Mathilde Couturier

Observatoire Global du Saint Laurent - OGSL

The transformations of chemical constituents in subterranean estuaries (STEs) control the delivery of nutrient loads from coastal aquifers to the ocean. It is important to determine the processes and sources that alter nutrient concentrations at a local scale in order to estimate accurate regional and global nutrient fluxes via submarine groundwate...

This paper reports on the distribution of DOM along the subterranean estuary (STE) of a microtidal beach located in the Gulf of St-Lawrence (Îles-de-la-Madeleine, Quebec, Canada). We combined porewater DOC concentrations as well as CDOM absorbance- and fluorescence-derived indices (SR, SUVA254, FI and BIX) to explore the groundwater-borne DOM trans...

Submarine groundwater discharge (SGD) is now recognized as an important coastal process affecting local and regional sources of solutes to coastal oceans. The objective of this study was to compare SGD estimates through Martinique Beach (Îles-de-la-Madeleine, QC, Canada) using different sampling techniques in order to quantify SGD fluxes of dissolv...

The paper presents evidence of the complexity of describing carbon transport from submarine groundwater discharge and chemical reactions in the subterranean estuary. Vertical and horizontal profiles of total alkalinity (TA) and dissolved inorganic carbon (DIC) concentrations were analyzed in a cross-shore transect of a sandy beach and an evaluation...

it is now well known that submarine groundwater discharge (SGD) transport nutrients, carbon and trace elements which may contribute to eutrophication in coastal waters. Nevertheless transports and transformations pathways from coastal aquifers to the ocean are still poorly constrained, particularly in permeable sandy beaches which are recognized as...

In this Perspective, we put forward an integrative framework to improve estimates of land-atmosphere carbon exchange based on the accumulation of carbon in the landscape as constrained by its lateral export through rivers. The framework uses the watershed as the fundamental spatial unit and integrates all terrestrial and aquatic ecosystems as well...

Over the last 40 years, dissolved organic carbon (DOC) has been increasing in freshwater across many boreal regions. The extent to which these long‐term changes have affected lake CO2 dynamics is unclear. We have studied the temporal trends in DOC and pressure of CO2 (pCO2) over 40 years in 15 lakes in two regions of Ontario (Canada) subjected to b...

Understanding the behavior of terrestrially derived dissolved organic carbon (DOC) through subterranean estuaries (STEs) is essential for determining the carbon budget in coastal waters. However, few studies exist on the interaction of organic carbon (OC) and iron (Fe) in these dynamic systems, where fresh groundwater mixes with recirculated seawat...

The study is based on a complex and unique data set of water stable isotopes (i.e., δ18O and δ2H), radon-222 activities (i.e., 222Rn) and groundwater levels to better understand the interaction of fresh groundwater and recirculated seawater in a snowmelt-affected subterranean estuary (STE) in a boreal region (Îles-de-la-Madeleine, Qc, Canada). By u...

Sandy beaches are reactive biogeochemical zones that play a major role in the cycling of elements at the land/sea interface. When connected to coastal aquifer, these systems act as subterranean estuaries (STE) where seawater mixes with fresh groundwater, which is a potential source of terrestrial organic carbon (OC) to coastal ecosystems. In marine...

The transformations of chemical constituents in subterranean estuaries (STE) control the delivery of 10 nutrient loads from aquifers to the coastal ocean. It is important to determine the processes and sources that affect nutrient concentrations at a local scale in order to accurately estimate global nutrient fluxes via submarine groundwater discha...

The transformations of chemical constituents in subterranean estuaries (STE) control the delivery of nutrient loads from aquifers to the coastal ocean. It is important to determine the processes and sources that affect nutrient concentrations at a local scale in order to accurately estimate global nutrient fluxes via submarine groundwater discharge...

Lorsqu’elles sont connectées aux aquifères côtiers, les plages de sédiments perméables agissent comme des estuaires souterrains (ES) où les eaux des aquifères se mélangent aux eaux côtières. Ces systèmes souterrains sont des voix d’échange de matière, notamment de carbone organique dissous (COD), entre les deux milieux. Dans l’ES de la plage d’étud...

Résultats préliminaires de projet de maitrise qui vise à mieux comprendre le piégeage du DOC et du DOM sur les oxydes de fer dans la zone de décharge d’une plage.