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Recent Submissions

Access status: Open Access ,
MECHANISMS DRIVING KELP DETRITAL PARTICULATE ORGANIC CARBON (POC) UNCERTAINTIES AND POPULATION DYNAMICS IN THE EASTERN SHORE ISLANDS, NOVA SCOTIA
(2025-11-12) Savard-Drouin, Alexis; Not Applicable; Master of Science; Department of Oceanography; Not Applicable; Ramon Filgueira; Not Applicable; Katja Fennel; Kira Krumhansl; Anna Metaxas
Kelps are large brown algae that sustain marine life, support fisheries, and provide valuable ecosystem services. Carbon cycling is an important ecosystem service for kelp forests as they are among the most productive and widespread coastal vegetated ecosystems globally. However, current detrital carbon production estimates from kelp forests carry large uncertainties and studies rarely offer tangible solutions to improve them. We addressed this gap by quantifying population dynamics and demographic rates for the two dominant kelp species in Nova Scotia, Laminaria digitata and Saccharina latissima and estimate the detrital carbon production of both species. These estimates account for kelp size, since larger individuals produce more detritus, and for seasonal patterns, as most detrital production occurs in autumn. We found that most of the uncertainty in detrital carbon production estimates stems from variability in kelp density and population size structure. Incorporating seasonally varying erosion rates also reduces uncertainty as annual averages tend to over-simplify temporal patterns. Carbon cycling in kelp forests may be at risk as populations in Nova Scotia have undergone cycles of decline and recovery, with recent decades marked by substantial losses. While the causes of decline, warming waters, increased storm frequency, grazing by mesograzers, and invasive species, are known to affect individual kelps, their effects on population-level processes remain less understood. We constructed matrix population models to investigate the life history mechanisms driving the population dynamics of both species. We found that small individuals are critical for long-term population persistence. L. digitata depends on the year-round survival of small individuals, while S. latissima relies on autumn spore release, winter recruitment, and spring growth of small individuals. Stressors disrupting these life history events such as warming, turf algal competition, impacts from the invasive bryozoan Membranipora membranacea, and the mesograzer snail Lacuna vincta are therefore likely to drive kelp population dynamics. We also found that large individuals are essential for short-term population persistence and recovery. Both warming and M. membranacea negatively affect juvenile life histories and reduce the presence of large adults. The loss of large adults also would negatively impact detrital carbon production from kelps. These stressors are synergistic as warming promotes the population growth of M. membranacea. Together, our findings provide a mechanistic understanding for how continued ocean warming may undermine both the ecosystem functions and population resilience of kelp forests in Nova Scotia.
Access status: Embargo ,
Utilizing Metabolomics and Genomics to Enhance Parasite Resistance in Sheep
(2025-11-06) Jawad, Hamza; Not Applicable; Master of Science; Faculty of Agriculture; Received; Dr. Luiz F. Brito; No; Dr. Younes Miar; Dr. John Gilleard; Dr. Ghader Manafiazar
Gastrointestinal parasites, particularly Haemonchus contortus, significantly compromise sheep farm profitability. We integrated metabolomics and genomics data from 78 Rideau Arcott ewe lambs during controlled infection to develop diagnostic and genetic tools for parasite management. Metabolomic analysis identified candidate biomarkers—including indole acetic acid and trans-hydroxyproline—that demonstrated the potential to detect subclinical infections with progressive diagnostic accuracy. After validation, these metabolites could enable earlier diagnosis and treatment in precision livestock systems. Whole-genome sequencing revealed copy number variation patterns associated with parasite resistance and susceptibility. We identified key genes influencing immune function and disease resistance, particularly CLCA1 duplication. These findings provide practical tools for integrated parasite management: metabolite candidate biomarkers can be incorporated into field-deployable point-of-care diagnostics for on-farm detection, while genomic markers enable genomic selection for parasite resistance in breeding programs. Implementation of these diagnostic and genetic tools will help the Canadian sheep industry reduce anthelmintic dependence while improving productivity.
Access status: Embargo ,
Investigation of Gas Evolution and Safety of Materials for Lithium and Sodium-Ion Batteries
(2025-10-30) Tulloch, Meredith; Not Applicable; Master of Applied Science; Department of Process Engineering and Applied Science; Not Applicable; n/a; Not Applicable; Jeff Dahn; Alison Scott; Michael Metzger
The increased use of rechargeable batteries is one strategy in the fight against climate change, as a higher battery usage allows for the integration of more renewable energy sources. However, the development of batteries, particularly sodium-ion batteries, is still underway, with improvements to energy density and lifetime as the main research goals. Changes to the cell chemistry, the use of electrolyte additives, alloying negative electrode materials, and increasing the upper cut-off voltage to achieve higher cell capacity are all viable options to improve cell performance. This work explores electrolyte additives and Pb as a negative electrode material in sodium ion cells through on-line electrochemical mass spectrometry to investigate how these components impact the gases that are produced during battery operation. The electrolyte additives sodium difluorophosphate and 1,3,2-dioxathiolane 2,2-dioxide were studied in comparison to a control electrolyte through half cell tests and storage tests with notable differences in the gases evolved. Pb was compared to hard carbon and a blended electrode containing both materials to study the differences in carbonate and ether based electrolytes. Lastly, accelerating rate calorimetry was used to characterize the safety limits of a layered oxide positive electrode material for lithium-ion cells. Various upper cut-off voltages were used to probe the safety limitations of the material. Further investigation into the thermal response of the layered oxide positive electrode was completed using x-ray diffraction analysis. Overall, this work provides results for the gases produced from various cell chemistries in sodium-ion batteries, as well as the thermal responses seen in lithium-ion positive electrodes.
Access status: Open Access ,
Integrating Hydrologic Climate Projections into Source Water Protection Planning in Small Atlantic Canadian Communities
(2025-10-30) Dort, Amber; Not Applicable; Master of Applied Science; Department of Civil and Resource Engineering; Not Applicable; n/a; Not Applicable; Graham Gagnon; Andrew Medeiros; Lauren Somers
Climate change is a critical driver of hydrologic change in Atlantic Canada, where small utilities often manage source water with limited capacity. This research supports small communities in assessing climate change impacts on water supplies and identifies efficient modelling approaches. Lake George, the water source for Yarmouth, Nova Scotia, served as the study site. The hydrological system was characterized using public data and field observations, followed by three modelling schemes of varying complexity to simulate lake water balance. Downscaled climate projections were applied to evaluate future impacts. Lake levels were most sensitive to summer precipitation, followed by temperature and usage. Complex models with site-specific hourly data outperformed the simpler daily model, projecting more extreme impacts, including levels dropping below an outlet but not the treatment intake. While complex models provide quantitative insight, simpler models can guide qualitative assessments. Findings informed Yarmouth's Source Water Protection Plan and can guide similar communities.
Access status: Open Access ,
Decent Work and Temporary Stay: An Overview of the ILO Agri-Food Guidelines Affecting Migrant Workers in Canada
(McMaster University, 2025-11-07) Bejan, Raluca; Allain, Kristi A; Lyubchenko, Olena
This report uses a realist review methodology, focusing on three Canadian provinces – Alberta, New Brunswick, and Ontario – to examine labour protections in the meat packing, agriculture, and seafood processing industries. The research team examined grey and academic literature on working conditions and social protections for temporary foreign workers, a group of workers particularly vulnerable to labour exploitation. The report synthesizes scholarly and grey literature from January 2020 to December 2024, using a comprehensive keyword strategy to address the realist review questions of What works? For whom? Under what circumstances? And how? – questions that pertain to the design and implementation of protective occupational guidelines across the three provinces.
Access status: Open Access ,
Africville: Reparation in the Paradoxical Legal Construction and Deconstruction of an African Canadian Community
(2001-06) Sparks, Corrine E.; Not Applicable; Master of Laws; Faculty of Law; Not Applicable; unknown; Not Applicable; Philip V. Girard; Leon E. Trakman; Jennifer K. Bankier
This thesis examines the circumstances surrounding the relocation of the community of Africville with a view to reparations for the former Africville residents. There is a discussion of the theory of reparations. From a Critical Race perspective this thesis explores the historical significance of Africville in relation to other Black Nova Scotia communities. It also explores the involvement of Blacks in relation to the early colonial settlement of Nova Scotia. From personal interviews there is a documentation of the human toll which was paid by the former Africville residents when they were relocated in 1969. These anecdotal accounts also illustrate the inequities involved with the mass relocation of an entire community. There is also a brief comparison of redress for Japanese Canadians with a view to how Japanese Canadians were successful in obtaining redress for their years of suffering as a result of mass relocation and confiscation of their property in British Columbia in the 1940's during the Second World War. In order to further contextualize the historical experience of Nova Scotian Blacks, there is an examination of how the Black community has progressed since the Africville relocation. The social advocacy which was lacking during the Africville relocation has now developed with numerous professional associations which may be able to assist Africville residents as they seek redress. There is a review of two legal claims; unjust enrichment and unconscionability. Both of these equitable claims may prove helpful during litigation for the Africville residents. These two claims are based in equity and lend themselves to judicial discretion as well as principles developed through caselaw. Equitable remedies are also examined. These legal alternatives are discussed in light of two main jurisprudential theories; Legal Realism and Critical Race Theory. This discussion reveals the importance of jurisprudential approaches in the resolution of race based litigation. Finally, there are recommendations for how the Africville aftermath can be resolved so that the Black community can begin to heal in the face of horrendous racial injustice. If these measures are implemented, race relations could be greatly improved in the province of Nova Scotia.