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Recent Submissions

Access status: Open Access ,
Recruitment in Threatened Riverine Species of Nova Scotia: Atlantic Salmon (Salmo salar) and Brook Floater (Alasmidonta varicosa).
(2026-04-15) Roland, Joshua; Not Applicable; Master of Science; Department of Biology; Received; Trevor Avery; Not Applicable; Cindy Breau; Glenn Crossin; Timothy Rawlings; Robert Lennox
Freshwater ecosystems are among the most threatened ecosystems globally, with unionids and salmonids experiencing severe declines. Conservation requires understanding recruitment and identifying where disruptions occur across life stages. This thesis examines recruitment in two freshwater species to inform conservation strategies. Chapter two used radio telemetry to assess Atlantic salmon spawning distribution in the Margaree River, Nova Scotia. Results indicated high residency in lower river reaches before spawning, with use of upper reaches occurring only in late fall (October–November). Chapter three investigated host relationships of brook floater mussels in the East St. Mary’s and Wallace rivers. PCR and sequencing of glochidia from fish gills identified lake chub as a host species in the St. Mary’s River. Additionally, a non-lethal method for sampling glochidia from fish gills was evaluated. Together, these studies address key knowledge gaps in salmon movement ecology and brook floater host associations, supporting improved conservation and management strategies.
Access status: Open Access ,
Exploring wellbeing among commercial lobster fishers in Nova Scotia, Canada
(2026-04-15) MacKeracher, Tracy; No; Doctor of Philosophy; Department of Biology; Received; Dr. Alyne Delaney; No; Dr. Hannah Harrison; Dr. Adam Cook; Dr. Anthony Charles; Dr. Megan Bailey; Dr. Aaron MacNeil
Wellbeing is a multi-dimensional concept. It is both a desirable outcome, and a lens through which to understand the ways that people perceive, pursue, and experience ‘a life well lived’. As wellbeing gains popularity as a relevant measure of social progress, it is increasingly being applied to understand the health and functioning of ecosystems. Within fisheries, a wellbeing approach is useful for understanding peoples’ connections to fishing – specifically, how fishers relate to, perceive, and benefit from their occupation. This understanding can provide insight into the potential wellbeing impacts of regulatory, environmental, and policy changes, and how the pursuit of wellbeing shapes decision-making. It also provides a useful socioeconomic indicator of fishery health, and can inform efforts to support wellbeing via management and policy. However, unpacking the connection between fishing and harvester wellbeing is not straightforward. Both peoples’ connections to resources, and the determinants of wellbeing, are shaped by a number of contextual and individual factors. As such, understanding how fisheries contribute to wellbeing requires evaluating how wellbeing dimensions vary among resource users. With a focus on participants in Nova Scotia’s commercial owner-operator fishery for American lobster (Homarus americanus), the goal of my thesis was to explore patterns of differentiation in the connection and contribution of fishing to wellbeing, as perceived by fishers. First, I applied a framework for social wellbeing to explore patterns of differentiation in material, relational, and subjective dimensions. Next, I applied a wellbeing framework developed for integrated ecosystem assessments to explore the non-material benefits of fishing, and their contribution of fishing to the conditions, connections, and capabilities dimensions of wellbeing. I then quantified the connection between measurable outcomes of fishing – specifically, catch volume, time on the water, and income – to explore how contextual and individual factors shape the connection between wellbeing and aspects of fishing that can be connected to fishery management levers. Finally, I explore patterns in economic wellbeing of fishers, to identify which fishers are most vulnerable to changing economic conditions in the fishery. This thesis can contribute to decision-making that better considers what matters most to participants in Canada’s most economically valuable fishery.
Access status: Embargo ,
Wind, Ice, and Tide Controls on the Dynamics of Mixing, Stratification, and Internal Waves in the Canadian Arctic Archipelago
(2026-04-14) Rotermund, Lina M; Yes; Doctor of Philosophy; Department of Oceanography; Not Applicable; Dr. Stephanie Waterman; Yes; Dr. Daniel Kelley; Dr. Kumiko Azetsu-Scott; Dr. Ruth Musgrave; Dr. Clark Richards
The Canadian Arctic Archipelago (CAA) plays a vital role in the global climate as a major oceanic gateway between the Arctic and Atlantic Oceans. Barrow Strait, a high-latitude, seasonally ice-covered channel with complex bathymetry, accounts for 30 – 50 % of the volume transport through the CAA and is located within the ecologically significant Tallurutiup Imanga National Marine Conservation Area. Despite its recognized importance, how waters are mixed and modified in the region remains poorly constrained. This dissertation addresses this knowledge gap by investigating the variability in stratification and wind- and tide-driven dynamics within Barrow Strait, processes widely recognized to contribute to ocean mixing and internal wave activity. Analyses integrate in situ observations, including ocean and ice velocities, water column stratification, and sea ice draft, from four locations across the Strait spanning up to 18 years (1998 – 2011 and 2017 – 2022), together with reanalysis products, including wind velocity, surface buoyancy fluxes, and ice concentration. These datasets are complemented by idealized models, including a one-dimensional ice-ocean coupled slab model and three-dimensional sloping channel tidal simulations. In Chapter 2, a potential energy anomaly framework is used to diagnose seasonal density stratification and assess the contributions of local surface buoyancy forcing and vertical mixing. Stratification is found to be predominantly determined by local and upstream sea ice melt and growth. Chapters 3 and 4 examine the wind- and tide-driven internal wave field. Barrow Strait lies at the critical latitude of the semidiurnal tide, coupling wind-driven near-inertial waves and semidiurnal internal tides. Near-inertial motions are elongated along the channel, influenced by its geometry. They also exhibit a marked seasonal increase from July through October, arising from the kinematic effects of mixed layer depth and modulation of wind stress by sea ice. Diurnal subinertial tides are bottom-amplified during periods of westward low-frequency flow and increased stratification, while the semidiurnal near-inertial tide is strongly damped in the ice-ocean boundary layer, enhancing near-surface and bottom shear with implications for mixing. Overall, this dissertation presents an unprecedented and detailed characterization of stratification variability and of near-inertial and tidal dynamics utilizing long-term datasets within Barrow Strait.
Access status: Open Access ,
The Birth of a Navy: The Role of Imperialism and Nationalism in the Creation of the Royal Canadian Navy, 1910-1914
(2026-04-15) Webb, Ben; Not Applicable; Master of Arts; Department of History; Not Applicable; n/a; Not Applicable; Kassandra Luciuk; Shirley Tillotson; Jerry Bannister
This thesis examines the early years of the Canadian Navy from 1910 to 1914. It argues that early twentieth-century imperialism and nationalism had a direct influence in shaping Canadian naval policy and the creation of the Canadian Navy. Using newspapers, diaries, political debates and campaign materials, this thesis illustrates how both the Liberals and Conservatives influenced naval policy through their respective understandings of imperialism. The Liberal naval policy reflects the influence of liberal imperialism; conversely, the Conservative naval policy was influenced by their tory imperialist understanding of imperialism. Unlike most conventional studies in naval history, this thesis uses the Canadian Navy as a vehicle to examine Canadian imperialism and nationalism in the early twentieth century. Contemporarily, Canadian citizens are divided over both national identity and military capabilities. This thesis explores the origins of these questions by highlighting both the creation of the Canadian Navy and Canadian identity.
Access status: Open Access ,
Low-resistivity Metal/2D-Semiconductor Contacts through Electrene Insertion
(2026-04-15) Rafiee Diznab, Mohammad; Yes; Doctor of Philosophy; Department of Physics & Atmospheric Science; Not Applicable; Prof. Eva Zurek; Not Applicable; Prof. Penghao Xiao; Prof. Kimberley Hall; Prof. Jesse Maassen; Prof. Erin R. Johnson
Achieving low-resistance metal contacts to 2D semiconductors is crucial for improving the efficiency of nanodevices, through reduced power dissipation, higher speed, and enhanced carrier injection efficiency. Although transition-metal dichalcogenides (TMDCs), including MoS2, are promising for electronic applications, their performance is limited by high contact resistance due to strong Fermi-level pinning and the presence of a tunnelling barrier. In this thesis, we explore computationally a strategy utilizing two-dimensional (2D) alkaline-earth sub-pnictide electrenes with a general formula of M2X (M = Ca, Sr, Ba; X = N, P, As, Sb) as an intermediate material between the TMDC and metal. Electrenes possess one excess electron per formula unit, resulting in the formation of 2D sheets of charge on their surfaces. This charge can be readily donated when interfaced with a TMDC semiconductor, thereby lowering its conduction band below the Fermi level and eliminating Schottky and tunnelling barriers. Density-functional theory (DFT) calculations were performed for Cu,Au/electrene/MoS2 heterojunctions involving all stable M2X electrenes. To identify the material combinations that provide the most effective Ohmic contacts, the charge transfer, band structure, and electrostatic potential were analyzed. Ca2N was found to be the most promising electrene due to its high surface charge density. The electrene insertion strategy was also tested for MoSe2, MoTe2, WS2, and WSe2, and all were found to form Ohmic contacts with the metal in the presence of Ca2N as the interfacial layer. Finally, the non-equilibrium Green's function formalism, combined with DFT, was used to simulate charge injection into selected monolayer TMDCs using Ca2N as a contact material. For direct comparison, conventional metal (Cu/MoS2) and semi-metal (Sb/MoS2 and Bi/MoS2) contacts were also studied using the same computational framework. Strong charge transfer from Ca2N to the TMDC enables effectively barrier-free charge injection, yielding contact resistance values approaching the quantum limit. In particular, Ca2N/MoS2 exhibits a contact resistance of ~15 Ohm-micrometers, comparable to the values computed for state-of-the-art Sb/MoS2 and Bi/MoS2 contacts. However, in contrast to conventional metals and semi-metals that predominantly exhibit edge-dominated injection, Ca2N/TMDC interfaces support distributed, areal charge injection across the contacted region. Electrene materials therefore offer a promising route toward barrier-free contacts in 2D electronics, despite challenges associated with their synthesis and integration.
Access status: Open Access ,
Assessing Thinopyrum intermedium establishment and agronomy in the maritime region of Canada
(2026-04-15) Cole, Brittany; Not Applicable; Doctor of Philosophy; Faculty of Agriculture; Not Applicable; Dr. Jacob Jungers; Not Applicable; Dr. Douglas Cattani; Dr. Yunfei Jiang; Dr. Travis Esau; Dr. Aaron Mills
Agricultural intensification has favoured simplified annual cropping systems to maximize short-term yield, but these practices have contributed to soil degradation, nutrient loss, and a reduced climate resilience. Integrating perennial plants into annual dominated agriculture offers an opportunity to balance productivity with ecological function. However, perennials operate under different developmental and resource allocation strategies than annuals, which creates challenges for the breeding and adoption of perennial crops for grain production. In addition, there is a limited understanding of perennial grass optimization for agriculture across diverse climates. Thinopyrum intermedium (intermediate wheatgrass; Kernza®) is a perennial grass developed for dual purpose grain and forage production. The deep rooting system of Th. intermedium provides environmental benefits that improve soil health and mitigate the impact of annual cropping systems. This thesis evaluated the agronomy required to optimize Th. intermedium performance under maritime conditions in Canada. The establishment strategies, stand age dynamics, intercropping compatibility, and nitrogen management were assessed in field experiments. Results demonstrated that stand age was a dominant regulator of plant trait expression and grain yield, and that early establishment conditions influenced the long-term plant allocation strategies. Compatible intercropping systems, particularly annual forage mixtures, enhanced cumulative biomass production in stands without compromising Th. intermedium persistence or grain yield. Annual barley was an incompatible intercropping species and inhibited the establishment of Th. intermedium, resulting in reduced stand performance. Nitrogen management influenced the developmental plant traits but did not prevent grain yield declines with stand age, highlighting perennial trade-offs between reproduction and persistence. Collectively, this research advances the understanding of perennial grain management by identifying agronomic decision pathways for performance optimization, aligning management with perennial developmental phases, and supporting the integration of diversified cropping systems in the maritime region of Canada. Widespread adoption of perennial grains requires framing agricultural success in terms of economic stability and ecological function. This thesis contributes to the development of agricultural systems that align productivity with environmental stewardship to secure stability in food production.