Faculty Profiles

Lewis Molot

BSc (Zoology) - Toronto
MSc (Limnology) - Toronto
PhD (Oceanography) - Alaska

Areas of Academic Interest

  • Aquatic science


I am part of a small group of applied scientists in the Faculty of Environmental Studies. My interests focus on aquatic systems, specifically lakes and streams. I teach undergraduate and graduate courses in applied ecology, and I am an active member of several professional organizations including the American Geophysical Union and the Canadian Society of Limnologists. Often, I work with graduate students in FES who conduct research examining relationships between science and sustainable development.

I also supervise graduate students pursuing scientific research in the Departments of Biology or Geography. Students with a BSc or MSc interested in pursuing a graduate degree in one of the scientific research projects described below should contact me at lmolot@yorku.ca.

Major research projects

  • Development and maintenance of harmful cyanobacterial blooms in freshwaters.

Eutrophication (the condition created by excessive inputs of plant nutrients, especially phosphorus, to surface waters) remains an important global issue in spite of the wealth of attention paid to it in the last 50 years. The presence of cyanobacteria blooms in eutrophic waters is a major public health concern because many strains produce potent liver and nerve toxins as well as compounds that alter taste and odour of drinking waters. Cyanobacterial blooms have long been associated with excessive nutrient loading, prompting investment of large amounts of money in sewage treatment. In spite of many years of research, the specific mechanism causing cyanobacterial dominance of phytoplankton communities was not well understood until recently. My lab is studying (1) how the development of anoxic (oxygen-free) sediments triggers growth of cyanobacteria and displacement of more benign algal species, (2) the role of trace metals in initiating and sustaining cyanobacteria blooms, and (3) how sediment anoxia is affected by climate change.

Selected Publications

Refereed Journal Articles

Li, J., L.A. Molot, M.E. Palmer, J.G. Winter, J.D. Young and E.A. Stainsby. 2018. Long-term changes in hypolimnetic dissolved oxygen in a large lake: Effects of invasive mussels, eutrophication and climate change on Lake Simcoe, 1980-2012. Journal of Great Lakes Research, in press, doi.org/10.1016/j.jglr.2018.05.016.

Kelly, N.E., J. Young, E. Stainsby, J. Winter, M. Palmer, and L.A. Molot. 2017. Sequential rather than interactive effects of multiple stressors as drivers of phytoplankton community change in a large lake. Freshwater Biology, 62: 1288-1302, doi.org/10.1111/fwb.12945.

Schiff S.L., J.M. Tsuji, L. Wu, J.J. Venkiteswaran, L.A. Molot, R.J. Elgood, M.J. Paterson and J.D. Neufeld. 2017. Photoferrotrophy in an anoxic Boreal Shield lake can be used to probe the evolution of Archaean Life. Science Reports, 7:46798: 1-11, DOI: 10.1038/srep46708

Molot, L.A. 2017. The effectiveness of cyanobacteria nitrogen fixation: Review of bench top and pilot scale nitrogen removal studies and implications for nitrogen removal programs. Environmental Reviews. 25: 292-295. doi.org/10.1139/er-2016-0107.

Verschoor, M.J., C.R. Powe, E. McQuay,  S.L. Schiff, J.J. Venkiteswaran, J. Li and L.A. Molot. 2017. Reduced iron and warm temperatures as pre-conditions for cyanobacterial dominance in embayments along Georgian Bay, Great Lakes. Canadian Journal of Fisheries and Aquatic Sciences. 74: 1439-1453. dx.doi.org/10.1139/cjfas-2016-0377.

Kelly, N.E., E. O'Connor, R. Wilson, J. Young, J. Winter and L.A. Molot. 2016. Multiple stressors effects on stream health in the Lake Simcoe watershed. Journal of Great Lakes Research. 42: 953-964.

Porcal, P., P.J. Dillon and L.A. Molot. 2015. Temperature dependence of photodegradation of dissolved organic matter to dissolved organic matter and particulate organic matter. PLOS One. dx.doi:10.1371/journal.pone.0128884, June 24, 2015.

Schwalb, A., D. Bouffard, L. Boegman, L. Leon, J.G. Winter, L.A. Molot, R.E.H. Smith. 2015. 3D modelling of dreissenid mussel impacts on phytoplankton in a large lake supports the nearshore shunt hypothesis and the importance of wind-driven hydrodynamics. Aquatic Sciences. 77(1): 95-114, DOI 10.1007/s00027-014-0369-0.

Porcal, P., P.J. Dillon and L.A. Molot. 2014. Interaction of extrinsic chemical factors affecting photodegradation of dissolved organic matter in aquatic ecosystems. Photochemical and Photobiological Sciences. 13: 799-812.

Molot, L.A., S.B. Watson, I.F. Creed, C.G. Trick, S.K. McCabe, M.J. Verschoor, R.J. Sorichetti, C. Powe, J.J. Venkiteswaran and S.L. Schiff. 2014. A novel model for cyanobacteria bloom formation: The critical role of anoxia and ferrous iron. Freshwater Biology. 59(6): 1323-1340, DOI 10.1111/fwb.12334.

Oni, S.K., M.N. Futter, L.A. Molot, P.J. Dillon and J. Crossman. 2014. Uncertainty assessments and hydrological implications of climate change in two adjacent agricultural catchments of a rapidly urbanizing watershed.  Science of the Total Environment. 473-474:326-337.

Porcal, P., P.J. Dillon, L.A. Molot. 2013. Seasonal changes in photochemical properties of dissolved organic matter. Biogeosciences. 10: 5533-5543.

Nürnberg, G.K., L.A. Molot, E. O’Connor, H. Jarjanazi, J.G. Winter and J.D. Young. 2013. Evidence for internal phosphorus loading, hypoxia and effects on phytoplankton in partially polymictic Lake Simcoe, Ontario. Journal of Great Lakes Research. 39(2): 259-270.

Nürnberg, G.K., B.D. LaZerte, P.S. Loh, L.A. Molot. 2013. Quantification of internal phosphorus load in large, partially polymictic and mesotrophic Lake Simcoe, Ontario. Journal of Great Lakes Research. 39(2): 271-279.

Porcal, P., P.J. Dillon, L.A. Molot. 2013. Photochemical production and decomposition of particulate organic carbon in a freshwater stream. Aquatic Sciences. 75: 469-482.

Verschoor, M. and L.A. Molot. 2013. A comparison of three colorimetric methods of ferrous and total reactive iron measurement in freshwaters. Limnology and Oceanography: Methods. 11: 113-125.

Loh, P.S., L.A. Molot, G.K. Nurnberg, S.B. Watson and B. Ginn.  2013. P and Fe release rates from anoxic sediments in Lake Simcoe, Lake Winnipeg and Hamilton Harbor and their relationship to sediment fractions. Can release be predicted by sediment fraction chemistry? Inland Waters. 3: 105-118.

North, R.L., D. Barton, A.S. Crowe, P.J. Dillon, R.M.L. Dolson, D.O. Evans, B.K. Ginn, J. Hawryshyn, H. Jarjanazi, J.W. King, J.K.L. La Rose, L. León, C.F.M. Lewis, G.E. Liddle, Z.H. Lin, F.J. Longstaffe, R.A. Macdonald, L. Molot, T. Ozersky, M.E. Palmer, R. Quinlan, M.D. Rennie, M.M. Robillard, D. Rodé, K.M. Rühland, A. Schwalb, J.P. Smol, E. Stainsby, J.J. Trumpickas, J.G. Winter and J.D.Young. 2013. The state of Lake Simcoe (Ontario, Canada): long-term responses to multiple stressors. Inland Waters. 3: 51-74.

Oni, S.K., M.N. Futter, L.A. Molot and P.J. Dillon. 2012. Adjacent catchments with similar patterns of land use and climate have markedly different DOC and runoff dynamics.  Hydrological Processes. 28: 1436-1449.

Oni, S.K., M.N. Futter, L.A. Molot and P.J. Dillon. 2012. Modelling the long term impact of climate change on the carbon budget of Lake Simcoe, Ontario using INCA-C. Science of the Total Environment, 414: 387-403.

Young, J., J. Winter and L.A. Molot. 2011. A re-evaluation of the empirical relationships connecting dissolved oxygen and phosphorus loading after zebra mussel invasion in Lake Simcoe. Journal of Great Lakes Research. 37(Supplement 3): 7-14.

Persaud, A., P.J. Dillon and L.A. Molot. 2011. Relationships between body size and trophic position of consumers in temperate freshwater lakes. Aquatic Sciences. 73:  DOI 10.1007/s00027-011-0212-9.

Koprivnjak, J-F., P.J. Dillon and L.A. Molot. 2010.  Importance of CO2 evasion from small boreal streams. Global Biogeochemical Cycles, 24: GB4003, doi:10.1029/2009GB003723.

Molot, L.A., G. Li, D.L. Findlay and S.B. Watson. 2010. Iron-mediated suppression of cyanobacteria blooms by oxine in a eutrophic lake. Freshwater Biology, 55:1102-1117.

Zhang, J., J. Hudson, R. Neal, T. Clair, M. Turner, D. Jeffries, P.J. Dillon, L.A. Molot, K. Somers and R. Hesslein. 2010. Long-term patterns of dissolved organic carbon in lakes across eastern Canada: evidence of a pronounced climate effect. Limnology and Oceanography. 55:30-42.

Porcal, P., J-F. Koprivnjak, L.A. Molot, and P.J. Dillon. 2009.  The biogeochemistry of dissolved organic carbon and its interactions with climate change.  Environmental Science and Pollution Research International: Humic Substances Part 7. 16(6): 714-726. (invited review)

O’Connor, E.M., P.J. Dillon, L.A. Molot and I.F. Creed. 2009. Modeling regional-scale dissolved organic carbon mass balances for lakes of the Muskoka River Watershed. Hydrology Research 40: 273-290.

Book Chapters

Watson, S.B. and L.A. Molot. 2013. Harmful algal blooms. In Encyclopedia of Aquatic Ecotoxicology, J.F. Férard and C. Blaise (eds). Springer, DOI 10.1007/978-94-007-5704-2.

Molot, L.A., Color of Aquatic Ecosytems. 2009. In Encyclopedia of Inland Waters, G.E. Likens (editor), Volume 2, pp. 657-663, (invited), Elsevier.