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M.Sc (Geology) McMaster University, Hamilton ON

B.Sc Hon. (Geology) University of Toronto, Toronto ON


Raymond Semkin

Physical Chemist - Study Leader, Hydrogeochemical Response of the Turkey Lakes Watershed to Acidic Deposition

CURRENT S&T / RESEARCH - Developing scientific knowledge to assess the impact of air pollutants on surface and ground waters

  • Hydrogeochemical response of the Turkey Lakes Watershed (TLW) in north-central Ontario to acidic deposition
  • Investigating chemical and hydrological budgets for lakes
  • Quantification and chemical characterization of atmospheric deposition in precipitation, throughfall, snowpack and snowmelt
  • Impact of climate change on the acidification / recovery of surface and ground waters
  • Characterization of water chemistry in remote lakes in western Canada and in the Arctic


Reasearch and monitoring at the Turkey Lakes Watershed in north-central Ontario - hydrometeorolgy, hydrogeochemistry and limnology

Lake water chemistry in the northern Boreal Forest and in the High Arctic

Integrated, multi-disciplinary and multi-agency watershed studies


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. Geochim. Cosmochim. Acta. 71: 3757-3771.

Semkin, R.G., G. Mierle and R.J. Neureuther. 2005. Hydrochemistry and mercury cycling in a High Arctic watershed. Sci. Total Environ. 342(1-3): 199-221.

Laudon, H., P.J. Dillon, M.C. Eimers, R.G. Semkin and D.S. Jeffries. 2004. Climate-induced episodic acidification of streams in central Ontario. Environ. Sci. Technol. 38: 4723-4727.

Harner, T., T. Bidleman, L. Jantunen, F. Wania, P. Helm, Y-F Li, D. Muir, W. Strachan, G. Stern, M. Evans, M. Ikonomou, W. Lockhart, D. Rawn, P. Roach, B. Rosenberg, G. Tomy, P. Blanchard, H. Hung, C. Halsall, P. Fellin, L. Barrie, A. Konoplev, B. Rosenberg, S. Friesen, H. Li, R. Bailey, E. Brorstrom-Lunden, S. Juntto, M. Alaee, C. Cannon, A. Steffen, W. Schroeder, L. Poissant, R. Macdonald, G. Honninger, G. Lawson, C. Banic, S. Gong, J. Smith, D. Gregor, J. Stow, D. Kennedy, K. Reimer, C. Ollson, Z. Kuzyk, I. Koch, C. Hough, N. Burgess, S. Solomon, M. Diamond, R. Semkin, S. Law and J. Fyfe. 2003. in Bidleman, Macdonald and Stow (eds), Canadian Arctic Contaminants Assessment Report II: Sources, Occurrence, Trends and Pathways in the Physical Environment. Indian and Northern Affairs Development, Ottawa.

Semkin, R.G., P.W. Hazlett, F.D. Beall and D.S. Jeffries. 2002. Development of stream water chemistry during spring melt in a northern hardwood forest. Wat. Air Soil Pollut.: Focus. 2(1): 37-61.

Jeffries, D.S., R.G. Semkin, F.D. Beall and J. Franklyn. 2002. Temporal trends in water chemistry in the Turkey Lakes Watershed, Ontario, Canada. Wat. Air Soil Pollut.: Focus. 2(1): 5-22.

Expertise Categories associated with this S&T Expert:

Nature & Wildlife
     Ecosystems & Habitats
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