Skip to main content Skip to local navigation

Jennifer B. Korosi

Jennifer B. Korosi

Associate Professor

Environmental Science Coordinator


BScH, PhD, Queen's University

Research Keywords

Lakes; Environmental Change; Environmental Contaminants; Permafrost Thaw; Biogeochemistry; Biogeography.

Jennifer B. Korosi

Contact Information

4700 Keele Street
Toronto, ON M3J1P3

416 736 2100

Research Interests

I am an environmental scientist and limnologist (limnology = study of inland waters) who seeks to understanding the nature and underlying mechanisms of environmental change. Lakes are sentinels of environmental change, as they archive changes occurring both within the lake, and in the surrounding terrestrial ecosystems within its watershed. My research uses lake sediment cores (the field of paleolimnology) to infer past environmental conditions and trajectories of ecosystem change. I study the role of climate warming and permafrost thaw as a driver of terrestrial and lake ecosystem change in high-latitude regions. I am also interested in the role of climate change in influencing the cycling and ecotoxicity of industrial contaminants. My research also examines regime shifts and ecosystem resilience in southern Ontario lakes impacted by multiple stressors, with a focus on the Kawartha Lakes watershed.

Research Projects

Trajectories of landscape and lake ecosystem change in thawing permafrost landscapes

Principal Investigator

NSERC Discovery Grant


Permafrost, defined as soil or rock that remains frozen for at least two consecutive years, is a dominant feature of the Canadian landscape. Rates of permafrost thaw have accelerated in recent decades, a trend that will continue with future climate warming. The thawing of permafrost represents a major stressor on northern lakes that may negatively impact the provision of essential lake ecosystem services.  Empirical evidence of long-term impacts to lake ecological and biogeochemical function is lacking, as most studies into the effects of permafrost thaw on lakes are based on short-term observations. We are using paleoenvironmental techniques to track permafrost landscape change in the Northwest Territories, and the resulting lake ecosystem responses, over centennial to millennial timescales. Our field sites are based in the Inuvik-Tuktoyaktuk region (ice-rich, continuous permafrost), and the Dehcho region (discontinuous permafrost). 

Research Output

Cheney, C.L., Eccles, K.M., Kimpe, L.E., Thienpont, J.R., Korosi, J.B., and Blais, J.M. (2020) Reconstructing the legacy of sediment-associated contaminants in lakes influenced by historic gold mining using a palaeotoxicity approach. Science of the Total Environment 718: 137308.

Korosi, J.B., Thienpont, J.R., Eickmeyer, D.C., Kimpe, L.E., and Blais, J.M. (2020). A paleolimnological approach for interpreting Aquatic Effects Monitoring at the Diavik Diamond Mine (Lac de Gras, Northwest Territories, Canada). Lake and Reservoir Management doi: 10.1080/10402381.2020.1777232.

Saleem, A., Bell, M., Kimpe, L.E., Korosi, J.B., Arnason, J.T., Blais, J.M. (2019). Identifying novel treeline biomarkers in lake sediments using an untargeted screening approach. Science of the Total Environment 694: 133684.

Sivarajah, B., Korosi, J.B., Blais, J.M., and Smol, J.P. (2019). Diatom assemblages across an arsenic gradient from 33 subarctic lakes near gold mines in Yellowknife, Northwest Territories, Canada. Hydrobiologia 841: 133-151.

Coleman, K. A., Palmer, M. J., Korosi, J. B., Thienpont, J. R., Blais, J. M., and Smol, J. P. (2019). Assessing long-term changes in aquatic ecosystems near a small conventional oil and gas operation in the Cameron Hills, southern Northwest Territories, Canada. Fundamental and Applied Limnology, 192: 181-197

Thienpont, J.R., Perreault, J., Pisaric, M.F.J., Korosi, J.B., and Blais, J.M. (2018). Has natural lake expansion and landscape inundation resulted in mercury increases in flooded lakes of the Great Slave Lowlands (Northwest Territories, Canada)? Journal of Paleolimnology 61: 345-354.

Harner, T., Rauert, C., Muir, D., Schuster, J., Hsu, Y-M., Zhang, L., Marson, G., Watson, J.G., Ahad, J., Cho, S., Jariyasopit, N., Kirk, J., Korosi, J.B., Landis, M., Martin, J., Zhang, J.,  Fernie, K., Wentworth, G.R., Wnorowski, A., Dabek, E., Charland, J-P., Pauli, B., Wania, F., Galarneau, E., Cheng, I., Makar, P., Whaley, C., Chow, J.C., Wang, X. (2018). Air synthesis review on polycyclic aromatic compounds in the Oil Sands Region.  Environmental Reviews 26: 430-468.

Korosi, J.B., Griffiths, K., Smol, J.P., and Blais, J.M. (2018). Trends in historical mercury deposition inferred from lake sediment cores across a climate gradient in the Canadian High Arctic. Environmental Pollution 241: 459-467.

Thienpont, J.R., Desjardins, C.M., Kimpe, L.E., Korosi, J.B., Kokelj, S.V., Palmer, M.J., Muir, D.C.G., Kirk, J.L., Smol, J.P., and Blais, J.M. (2017) Comparative histories of polycyclic aromatic compound accumulation in lake sediments near petroleum operations in western Canada. Environmental Pollution 231: 13-21.

Korosi, J.B., Thienpont, J.R., Blais, J.M., and Smol, J.P. 2017 Paleo-ecotoxicology: what can lake sediments tell us about ecosystem responses to environmental pollutants? Environmental Science & Technology 51: 9446-9457.

Korosi, J.B.*, Thienpont, J.R.*, Pisaric, M.F.J., deMontigny; P., Perreault, J.T., McDonald, J., Simpson, M.J., Armstrong, T., Kokelj, S.V., Smol, J.P., and Blais, J.M. (2017) Broad-scale lake expansion and flooding inundates critical wood bison habitat. Nature Communications doi: 10.1038/NCOMMS14510.

*Both authors contributed equally to the publication and are listed alphabetically

Bouchard, F., MacDonald, L.A., Turner, K.W., Thienpont, J.R., Medeiros, A.S., Biskaborn, B.K., Korosi, J.B., Hall, R.I., Pienitz, R., and Wolfe, B.B. (2017) Paleolimnology of thermokarst lakes: a window into permafrost landscape evolution. Arctic Science 3: 91-117.

Korosi, J.B., Cooke, C.A., Eickmeyer, D.C., Kimpe, L.E., and Blais, J.M. (2016) In-situ bitumen extraction associated with increased petrogenic polycyclic aromatic compounds in lake sediments from the Cold Lake heavy oil fields (Alberta, Canada). Environmental Pollution 218: 915-922.

Thienpont, J.R., Korosi, J.B., Hargan, K.E., Williams, T., Eickmeyer, D., Kimpe, L.E., Palmer, M.J., Smol, J.P., and Blais, J.M. (2016) Multi-trophic level response to extreme metal contamination from gold mining in a subarctic lake. Proceedings of the Royal Society Biological 283: 20161125.

Korosi, J.B., Eickmeyer, D.C., Chin, K.S., Palmer, M.J., Kimpe L.E., and Blais, J.M. (2016) Examining spatial patterns in polycyclic aromatic compounds measured in stream macroinvertebrates near a small, subarctic oil and gas operation. Environmental Monitoring and Assessment, doi: 10.1007/s10661-016-5175-9.

Korosi, J.B., Eickmeyer, D.C., Thienpont, J.R., Palmer, M.J., Kimpe, L.E., and Blais, J.M. (2016) Assessing the contribution of combustion-derived contaminants to a remote subarctic environment from traffic on the Tibbitt to Contwoyto winter road (Northwest Territories, Canada). Science of the Total Environment 553: 96-106.

Labaj, A.L., Korosi, J.B., Kurek, J., Jeziorski, A., Keller W.B., and Smol, J.P. (2016) The responses of Bosmina size structure to acidification and subsequent recovery of lakes near Sudbury, Canada. Journal of Limnology 75: 22-29.

Stewart, E., Coleman, K.A., Korosi, J.B., Thienpont, J.R., Palmer, M.J., Blais, J.M., and Smol, J.P. (2015) Assessing environmental stressors on a commercial walleye fishery from a large northern ecosystem (Tathlina Lake) using water chemistry and paleolimnology. Journal of Great Lakes Research 42: 217-222.

Korosi, J.B., McDonald, J., Coleman, K.A., Palmer, M.J., Smol, J.P, Simpson, M.J., and Blais, J.M. (2015) Long-term changes in organic matter and mercury transport to lakes in the sporadic discontinuous permafrost zone related to peat subsidence. Limnology and Oceanography 60: 1550-1561.

Thienpont, J.R., Korosi, J.B., Cheng, E.S., Deasley, K., Pisaric, M.F.J., Smol, J.P. (2015) Recent climate warming favours more specialized cladoceran taxa in western Canadian Arctic lakes. Journal of Biogeography 42: 1553–1565.

Coleman, K.A., Palmer, M.J., Korosi, J.B., Kokelj, S.V., Jackson, K., Hargan, K., Courtney Mustaphi, C., Thienpont, J.R., Kimpe, L.E., Blais, J.M., Pisaric, M.F.J., and Smol, J.P. (2015) Tracking the impacts of recent warming and thaw of permafrost peatlands on aquatic ecosystems: a multi-proxy approach using remote sensing and lake sediments. Boreal Environment Research 20: 363–377.

Jeziorski, A., Tanentzap, A.J., Yan, N.D., Paterson, A.M., Palmer, M.E., Korosi, J.B., Rusak, J.A., Arts, M.T., Keller, W., Ingram, R., Cairns A., and Smol, J.P. (2015) The jellification of north temperate lakes. Proceedings of the Royal Society Biological 282: 20142449.

Korosi, J.B, Chen, W., and Blais, J.M. (2015) Organic Pollutants in Sediment Core Archives. Pages 161-185. IN:  Blais, J.M., Rosen, M.R. and Smol, J.P. [Editors]. Environmental Contaminants: Using Natural Archives to Track Sources and Long-Term Trends of Pollution. Springer, Dordrecht.

Recognition & Awards

  • Dean’s Award for Distinction in Research (Emerging Researcher), Faculty of Liberal Arts and Professional Studies, York University
  • Julian M. Szeicz Award for Early Career Achievement, Canadian Association of Geographers
  • Early Researcher Award, International Paleolimnology Association
  • Petro-Canada Young Innovator Award, York University


Course CodeTitle
EU/SC/GEOG 2500 3.00 Introduction to Vegetation and Soils
EU/SC/GEOG 3500 3.00Biogeography
EU/SC/GEOG 4200 3.00Water Quality and Stream Ecosystems
GS/GEOG 5610 3.00Biogeochemistry of Stream Ecosystems         
GS/GEOG 5600 3.00Research Seminar in Physical Geography