 1

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Nicolas Marusczak. Etude du transfert du mercure et du méthylmercure dans les écosystèmes lacustres alpins. Autre. Université de Grenoble, 2010. Français. ⟨tel-00553704⟩

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