Photomineralization of the organic matter mobilized by permafrost thawing in ponds of East Canadian Arctic

The experimental design includes laboratory experiments under natural light conditions, as well as in-situ field experiments. Two study sites have been selected for the PhD (Whapmagoostui-Kuujjuarapik and Bylot island), representing a gradient in permafrost and climatic conditions. In 2016, only the site in Nunavik has been investigated (all main limnological variables, light penetration, lab experiments). The experiment consists in incubating surface pond water in triplicate teflon bottles under five treatments using a factorial design: with and without light, with and without bacteria (0.2 µm filtration), and one last treatment with a pre-incubation to sunlight before its incubation with bacteria (to remove negative UV effects). This allows studying the effects of each factor applied alone or together, and applied one after another. The following variables were monitored over three weeks: dissolved GHG, dissolved organic carbon, colored organic matter properties (absorbance, fluorescence), bacterial abundance (flow cytometry) and production (tritiated leucine, O2 consumption). In 2017, limnology and light penetration were studied in the second site, in Bylot Island. Two in situ incubation experiments were carried out directly on the field. One aims at investigating the influence of DOM composition on its photodegradability. The other aims at studying the effects of water column attenuation on DOM photodegradation efficiency. Incubation protocols adapted to each goal but similar to the one of 2016 were realized. Besides of analysis mentioned above, high-resolution mass spectrometry will allow to check DOM molecular change during the incubations. The limnological properties of selected lakes at each site will be characterized: vertical profiles of temperature, oxygen and light (8 wavelengths), along with concentrations in total suspended solids, nutrients, major ions and chlorophyll.

Metadata Access
Creator LAURION, Isabelle; MAZOYER, Flora; GUILLEMETTE, François; PACOUREAU, Thomas; PRESKIENIS, Vilmantas; RAUTIO, Milla
Publisher Canadian Cryospheric Information Network
Contributor Polar Data Catalogue
Publication Year 2018
Rights Research programs, CCIN, or ArcticNet take no liability for the use or transmission of this data
OpenAccess true
Contact isabelle.laurion(at); pdc(at)
Language English
Format Computer file
Discipline Environmental Research
Spatial Coverage (-83.000W, 54.000S, -74.000E, 75.000N)
Temporal Coverage Begin 2016-03-19T00:00:00Z
Temporal Coverage End 2019-12-29T00:00:00Z