backResearcher Profile

Dr. Michael R. Twiss

Job Title: Assistant professor
Employer: Ryerson Polytechnic University
Place of Birth: Bryn Mawr, Pennsylvania, USA
Public School attended: A.B. Ellis Public School, Espanola, Ontario
High School attended: Espanola high School, Espanola, Ontario
Further Education: Trent University (B.Sc.), University of Toronto (M.Sc.), INRS-Eau, Université du Québec (Ph.D.).
Geographic focus of research: Great Lakes, and Canadian Shield lakes in Ontario and Quebec, USA, Great lakes, upstate New York and Atlantic coastal regions

Brief synopsis of current research:
- development of analytical techniques (DGT probes) for measuring Cd and Pb speciation in aquatic systems in order for the bioavailability of these elements to aquatic organisms to be predicted.
- measuring trophic transfer of the toxic metal thallium through the microbial food chain (bacteria, phytoplankton, zooplankton) in the the lower Great Lakes (Lake Erie and Lake Ontario)
- determining the aquatic speciation of Cu in Great Lakes using competitive ligand exchange-adsorptive cathodic stripping voltammetry
- assessing the nutritive requirements (Zn) of phytoplankton isolated from Lake Erie
- field assays of Fe and Zn limitation of plankton in Lake Erie conducted on Great Lakes research ships.

Website:
www.ryerson.ca/ensciman/

Recent Publications:

Twiss, M.R., Auclair, J.-C., and Charlton, M.N. 2000. Iron-stimulated phytoplankton productivity in the pelagic surface water of eastern and central Lake Erie during thermal stratification: a field investigation using trace metal clean techniques. Canadian Journal of Fisheries and Aquatic Science. vol. 56 (issue 1): in press.

Twiss, M.R. and Campbell, P.G.C. 1998. Modeling the fate of trace metals in the surface waters of Lake Erie: Linking ecological and geochemical fates. Journal of Great Lakes Research. 24: 791-807.

Campbell, P.G.C., Twiss, M.R., and Wilkinson, K.J. 1997. Accumulation of natural organic matter on the surface of living cells - implication for the interaction of aquatic biota with toxic solutes. Canadian Journal of Fisheries and Aquatic Science 54: 2543-2554.

Twiss, M.R., Campbell, P.G.C., and Auclair, J.-C. 1996. Regeneration, recycling and trophic transfer of trace metals by microbial food web organisms in the pelagic surface waters of Lake Erie. Limnology and Oceanography 41: 1425-1437.

Twiss, M.R. and Campbell, P.G.C. 1995. Regeneration of trace metals from picoplankton by nanoflagellate grazing. Limnology and Oceanography 40: 1418-1429.

Comments:
Aquatic science in Canada is essential to the environmental and human health of the nation. I chose to study limnology because I grew up in, on, and near lakes and when I found out that you could find out more about them it was natural for me to follow that current. Aquatic sciences are a very multi-disciplinary field (e.g. geology, chemistry, biology, geography, physics, engineering) and being an aquatic scientist requires good knowledge of more than one scientific discipline.