Dépôt numérique
RECHERCHER

Spatial Variation in the Optical Properties of Dissolved Organic Matter (DOM) in Lakes on the Canadian Precambrian Shield and Links to Watershed Characteristics.

Mueller, Kristin K.; Fortin, Claude; Campbell, Peter G. C. (2012). Spatial Variation in the Optical Properties of Dissolved Organic Matter (DOM) in Lakes on the Canadian Precambrian Shield and Links to Watershed Characteristics. Aquatic Geochemistry , vol. 18 , nº 1. p. 21-44. DOI: 10.1007/s10498-011-9147-y.

Ce document n'est pas hébergé sur EspaceINRS.

Résumé

In the present study, we explored the use of various optical parameters to detect differences in the composition of the dissolved organic matter (DOM) in a set of lakes that are all located on the Canadian Precambrian Shield, but within which Cu and Ni speciation predictions were previously shown to diverge from measured values in some lakes but not in others. Water samples were collected with in situ diffusion samplers in 2007 (N = 18 lakes) and 2008 (N = 8 lakes). Significant differences in DOM quality were identified between the sampling regions (Rouyn-Noranda, Québec and Sudbury, Ontario) and among lakes, based on dissolved organic carbon concentrations ([DOC]), specific UV absorbance (SUVA₂₅₄), fluorescence indices (FI), and excitation–emission matrix (EEM) fluorescence measurements. Parallel factor analysis (PARAFAC) of the EEM spectra revealed four components, two of which (C₃, oxidized quinone fluorophore of allochthonous origin, and C₄, tryptophan-like protein fluorescence of autochthonous origin) showed the greatest inter-regional variation. The inter-lake differences in DOM quality were consistent with the regional watershed characteristics as determined from satellite imagery (e.g., watershed-to-lake surface area ratios and relative percentages of surface water, rock outcrops vegetative cover and urban development). Source apportionment plots, built upon PARAFAC components ratios calculated for our lakes, were used to discriminate among DOM sources and to compare them to sources identified in the literature. These results have implications for other areas of research, such as quantifying lake-to-lake variations in the influence of organic matter on the speciation of trace elements in natural aquatic environments.

Type de document: Article
Mots-clés libres: dissolved organic matter (DOM); Lakes; Canadian Precambrian Shield; allochthonous; autochthonous; PARAFAC fluorescence; absorbance
Centre: Centre Eau Terre Environnement
Date de dépôt: 19 oct. 2018 14:14
Dernière modification: 19 oct. 2018 14:14
URI: http://espace.inrs.ca/id/eprint/7244

Actions (Identification requise)

Modifier la notice Modifier la notice