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Jennifer B. Korosi

Jennifer B. Korosi

Associate Professor


BScH, PhD, Queen's University

Research Keywords

Lakes; Environmental Change; Permafrost; Pollution; Biogeography; Biogeochemistry

Graduate Supervision

I supervise students in the graduate program in Geography

Jennifer B. Korosi

Contact Information

4700 Keele Street
Toronto, ON M3J 1P3

416 736 2100 (ext. 22491)

Google Scholar Profile

Research Interests

I am a limnologist (limnology = study of inland waters) who seeks to understand the underlying mechanisms and impacts of environmental change. Lakes are sentinels of environmental change. They reflect changes occurring within the lake as well as the watershed. Lakes also respond rapidly to climate change. 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 drivers of terrestrial and lake ecosystem transformation in cold regions. I am also interested in the role that climate change will play in altering the cycling and ecotoxicity of legacy contaminants.

Research Projects

Title: Lake and landscape change in rapidly thawing discontinuous permafrost peatlands

Role: Principal Investigator

Research Grant: NSERC Discovery and NSERC Alliance

Duration: 2017-2024

Summary:  Boreal peatlands at the southern limit of permafrost are experiencing a rapid loss of permafrost in response to climate warming. This has substantial implications for the movement, storage, and processing of water, carbon, and mercury on the landscape. Consequently, the ability to forecast the future ecosystem states of boreal permafrost peatlands is essential for climate change mitigation and adaptation efforts. Small lakes are abundant across boreal peatlands and can offer useful insights into landscape processes as both sentinels and agents of environmental change. This project seeks to understand how lakes are responding to permafrost thaw in the Dehcho region (southern Northwest Territories), one of the most rapidly warming regions on Earth. It is being conducted in partnership with knowledge producers, mobilisers and users from universities, Indigenous communities, government and industry, working collaboratively to improve the understanding of and ability to predict and mitigate the impacts of permafrost thaw on the NWT's water resources.

Title: Assessing the impact of aerator installation on the chemical and biological recovery of Frame Lake.

Role: Co-Investigator

Principal Investigator: Dr. Michael Palmer, Aurora College

Other Co-Investigators: Dr. Derek Gray (Wilfrid Laurier University), Dr. Heidi Swanson (Wilfrid Laurier University), and Dr. Pete Cott (Government of the Northwest Territories, Department of Environment and Climate Change)

Research Grant: Northwest Territories Cumulative Impacts Monitoring Program

Duration: 2023-2026

Summary:  Municipal development and land use changes have led to the degradation of aquatic habitats in urban areas across Canada. In recent decades there has been a push to rehabilitate previously impacted lakes so that they may once again support healthy aquatic ecosystems. Frame Lake is located within the City of Yellowknife and has been impacted by decades of land use changes within its catchment, as well as the deposition of contaminants from municipal waste and mining activities. The lake currently cannot support fish, because of oxygen depletion over winter. The installation of an aerator planned for the summer of 2023 is intended to maintain sufficient dissolved oxygen levels over winter, which is needed to support self-sustaining populations of fish. The aerator may also promote the chemical and biological recovery of the lake from legacy arsenic and phosphorus pollution currently held within the sediments. This project will investigate the influence of aerator installation on the chemical and biological recovery of Frame Lake through regular sampling of water chemistry, phytoplankton, and zooplankton across seasons before and after aerator installation.

Research Output

Coleman, K.A., Hoskin, G.N., Chasmer, L., Thienpont, J.R., Quinton, W.L., and Korosi, J.B. (2023) Limnology and diatom ecology of shallow lakes in a rapidly thawing discontinuous permafrost peatland. Inland Waters.

Sivarajah, B., Korosi, J.B., Thienpont, J.R., Kimpe, L., Blais, J., and Smol, J.P. (2022) Biological responses to metal(loid) pollution, urbanization, and climatic changes in sub-Arctic lakes around Yellowknife, Canada. Arctic Science, DOI: 10.1139/AS-2021-0052.

Gruia, S-A., Thienpont, J.R., Coleman, K.A., and Korosi, J.B. (2022) Climatic drivers of limnological change in Iqallukvik Lake, Tuktoyaktuk, Northwest Territories, Canada. Arctic Science,

Korosi, J.B., Coleman, K.A., Hoskin, G., Little, A.J., Stewart, E., and Thienpont, J.R. (2022). Paleolimnological perspectives on the shifting geographic template of permafrost landscapes and its implications for Arctic freshwater biodiversity. Canadian Journal of Fisheries and Aquatic Sciences,

Murdoch, A., Gray, D.K., Korosi, J.B., Vucic, J.M., Cohen, R.S., and Sharma, S. (2021) Drivers of fish biodiversity in a rapidly changing permafrost landscape. Freshwater Biology 66: 2301-2321.

Labaj, A.L., Jeziorski, A., Kurek, J., Bennett, J.R., Cumming, B.F., DeSellas, A.M., Korosi, J.B., Paterson, A.M., Sweetman, J.N., Thienpont, J.R., and Smol, J.P. (2021) Environmental drivers of cladoceran assemblages at a continental scale: a synthesis of Alaskan and Canadian datasets. Freshwater Biology 66: 949-967.

Perrett, M., Sivarajah, B., Cheney, C.L., Korosi, J.B., Kimpe, L., Blais, J.M., and Smol, J.P. (2021) Impacts on aquatic biota from salinization and metalloid contamination by gold mine tailings in sub-Arctic lakes. Environmental Pollution, 278: 116815.

Persaud, A.A., Cheney, C.L., Sivarajah, B., Blais, J.M., Smol, J.P., and Korosi, J.B. (2021) Regional changes in Cladocera (Branchiopoda, Crustacea) assemblages in subarctic (Yellowknife, Northwest Territories, Canada) lakes impacted by historic gold mining activities. Hydrobiologia,

Hoskin, G.N., and Korosi, J.B. (2021) Long-term ecosystem change in two highly degraded Lake Ontario (Canada) coastal wetlands. Journal of Paleolimnology 65: 393-405.

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 36: 297-313.

Cheney, C.L., Eccles, K.M., Kimpe, L.E., Thienpont, J.R., Korosi, J.B., and Blais, J.M. (2020) Determining the effects of past gold mining using a sediment palaeotoxicity model. Science of the Total Environment 718: 137308.

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

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.

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. ǂ, 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.

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.

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.

Korosi, J.B., and Smol, J.P. (2012) An illustrated guide to the identification of cladoceran subfossils from lake sediments in northeastern North America: Part 1 - the Daphniidae, Leptodoridae, Bosminidae, Polyphemidae, Holopedidae, Sididae, and Macrothricidae. Journal of Paleolimnology 48: 571-586.

Korosi, J.B., and Smol, J.P. (2012) An illustrated guide to the identification of cladoceran subfossils from lake sediments in northeastern North America: Part 2 – the Chydoridae. Journal of Paleolimnology 48: 587-622.

Korosi, J.B., Burke, S.M., Thienpont, J.R., and Smol, J.P. (2012) Anomalous rise in algal production linked to lakewater calcium decline through food web interactions. Proceedings of the Royal Society Biological 279: 1210-1217.

Scugog Lake Stewards, educational outreach videos (2017-2018)

Recognition & Awards

  • J.C. Stevenson Award & Plenary Lecture (2020), Canadian Journal of Fisheries and Aquatic Sciences “A lectureship conferred upon a young, energetic and creative researcher at the cutting edge of an aquatic discipline”.
  • 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 3.0Introduction to Vegetation and Soils
EU/SC/GEOG 3100 3.00Global Biogeochemical Cycles
EU/SC/GEOG 4200 3.00Water Quality and Stream Ecosystems
EU/SC/GEOG 4800 3.00Environmental Science Capstone