A5034034951- Mercury impact and mitigation studies
- Peatlands and Wetlands Ecology
- Toxic Organic Pollutants Impact
- Coastal wetland ecosystem dynamics
- Marine animal studies overview
- Hydrology and Watershed Management Studies
- Heavy metals in environment
- Heavy Metal Exposure and Toxicity
- Isotope Analysis in Ecology
- Climate change and permafrost
- Soil erosion and sediment transport
- Avian ecology and behavior
- Soil and Water Nutrient Dynamics
- Botany and Plant Ecology Studies
- Fish Ecology and Management Studies
- Urban Stormwater Management Solutions
- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Air Quality and Health Impacts
- Fire effects on ecosystems
- Bird parasitology and diseases
- Hydrology and Sediment Transport Processes
- Water Treatment and Disinfection
- Plant Water Relations and Carbon Dynamics
- Atmospheric and Environmental Gas Dynamics
Western University
2016-2025
Université de Reims Champagne-Ardenne
2024
Kitasato University
2024
University of Geneva
2024
Sejong University
2024
Institut Català de Ciències del Clima
2024
Institut de Ciències del Mar
2024
Consejo Superior de Investigaciones Científicas
2024
Guangdong Technion-Israel Institute of Technology
2024
Environment and Climate Change Canada
2021
Methylmercury contamination of fisheries from centuries industrial atmospheric emissions negatively impacts humans and wildlife worldwide. The response fish methylmercury concentrations to changes in mercury deposition has been difficult establish because sediments/soils contain large pools historical contamination, many factors addition affect mercury. To test directly the changing deposition, we conducted a whole-ecosystem experiment, increasing load lake its watershed by enriched stable...
Abstract The composition of a peatland plant community has considerable effect on range ecosystem functions. Peatland structure is predicted to change under future climate change, making the quantification direction and magnitude this research priority. We subjected intact, replicated vegetated poor fen peat monoliths elevated temperatures, increased atmospheric carbon dioxide (CO 2 ), two water table levels in factorial design determine individual synergistic effects factors composition....
Recent studies have found that “pristine” peatlands high peat and pore water methylmercury (MeHg) concentrations may act as large sources of MeHg to the downstream aquatic system, depending upon degree hydrologie connectivity catchment physiography. Sulphate‐reducing bacteria been implicated principal methylators inorganic mercury in many environments with previous research focused primarily on methylation sediments. Experiments a poor fen Experimental Lakes Area, northwestern Ontario,...
Many wetlands are sources of methylmercury (MeHg) to surface waters, yet little information exists about the distribution MeHg within wetlands. Total mercury (THg) and in peat pore waters were studied four peatlands spring, summer, fall 2005. Marked spatial variability MeHg, %MeHg as a proxy for net production, was observed, with highest values occurring discrete zones. We denote these zones "MeHg hot spots", defined an area where water exceeded 90th percentile data set (n = 463) or >22% THg...
Peatlands are an important source of the atmospheric greenhouse gas methane (CH4). Although CH4 cycling and fluxes have been quantified for many northern peatlands, imprecision in process-based approaches to predicting emissions suggests that our understanding underlying processes is incomplete. Microbial anaerobic oxidation (AOM) sink marine sediments, but AOM has only recently identified a few nonmarine systems. We used (13)C isotope tracers followed fate into CO2 peat order study...
Atmospheric mercury (Hg) measurements from across Canada were compiled and analysed as part of a national Hg science assessment. Here we update long-term trends in air precipitation, present more extensive on patterns speciated species (gaseous elemental mercury—GEM, reactive gaseous mercury—RGM, total particulate particles <2.5 μm—TPM2.5) at several sites. A spatial analysis revealed higher concentrations wet deposition the vicinity local regional emission sources, lower mid-latitude...
Mercury (Hg) is increasing in marine food webs, especially at high latitudes. The bioaccumulation and biomagnification of methyl mercury (MeHg) has serious effects on wildlife, most evident apex predators. MeHg body burden birds the balance ingestion excretion, feathers an effective indicator overall burden. Ivory gulls (Pagophila eburnea), which consume ice-associated prey scavenge mammal carcasses, have highest egg Hg concentrations any Arctic bird, species declined by more than 80% since...
Abstract It is commonly assumed that most (>95%) of the mercury (Hg) found in fish muscle toxic form, methylmercury (MeHg), due to its efficient assimilation and retention biotic tissue. However, this assumption largely based on studies examining percentage MeHg (%MeHg [the fraction total Hg as MeHg]) from mostly large‐bodied predatory fish; less known about %MeHg smaller bodied individuals or those different trophic guilds. The present study analyzed concentrations 2 piscivores (walleye...
Anthropogenic releases of mercury (Hg)1-3 are a human health issue4 because the potent toxicant methylmercury (MeHg), formed primarily by microbial methylation inorganic Hg in aquatic ecosystems, bioaccumulates to high concentrations fish consumed humans5,6. Predicting efficacy pollution controls on MeHg is complex many factors influence production and bioaccumulation MeHg7-9. Here we conducted 15-year whole-ecosystem, single-factor experiment determine magnitude timing reductions following...
A hydrobiogeochemical investigation of a small headwater peatland located in the Experimental Lakes Area, northwestern Ontario, Canada, examined surface and subsurface hydrologic pathways their relation to movement spatial variability methylmercury (CH 3 Hg + ). The hydrology controls mass flux CH downstream pond from terrestrial ecosystems, influences production and/or accumulation peatland. Distinct zones groundwater recharge discharge were observed within peatland, these corresponded, low...
Abstract In forested catchments, the exceedance of rainfall and antecedent water storage thresholds is often required for runoff generation, yet to our knowledge these threshold relationships remain undescribed in tropical dry forest catchments. We, therefore, identified controls streamflow activation timing magnitude a catchment near Pacific coast central Mexico. During 52 day transition phase from wet season, soil movement was dominated by vertical flow which continued until moisture...
Abstract A series of severe droughts during the course a long‐term, atmospheric sulfate‐deposition experiment in boreal peatland northern Minnesota created unique opportunity to study how methylmercury (MeHg) production responds drying and rewetting events peatlands under variable levels sulfate loading. Peat oxidation extended dry periods mobilized sulfate, MeHg, total mercury (Hg T ) pore waters events. Pore water concentrations were inversely related antecedent moisture conditions...
Abstract Wetlands form 14% of the Canadian landscape and, consequently, have considerable interaction with hydrological resources, including water quantity and quality, both within downstream them. Most these are peatlands, particularly in boreal northern environments, been well researched recently. New data also exist for mineral wetlands (e.g. prairie sloughs). Relatively little attention has given to coastal wetlands, or complicated systems Western Cordillera. This paper reviews current...
Abstract Thresholds in terrestrial water storage were quantified to explain differences observed rainfall‐runoff relationships for a 71·5 ha research catchment northwestern Ontario, Canada. Using terrain analysis techniques, the was partitioned into discrete hydrologic response units (HRUs). Unsaturated and saturated calculated depression midslope HRUs using continuous hydrometric measurements depth function drainable porosity. The relationship between total these discharge then examined...
Methylmercury (MeHg) bioaccumulation in marine food webs poses risks to fish-consuming populations and wildlife. Here we develop test an estuarine mercury cycling model for a coastal embayment of the Bay Fundy, Canada. Mass budget calculations reveal that MeHg fluxes into sediments from settling solids exceed losses sediment-to-water diffusion resuspension. Although measured methylation rates benthic are high, rapid demethylation results negligible net situ production MeHg. These suggest...
Abstract In arctic and sub‐arctic environments, mercury (Hg), more specifically toxic methylmercury (MeHg), is of growing concern to local communities because its accumulation in fish. these regions, there particular interest the potential mobilization atmospherically deposited Hg sequestered permafrost that thawing at unprecedented rates. Permafrost thaw resulting ground surface subsidence transforms forested peat plateaus into treeless permafrost‐free thermokarst wetlands where inorganic...