Raoul-Marie Couture

Raoul-Marie Couture
Laval University | ULAVAL · Department of Chemistry

Ph.D. Water Sciences, B.Sc. Chemistry

About

105
Publications
28,607
Reads
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2,555
Citations
Citations since 2017
48 Research Items
2134 Citations
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Introduction
I am a researcher in aquatic geochemistry. My goal is to understand how the speciation and fate of chemical elements in freshwater systems respond to anthropogenic and climatic factors. My projects and publications have so far focussed on: catchment-lake interactions, aqueous geochemistry of metal(oid)s, and the modelling of sediment diagenesis. To perform my research I combine field measurements of water, sediment and pore-water with instrumental analysis and process-oriented modelling.
Additional affiliations
February 2018 - present
Laval University
Position
  • Professor (Associate)
April 2017 - February 2018
Norwegian Institute for Water Research
Position
  • Section leader
March 2013 - April 2017
Norwegian Institute for Water Research
Position
  • Professor

Publications

Publications (105)
Article
Sulfur controls the fate of many geochemical elements in lake sediments, including iron, phosphorus and environmentally important trace elements. We measured the speciation of pore-water and sediment-bound7 sulfur (aqueous sulphate and sulfides, elemental sulfur, iron monosulfide, pyrite, organic sulfur) and supporting geochemical variables (carbon...
Article
Full-text available
Domestic wastewater and agricultural activities are important sources of nutrient pollutants such as phosphorus and nitrogen. Upon reaching freshwater, these nutrients can lead to extensive growth of harmful algae, which results in eutrophication. Many Chinese lakes are subject to such eutrophication, especially in highly polluted areas, and as suc...
Article
Full-text available
Excess nutrient inputs and climate change are two of multiple stressors affecting many lakes worldwide. Lake Vansjø in southern Norway is one such eutrophic lake impacted by blooms of toxic blue-green algae (cyanobacteria), and classified as moderate ecological status under the EU Water Framework Directive. Future climate change may exacerbate the...
Article
Full-text available
Are small lakes passive pipes transporting terrigenous organic carbon (dissolved organic carbon [DOC]), or chimneys for CO2 release in the landscape? Using a unique combination of 30‐yr measurements, sediment dating and modeling of a small humic lake and its catchment in southeast Norway, we calculated lateral DOC fluxes and in‐lake retention. Conc...
Article
Full-text available
We expanded the existing one‐dimensional MyLake model by incorporating a vertically resolved sediment diagenesis module and developing a reaction network that seamlessly couples the water column and sediment biogeochemistry. The application of the MyLake‐Sediment model to boreal Lake Vansjø illustrates the model's ability to reproduce daily water q...
Article
Floating solar photovoltaic (FPV) deployments are increasing globally as the switch to renewable energy intensifies, representing a considerable water surface transformation. FPV installations can potentially impact aquatic ecosystem function, either positively or negatively. However, these impacts are poorly resolved given the challenges of collec...
Article
Full-text available
While the sentinel nature of freshwater systems is now well-recognized, widespread integration of freshwater processes and patterns into our understanding of broader climate-driven Arctic terrestrial ecosystem change has been slow. We review the current understanding across Arctic freshwater systems of key sentinel responses to climate, which are a...
Article
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Lake evaporation plays an important role in the water budget of lakes. Predicting lake evaporation responses to climate change is thus of paramount importance for the planning of mitigation and adaption strategies. However, most studies that have simulated climate change impacts on lake evaporation have typically utilised a single mechanistic model...
Article
Full-text available
Empirical evidence demonstrates that lakes and reservoirs are warming across the globe. Consequently, there is an increased need to project future changes in lake thermal structure and resulting changes in lake biogeochemistry in order to plan for the likely impacts. Previous studies of the impacts of climate change on lakes have often relied on a...
Preprint
Full-text available
Climate warming and related drivers of soil thermal change in the Arctic are expected to modify the distribution and dynamics of carbon contained in perennially frozen grounds. Thawing of permafrost in the Mackenzie Delta region of northwestern Canada, coupled with increases in river discharge and coastal erosion, trigger the release of terrestrial...
Article
Sustained eutrophication of the aquatic environment by the remobilization of legacy phosphorus (P) stored in soils and sediments is a prevailing issue worldwide. Fluxes of P from the sediments to the water column, referred to as internal P loading, often delays the recovery of water quality following a reduction in external P loads. Here, we report...
Preprint
Full-text available
Sustained eutrophication of the aquatic environment by the remobilization of legacy phosphorus (P) stored in soils and sediments is a prevailing issue worldwide. Fluxes of P from the sediments to the water column, referred to as internal P loading, often delays the recovery of water quality following a reduction in external P loads. Here, we report...
Article
Full-text available
Recent studies have demonstrated that projected climate change will likely enhance nitrogen (N) and phosphorus (P) loss from farms and farmland, with the potential to worsen freshwater eutrophication. Here, we investigate the relative importance of the climate and land use drivers of nutrient loss in nine study catchments in Europe and a neighborin...
Preprint
Full-text available
Empirical evidence demonstrates that lakes and reservoirs are warming across the globe. Consequently, there is an increased need to project future changes in lake thermal structure and resulting changes in lake biogeochemistry in order to plan for the likely impacts. Previous studies of the impacts of climate change on lakes have often relied on a...
Article
Full-text available
Phytoplankton blooms are a global water quality issue, and successful management depends on understanding their responses to multiple and interacting drivers, including nutrient loading and climate change. Here, we examine a long‐term dataset from Lake 227, a site subject to a fertilization experiment (1969–present) with changing nitrogen:phosphoru...
Article
Full-text available
The highest CH4 production rates can be found in anoxic inland water surface sediments however no model quantifies CH4 production following fresh particular organic matter (POM) deposition on anoxic sediments. This limits our capability of modeling CH4 emissions from inland waters to the atmosphere. To generate such a model, we quantified how the P...
Article
Lake sediments are widely used as environmental archives to reconstruct past changes in contaminants deposition, provided that they remain immobile after deposition. Arsenic (As) is a redox-sensitive element that may be redistributed in the sediments during early diagenesis, for instance along with iron and manganese, and thus depth profiles of As...
Article
Full-text available
Gold mining operations near Yellowknife (Northwest Territories, Canada) released vast quantities of arsenic trioxide during the 1950s, which dispersed across the landscape. Contemporary measurements of arsenic concentrations in lake water and surficial sediment identify enrichment within a 30 km radius. However, paleolimnological studies have ident...
Article
We present and evaluate an update to the process‐based lake model MyLake that includes a time‐varying linkage between light attenuation of both photosynthetically active radiation (PAR) and ultraviolet (UV) radiation wavelengths to changes in dissolved organic carbon (DOC). In many parts of northeastern North America and Europe, DOC in lakes has ra...
Article
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Background: The sulfur cycle encompasses a series of complex aerobic and anaerobic transformations of S-containing molecules and plays a fundamental role in cellular and ecosystem-level processes, influencing biological carbon transfers and other biogeochemical cycles. Despite their importance, the microbial communities and metabolic pathways invol...
Article
Full-text available
Eutrophication of lake ecosystems is a pervasive global environmental problem, exacerbated by urbanization, industrialization, and intensification of agriculture. Excess loading of the macronutrients nitrogen and phosphorus from a myriad of human activities in catchment areas has forced many lake ecosystems into turbid, eutrophic states from which...
Article
Full-text available
Climate and land-use change drive a suite of stressors that shape ecosystems and interact to yield complex ecological responses, i.e. additive, antagonistic and synergistic effects. Currently we know little about the spatial scale relevant for the outcome of such interactions and about effect sizes. This knowledge gap needs to be filled to underpin...
Preprint
Full-text available
Background The sulfur cycle encompasses a series of complex aerobic and anaerobic transformations of S-containing molecules, and plays a fundamental role in cellular and ecosystems level-processes, influencing biological carbon transfers and other biogeochemical cycles. Despite their importance, the microbial communities and metabolic pathways invo...
Article
Significance Due to different rates of change in total nitrogen (TN) and total phosphorus (TP) concentrations in lakes, increases in TN/TP mass ratios were observed in many China’s freshwater lakes during 2008 to 2017. This growing imbalance has important implications for aquatic ecology that remain poorly considered and understood. Here, we show t...
Article
Lake Auburn, Maine, USA, is a historically unproductive lake that has experienced multiple algal blooms since 2011. The lake is the water supply source for a population of ~60,000. We modeled past temperature, and concentrations of dissolved oxygen (DO) and phosphorus (P) in Lake Auburn by considering the catchment and internal contributions of P a...
Article
Full-text available
Lake ecosystems across the world are under combined pressures of eutrophication and climate change, which increase the risk of harmful cyanobacteria blooms, reduced ecological status, and degraded ecosystem services. In Europe, the third cycle of river basin management plans (2021–2027) according to the Water Framework Directive must take into acco...
Poster
Full-text available
The cumulative effects of periodic redox cycling on the mobility, speciation and toxicity of As, Fe, Se and S from alluvial sediment and floodplain soil were investigated using a batch bioreactor system stimulating successive half-cycles of oxidizing and reducing conditions. The evidence shows that the mobility of these As and Se species strongly d...
Article
Full-text available
Waste tanks at the nuclear facility located at Sellafield, UK, represent a nuclear source which could release radionuclides to the atmosphere. A model chain which combines atmospheric transport, deposition as well as riverine transport to sea has been developed to predict the riverine activity concentrations of ¹³⁷Cs. The source term was estimated...
Preprint
Full-text available
Phytoplankton blooms respond to multiple drivers, including climate change and nutrient loading. Here we examine a long-term dataset from Lake 227, a site exposed to a fertilization experiment (1969–present). Changes in nitrogen:phosphorus loading ratios (high N:P, low N:P, P-only) did not impact mean annual biomass, but blooms exhibited substantia...
Article
Full-text available
Forest ecosystems worldwide are subjected to human-induced stressors, including eutrophication and acidification, and to natural disturbances (for example, insect infestation, windstorms, fires). The occurrence of the later is expected to increase due to the ongoing climate change. These multi-stressor forcings modify ecosystem biogeochemistry, inc...
Article
The impact ofseasonal fluctuations linked to monsoon and irrigation generates redox oscillations in the subsurface, influencing the release ofarsenic (As) in aquifers. Here, the biogeochemical control on As mobility was investigated in batch experiments using redox cycling bioreactors and As- and SO4 2−-amended sediment. Redox potential (Eh) oscill...
Article
There are infinite possible future scenarios reflecting the impacts of anthropogenic multiple stress on our planet. These impacts include changes in climate and land cover, to which aquatic ecosystems are especially vulnerable. To assess plausible developments of the future state of European surface waters, we considered two climate scenarios and t...
Article
Full-text available
This study presents a specifically designed Mercury module in a coupled benthic-pelagic reactive-transport model - Bottom RedOx Model (BROM) that allows to study mercury (Hg) biogeochemistry under different conditions. This module considers the transformation of elemental mercury (Hg(0)), divalent mercury (Hg(II)) and methylmercury (MeHg). The beha...
Article
Full-text available
The cumulative effects of periodic redox cycling on the mobility of As, Fe, and S from alluvial sediment to groundwater were investigated in bioreactor experiments. Two particular sediments from the alluvial floodplain of the Mekong Delta River were investigated: Matrix A (14 m deep) had a higher pyrite concentration than matrix B (7 m deep) sedime...
Article
Emerging investigator series: Thousands of boreal lakes were limed for decades in Scandinavia to counteract the effect of anthropogenic acidification. We measured the concentrations of alkali earth metals (Ca, Mg, Ba), metals (Mn, Fe, Al, Co, Cd, Pb, Zn), metalloids (As, Mo) and phosphorus (P) in 165 surface sediment samples from 17 limed lakes, as...
Article
Redox electrodes are commonly used to measure redox potentials (EH) of natural waters. The recorded EH values are usually interpreted in terms of the dominant inorganic redox couples. To further advance the interpretation of measured EH distributions along temporal and spatial redox gradients, we performed a series of reactor experiments in which o...
Article
Full-text available
Argillaceous geological formations are considered promising repositories for waste containing inorganic con- taminants. However, the sequestration capacity of an argillaceous natural barrier may change as a result of dynamic environmental conditions, in particular changes in redox state. Here, we imposed redox cycles to ar- gillaceous suspensions a...
Article
Full-text available
We constructed a model chain into which regional climate-related variables (air temperature, precipitation) and a lake’s main tributary hydrological indicators (river flow, dissolved inorganic carbon) were employed for predicting the evolution of planktonic blue-green algae (cyanobacteria) and zooplankton (rotifer) biomass in that lake for the mid-...
Article
Full-text available
Interactions between seawater and benthic systems play an important role in global biogeochemical cycling. Benthic fluxes of some chemical elements (e.g., C, N, P, O, Si, Fe, Mn, S) alter the redox state and marine carbonate system (i.e., pH and carbonate saturation state), which in turn modulate the functioning of benthic and pelagic ecosystems. T...
Technical Report
Full-text available
Summary D5.1-1 Part 1: Multi-stressors on surface water and effects on ecological statusHumans have increased the discharge of pollution, altered water flow regime and modified the morphology of rivers. All these actions have resulted in multiple pressures on freshwater ecosystems, undermining their biodiversity and ecological functioning. The Euro...
Article
AbstractMany surface waters in Europe suffer from the adverse effects of multiple stresses. The Otra River, southernmost Norway, is impacted by acid deposition, hydropower development and increasingly by climate change. The river holds a unique population of land-locked salmon and anadromous salmon in the lower reaches. Both populations have been s...
Chapter
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MyLake is a simple one-dimensional (1D) daily time-step model that can be used to simulate seasonal changes in ice coverage in lakes. This model is aimed at researchers who prefer to use Matlab/Octave language for scientific computing applications. This factsheet describes briefly how to set-up the MyLake lake model in order to simulate thermal str...
Article
Full-text available
Eutrophication of lakes and the risk of harmful cyanobacterial blooms due is a major challenge for management of aquatic ecosystems, and climate change is expected to reinforce these problems. Modelling of aquatic ecosystems has been widely used to predict effects of altered land use and climate change on water quality, assessed by chemistry and ph...
Technical Report
Full-text available
Deliverable D4.1 is a synthesis report of the 16 regional case studies being undertaken in WP4 (Multi-stressors at the river basin scale. The report is composed of 3 parts. Part 1: Task 4.2 - Southern Basins region Part 1 reports the background to, and results and conclusions from Task 4.2 on four case studies from the Southern Basins region. The...
Technical Report
Full-text available
The modelling undertaken across the study basins allow us to have an understanding of the trends displayed by the data gathered at the various case-studies, encompassing a global view of European riverscapes. Overall, the studies highlight a general difficulty to identify significant pair-wise multi-stressor interactions, even if considering that s...
Article
Full-text available
Abstract INCA-P is a dynamic, catchment-scale phosphorus model which has been widely applied during the last decade. Since its original release in 2002, the model structure and equations have been significantly altered during several development phases. Here, we provide the first full model description since 2002 and then test the latest version of...
Article
We assessed the potential of zero valent iron (Fe0)-based permeable reactive barriers (PRB) systems for arsenic (As) remediation in the presence or absence of microbial sulfate reduction. We conducted long-term (200 days) flow-through column experiments to investigate the mechanisms of As transformation and mobility in aquifer sediment, in particul...
Article
Full-text available
This report gives an overview of biological and other environmental monitoring data from Lake Vansjø in the Morsa river basin district, South-East Norway. The lake is impacted by eutrophication and has been subject to several nutrient abatement measures. The dataset comprises phytoplankon data at species level from 2005-2015, and water chemistry da...
Technical Report
Part 1: This deliverable consists two manuscripts (MS) of lake time-series analysis in north-temperate region of Europe. 1st MS: ‘Is fish able to regulate filamentous blue-green dominated phytoplankton?’ submitted to ‘Hydrobiologia’, analyzes >40-year data on biota, fish catches, hydrochemistry, hydrology, and meteorological parameters in Lake Võrt...
Technical Report
Part 1: This deliverable consists two manuscripts (MS) of lake time-series analysis in north-temperate region of Europe. 1st MS ‘Is fish able to regulate filamentous blue-green dominated phytoplankton?’ submitted to ‘Hydrobiologia’, analyzes >40-year data on biota, fish catches, hydrochemistry, hydrology, and meteorological parameters in Lake Võrts...
Article
Full-text available
Interaction between seawater and benthic sediments plays an important role in global biogeochemical cycling. Benthic fluxes of chemical elements (C, N, P, O, Si, Fe, Mn, S) directly affect redox state and acidification (i.e. pH and carbonate saturation), which in turn determine the functioning of the benthic and pelagic ecosystems. The redox state...
Conference Paper
Full-text available
The key results from the application of catchment-scale biophysical models to assess the likely effectiveness of nutrient pollution mitigation measures set in the context of projected land management and climate change are presented. The assessment is based on the synthesis of modelled outputs of daily river flow, river and lake nitrogen and phosph...
Conference Paper
Full-text available
The key results from the application of catchment-scale biophysical models to eight river-systems across Europe to assess the effects of projected environmental change (change in climate, land use, nitrogen deposition and water use) on water quantity and quality will be presented. Together the eight sites represent a sample of key climate and land...
Article
Full-text available
Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been...
Article
Boreal lakes are impacted by climate change, reduced acid deposition, and changing loads of dissolved organic carbon (DOC) from catchments. We explored, using the process-based lake model MyLake, how changes in these pressures modulate ice phenology and the dissolved oxygen concentrations (DO) of a small boreal humic lake. The model was parametrize...
Article
The Sancho Reservoir in SW Spain has been impacted by acid mine drainage (AMD) since the Tharsis mine stopped activity in 1998. As a result, the reservoir exhibits low pH (~ 3.5) and high aqueous concentrations of sulfate, aluminum, iron and trace metals. Thus far, removal of contaminants by sediment burial has not been as effective as expected in...