Geography

Permanent URI for this collectionhttps://hdl.handle.net/10315/27574

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Now showing 1 - 20 of 149

Access status: Open Access ,
Characterizing Boreal Forest Fire Disturbance Boundaries Through Space And Time In Ontario
(2025-07-23) Keshmiri, Nadia; Remmel, Tarmo K.
The Ontario boreal forest contains vast natural resources but is increasingly threatened by wildland fires, which are becoming more frequent and affecting larger areas due to climate change. In response, this thesis compares wildland fire boundaries derived from vegetation index slopes with those provided by BorealDB a newly developed database that compiles consistent disturbance maps from 1972 to the present. BorealDB includes various attribute combinations and an ensemble confidence measure that shows how often different data sources agree. By examining which attribute combinations produce fire boundaries that most closely match remote sensing data, this research offers practical guidance for BorealDB users on selecting the most reliable disturbance points for their analyses.
Access status: Open Access ,
From Caregiver to Personal Support Worker: Canada's Caregiver Programs and Labour Market Segmentation Among Filipina Women in Toronto
(2025-07-23) Pagaling, Nikki Mary; Kelly, Philip
The lowest rung of the Canadian healthcare system is occupied by those categorized as personal support workers (PSWs). Despite their important contributions to Canada’s healthcare system, this work is stigmatized, devalued and characterized by multiple dimensions of precarity. It is also a labour segment that is increasingly differentiated by gender, race, and citizenship, with Filipina immigrants accounting for 30% of immigrants in this workforce. Recent scholarship has drawn connections between Canada’s Live-in Caregiver Program (LCP) and the overrepresentation of Filipina immigrants in PSW roles. While these studies demonstrate how most caregiver migrants eventually transition out of caregiving, many remain in a narrow set of low-wage, “low-skilled” occupations, with PSW work emerging as a notable choice. By centering the experiences of Filipina PSWs in Toronto who migrated to Canada as live-in caregivers, this thesis explores how the caregiver-to-PSW pathway is constituted in the local labour market and within the lifeworlds of Filipina former caregivers. Using a feminist economic geography framework, this research calls attention to: 1) the social and institutional mechanisms that construct a pathway towards PSW labour; and 2) the racialized and gendered discourses that construct idealized PSW subjectivities and the ways in which they overlap with notions of Filipina identity. Key theoretical concepts include the social embeddedness of labour markets, embodiment and interpellation, and citizenship. I situate this research within the wider institutional landscape of Canada’s temporary migrant caregiver programs and the gendered politics of transnational labour migration in the Philippines to illustrate the context in which Filipina women come to view PSW work as a viable and suitable post-caregiver program career.
Access status: Open Access ,
Guano Rain and Growing Pain: Co-Nesting Dynamics of Double-Crested Cormorants and Black-Crowned Night-Herons at Tommy Thompson Park
(2025-07-23) Weiderick, Baillie Marie; Podur, Justin
This study investigates the co-nesting dynamics between double-crested cormorants (Nannopterum auritum) and black-crowned night-herons (Nycticorax nycticorax) in Tommy Thompson Park, Toronto, Canada, from 1992 to 2023. Linear mixed models with Bayesian inference were used to examine the impacts of cormorant abundance, nest density, management practices, and environmental factors on night-heron population growth. The strongest and only statistically significant relationship was a positive association between cormorant and night-heron growth indices. Results showed substantial uncertainty in the effects of most variables on night-heron growth indices, with wide credible intervals for nest densities, night-heron road proximity, and management activities. Nest densities of both species and proximity to roads had minimal effects on night-heron colony growth, with posterior means near zero. Management activities showed a slight positive but non-significant effect on night-herons. The study revealed that while cormorant population growth generally benefited night-herons, there was high uncertainty in parameter estimates, potentially due to small sample sizes and ecosystem complexity.
Access status: Open Access ,
Chronically Excluded? Public Toilet Access for Youth with Gastrointestinal Illnesses
(2025-07-23) Kiriazis, Stefanie; Bain, Alison
This thesis explores the intersection between public infrastructure, health and youth geographies, time geography, and sensuous and emotional embodiments to highlight public toilets as a critical yet often overlooked urban space. Through these intersections, this thesis not only spotlights public toilets as central nodes in everyday life, but also the differential ways these spaces impact populations who rely on them most for medical needs. Through a feminist methodological approach that employs semi-structured interviews and space-time diaries, this thesis asks: How do the daily mobility patterns of youth with chronic gastrointestinal illnesses depend on the spatial and temporal availability and accessibility of public and private toilet facilities? This thesis investigates the constraints to mobility and wellness that these individuals face when met with inadequate and inaccessible toilet infrastructure, with a case study in the Greater Toronto Area. Encompassing both suburbs and city centre, the research sample illustrates the infrastructural disparities between dense and sparse landscapes. From the ‘in-betweens’ from one toilet to the next, to the sensuous and emotional experiences felt within these spaces themselves, this research investigates how the everyday lifeworlds of chronically ill youth – through work, school, and play – can be enabled and disabled by the quality of infrastructure they are met with, and the coping mechanisms they employ to aid their journeys and experiences, attributing to overall wellness.
Access status: Open Access ,
An Immigrant Neighbourhood as a Site of Planetary Urbanization: The Case of St. James Town, Toronto
(2025-07-23) Formanowicz, Dominik Tadeusz; Mensah, Joseph
Immigration is a contested topic in a global reality defined by the spatiality of nation-states. However, in the case of South-North mobility, the public debate usually overlooks the role of colonial legacies and capitalist dependencies in shaping the patterns and trajectories of migration. On the scale of the Global North’s cities, narratives tend to revolve around the immigrant enclaves as problematic or dangerous. This dissertation informs the debate with a qualitative overview of the neighbourhood of St. James Town in Toronto, an area characterized by a strong immigrant presence. Analyzing the spatiality of immigrants on the scale of the nation-state, the city and the neighbourhood itself, it employs the conceptual framework of planetary urbanization to explain the role of newcomers as agents creating and maintaining global flows of capital and ideas, actively taking part in the production of space in Canada and far beyond it. At the same time, this work examines the spatiality of an immigrant enclave as an expression of a settler colonial nation-state, highlighting the vital role of spaces such as St. James Town in global and domestic patterns of precarity and exploitation. Portraying the neighbourhood in a dynamic moment of change, both in terms of infrastructural interventions as well as population structure, this dissertation highlights the resilience and community-formation skills of newcomers as well as the great cost of spatial and social adaptation. It also points out the shortcomings of the planetary urbanization concept, underscoring the necessity to include post-colonial criticisms and a nuanced, multi-faceted role of human mobility in explaining the works of global capitalism.
Access status: Open Access ,
Mining Networks In The Making: River Sand And Stone Mining In South Sulawesi, Indonesia
(2025-04-10) Medina De Loera, Wendy Alejandra; Vandergeest, Peter
This dissertation examines the factors and processes that have shaped sand and stone mining activities in the Jeneberang river, in South Sulawesi, Indonesia from the 1970s to 2022. My focus is the making of “mining networks” which, following Actor Network Theory, I frame as socio-material associations/processes that take provisional forms. Like other social scientific research on sand mining, I consider various political, economic and sociocultural aspects that shape who participates in mining, how and why. Additionally, I examine the material dimensions of both the geographical area that I study and the mined river materials to provide a spatially grounded analysis of the regional political economy of sand and stone mining in the Jeneberang river. I also analyze the actions that local people undertake to shape how mining happens so that they gain some benefits. Thus, this dissertation is grounded in terms of sociocultural dynamics and political economic processes but it is also place-based in terms of material features and changes. My research questions query how material and human factors shape mining networks and with what implications for local people and local mining businesses. To account for the agency of the material and people in shaping socio-material and political economic outcomes, I draw on a materiality approach and the moral economy framework. I combine insights from recent social scientific research on sand mining, critical resource geography’s focus on materiality, political ecology’s ideas on the relationship between materiality and resource access, political economy of mining’s focus on social mobilization and resistance processes, and the moral economy framework. I argue that material elements —including the river, water, sand, stones, topography— and human elements —such as the actions of local people— actively participate in a continuous shaping of mining networks. I also put forward the idea that mining networks can be better understood as “in the making” rather than as end products. The dissertation contributes to the sand mining literature which has generally approached the material aspects of mining settings as the contexts within which social phenomena unfold and has yet to further explore the actions of local people in shaping how mining happens.
Access status: Open Access ,
Investigating The Impact Of Cryogenic Landslides On Lakes In The Eastern Mackenzie Delta, NT, Canada Using A Paleolimnological Framework
(2025-04-10) Carroll, Victoria Marie; Thienpont, Joshua
The Canadian Northwest is warming at an accelerated rate compared to other Arctic regions, the rest of Canada, and the rest of the globe. Enhanced temperatures can influence the development of thermokarst features, including cryogenic landsliding, which can impact downstream limnological systems physically, chemically, and biologically. In the summer of 2023, sediment cores were collected from three landslide-impacted lakes and one control lake at the eastern edge of the Mackenzie Delta (Northwest Territories, Canada). They were analyzed for total mercury, nitrogen, and carbon content. This research shows how cryogenic landslides can impact the conditions of receiving waterbodies in the eastern Mackenzie Delta, which is particularly important because permafrost thaw can affect people, wildlife, and natural environmental processes. Researchers, ecosystem managers, and land users can use this paleoenvironmental data to support informed decision-making regarding the trajectories of lake ecosystem change associated with terrestrial mass movement into lakes following permafrost thaw.
Access status: Open Access ,
Triggered Town: Situating Communal Violence And Dissonance In The Wake Of The Gujarat Earthquake
(2025-04-10) Chowdhary, Misba; Wood, Patricia
This thesis investigates the intertwined narratives of the 2001 Gujarat, India earthquake and the 2002 anti-Muslim pogrom in Ahmedabad. It examines the impact of these events on the city's urban population to explore the intersections of natural disasters, religion, caste violence, and rapid urbanization. Focusing on the rise of Ahmedabad's middle class, the study uses personal interviews with Hindu upper-castes and upper-middle-class earthquake victims to explore their evolving attitudes towards the environment, state politics, inter-community relationships and political amnesia. And more specifically, it seeks to delve into how this section of civil society who were impacted by both events, albeit differently, have interpreted and responded to them over the long term. It reveals how memories can be shaped and reconstructed with effective state-propagated distortions which in turn have led to widespread denial of social realities and contributed to then-chief minister Narendra Modi’s electoral victories. Over two decades, the influence of the Sangh Parivar and political leader Narendra Modi has fostered economic pride and aspirations among these citizens, overshadowing the city's traumatic seismic history together with religious, class and caste divides. As increasing climate induced disasters loom over India together with authoritarian supremacist threats to India's secular democracy, this research aims to highlight the potential contemporary crises that inland urban metropolises such as Ahmedabad are likely to face given their tumultuous environmental and political histories.
Access status: Open Access ,
The Affective Geographies Of Social Reproduction: The Case Of Athens Under Austerity
(2025-04-10) Katsikana, Mantha Alkisti; Peake, Linda
This dissertation titled “Affective geographies of social reproduction: the case of Athens under austerity”, explores the ways women’s and feminized subjects’ socially reproductive labor, in the context of everyday life and solidarity organizing in Athens, is socio-spatially performed, organized, and experienced under austerity. The dissertation introduces Athens as a locus of original knowledge production, centering social reproduction and affect in research on the affective dimensions of the austerity ‘crisis’, and on spatialized processes of resistance and anti-capitalist commoning against austerity urbanism. The dissertation covers the period from 2005 to 2021, providing an alternative, expanded timeline of austerity in the Athenian context, focusing on the lives of women and feminized subjects living, working and organizing in its underprivileged downtown neighborhoods: Omonia, Exarcheia, Sepolia Agios Panteleimonas, Gkyzi, Kypseli, Ano Patisia and Kato Patisia. Through its research questions, the dissertation addresses: the ways everyday socially productive labor, performed by women and feminized subjects, is vital to placemaking and the right to the city in Athens; the way women and feminized subjects navigate, process and produce the Athenian urban through affective, emotional, relational, and embodied understandings of the self and community in the city-in-crisis; and they ways women’s and feminized subjects everyday struggles for survival over social reproduction, and against austerity and neoliberalism, inform expanded understandings of the political and of the right to the city. Within the context of feminist and critical urban geography, the dissertation answers these questions by synthesizing a theoretical framework of social reproduction and affect in a context of decolonial knowledge production and critical historiography, utilizing digital geohumanities methods to analyze primary data from fieldwork conducted between June 2021 to April 2022.
Access status: Open Access ,
Platform Labour, Migration, And Resistance: Organizing Against Hyper-Exploitation In Paris And Toronto's Food Delivery Industries
(2025-04-10) Baril, Emile; Tufts, Steven
This doctoral thesis combines empirical research and theoretical innovations aimed at comprehending the dynamics of platform labour within advanced-capitalist economies. Through case studies in Paris, France, and Toronto, Canada, the thesis contributes to the evolving landscape of platform labour studies, migration studies, and labour geography. The over-representation of racialized immigrants engaged in platform food delivery has attracted significant attention from both academia and mainstream media, notably in Toronto with international students from India and in Paris with sans-papiers from Africa. Focusing specifically on migration and working conditions, this study unveils hyper-precarity in Euro-American cities. The primary objective of the thesis is to provide a new perspective that includes immigration and citizenship within current discourse on platform labour. Drawing inspiration from critical urban studies, migration studies, and science and technology studies, the research introduces two conceptual propositions: i) “citizen-rentier-ship”, designed to elucidate how various stakeholders benefit from precarious citizenship status, and ii) a “relational comparison” of platform labour resistance, offering insights into the evolution of the unrest against platform labour exploitation—a crucial facet of urban development. The thesis is based on extensive interviews with food riders, workers, spokespersons, and other key actors, shedding light on their capacity for self-organization within advanced capitalist societies. By exploring strategies, limitations, and the dimensions of resistance—both digital and physical—through interactions with riders and individuals who resisted deactivation, low wages, and algorithmic management, the research contributes to a nuanced understanding of the challenges and opportunities faced by these workers. The case studies place emphasis on migrant workers’ perspectives. They reshape ongoing debates about global platforms by centering attention on the bottom ends of labour markets. In conclusion, the study contends that the struggles of migrant workers are deeply entwined with labour laws, immigration policies, misclassification practices, and urban policies in France and Canada.
Access status: Open Access ,
Walking Potatoes & Wilder-Beasts: An Examination Of The Socio-Ecological Relationship Between Humans And Mammals In Urban Agriculture
(2024-11-07) Buckvold-Beirne, Elle Clare; Podur, Justin
This project explores the positive and negative interactions and conflicts that arise between the people and mammals working, visiting, and living in urban farms and community gardens. This involved an anonymous survey of people that work and grow in the research sites, and the use of trail cameras to capture the mammals that visited the sites. The study examined two urban agricultural sites from August to November 2022, in Toronto, ON: one urban farm and one community garden, both with proximity to urban wildlife habitat. Growers have a complicated, nuanced relationship with the various species living in and benefitting from these miniature agricultural landscapes. Trail cameras at both sites captured numerous species, as well as several individuals who made repeated visits. Conflicts at both sites arose from the eating and spoiling of crops, and damage to infrastructure by wildlife, but some participants felt positively about their interactions with some species.
Access status: Open Access ,
Consciousness and Action among Auto Workers in India: The Maruti Movement, 2007-2017
(2024-11-07) Pati, Charvaak; Das, Raju J.
This dissertation is a study of the dialectical relation between class consciousness and collective action among auto workers in India. Specifically, it examines how the existing state of class consciousness shapes and, in turn, is shaped by class struggle in the context of the militant working class struggle in Maruti Suzuki India Limited (MSIL), India’s largest carmaker. This dialectic of consciousness and action among the Maruti workers is shaped by workers’ working and living conditions, their own political organisations, and interventions by the institutions of the state. There are distinctive political barriers to class consciousness and class struggle such as caste, ethnicity and regional identities. Yet, there are objective economic and political conditions such as low wages and denial of trade union rights which have the potential to weaken these political barriers without undermining the importance of these identities for the working class. This dissertation argues that in the absence of political organisation/s imbued with a political consciousness that underscores the centrality of capitalism and the capitalist state and the limits (both material and discursive) they put on working class struggle and consciousness, it is not possible to scale up place-specific and plant-based militant trade union struggles.
Access status: Open Access ,
Moving, waiting, searching across borders: Gendered geographies of violence, disappearance and contestation in southern Mexico
(2024-11-07) Biorklund Belliveau, Linn Maria Gunilla; Hyndman, Jennifer
Women displaced by violence from Central America are the protagonists of this dissertation. Their intimate stories and acts of survival and care are foregrounded as they move, wait and search in social spaces in southern Mexico. They are mobilized to reconceptualize mainstream academic, political and humanitarian thinking about bordering practices as integral parts of states’ tactics to control people’s movement only. The dissertation delves into migrant and body-territory epistemologies of everyday politics, arts-based contestations and performative acts, revealing and making present the bodies, spatialities, and knowledges that populate a geopolitically manufactured border and migration “crisis” in southern Mexico. The research explores bordering practices at the scale of their everyday implementation on the ground, theorizing how borders and bordering as a violent state-driven apparatus operate, how it is experienced differently, whom it impacts, and how it is negotiated across space and time. The research is situated at the intersection of political geography, critical border studies, refugee studies and transnational feminist approaches. The study and grounded analysis originate from feminist ethnographic and participatory action research with migrant women, feminist and women’s groups, collectives searching for the disappeared and others accompanying border-crossers in 2022-23. The methods applied include life history narratives, in-depth semi-structured interviews, workshops, and the accompaniment of people moving, waiting and searching along migratory routes. This dissertation contributes to debates on bordering practices, gender violence, migrant disappearances, and care, making four unique contributions to the literature. First, the methodological approach fosters novel narratives about borders and the acts of people crossing them despite fears. Second, the research reveals a gendered and intimate geopolitical analysis that highlights women’s experiences and survival strategies and considers their exclusion to move quickly across borders that shape and are shaped by state practices. Third, the research re-conceptualizes the outcomes of bordering practices, exposing the protagonism and spaces of care while underlining the experience of waiting in borderlands, all of which are frequently overlooked and undocumented. Finally, the research reads disappearances as violence towards (feminized) migrant bodies and territories and probes subsequent performative searches by friends and family that defy the salient maternalist and state-centric discourses.
Access status: Open Access ,
Feminist counter-geopolitics: knowledges, practices, and spaces of activism in Iranian diasporas
(2024-11-07) Lashkari, Maryam; Bain, Alison
In the face of growing state authoritarianism, particularly targeting feminist and women’s rights activists in Iran and forcing many to leave the country, the question of whether and how feminist activism outside the country’s national border negotiates and contests political structures of gendered violence and displacement is of growing importance. This dissertation explores how knowledges, practices, and spaces of activism in Iranian diasporas across selected European and Canadian cities create alternatives to state political structures. The present research was conducted between December 2021 and June 2023 and employed different qualitative research methods, including semi-structured interviews with 39 activists, academics, artists, policymakers, and diaspora community members whose work intersects with feminism, women’s rights, and gender-based violence. I draw upon the concept of feminist counter-geopolitics, discussing what knowledges, practices, and spaces constitute them. By focusing on feminist activist experiences as the focal point of analysis, the dissertation questions the lack of attention to activism in diaspora in critical, feminist, and urban geopolitics. I examine how activist knowledge of gender and sexual-based violence changes as they cross national borders and illustrate the challenges and opportunities of translating knowledge in a transnational context. Despite significant obstacles in materializing these knowledges such as economic hardships, political kinships among activists provide important sources of material and emotional support for activists. Furthermore, I show how, despite the dominant logic of Iranian nationalism, transnational solidarities among activists in diasporas resist such exclusionary discourses in the context of the 2022 Woman, Life, Freedom uprising. I discuss how such knowledges, practices, and spaces illustrate intimate geopolitics that challenge the state-centric understanding of geopolitics, pointing toward emancipatory aspects of feminist counter-geopolitics.
Access status: Open Access ,
Masculinity and Gig Work: A Case Study of Rideshare Workers in Toronto
(2024-11-07) Campo, Maya Selina; Tufts, Steven
This thesis examines shifting masculinities and platform labour, following eleven semi-structured interviews conducted with male Toronto-based Uber and Lyft rideshare workers with dependents (children). Women have commonly done non-standard work, hence the proliferation of non-standard work being contextualized as the ‘feminization of work’ (Zahn, 2019). In contrast, rideshare work is a non-standard form of gig work done predominantly by men, rendering it a relevant form of platform work to examine with its complicated relationship to the historical context of gender and nonstandard work. This thesis argues for a need to organize the worker as a whole, examining how workers’ unpaid social reproductive labour and balancing of rideshare work, and often another form of paid work, impacts the viability of classic organizing methods. I argue that these issues of convoluted boundaries between paid and unpaid work must be incorporated into the potential organizing demands of a rideshare workers’ union and identify areas for further research on organizing rideshare workers accounting for shifting masculinities.
Access status: Open Access ,
Animals and Development: A Case Study of the Canadian International Food Security Research Fund
(2024-07-22) Legault, Danielle Desiree Emily; Hovorka, Alice J.
Food animals such as cattle, chickens, goats, fish and bees are central to Canada’s international development initiatives which are attempting to eradicate global poverty, hunger, and foster sustainable development. Yet, despite the economic and social prevalence of these programs globally, the animals in these projects are often only counted as economic units; their relationships with the people and environment they interact with, and their welfare are left invisible and unaccounted for. This research centres the animals at the heart of Canadian international development interventions. Through a mixed methods approach, this research documents the historic roles of animals in Canadian development interventions, both domestically and globally; the actors, roles and representations of animals through a contemporary case study of the Canadian International Food Security Research Fund (CIFSRF); and looks to the future of animals in development by interrogating the synergies and tensions of the implementation of animal welfare paradigms such as the One Welfare framework. This interdisciplinary research unites animal geographies and development studies to provide scholarly insights on global animal-human relationships, animal welfare, and global well-being to inform future animal-human practices in development.
Access status: Open Access ,
Process- Versus Pattern-Based Measures of Fragmentation: A Simulated Sensitivity Analysis
(2024-07-18) Kerr, Barbara; Remmel, Tarmo
Landscape fragmentation, which has demonstrated links to habitat loss, increased isolation, a loss of connectivity, decreased biodiversity, and reduced connectivity is difficult to quantify. Traditional metrics have been calculated using landscape patterns of composition and configuration. The objective of this study was to examine an alternative process-based approach using the cost of traversing a landscape as a proxy for fragmentation and compare it with the traditional approach. One thousand binary landscapes varying in composition and configuration were simulated, and least-cost path analysis provided the data to calculate the process-based metrics, which were compared with the computed pattern-based metrics. The process-based quantification of landscape fragmentation was more sensitive to landscape fragmentation than a pattern-based quantification. My study provides a methodological foundation for further studies as it is not associated with a specific species or ecological process, and thus can be easily adapted to numerous settings.
Access status: Open Access ,
Technologies of Transparency: The Role of Information and Communications Technologies in Promoting Labour Rights in Distant Water Fisheries
(2024-07-18) Ebrahimirad, Amir-Ali; Kelly, Philip
Ethical production networks and supply chains have garnered significant attention in both academia and industry. The ethical supply chain has become a topic of significant debate in the global fishing industry in particular, and especially in distant water fishing (DWF). Monitoring labour rights/abuses presents a challenge in this field, as workers are employed on fishing vessels operating in isolated and remote waters, often outside any effective oversight or regulation. This study aims to investigate the potential of various information and communication technologies (ICTs) in tracking, monitoring, and promoting labour rights in DWF. In pursuing this question, I use the intersection of global production networks (GPN) and labour regimes as a theoretical framework. While GPN theory addresses the institutions, actors and power relations in global production processes, labour regime theory provides a conceptual understanding of how workers are both disciplined and exert agency within global production systems. The study is based on qualitative interviews with stakeholders who are active in both developing and deploying various technologies in relation to migrant labour rights in fisheries, complemented by an extensive review of secondary documentation. The findings indicate that, within this framework, ICTs can be primarily classified into two distinct categories based on their approach to monitoring and observing labour conditions: a) remote monitoring and b) on-board/community-based monitoring and reporting systems. I will argue that the use of such technologies holds significant potential for advancing transparency and accountability in terms of the labour rights and working conditions of fishing crews. In this way, new possibilities for labour agency and the re-regulation of labour regimes in global production are being opened up, while, at the same time, limitations on the application of ICTs still remain.
Access status: Open Access ,
Assessing Long-Term Ecological Changes in Lake Scugog (Southern Ontario, Canada) from ~1700 to 2019 Using Cladocera (Branchipoda, Crustacea) Subfossil Remains as Paleoecological Indicators
(2024-03-16) Jeyarajah, Januja; Korosi, Jennifer
Lake Scugog is a shallow impoundment located in southern Ontario that is encountering several anthropogenic stressors, such as the introduction of invasive species, eutrophication, periodic algal blooms, and climate change. This thesis used a paleolimnological approach to assess the long-term (~200 years) ecological changes in the west and east arms of Lake Scugog using Cladocera (crustacean zooplankton, Class Branchiopoda) remains as bioindicators. Bosmina and C. brevilabris were the dominant cladocerans in Lake Scugog throughout the last several hundred years. Measured Bosmina body sizes were small, indicating high fish planktivory pressure on Bosmina. The changes in subfossil Cladocera and Bosmina in sediments suggest that the stress levels associated with eutrophication, climate change and invasive species have not been large enough to significantly alter predation levels or this part of the zooplankton community in Lake Scugog.
Access status: Open Access ,
Carbon and Mercury Accumulation in Lake Sediments of Rapidly Thawing Discontinuous Permafrost Peatlands (Northwest Territories, Canada)
(2024-03-16) Abulu, Rachael Ehimen; Korosi, Jennifer
This research uses a paleolimnological approach to address gaps in our understanding of lakes as potential sinks for carbon and mercury released from thawing discontinuous permafrost peatlands. Sediment cores were collected from 14 small lakes in the southern Northwest Territories, and core chronologies and sediment accumulation rates established using 210Pb radioisotopes. Most lakes exhibited increases in mercury concentrations independent of organic carbon. Atomic C/N ratios indicated that the proportion of organic carbon from algal sources has also increased. The low sediment focussing factor (< 1.0) observed in the majority of the lakes suggests that small, hydrologically connected shallow lakes act as flow-through systems, which may promote the downstream transport of sediment (and associated carbon and mercury) through sub-arctic watersheds draining thawing permafrost peatlands, rather than acting primarily as carbon and mercury sinks.

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