Dehcho Collaborative on Permafrost

The Dehcho Collaborative on Permafrost aims to develop and mobilize knowledge on discontinuous permafrost distribution, evolution, and resultant landscape change trajectory in the Dehcho region (Northwest Territories) to better predict and adapt to permafrost thaw. Our lab is contributing paleolimnological perspectives to the collaborative. We are working to reconstruct landscape change in the Dehcho over the Holocene and link it to changes in lake ecosystem structure and function. Much of our field research is based out of the Scotty Creek Research Station.

The Changing Waterscape of North America’s Largest Arctic Delta Region

The Mackenzie Delta Region is underlain by ice-rich continuous permafrost and is experiencing dramatic geomorphic changes as a result of permafrost thaw. Key lake disturbances include mass movement (slope thermokarst disturbances) and lake drainage. Together with collaborators Dr. Steve Kokelj (NT Geological Survey), and Dr. John Smol (Queen's University), we are using paleolimnological approaches to reconstruct thermokarst impacts on lakes, focusing on sediment erosion from shoreline retrogressive thaw slumps. 

Legacy Arsenic in Yellowknife Lakes

Giant Mine is a gold mine that operated in the Yellowknife region between 1948-2004 that has left a legacy of arsenic (and other) contamination in lakes located within a ~15km radius of the mine. Our research uses phytoplankton and zooplankton as ecotoxicological indicators of legacy arsenic impacts, examining extant communities as well as subfossil remains preserved in lake sediment cores. We are particularly interested in the impact that climate change may have on arsenic cycling and ecotoxicity. We are working with collaborators Michael Palmer (Aurora College) and Dr. Marc Amyot (Université de Montréal) to examine seasonal controls on arsenic cycling/ecotoxicity, and with Dr. John Smol (Queen's University) and Dr. Jules Blais (University of Ottawa) to apply a paleo-ecotoxicological framework to legacy arsenic pollution. 

Paleolimnology of Lake Nipigon

Lake Nipigon is the largest inland lake found entirely within Ontario borders. It is part of the Laurentian Great Lakes drainage basin, located ~80 km north of Lake Superior. A history of mining, water diversions for hydroelectric power, and climate change have undoubtedly had an impact on lake water quality yet very little is known about the basic limnology of Lake Nipigon, or its sensitivity to environmental change. We are working with the Biinjitiwaabik Zaaging Anishinaabek (also known as the Rocky Bay First Nation), Dr. Dan Walters (Nipissing University), Dr. Lewis Molot (York University), Dr. Robert Stewart (Lakehead University), Nathan Wilson (Lakehead University), and others to generate a holistic  understanding of environmental challenges in the Lake Nipigon watershed. Our lab will conduct a paleolimnological reconstruction of environmental change over the last 300-500 years in small bays of Lake Nipigon.

Cyanobacteria blooms in Ontario lakes

Reports of cyanobacteria blooms are becoming more frequent in Ontario lakes, which is a concern because of the potential for cyanobacteria to produce toxins. Traditionally, nutrients have been considered the primary cause of cyanobacteria blooms; however, climate change has been implicated as a driver of recent increases in cyanobacteria related to increased surface water temperatures and thermal stability that leads to oxygen depletion at the sediment-water interface. We are interested in the drivers of cyanobacteria blooms in oligotrophic (low nutrient) lakes of south-central Ontario. We are also using paleoecological techniques to study long-term trends in cyanobacteria in Lake  Scugog, a large, shallow, eutrophic lake in the Durham and Kawartha Lakes regions. Lake Scugog has documented frequent cyanobacteria blooms since 2014 but has no previous record of problems with cyanobacteria. Collaborators and partners include Dr. Andrea Kirkwood (Ontario Tech University), Dr. Lewis Molot (York University), Dr. Dan Walters (Nipissing University), Scugog Lake Stewards, and Kawartha Conservation.

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In the Dehcho region (Northwest Territories), "drunken forests" are a sign of thawing permafrost. The conversion of forests into wetlands alters the transport of organic carbon and mercury to lake ecosystems. 

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A lake in the uplands east of the Mackenzie Delta (in the Inuvialuit Settlement Region) impacted by a shoreline retrogressive thaw slump.

Giant Mine, a gold mine in Yellowknife, Northwest Territories that operated from 1948-2004 (Photo credit: L. Kimpe)

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Satellite image of Lake Nipigon (northwestern Ontario, Canada)

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A view of the Port Perry Marina on Lake Scugog. Lake Scugog is a large, shallow, macrophyte-dominated lake located north of the town of Oshawa (Ontario) that may be experiencing a transition to an algal-dominated state.