John Spoelstra

Chercheur scientifique - Section de l'évaluation et de la qualité de l'eau souterraine
Environnement et Changement climatique Canada

Recherche et / ou projets en cours

Contribue au mandat d'Environnement Canada pour garantir la conservation et la protection des écosystèmes aquatiques

  • Sources et devenir des contaminants azotés dans les eaux souterraines et les eaux de surface
  • Utilisation d'édulcorants artificiels pour détecter les eaux usées dans l'environnement
  • Impacts de la gestion des terres sur la qualité de l'eau dans les bassins hydrographiques forestiers et agricoles
  • Développement et application d'outils isotopiques stables pour la recherche en biogéochimie
  • Questions sur la qualité des eaux souterraines du bassin des Grands Lacs

Prix et études

Ph.D., Sciences de la Terre, Université de Waterloo, 2004

Baccalauréat ès sciences avec spécialisation, Université de Waterloo, 1996

Principales publications

Spoelstra, J., N.D. Senger, S.L. Schiff. (In press) Artificial sweeteners reveal septic system effluent in rural groundwater.  Journal of Environmental Quality. doi: 10.2134/jeq2017.06.0233.

Roy, J.W., J. Spoelstra, W.D. Robertson, W. Klemt, S.L. Schiff. (In press) Contribution of phosphorus to Georgian Bay from groundwater of a coastal beach town with decommissioned septic systems. Journal of Great Lakes Research. doi: 10.1016/j.jglr.2017.09.001.

Snider, D.M., J.W. Roy, W.D. Robertson, D.I. Garda, J. Spoelstra. (2017) Concentrations of artificial sweeteners and their ratios with nutrients in septic system wastewater. Groundwater Monitoring & Remediation 37(3): 94-102. doi:10.1111/gwmr.12229.

Snider, D.M., C. Wagner-Riddle, J. Spoelstra. (2017) Stable isotopes reveal rapid cycling of soil nitrogen after manure application.  Journal of Environmental Quality 46: 261-271. doi:10.2134/jeq2016.07.0253.

Van Stempvoort, D.R., J. Spoelstra, N.D. Senger, S.J. Brown, R. Post, J. Struger. (2016) Glyphosate residues in rural groundwater, Nottawasaga River Watershed, Ontario, Canada. Pest Management Science 72: 1862-1872. doi:10.1002/ps.4218.

Robertson, W.D., D.R. Van Stempvoort, J. Spoelstra, S.J. Brown, and S.L. Schiff. (2016) Degradation of sucralose in groundwater and implications for age dating contaminated groundwater. Water Research 88: 653-660. doi:10.1016/j.watres.2015.10.051.

Robertson, W.D., D.R. Van Stempvoort, J.W. Roy, S.J. Brown, J. Spoelstra, S.L. Schiff, D.R. Rudolph, S. Danielescu, and G. Graham. (2016) Use of an artificial sweetener to identify sources of groundwater nitrate contamination. Groundwater, 54: 579-587. doi:10.1111/gwat.12399.

Snider, D.M., K.A. Thompson, C. Wagner-Riddle, J. Spoelstra, and K.E. Dunfield. (2015) Molecular techniques and stable isotope ratios at natural abundance give complementary inferences about N2O production pathways in an agricultural soil following a rainfall event. Soil Biology & Biochemistry 88: 197-213. doi:10.1016/j.soilbio.2015.05.021.

Snider, D.M., J.J. Venkiteswaran, S.L. Schiff, and J. Spoelstra. (2015) From the ground up: nitrous oxide sources are constrained by stable isotope values. PLoS ONE 10(3): e0118954. doi:10.1371/journal.pone.0118954.

Li, L., J. Spoelstra, W.D. Robertson, S.L. Schiff, and R.J. Elgood. (2014) Nitrous oxide as an indicator of nitrogen transformation in a septic system plume. Journal of Hydrology 519: 1882–1894.

Spoelstra, J., S.L. Schiff, and S.J. Brown. (2013) Artificial sweeteners in a large Canadian river reflect human consumption in the watershed. PLoS ONE 8(12): e82706. doi:10.1371/journal.pone.0082706.

Spoelstra, J., S.L. Schiff, R.G. Semkin, D.S. Jeffries and R.J. Elgood. 2010. Nitrate attenuation in a small temperate wetland following forest harvest. Forest Ecology and Management 259: 2333-2341.

Spoelstra, J., S.L. Schiff, P.W. Hazlett, D.S. Jeffries and R.G. Semkin. 2007. The isotopic composition of nitrate produced from nitrification in a hardwood forest floor. Geochimica et Cosmochimica Acta. 71: 3757-3771.

Schiff, S.L., J. Spoelstra, R.G. Semkin and D.S. Jeffries. 2005. Drought induced pulses of SO42- from a Canadian Shield wetland: Use of δ34S and δ18O in SO42- to determine sources of S. Applied Geochemistry. 20: 691-700.

Spoelstra, J., S.L. Schiff, R. Elgood, R.G. Semkin, and D.S. Jeffries. 2001. Tracing the sources of exported nitrate in the Turkey Lakes Watershed using 15N/14N and 18O/16O isotopic ratios. Ecosystems. 4:536-544.